INTERNATIONAL COURT OF JUSTICE
DISPUTE CONCERNING THE CONSTRUCTION OF A ROAD IN
COSTA RICA ALONG THE SAN JUAN RIVER
NICARAGUA v. COSTA RICA
INTERNATIONAL COURT OF JUSTICE
COUR INTERNATIONALE DE JUSTICE
CERTAIN ACTIAREA (COSTA RICA v. NICARAGUA)A IN THE BORDER
CERTAINES ACTIVITÉS MENÉES PAR LE NICARAGUA DANS LA RÉGION
FRONTALIÈRE (COSTA RICA c NICARAGUA
COUNTER-MEMORIAL OF COSTA RICA OF PROVISIONAL MEASURES
DEMANDE EN INDICATION DE MESURES CONSERVATOIRES
VOLUME I
JUDGES’ FOLDER FOR COSTA RICA’S PRESENTATION
14 OCTOBER 2013
DOSSIER DE PLAIDOIRIES DU COSTA RICA
14 OCTOBRE 2013
19 DECEMBER 2013 TABLE OF CONTENTS
Chapter 1
Introduction
A. Overview of the dispute ..................................... 1
B. Physical geography of the relevant area ........................ 3
C. Description of the Border Road ............................... 6
D. Circumstances leading to the building of the Border Road ........ 7
E. The Court’s jurisdiction .................................... 14
F. The Structure of this Counter Memorial ...................... 17
Chapter 2
Circumstances leading to the Construction of the Road
A. Introduction and background ............................... 21
B. Nicaragua’s conduct and further threats to Costa Rica .......... 22
(1) Nicaragua’s obstruction of the right to navigate the San Juan River 22
(2) Nicaragua’s illegal occupation of Costa Rican territory 26
(3) Nicaragua’s threats to the Colorado River and increased
presence of military personnel in the border area 29
(4) The need for Costa Rica to have land access to its police pos31
(5) Further provocative and unsettling behaviour by Nicaragua 35
C. The Emergency Decree and its Implementation ................ 36
Chapter 3
TheAbsence ofAdverse Impact on the San Juan River
A. Nicaragua’s Case in Brief ................................... 47
B. Sedimentation: the True Picture ............................. 48
(1) Impact of the Road on the suspended sediment load of the San
Juan River: before and after 52
(2) Estimates of sediment eroded from the Road to the River 56
(3) Impact of the sediment eroded from the Road on the total
sediment load of the River 66
iii (4) Impact of the sediment eroded from the Road on the bed in the
Lower San Juan 67
(5) Potential impact of rainfall from a hurricane 69
(6) The Road has had no adverse impact on sediment in the River 70
C. There is No Risk ofAny OtherAdverse Impact on the San
Juan River ............................................... 74
(1) Water quality 76
(2) Morphology 77
(3) Navigation 80
(4) Ecosystem, Tourism and Health 82
D. The “Judgment” of the CACJ Should be given No Weight ........ 87
E. Conclusion ............................................... 92
Chapter 4
The Treaty of Limits has no Bearing on the Present Proceedings
A. Introduction .............................................. 95
B. Nothing in the 1858 Treaty of Limits prevents Costa Rica from
undertaking Road Infrastructure Works ...................... 96
C. The Treaty of Limits and the motivation behind the Nicaraguan
claim ................................................... 103
D. Conclusions ............................................. 104
Chapter 5
Alleged Breaches of Obligations in respect of the Environment
A. Introduction ............................................. 107
B. Environmental impact assessment ........................... 109
(1) Threshold requirements in respect of the obligation to conduct
an environmental impact assessment 110
(2) Environmental impact assessment in the particular context of
emergency 112
C. Notification .............................................. 116
D. Alleged significant transboundary harm. . . . . . . . . . . . . . . . . . . . . .118
iv E. Other treaties relied on by Nicaragua ........................ 119
(1) Alleged breaches of the Convention on Biological Diversity 119
(2) Alleged breaches of the Ramsar Convention 121
(3) Alleged breaches of the Central American Convention for the
Protection of the Environment and other regional instruments 122
(4) Agreement on Border Protected Areas 125
F. Conclusions ............................................. 126
Chapter 6
Remedies
A. Introduction ............................................. 127
B. Nicaragua’s Requests for Provisional Measures ............... 127
C. Nicaragua’s requests for declaratory relief .................... 132
D. Nicaragua’s Remedial Claims .............................. 134
E. Nicaragua’s Request to Suspend Costa Rica’s Perpetual Right
of Free Navigation ........................................ 136
Submissions .................................................... 143
Appendix A .................................................... 145
Certification .................................................... 277
List of annexes .................................................. 279
vvi Chapter 1
Introduction
A. Overview of the dispute
1.1 The boundary regime applicable between Costa Rica and Nicaragua
1
is that established by the 1858 Treaty of Limits, as interpreted and applied
in subsequent arbitral awards and judicial decisions. 2 That regime
establishes and defines the boundary, certain common areas and facilities,
and concurrently stipulates Costa Rica’s perpetual right of free navigation
for purposes of commerce and for the benefit of riparians along the Costa
Rican bank. Nicaragua’s actions over the past several years have
demonstrated a poli cy of disregard for that well-established boundary
regime.
1.2 Faced with the risk of a further violation of its sovereignty and
territorial integrity , Costa Rica undertook urgent infrastructure works to
improve access to the police posts and remote communities located along its
border. Costa Rica ’s response – consolidating pre-existing dirt tracks and
constructing new stretches of road – was peaceful and conducted entirely
within its own territory.
1 NM, Annex 5.
2
The relevant arbitral awards and judicial decisions are:
- the Cleveland Award, NM, Annex 6(1);
- the Alexander Awards, NM, Annexes 6(2)-(5); and
- the decision of this Court in Dispute regarding Navigational and Related
Rights (Costa Rica v Nicaragua), Judgment, I C J Report s 2009, p. 213.
1 1.3 In its Me morial, Nicaragua criticises Costa Rica’s decision to take
3
those urgent measures. However, it is not for Nicaragua to challenge the
decision of another S tate to undertake urgent infrastructure works entirely
within its own territory. As to substantive obl igations, Nicaragua may only
complain if and to the extent that there has been significant transboundary
harm. As to obligations of notification and assessment, Nicaragua chooses
to ignore the pressing circumstances in which the Road was constructed,
which derive from its own unlawful and/or provocative conduct . Those
pressing circumstances are further particularised in Chapter 2 below.
1.4 As to actual harm, Nicaragua claims that “ massive” 4 and
“enormous” amounts of sediment have already been deposited in the San
6
Juan River and that erosion has “astronomically accelerated”. This grossly
overstates the volume of sediment that has or could have resulted from the
construction of the Road: as will be demonstrated in Chapter 3, on the
worst-case analysis the volu me of added sediment is insignificant having
regard to the sediment load of this sediment-heavy River. A fortiori
Nicaragua grossly exaggerates any actual transboundary impact the works
could possibly have had. In fact (as will be demonstrated here) the re has
been no significant effect. Indeed Nicaragua — on whom the burden of
proof lies — has not established that it has suffered any resulting harm from
any additional sediment , let alone significant harm of the character and
3
See e.g. NM, paras. 1.9 and 5.20.
4 NM, para. 1.9. See also e.g. NM, para. 3.60.
5
NM, para. 3.2.
6 NM, para. 3.77 (quoting Dr. Kondolf). Nicaragua also exaggerates that, for example, the
Border Road “importantly worsened the alrecritical situation of the sediments within
the River” and that it has had a “tremendous” impact and resulted in “irreparable” harm:
NM, paras. 2.35, 4.19 and 5.67.
21.3 In its Me morial, Nicaragua criticises Costa Rica’s decision to take
3
those urgent measures. However, it is not for Nicaragua to challenge the
decision of another S tate to undertake urgent infrastructure works entirely
within its own territory. As to substantive obl igations, Nicaragua may only
complain if and to the extent that there has been significant transboundary
harm. As to obligations of notification and assessment, Nicaragua chooses
to ignore the pressing circumstances in which the Road was constructed,
which derive from its own unlawful and/or provocative conduct . Those
pressing circumstances are further particularised in Chapter 2 below.
1.4 As to actual harm, Nicaragua claims that “ massive” 4 and
“enormous” amounts of sediment have already been deposited in the San
6
Juan River and that erosion has “astronomically accelerated”. This grossly
overstates the volume of sediment that has or could have resulted from the
construction of the Road: as will be demonstrated in Chapter 3, on the
worst-case analysis the volu me of added sediment is insignificant having
regard to the sediment load of this sediment-heavy River. A fortiori
Nicaragua grossly exaggerates any actual transboundary impact the works
could possibly have had. In fact (as will be demonstrated here) the re has
been no significant effect. Indeed Nicaragua — on whom the burden of
proof lies — has not established that it has suffered any resulting harm from
any additional sediment , let alone significant harm of the character and
3
See e.g. NM, paras. 1.9 and 5.20.
4 NM, para. 1.9. See also e.g. NM, para. 3.60.
5
NM, para. 3.2.
6 NM, para. 3.77 (quoting Dr. Kondolf). Nicaragua also exaggerates that, for example, the
Border Road “importantly worsened the alrecritical situation of the sediments within
the River” and that it has had a “tremendous” impact and resulted in “irreparable” harm:
NM, paras. 2.35, 4.19 and 5.67. 10
Rivers.
Figure 1. Bi-national basin of San Juan-Colorado rivers. Source: “PROCUENCA.
Diálogo sobre agua y Clima. Enfrentando la variabilidad del clima en una cuenca
transfronteriza de América Central: La cuenca del río San Juan (Costa Rica y
Nicaragua)”. Available at: http://www.oas.org/sanjuan/spanish/documentos/
dialogo/dialogo/01-characterization/mapas/map1.html
1.8 The San Juan River extends over approximately 205 km from its
source in Lake Nicaragua to its outlet in the Atlantic Ocean. Some 30 km
10 Vol 2, Annex No 4, Costa Rican Institute of Electricity (ICE), SBU Projects and Associated
Services, Centre for Basic Engineering Studies, Department of Hydrology, Report on
Hydrology and Sediments for the Costa Rican River Basins draining to the San Juan River ,
August 2013, Table 4, p. 14.
4 10
Rivers.
Figure 1. Bi-national basin of San Juan-Colorado rivers. Source: “PROCUENCA.
Diálogo sobre agua y Clima. Enfrentando la variabilidad del clima en una cuenca
transfronteriza de América Central: La cuenca del río San Juan (Costa Rica y
Nicaragua)”. Available at: http://www.oas.org/sanjuan/spanish/documentos/
dialogo/dialogo/01-characterization/mapas/map1.html
1.8 The San Juan River extends over approximately 205 km from its
source in Lake Nicaragua to its outlet in the Atlantic Ocean. Some 30 km
10 Vol 2, Annex No 4, Costa Rican Institute of Electricity (ICE), SBU Projects and Associated
Services, Centre for Basic Engineering Studies, Department of Hydrology, Report on
Hydrology and Sediments for the Costa Rican River Basins draining to the San Juan River ,
August 2013, Table 4, p. 14. River and 663 000 t yr into the lower San Juan River. In the Navigational
Rights case, Nicaragua acknowledged that the river carried over 10 200 000
t yr-1of sediment. 14
C. Description of the Border Road
1.11 In light of the circumstances described in the following sub- section,
and set out in greater detail in Chapter 2 , Costa Rica commenced road
works entirely within its own territory. Road works were first carried out so
as to provide access to the area bordering Nicaragua along the San Juan
River. These access routes leading to the border area comprise
15
approximately 382.7 km of road. Costa Rica also undertook road works in
the border area itself, so as to create a single road running parallel to the San
Juan River and further inland called Route 1856 Juan Rafael Mora Porras
16
(See Sketch Map 1). This road (hereafter the Border Road or simply the
Road) runs from Los Chiles to Delta Costa Rica, and is approximate ly
159.7 km in length . Much of it (101.5 km or 63.6%) was built on pre -
existing rural roads or tracks. Of the 159.7 km, approximately 108.2 km of
the Road runs between Marker II and Delta Colorado , 18i.e. the area where
13 Appendix A, Professor Colin Thorne, Assessment of the Impact of the Construof the
Border Road in Costa Rica on the San Juan River , para. 8.56.
14 See Dispute Concerning Navigational and Related Rights (Costa Rica v Nicaragua) , NCM,
para. 1.1.8.
15
Vol 2, Annex No 3, Allan Astorga G. and Andreas Mende, Route 1856: Analysis ofhe
Change in Land use Based on Satellite Images Before and After the Construction of the
Border Road, August 2013, p. 6.
16 The name of the Border Road was explained by the Ambassador Edgar Ugalde Álvarez,
Agent of Costa Rica, in CR 2013/29, p. 8, para. 2 (Álvarez).
17
Vol 2, Annex No 3, Allan Astorga G. and Andreas Mende, Route 1856: Analysis of the
Change in Land use Based on Satellite Images Before and After the Construction of the
Border Road, August 2013, p. 6.
18 Ibid, p. 4.
6River and 663 000 t yr into the lower San Juan River. In the Navigational
Rights case, Nicaragua acknowledged that the river carried over 10 200 000
t yr-1of sediment. 14
C. Description of the Border Road
1.11 In light of the circumstances described in the following sub- section,
and set out in greater detail in Chapter 2 , Costa Rica commenced road
works entirely within its own territory. Road works were first carried out so
as to provide access to the area bordering Nicaragua along the San Juan
River. These access routes leading to the border area comprise
15
approximately 382.7 km of road. Costa Rica also undertook road works in
the border area itself, so as to create a single road running parallel to the San
Juan River and further inland called Route 1856 Juan Rafael Mora Porras
16
(See Sketch Map 1). This road (hereafter the Border Road or simply the
Road) runs from Los Chiles to Delta Costa Rica, and is approximate ly
159.7 km in length . Much of it (101.5 km or 63.6%) was built on pre -
existing rural roads or tracks. Of the 159.7 km, approximately 108.2 km of
the Road runs between Marker II and Delta Colorado , 18 i.e. the area where
13 Appendix A, Professor Colin Thorne, Assessment of the Impact of the Construof the
Border Road in Costa Rica on the San Juan River , para. 8.56.
14 See Dispute Concerning Navigational and Related Rights (Costa Rica v Nicaragua) , NCM,
para. 1.1.8.
15
Vol 2, Annex No 3, Allan Astorga G. and Andreas Mende, Route 1856: Analysis ofhe
Change in Land use Based on Satellite Images Before and After the Construction of the
Border Road, August 2013, p. 6.
16 The name of the Border Road was explained by the Ambassador Edgar Ugalde Álvarez,
Agent of Costa Rica, in CR 2013/29, p. 8, para. 2 (Álvarez).
17
Vol 2, Annex No 3, Allan Astorga G. and Andreas Mende, Route 1856: Analysis of the
Change in Land use Based on Satellite Images Before and After the Construction of the
Border Road, August 2013, p. 6.
18 Ibid, p. 4. inhabitants of the Costa Rican bank] commonly used and still
uses the river for travel for the purpose of meeting the
essential needs of everyday life which require expeditious
transportation, such as transport to and from school or for
medical care.” 23
1.14 Costa Rican public officials have also provided essential health and
community services to the riparian communities by navigatin g on the San
24
Juan, in order to meet the necessities of daily life. Furthermore, a number
of Costa Rican police posts are located along the right bank of the San Juan
25
River. Costa Rica’s right of navigation for purposes of commerce, and by
public officials for the provision of essential health and community services
to the riparian community, was confirmed by the Court in its 2009 Judgment
26
in the Navigational Rights case.
27
1.15 However, in the months before Emergency Decree 36440-MP was
issued in February 2011, Nicaragua:
(a) obstructed navigation on the San Juan by Costa Rican riparians and
public service officials, thereby preventing communication with
28
these remote communities to meet the necessities of everyday life;
(b) occupied and claimed sovereignty over part of Costa Rica’s territory
29
in Isla Portillos;
23 Dispute regarding Navigational and Related Rights (Costa Rica v Nicaragua), Judgment,
I C J Reports 2009, p. 246, para. 78.
24
See Dispute regarding Navigational and Related Rights (Costa Rica v Nicaragua),
Judgment, I C J Reports 2009, p. 248, para. 84.
25 See Chapter 2, para. 2.20.
26
Dispute regarding Navigational and Related Rights (Costa Rica v Nicaragua), Judgment,
I C J Reports 2009, p. 270, para. 156(1)(g).
27 NM, Annex 11.
28
See Chapter 2, paras. 2.5-2.9.
8 inhabitants of the Costa Rican bank] commonly used and still
uses the river for travel for the purpose of meeting the
essential needs of everyday life which require expeditious
transportation, such as transport to and from school or for
medical care.” 23
1.14 Costa Rican public officials have also provided essential health and
community services to the riparian communities by navigatin g on the San
24
Juan, in order to meet the necessities of daily life. Furthermore, a number
of Costa Rican police posts are located along the right bank of the San Juan
25
River. Costa Rica’s right of navigation for purposes of commerce, and by
public officials for the provision of essential health and community services
to the riparian community, was confirmed by the Court in its 2009 Judgment
26
in the Navigational Rights case.
27
1.15 However, in the months before Emergency Decree 36440-MP was
issued in February 2011, Nicaragua:
(a) obstructed navigation on the San Juan by Costa Rican riparians and
public service officials, thereby preventing communication with
28
these remote communities to meet the necessities of everyday life;
(b) occupied and claimed sovereignty over part of Costa Rica’s territory
29
in Isla Portillos;
23 Dispute regarding Navigational and Related Rights (Costa Rica v Nicaragua), Judgment,
I C J Reports 2009, p. 246, para. 78.
24
See Dispute regarding Navigational and Related Rights (Costa Rica v Nicaragua),
Judgment, I C J Reports 2009, p. 248, para. 84.
25 See Chapter 2, para. 2.20.
26
Dispute regarding Navigational and Related Rights (Costa Rica v Nicaragua), Judgment,
I C J Reports 2009, p. 270, para. 156(1)(g).
27 NM, Annex 11.
28
See Chapter 2, paras. 2.5-2.9. MP was passed in February 2011, providing the legal framework for the
34
works. Costa Rica also informed the Secretary General of the United
35
Nations of the reasons which prompted con struction of the R oad. The
background facts leading to the construction of the Road are discussed in
greater detail in Chapter2 of this Counter-Memorial.
1.17 By contrast to Nicaragua’s silence in response to Costa Rica’s
repeated written requests for information regarding Nicaragua’s activities on
36
the San Juan River and in the border area , Costa Rica formally
communicated with Nicaragua through official channels, promptly and in
good faith, concerning the road infrastructure works on Costa Rican
territory, despite the fact that Nicaragua had taken military actions and made
threats to Costa Rica’s sovereignty and territorial integrity, and to the
welfare and safety of its inhabitants.
1.18 After having learned from the Nicaraguan press that high
Government officia ls in Nicaragua had voiced their concern about the
construction of the Border Road, on 29 November 2011 Costa Rica invited
Nicaragua, “in the spirit of a good neighbour policy and environmental
protection”, to detail its concerns to Costa Rica by providing “serious and
objective scientific information” in support of its allegations. 37 Thus, Costa
Rica took the initiative to promptly enter into a cooperative dialogue with
Nicaragua, although Nicaragua had not made any formal request or
34 See Chapter 2, para. 2.27.
35
Vol 3, Annex No 40, Note from the Minister of Foreign Affairs and Worship of Costa Rica
to the Secretary General of the United Nations, Ref: DM-AM-633-11, 14 December 2011.
36 See for example Certain Activities carried out by Nicaragua in the Border Area (Costa Rica
v Nicaragua), CRM, paras 1.9, 3.70-77.
37
Vol 3, Annex No 39, Note from the Minister of Foreign Affairs and Worship of Costa Rica
to the Minister of Foreign Affairs of Nicaragua, Ref: DM-AM-601-11, 29 November 2011.
10MP was passed in February 2011, providing the legal framework for the
34
works. Costa Rica also informed the Secretary General of the United
35
Nations of the reasons which prompted con struction of the R oad. The
background facts leading to the construction of the Road are discussed in
greater detail in Chapter2 of this Counter-Memorial.
1.17 By contrast to Nicaragua’s silence in response to Costa Rica’s
repeated written requests for information regarding Nicaragua’s activities on
36
the San Juan River and in the border area , Costa Rica formally
communicated with Nicaragua through official channels, promptly and in
good faith, concerning the road infrastructure works on Costa Rican
territory, despite the fact that Nicaragua had taken military actions and made
threats to Costa Rica’s sovereignty and territorial integrity, and to the
welfare and safety of its inhabitants.
1.18 After having learned from the Nicaraguan press that high
Government officia ls in Nicaragua had voiced their concern about the
construction of the Border Road, on 29 November 2011 Costa Rica invited
Nicaragua, “in the spirit of a good neighbour policy and environmental
protection”, to detail its concerns to Costa Rica by providing “serious and
objective scientific information” in support of its allegations. 37 Thus, Costa
Rica took the initiative to promptly enter into a cooperative dialogue with
Nicaragua, although Nicaragua had not made any formal request or
34 See Chapter 2, para. 2.27.
35
Vol 3, Annex No 40, Note from the Minister of Foreign Affairs and Worship of Costa Rica
to the Secretary General of the United Nations, Ref: DM-AM-633-11, 14 December 2011.
36 See for example Certain Activities carried out by Nicaragua in the Border Area (Costa Rica
v Nicaragua), CRM, paras 1.9, 3.70-77.
37
Vol 3, Annex No 39, Note from the Minister of Foreign Affairs and Worship of Costa Rica
to the Minister of Foreign Affairs of Nicaragua, Ref: DM-AM-601-11, 29 November 2011. Nicaragua persisted in contending that its unjustified allegation of potential
transboundary harm was sufficient to trigger the requirement for Costa Rica
to undertake an EIA, and it demanded that Costa Rica cease its
infrastructure works until Nicaragua “has had the chance to receive and
analyze the [EIA] on the project.” 42 Rather than engaging in constructive
dialogue with Costa Rica, Nicaragua thus sought to exercise a veto over
Costa Rica’s activities on undisputed Costa Rican territory.
1.21 On 20 December 2011 Costa Rica responded to Nicaragua’s notes of
29 November and 10 December, noting that the so- called “consequences”
outlined by Nicaragua in its note of 10 December 2011 we re
unsubstantiated, and that if Nicaragua could provide Costa Rica with any
demonstrated concerns of potential harm, Costa Rica would be well -placed
43
to address them. More specifically, Costa Rica requested from Nicaragua
any existing studies on the San Juan River, as well as “information relating
to historical records on turbidity in its waters, chemical composition,
historical sediment load, and all scientific data pertinent to the assessment of
44
the river’s condition, so as to detect any possible affectat ions.” Costa Rica
thus sought to address Nicaragua’s allegations in a rational, cooperative
manner.
1.22 While Costa Rica reiterated through this Note its invitation for
Nicaragua to substantiate its concerns regarding potential harm to its
42 NM, Annex 16, Note from the Minister of Fore ign Affairs of Nicaragua, to the Minister of
Foreign Affairs of Costa Rica, Referece MRE/DVS/VJW/0685/12/11, Managua,
10 December, 2011.
43
Minister of Foreign Affairs o f Nicaragua, Reference DVM -AM-286-11, 20 December,o the
2011.
44 Ibid.
12Nicaragua persisted in contending that its unjustified allegation of potential
transboundary harm was sufficient to trigger the requirement for Costa Rica
to undertake an EIA, and it demanded that Costa Rica cease its
infrastructure works until Nicaragua “has had the chance to receive and
analyze the [EIA] on the project.” 42 Rather than engaging in constructive
dialogue with Costa Rica, Nicaragua thus sought to exercise a veto over
Costa Rica’s activities on undisputed Costa Rican territory.
1.21 On 20 December 2011 Costa Rica responded to Nicaragua’s notes of
29 November and 10 December, noting that the so- called “consequences”
outlined by Nicaragua in its note of 10 December 2011 we re
unsubstantiated, and that if Nicaragua could provide Costa Rica with any
demonstrated concerns of potential harm, Costa Rica would be well -placed
43
to address them. More specifically, Costa Rica requested from Nicaragua
any existing studies on the San Juan River, as well as “information relating
to historical records on turbidity in its waters, chemical composition,
historical sediment load, and all scientific data pertinent to the assessment of
44
the river’s condition, so as to detect any possible affectat ions.” Costa Rica
thus sought to address Nicaragua’s allegations in a rational, cooperative
manner.
1.22 While Costa Rica reiterated through this Note its invitation for
Nicaragua to substantiate its concerns regarding potential harm to its
42 NM, Annex 16, Note from the Minister of Fore ign Affairs of Nicaragua, to the Minister of
Foreign Affairs of Costa Rica, Referece MRE/DVS/VJW/0685/12/11, Managua,
10 December, 2011.
43
Minister of Foreign Affairs o f Nicaragua, Reference DVM -AM-286-11, 20 December,o the
2011.
44 Ibid. 48
Rican territory, specifically the province of Guanacaste, and has contested
Costa Rica’s well -established and Treaty -based joint sovereignty over the
49
Bay of San Juan del Norte . In these and other respects it has conducted
what amounts to a campaign of provocation (and in this respect reference is
made to paragraphs 44 to 47 of the Court’s provisional measures order of
22 November 2013 in the Certain Activities case).
E. The Court’s jurisdiction
1.25 In its Memorial, Nicaragua submits that ‘ [i]n accordance with the
provisions of Article 36, paragraph 1, of the Statute, jurisdiction exists by
virtue of Article XXXI of the American Treaty on Pacific Settlement signed
in Bogotá on 30 April 1948 ( Pact of Bogotá) ’ and that “ [i]n accordance
with the provisions of Article 36, paragraph 2, of the Statute, jurisdiction
also exists by virtue of the operation of the Declaration of the Applicant
State dated 24 September 1929 and the Declaration of Costa Rica dated
50
20 February 1973”.
1.26 In its Memorial, Nicaragua states:
“In accordance with the provisions of Article 36, paragraph
1, of the Statute, jurisdiction exists by virtue of Article XXXI
of the American Treaty on Pacific Settlement signed in
Bogotá on 30 April 1948 (Pact of Bogotá). Both the Republic
of Nicaragua and the Republic of Costa Rica are parties to
the Pact of Bogotá, the former without any pertinent
reservation, and the latter with no reservations. In accordance
with the provisions of Article 36, paragraph 2, of the Statute,
jurisdiction also exists by virtue of the operation of the
48 See Chapter 2, paras. 2.24 and 2.27.
49 See Chapter 2, paras.2.18-2.19.
50 NM, para. 1.4.
14 48
Rican territory, specifically the province of Guanacaste, and has contested
Costa Rica’s well -established and Treaty -based joint sovereignty over the
49
Bay of San Juan del Norte . In these and other respects it has conducted
what amounts to a campaign of provocation (and in this respect reference is
made to paragraphs 44 to 47 of the Court’s provisional measures order of
22 November 2013 in the Certain Activities case).
E. The Court’s jurisdiction
1.25 In its Memorial, Nicaragua submits that ‘ [i]n accordance with the
provisions of Article 36, paragraph 1, of the Statute, jurisdiction exists by
virtue of Article XXXI of the American Treaty on Pacific Settlement signed
in Bogotá on 30 April 1948 ( Pact of Bogotá) ’ and that “ [i]n accordance
with the provisions of Article 36, paragraph 2, of the Statute, jurisdiction
also exists by virtue of the operation of the Declaration of the Applicant
State dated 24 September 1929 and the Declaration of Costa Rica dated
50
20 February 1973”.
1.26 In its Memorial, Nicaragua states:
“In accordance with the provisions of Article 36, paragraph
1, of the Statute, jurisdiction exists by virtue of Article XXXI
of the American Treaty on Pacific Settlement signed in
Bogotá on 30 April 1948 (Pact of Bogotá). Both the Republic
of Nicaragua and the Republic of Costa Rica are parties to
the Pact of Bogotá, the former without any pertinent
reservation, and the latter with no reservations. In accordance
with the provisions of Article 36, paragraph 2, of the Statute,
jurisdiction also exists by virtue of the operation of the
48 See Chapter 2, paras. 2.24 and 2.27.
49 See Chapter 2, paras.2.18-2.19.
50 NM, para. 1.4. including the suspension of Costa Rica's right of navigation in the San Juan
55
de Nicaragua River”.
1.29 The extent of Costa Rica’s right of navigation was settled by Article
VI of the 1858 Treaty of Limits, with it being agreed that Costa Rica was to
have a “perpetual” right. That Article provides:
“The Republic of Nicaragua shall have exclusive dominium
and imperium over the waters of the San Juan river from its
origin in the lake to its mouth at the Atlantic Ocean; the
Republic of Costa Rica shall however have a perpetual right
of free navigation on the said waters between the mouth of
the river and a poin56located three English miles below
Castillo Viejo ...”
Nicaragua cannot reopen the matter. As stated by the Court in Territorial
and Maritime Dispute (Nicaragua v Colombia):
“… the clear purpose of [Article VI of the Pact of Bogotá ]
was to preclude the possibility of using those procedures, and
in particular judicial remedies, in order to reopen such
matters as were settled between the par ties to the Pact,
because they had been the object of an international judicial
decision or a treaty.” 57
1.30 As this particular matter has been settled, there is no extant “legal
dispute” regarding Costa Rica’s navigational rights and t o this extent the
Court does not have jurisdiction over the matter under Article 36(2) of the
55 NM, Submissions, para. 3(iii).
56
Treaty of Limits between Costa Rica and Nicaragua (Cañas-Jerez), San José, 15 April 1858,
Art. VI, as quoted in Dispute regarding Navigational and Related Rights (Costa Rica v
Nicaragua), Judgment, I C J Reports 2009, p. 236, para. 44.
57 Territorial and Maritime Dispute (Nicaragua v Colombia), Preliminary Objections,
Judgment, I C J Reports 2007, p. 858, para. 77.
16including the suspension of Costa Rica's right of navigation in the San Juan
55
de Nicaragua River”.
1.29 The extent of Costa Rica’s right of navigation was settled by Article
VI of the 1858 Treaty of Limits, with it being agreed that Costa Rica was to
have a “perpetual” right. That Article provides:
“The Republic of Nicaragua shall have exclusive dominium
and imperium over the waters of the San Juan river from its
origin in the lake to its mouth at the Atlantic Ocean; the
Republic of Costa Rica shall however have a perpetual right
of free navigation on the said waters between the mouth of
the river and a poin56located three English miles below
Castillo Viejo ...”
Nicaragua cannot reopen the matter. As stated by the Court in Territorial
and Maritime Dispute (Nicaragua v Colombia):
“… the clear purpose of [Article VI of the Pact of Bogotá ]
was to preclude the possibility of using those procedures, and
in particular judicial remedies, in order to reopen such
matters as were settled between the par ties to the Pact,
because they had been the object of an international judicial
decision or a treaty.” 57
1.30 As this particular matter has been settled, there is no extant “legal
dispute” regarding Costa Rica’s navigational rights and t o this extent the
Court does not have jurisdiction over the matter under Article 36(2) of the
55 NM, Submissions, para. 3(iii).
56
Treaty of Limits between Costa Rica and Nicaragua (Cañas-Jerez), San José, 15 April 1858,
Art. VI, as quoted in Dispute regarding Navigational and Related Rights (Costa Rica v
Nicaragua), Judgment, I C J Reports 2009, p. 236, para. 44.
57 Territorial and Maritime Dispute (Nicaragua v Colombia), Preliminary Objections,
Judgment, I C J Reports 2007, p. 858, para. 77. addresses why the fundamental instrument governing the relationship
between Costa Rica and Nicaragua, the 1858 Treaty of Limits, has no
bearing on the dispute before the Court . That boundary t reaty does not
regulate the exercise of Costa Rica’s sovereignty within its own territory.
Chapter 5 then establishes that the construction of the Road has not
breached any conventional or customary international law obligation.
Finally, Chapter 6 addresses why Nicaragua is not entitled to the remed ies
it seeks.
1.34 Attached to this Counter -Memorial as Appendix A is the Expert
Report of Professor Colin Thorne of November 2013, together with the
following related expert reports.
(a) Costa Rican Institute of Electricity (ICE), SBU Projects and
Associated S ervices, Centre for Basic Engineering Studies,
Department of Hydrology, Report on Hydrology and Sediments for
the Costa Rican River Basins draining to the San Juan River, August
2013 (the ICE Report) (Annex 4; also submitted as Attachment CR-
60
1 on Nicaragua’s Request for Provisional Measures);
(b) University of Costa Rica Centre for Research in Sustainable
Development, Department of Civil Engineering, Report on
Systematic Field monitoring of Erosion and Sediment Yield along
Route 1856, September 2013 (the U CR Report ) (Annex 1; also
submitted as Attachment CR -2 on Nicaragua’s Request for
Provisional Measures); and
60 Vol 2, Annex No 4, Costa Rican Institute of Electricity (ICE), SBU Projects and Associated
Services, Centre for Basic Engineering Studies, Department of Hydrology, Report on
Hydrology and Sediments for the Costa Rican Ri ver Basins draining to the San Juan River ,
August 2013, p. 2.
18addresses why the fundamental instrument governing the relationship
between Costa Rica and Nicaragua, the 1858 Treaty of Limits, has no
bearing on the dispute before the Court . That boundary t reaty does not
regulate the exercise of Costa Rica’s sovereignty within its own territory.
Chapter 5 then establishes that the construction of the Road has not
breached any conventional or customary international law obligation.
Finally, Chapter 6 addresses why Nicaragua is not entitled to the remed ies
it seeks.
1.34 Attached to this Counter -Memorial as Appendix A is the Expert
Report of Professor Colin Thorne of November 2013, together with the
following related expert reports.
(a) Costa Rican Institute of Electricity (ICE), SBU Projects and
Associated S ervices, Centre for Basic Engineering Studies,
Department of Hydrology, Report on Hydrology and Sediments for
the Costa Rican River Basins draining to the San Juan River, August
2013 (the ICE Report) (Annex 4; also submitted as Attachment CR-
60
1 on Nicaragua’s Request for Provisional Measures);
(b) University of Costa Rica Centre for Research in Sustainable
Development, Department of Civil Engineering, Report on
Systematic Field monitoring of Erosion and Sediment Yield along
Route 1856, September 2013 (the U CR Report ) (Annex 1; also
submitted as Attachment CR -2 on Nicaragua’s Request for
Provisional Measures); and
60 Vol 2, Annex No 4, Costa Rican Institute of Electricity (ICE), SBU Projects and Associated
Services, Centre for Basic Engineering Studies, Department of Hydrology, Report on
Hydrology and Sediments for the Costa Rican Ri ver Basins draining to the San Juan River ,
August 2013, p. 2.20 Chapter 2
Circumstances leading to the Construction of the Road
A. Introduction and background
2.1 The claims made by Nicaragua against Costa Rica in the present
proceedings arise against the background of various attempts made by
Nicaragua to challenge the long -settled boundary regime between the two
States, established by the 1858 Treaty of Limits and related instruments. In
spite of the Court’s Judgment in the case concerning Dispute Regarding
Navigational and Related Rights (Costa Ric a v Nicaragua), rendered on
13 July 2009, Nicaragua has obstructed Costa Rica’s exercise of its right of
navigation on the San Juan River. Over a 16-month period, starting with the
occupation of the Costa Rican territory in the northern sector of Isla
Portillos, Nicaragua embarked on a course of hostile conduct against Costa
Rica, which prompted Costa Rica to take urgent measures, entirely on its
own undisputed territory, to safeguard its sovereignty and territorial
integrity, and to protect the welfare and safety of its inhabitants. These
measures included the issue of an Emergency Decree and the undertaking of
urgent road infrastructure works in the border area. These peaceful measures
were taken in full compliance with international and Costa Rican law.
2.2 This Chapter first describes the context under which the Border
Road was constructed , including the reasons motivating its construction,
which included the need to allow Costa Rican police direct and expeditious
access to the border are a, in order to provide the local population with
essential services (see Section B below). The Road was constructed
pursuant to Costa Rica’s Emergency Decree: that Decree and its
21 implementation are discussed in Section C below, together with the
remediation works which have been carried out and which are continuing.
B. Nicaragua’s conduct and further threats to Costa Rica
2.3 Four principal incidents constitute essential background to the
issuance of the Emergency Decree. They explain Costa Rica’s reasonable
perception of the urgent need for road infrastructure works in the border
area. They were: (1) Nicaragua’s obstruction of the exercise of Costa Rica’s
right to navigate the San Juan River; (2) Nicaragua’s illegal occupation of
Costa Rican territory in the northern sector of Isla Portillos; (3) Nicaragua’s
extraordinary claim to navigate on the Colorado River ; and (4) Nicaragua’s
increased military presence in the border area , creating a legitimate fear of
further incidents. An additional element was Costa Rica’s need to provide
land access to its police posts along the border . Since these events,
Nicaragua has embarked on further unsettling and provocative behaviour.
(1) Nicaragua’s obstruction of the right to navigate the San Juan
River
2.4 Nicaragua’s conduct must be viewed in the geographical context of
Costa Rica’s border area, which according to a survey conducted in 2012 by
Costa Rica’s Ministry of Planning is home to some 1,900 people living in
61
remote communities between Delta Colorado and Marker II near Tiricias.
(See Sketch Map 2 ) These individuals have historically relied on the San
Juan River as the means of communication in the border area , due to the
61
Information provided by Costa Rica’s Ministry of Planning and National Development,
based on data provided by the Ministry of Housing and Human Settlements and the Health
Areas of the Ministry of Public Health. There are approximately 4,000 inhabitants residing
in the whole area serviced by the Border Road, i.e. between the town of Los Chiles and
Delta Colorado.
22implementation are discussed in Section C below, together with the
remediation works which have been carried out and which are continuing.
B. Nicaragua’s conduct and further threats to Costa Rica
2.3 Four principal incidents constitute essential background to the
issuance of the Emergency Decree. They explain Costa Rica’s reasonable
perception of the urgent need for road infrastructure works in the border
area. They were: (1) Nicaragua’s obstruction of the exercise of Costa Rica’s
right to navigate the San Juan River; (2) Nicaragua’s illegal occupation of
Costa Rican territory in the northern sector of Isla Portillos; (3) Nicaragua’s
extraordinary claim to navigate on the Colorado River ; and (4) Nicaragua’s
increased military presence in the border area , creating a legitimate fear of
further incidents. An additional element was Costa Rica’s need to provide
land access to its police posts along the border . Since these events,
Nicaragua has embarked on further unsettling and provocative behaviour.
(1) Nicaragua’s obstruction of the right to navigate the San Juan
River
2.4 Nicaragua’s conduct must be viewed in the geographical context of
Costa Rica’s border area, which according to a survey conducted in 2012 by
Costa Rica’s Ministry of Planning is home to some 1,900 people living in
61
remote communities between Delta Colorado and Marker II near Tiricias.
(See Sketch Map 2 ) These individuals have historically relied on the San
Juan River as the means of communication in the border area , due to the
61
Information provided by Costa Rica’s Ministry of Planning and National Development,
based on data provided by the Ministry of Housing and Human Settlements and the Health
Areas of the Ministry of Public Health. There are approximately 4,000 inhabitants residing
in the whole area serviced by the Border Road, i.e. between the town of Los Chiles and
Delta Colorado. Limited Navigation Rights to the Republic of Costa Rica ”, which contained
a set of “Regulations Regarding Navigation on the San Juan River”. 65
2.6 As is indicated by the title of the document and from a summary
review of it, Decree 79-2009 is contrary to the Court’s Judgment of 13 July
2009. It regulates navigation on the San Juan River by Costa Ricans only. It
will be recalled that one of the conditions for regulation by Nicaragua of
navigation on the San Juan Ri ver is that such regulation “ must not be
66
discriminatory”, meaning that the regulation of navigation along the San
Juan River must apply equally to both Nicaraguans and Costa Ricans.
Decree 79-2009, however, discriminates against Costa Ricans.
2.7 Similarly, the Court held that a regulation “mu st only subject the
activity to certain rules without rendering impossible or substantially
67
impeding the exercise of the right of navigation”; that “it must be
68
consistent with the terms of the Treat y [of Limits] ”; that “it must have a
69 70
legitimate purpose”; and that “it must not be unreasonable”. Decree 79-
2009 imposes numerous requirements for navigation that are unreasonable
and inconsistent with the 1858 Treaty of Limits, and which in practice
65
Vol 3, Annex No 26, Nicaragua, Executive Decree No 79 -2009 of 24 September 2009,
‘Creation of the Inter-institutional Commission to Develop and Implement the Regulations
Regarding Navigation on the San Juan River, specifically where the International Court of
Justice Grants Limited Navigation Rights to the Republic of Costa Rica’, published in The
Gazette of 1 October 2009.
66 Dispute regarding Navigational and Related Rights (Costa Rica v Nicaragua), Judgment,
I C J Reports 2009, p. 249, para. 87(4).
66
CR 2011/2, p. 9, para. 7 (Argüello).
67 Dispute regarding Navigational and Related Rights (Costa Rica v Nicaragua), Judgment,
I C J Reports 2009, p. 249, para. 87(1).
68 Ibid, para. 87(2).
69
Ibid, para. 87(3).
70 Ibid, para. 87(5).
24Limited Navigation Rights to the Republic of Costa Rica ”, which contained
a set of “Regulations Regarding Navigation on the San Juan River”. 65
2.6 As is indicated by the title of the document and from a summary
review of it, Decree 79-2009 is contrary to the Court’s Judgment of 13 July
2009. It regulates navigation on the San Juan River by Costa Ricans only. It
will be recalled that one of the conditions for regulation by Nicaragua of
navigation on the San Juan Ri ver is that such regulation “ must not be
66
discriminatory”, meaning that the regulation of navigation along the San
Juan River must apply equally to both Nicaraguans and Costa Ricans.
Decree 79-2009, however, discriminates against Costa Ricans.
2.7 Similarly, the Court held that a regulation “mu st only subject the
activity to certain rules without rendering impossible or substantially
67
impeding the exercise of the right of navigation”; that “it must be
68
consistent with the terms of the Treat y [of Limits] ”; that “it must have a
69 70
legitimate purpose”; and that “it must not be unreasonable”. Decree 79-
2009 imposes numerous requirements for navigation that are unreasonable
and inconsistent with the 1858 Treaty of Limits, and which in practice
65
Vol 3, Annex No 26, Nicaragua, Executive Decree No 79 -2009 of 24 September 2009,
‘Creation of the Inter-institutional Commission to Develop and Implement the Regulations
Regarding Navigation on the San Juan River, specifically where the International Court of
Justice Grants Limited Navigation Rights to the Republic of Costa Rica’, published in The
Gazette of 1 October 2009.
66 Dispute regarding Navigational and Related Rights (Costa Rica v Nicaragua), Judgment,
I C J Reports 2009, p. 249, para. 87(4).
66
CR 2011/2, p. 9, para. 7 (Argüello).
67 Dispute regarding Navigational and Related Rights (Costa Rica v Nicaragua), Judgment,
I C J Reports 2009, p. 249, para. 87(1).
68 Ibid, para. 87(2).
69
Ibid, para. 87(3).
70 Ibid, para. 87(5). (2) Nicaragua’s illegal occupation of Costa Rican territory
2.10 Costa Rica’s Memorial in the Certain Activities c ase details the
events related to Nicaragua’s mil itary occupation of the Costa Rican
territory known as Finca Aragón, located in the northern sector of Isla
Portillos (‘the Area’), and registered under the Ramsar Convention by Costa
Rica as a wetland of international importance. It is nevertheless necessary to
recall these events briefly, as they constitute the relevant background to the
present proceedings.
2.11 On 20 October 2010, Costa Rican officials observed during an
overflight that Nicaraguan personnel had unlawfully entered the Ar ea, and
were unlawfully depositing on the Area sediment extracted from the San
Juan River as part of Nicaragua’s dredging programme. On 21 October
2010, Costa Rica formally protested the presence of Nicaraguan personnel
76
on its territory, and their activities. Subsequently Nicaragua withdrew its
personnel and removed its dredging equipment. On 22 October 2010, Costa
Rican police and civilian personnel entered Finca Aragón and discovered
that Nicaraguan personnel had felled a considerable portion of primary
forest.77
2.12 On 1 November 2010, Costa Rican officials observed during an
overflight that Nicaraguan military personnel had re -entered the Area and
had set up a military camp in close proximity to where they had previously
76 Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v ,icaragua)
CRM, para. 1.7, and Vol. III, Annex 47, Note from the Acting Minister o f Foreign Affairs
and Worship of Costa Rica to the Minister of Foreign Affairs of Nicaragua, Reference DM-
412-10, 21 October 2010.
77
Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v ,icaragua)
CRM, paras. 3.10-3.11.
26 (2) Nicaragua’s illegal occupation of Costa Rican territory
2.10 Costa Rica’s Memorial in the Certain Activities c ase details the
events related to Nicaragua’s mil itary occupation of the Costa Rican
territory known as Finca Aragón, located in the northern sector of Isla
Portillos (‘the Area’), and registered under the Ramsar Convention by Costa
Rica as a wetland of international importance. It is nevertheless necessary to
recall these events briefly, as they constitute the relevant background to the
present proceedings.
2.11 On 20 October 2010, Costa Rican officials observed during an
overflight that Nicaraguan personnel had unlawfully entered the Ar ea, and
were unlawfully depositing on the Area sediment extracted from the San
Juan River as part of Nicaragua’s dredging programme. On 21 October
2010, Costa Rica formally protested the presence of Nicaraguan personnel
76
on its territory, and their activities. Subsequently Nicaragua withdrew its
personnel and removed its dredging equipment. On 22 October 2010, Costa
Rican police and civilian personnel entered Finca Aragón and discovered
that Nicaraguan personnel had felled a considerable portion of primary
forest.77
2.12 On 1 November 2010, Costa Rican officials observed during an
overflight that Nicaraguan military personnel had re -entered the Area and
had set up a military camp in close proximity to where they had previously
76 Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v,Nicaragua)
CRM, para. 1.7, and Vol. III, Annex 47, Note from the Acting Minister o f Foreign Affairs
and Worship of Costa Rica to the Minister of Foreign Affairs of Nicaragua, Reference DM-
412-10, 21 October 2010.
77
Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v,Nicaragua)
CRM, paras. 3.10-3.11. 18 November 2010, Costa Rica initiated proceedings against Nicaragua
79
before the Court in the Certain Activities case and made a request for the
80
indication of provisional measures. The Court issued an Order for
81
Provisional Measures on 8 March 2011, which it recently had cause to
reaffirm when it issued a further Order for New Provisional Measures on
82
22 November 2013.
2.14 Following the close of the oral hearings on provisional measures in
2011, Nicaragua continued to station military troops in the Area, though it
claimed – incorrectly – that “no Nicaraguan military or other governmental
83
personnel have been present in the disputed area since December 2010.”
The presence of Nicaraguan military pers onnel in the Area on 19 January
2011 was documented by photographs taken by Costa Rican police during a
84
flyover of the Area and submitted to the Court. Nicaragua has since
acknowledged that its military camp remained on Costa Rican territory,
79 Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v Nicar,gua)
Application instituting proceedings, 18 November 2010.
80
Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v Nicar,gua)
Request for the Indication of Provisional Measures, 18 November 2010.
81 Certain Activities Carried out by Nicaragua in the Borde r Area (Costa Rica v Nicaragua),
Application for Provisional Measures, Order of 8 March 2011, I C J Reports 2011, p. 6.
82 Certain Activities Carried out by Nicaragua in the Border Area (Costa Rica v Nicaragua),
Application for Provisional Measures, Order of 22 November 2013, para. 59(1).
83
NM, para. 2.17.
84 Comments by Costa Rica on the Reply of Nicaragua to the questions put by Judges Simma,
Bennouna and Greenwood at the end of the hearing on provisional measures requested by
Costa Rica in Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v
Nicaragua), Reference ECRPB017-11, 20 January 2011. See also Certain Activities carried
out by Nicaragua in the Border Area (Costa Rica v Nicaragua) , CRM, para. 3.53.
2818 November 2010, Costa Rica initiated proceedings against Nicaragua
79
before the Court in the Certain Activities case and made a request for the
80
indication of provisional measures. The Court issued an Order for
81
Provisional Measures on 8 March 2011, which it recently had cause to
reaffirm when it issued a further Order for New Provisional Measures on
82
22 November 2013.
2.14 Following the close of the oral hearings on provisional measures in
2011, Nicaragua continued to station military troops in the Area, though it
claimed – incorrectly – that “no Nicaraguan military or other governmental
83
personnel have been present in the disputed area since December 2010.”
The presence of Nicaraguan military pers onnel in the Area on 19 January
2011 was documented by photographs taken by Costa Rican police during a
84
flyover of the Area and submitted to the Court. Nicaragua has since
acknowledged that its military camp remained on Costa Rican territory,
79 Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v Nicar,gua)
Application instituting proceedings, 18 November 2010.
80
Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v Nicar,gua)
Request for the Indication of Provisional Measures, 18 November 2010.
81 Certain Activities Carried out by Nicaragua in the Borde r Area (Costa Rica v Nicaragua),
Application for Provisional Measures, Order of 8 March 2011, I C J Reports 2011, p. 6.
82 Certain Activities Carried out by Nicaragua in the Border Area (Costa Rica v Nicaragua),
Application for Provisional Measures, Order of 22 November 2013, para. 59(1).
83
NM, para. 2.17.
84 Comments by Costa Rica on the Reply of Nicaragua to the questions put by Judges Simma,
Bennouna and Greenwood at the end of the hearing on provisional measures requested by
Costa Rica in Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v
Nicaragua), Reference ECRPB017-11, 20 January 2011. See also Certain Activities carried
out by Nicaragua in the Border Area (Costa Rica v Nicaragua) , CRM, para. 3.53. 89
Colorado River runs entirely within Costa Rican territory. Nicaragua has
no right of navigation on the Colorado River.
2.16 President Ortega’s threat to claim navigational rights on the
Colorado River was accompanied by an increased presence of Nicaraguan
90
soldiers along the San Juan River , particularly in the lower San Juan
River, i.e. the stretch between the Delta of the Colorado River (also known
as ‘Delta Costa Rica’) and the outlet of the San Juan in the Caribbean. In
light of Nicaragua’s aggressive rhetoric and its actions, including the
convergence of troops in the border area, Costa Ric a’s Minister of Public
Security considered that there was a real and present risk that the
Nicaraguan Government would aggravate the dispute concerning navigation
on the Colorado River by having Nicaraguan military personnel enter the
Colorado River by force. 91
2.17 On 11 January 2011 during the oral hearings on provisional
measures in the Certain Activities case, Nicaragua’s Agent, Mr. Argüello
Gómez, repeated Nicaragua’s threat to claim non -existent navigational
rights on the Colorado River in the following terms:
“Furthermore, he [President Ortega] indicated that Nicaragua would
also claim the right to navigate out to the Caribbean Sea via the
branch of the Colorado river at least until Nicaragua was able to
89 Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v N,caragua)
CRM, para. 1.3.
90 Vol 3, Annex No 70, La Nación (Costa Rica), ‘Nicaragua Reinforces Troops at the Border’,
24 October 2010, a vailable at http://www.nacion.com/sucesos/Nicaragua-refuerza -tropas-
frontera_0_1154884554.html.
91 Vol 3, Annex No 17, Costa Rica, Statement given under oath by Mr. José María Tijerino,
Minister of Public Security of Costa Rica, before the Permanent SpecialCommission for the
Control of Public Revenue and Expenses, Min utes of Extraordinary Session No50,
29 January 2013.
30 89
Colorado River runs entirely within Costa Rican territory. Nicaragua has
no right of navigation on the Colorado River.
2.16 President Ortega’s threat to claim navigational rights on the
Colorado River was accompanied by an increased presence of Nicaraguan
90
soldiers along the San Juan River , particularly in the lower San Juan
River, i.e. the stretch between the Delta of the Colorado River (also known
as ‘Delta Costa Rica’) and the outlet of the San Juan in the Caribbean. In
light of Nicaragua’s aggressive rhetoric and its actions, including the
convergence of troops in the border area, Costa Ric a’s Minister of Public
Security considered that there was a real and present risk that the
Nicaraguan Government would aggravate the dispute concerning navigation
on the Colorado River by having Nicaraguan military personnel enter the
Colorado River by force. 91
2.17 On 11 January 2011 during the oral hearings on provisional
measures in the Certain Activities case, Nicaragua’s Agent, Mr. Argüello
Gómez, repeated Nicaragua’s threat to claim non -existent navigational
rights on the Colorado River in the following terms:
“Furthermore, he [President Ortega] indicated that Nicaragua would
also claim the right to navigate out to the Caribbean Sea via the
branch of the Colorado river at least until Nicaragua was able to
89 Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v N,caragua)
CRM, para. 1.3.
90 Vol 3, Annex No 70, La Nación (Costa Rica), ‘Nicaragua Reinforces Troops at the Border’,
24 October 2010, a vailable at http://www.nacion.com/sucesos/Nicaragua-refuerza -tropas-
frontera_0_1154884554.html.
91 Vol 3, Annex No 17, Costa Rica, Statement given under oath by Mr. José María Tijerino,
Minister of Public Security of Costa Rica, before the Permanent SpecialCommission for the
Control of Public Revenue and Expenses, Min utes of Extraordinary Session No50,
29 January 2013. posts. This lack of access limited the services that Costa Rica could provide
to the local population in the border area.
2.21 The only means for accessing some of these police posts was by
Costa Rican rivers, such as the Colorado and the Sarapiquí. The only police
post that could be accessed by land was the post at Boca San Carlos. The
post at La Cureña had to be closed due to the impossibility of accessing it by
land. 96 The police post at Delta Colorado could only be accessed either by
travelling upstream through the Colorado and Caño Bravo rivers by boat
from Barra del Colorado (which in turn can only be accessed by plane or by
sea), or by boat travelling throug h smaller canals from the village of Puerto
Lindo and then following the Colorado or Caño Bravo rivers. Sketch Map 3
illustrates how these police posts could only be accessed through Costa
Rican rivers prior to the construction of the Border Road.
2.22 As noted in paragraph 2.16 above, in late 2010, Nicaragua was
increasing its military presence along the San Juan River, particularly in the
97
area of the lower San Juan River . In the circumstances, Costa Rica had a
very real and plausible concern that the situation would further escalate into
an armed conflict. On 1 December 2010 the Costa Rican Minister of Public
Security, Mr José Maria Tijerino, informed the Costa Rican Minister of
Public Works, Mr Francisco Jiménez, that the National Securit y Council
had studied land access in the northern area of the country, especially close
96 Dispute regarding Navigational and Related Rights (C osta Rica v Nicaragua) , Reply of
Costa Rica, para. 3.94(i).
97 Vol 3, Annex No 70, La Nación (Costa Rica), ‘Nicaragua Reinforces Troops at the Border’,
24 October 2010, available at http://www.nacion.com/sucesos/Nicaragua-refuerza -tropas-
frontera_0_1154884554.html .
32posts. This lack of access limited the services that Costa Rica could provide
to the local population in the border area.
2.21 The only means for accessing some of these police posts was by
Costa Rican rivers, such as the Colorado and the Sarapiquí. The only police
post that could be accessed by land was the post at Boca San Carlos. The
post at La Cureña had to be closed due to the impossibility of accessing it by
land. 96The police post at Delta Colorado could only be accessed either by
travelling upstream through the Colorado and Caño Bravo rivers by boat
from Barra del Colorado (which in turn can only be accessed by plane or by
sea), or by boat travelling throug h smaller canals from the village of Puerto
Lindo and then following the Colorado or Caño Bravo rivers. Sketch Map 3
illustrates how these police posts could only be accessed through Costa
Rican rivers prior to the construction of the Border Road.
2.22 As noted in paragraph 2.16 above, in late 2010, Nicaragua was
increasing its military presence along the San Juan River, particularly in the
97
area of the lower San Juan River . In the circumstances, Costa Rica had a
very real and plausible concern that the situation would further escalate into
an armed conflict. On 1 December 2010 the Costa Rican Minister of Public
Security, Mr José Maria Tijerino, informed the Costa Rican Minister of
Public Works, Mr Francisco Jiménez, that the National Securit y Council
had studied land access in the northern area of the country, especially close
96 Dispute regarding Navigational and Related Rights (C osta Rica v Nicaragua) , Reply of
Costa Rica, para. 3.94(i).
97 Vol 3, Annex No 70, La Nación (Costa Rica), ‘Nicaragua Reinforces Troops at the Border’,
24 October 2010, available at http://www.nacion.com/sucesos/Nicaragua-refuerza -tropas-
frontera_0_1154884554.html . sworn statement made by Minister Tijerino before the Costa Rican Congress
on 29 January 2013:
“... it is well known that our northern border is one of the less
developed regions of the country. Terrestrial communications in the
Northern Zone for decades had been a pending matter for all
governments. Probably the right of free navigation on the San Juan
River, which assists Costa Rica under international treaties, had made
the need for road development in the region less pressing.
From the moment when Nicaragua started to ignore the right of free
navigation, and to submit our fellow nationals who reside in the area
to all sorts of indignities, reaching the extreme of preventing by force
of arms any Costa Rican from navigating the waters of the river, it
became urgent to build a road along the entire border, which would
enable not only the exercise of sovereignty by the presence of the
security forces in this area of the country threatened by a regime
determined to ignore the existing borders for more than half a century,
but also the everyday life, in all its aspects, of the Costa Rican
inhabitants of the San Juan River.
The military invasion of a portion of the country and the threat that it
could extend along the northern border, made imperative the
government's decision to first, improve the existing roads to allow the
reinforcement and supply of our police posts; the expeditious
evacuation of the residents, if necessary, due to an escalation of the
conflict; medical assistance to those eventually wounded; and an
orderly retreat against the onslaught of the invader.
Those are the circumstances under which my office issued note 2278-
2012-DM on 1 December 2010, in which I ask the Minister of Public
Works and Transport responsible at the time, Francisco Jiménez
Reyes, his good offices for the repair of the roads leading to Delta
Costa Rica and Boca del Rio Sarapiquí in the canton of Sarapiquí , to
34sworn statement made by Minister Tijerino before the Costa Rican Congress
on 29 January 2013:
“... it is well known that our northern border is one of the less
developed regions of the country. Terrestrial communications in the
Northern Zone for decades had been a pending matter for all
governments. Probably the right of free navigation on the San Juan
River, which assists Costa Rica under international treaties, had made
the need for road development in the region less pressing.
From the moment when Nicaragua started to ignore the right of free
navigation, and to submit our fellow nationals who reside in the area
to all sorts of indignities, reaching the extreme of preventing by force
of arms any Costa Rican from navigating the waters of the river, it
became urgent to build a road along the entire border, which would
enable not only the exercise of sovereignty by the presence of the
security forces in this area of the country threatened by a regime
determined to ignore the existing borders for more than half a century,
but also the everyday life, in all its aspects, of the Costa Rican
inhabitants of the San Juan River.
The military invasion of a portion of the country and the threat that it
could extend along the northern border, made imperative the
government's decision to first, improve the existing roads to allow the
reinforcement and supply of our police posts; the expeditious
evacuation of the residents, if necessary, due to an escalation of the
conflict; medical assistance to those eventually wounded; and an
orderly retreat against the onslaught of the invader.
Those are the circumstances under which my office issued note 2278-
2012-DM on 1 December 2010, in which I ask the Minister of Public
Works and Transport responsible at the time, Francisco Jiménez
Reyes, his good offices for the repair of the roads leading to Delta
Costa Rica and Boca del Rio Sarapiquí in the canton of Sarapiquí , to of Costa Rican territory in the northern sector of Isla Portillos ,104 which
Nicaragua has already attempted to unlawfully annex by military force.
C. The Emergency Decreeand its Implementation
2.25 In response to Nicaragua’s host ile conduct towards Costa Rica,
explained in the preceding paragraphs, in December 2010 Costa Rica
commenced infrastructure work to improve dirt paths between Delta
Colorado and the town of Fatima and later on to Boca Sarapiquí, in order to
render the road usable for vehicle access. Shortly thereafter, in accordance
with the request made by Costa Rica’s Minister of Public Security, it was
decided that it was necessary to provide land access to other police posts at
Los Chiles, Boca San Carlos, and Puerto Li ndo. This entailed improvement
works on tracks that connected those police posts to other Costa Rican
communities, and in some cases constructing new sections of road. It was
also decided that it was necessary to construct a road along the border to
connect all the communities in these remote areas, to allow public
authorities and the local population to mobilize if necessary, particularly in
the event that an armed conflict instigated by Nicaragua were to break out ,
and to provide a means for the provision of other essential services to these
areas. Sketch Map 4 illustrates how the Border Road was conceived to
provide efficient land access to all of Costa Rica’s police posts along this
part of its territory and to allow the mobilization of its citizens in c ase of
need.
104 Vol 3, Annex No 80, El 19 (Nicaragua), ‘33rd Anniversary of the Naval Force’, 14 August
2013, available at http://www.el19digital.com/index.php/discurso/ver/12213/33-aniversario -
de-la-fuerza-naval- .
36of Costa Rican territory in the northern sector of Isla Portillos ,104 which
Nicaragua has already attempted to unlawfully annex by military force.
C. The Emergency Decreeand its Implementation
2.25 In response to Nicaragua’s host ile conduct towards Costa Rica,
explained in the preceding paragraphs, in December 2010 Costa Rica
commenced infrastructure work to improve dirt paths between Delta
Colorado and the town of Fatima and later on to Boca Sarapiquí, in order to
render the road usable for vehicle access. Shortly thereafter, in accordance
with the request made by Costa Rica’s Minister of Public Security, it was
decided that it was necessary to provide land access to other police posts at
Los Chiles, Boca San Carlos, and Puerto Li ndo. This entailed improvement
works on tracks that connected those police posts to other Costa Rican
communities, and in some cases constructing new sections of road. It was
also decided that it was necessary to construct a road along the border to
connect all the communities in these remote areas, to allow public
authorities and the local population to mobilize if necessary, particularly in
the event that an armed conflict instigated by Nicaragua were to break out ,
and to provide a means for the provision of other essential services to these
areas. Sketch Map 4 illustrates how the Border Road was conceived to
provide efficient land access to all of Costa Rica’s police posts along this
part of its territory and to allow the mobilization of its citizens in c ase of
need.
104 Vol 3, Annex No 80, El 19 (Nicaragua), ‘33rd Anniversary of the Naval Force’, 14 August
2013, available at http://www.el19digital.com/index.php/discurso/ver/12213/33-aniversario -
de-la-fuerza-naval- . The declaration of a state of emergency triggers a number of public duties in
the areas of health, security, the environment, public infrastructure, and the
provision of other public services.
2.29 Article 1 of the Emergency Decree declared a state of emergency in
the municipal jurisdictions along the entire length of the border between
Costa Rica and Nicaragua: La Cruz, Upala, Los Chiles, Sarapiquí, San
107
Carlos and Pococí. Article 3 of the Decree sets out the purpose of the
Decree and provides that:
“The present declaration of a state of emergency encompasses all the
actions and projects necessary for the protection of life, physic al
integrity [of persons], property and the environment, as well as those
necessary for the maintenance, rehabilitation, reconstruction and
restoration of infrastructure, housing, communications and disrupted
production activities as well as all damaged pu blic services within
the zone covered under article 1) of this Decree…” 108
2.30 Given the emergency situation in which the work was to be carried
out, the Department known by the Spanish acronym “CONAVI” of Costa
Rica’s Ministry of Public Wo rks and Transportation, acting pursuant to the
Decree, engaged the services of several local contractors to carry out the
necessary works on the Border Road. In order to advance the work in the
pressing circumstances of the national emergency, the Border R oad was
divided into five sections. Each of these was assigned to a different
contractor, with the intention that work could be carried out simultaneously
in all of them. Figure 2.2 is the official map prepared by CONAVI,
showing both the road connecting L os Chiles to Delta Colorado as well as
107
Vol 3 , Annex No 28, Executive Decree 36440 -MP, published in the Official Gazette
number 46 of 7 March 2011, Article 1.
108 Ibid, Article 3.
38The declaration of a state of emergency triggers a number of public duties in
the areas of health, security, the environment, public infrastructure, and the
provision of other public services.
2.29 Article 1 of the Emergency Decree declared a state of emergency in
the municipal jurisdictions along the entire length of the border between
Costa Rica and Nicaragua: La Cruz, Upala, Los Chiles, Sarapiquí, San
107
Carlos and Pococí. Article 3 of the Decree sets out the purpose of the
Decree and provides that:
“The present declaration of a state of emergency encompasses all the
actions and projects necessary for the protection of life, physic al
integrity [of persons], property and the environment, as well as those
necessary for the maintenance, rehabilitation, reconstruction and
restoration of infrastructure, housing, communications and disrupted
production activities as well as all damaged pu blic services within
the zone covered under article 1) of this Decree…” 108
2.30 Given the emergency situation in which the work was to be carried
out, the Department known by the Spanish acronym “CONAVI” of Costa
Rica’s Ministry of Public Wo rks and Transportation, acting pursuant to the
Decree, engaged the services of several local contractors to carry out the
necessary works on the Border Road. In order to advance the work in the
pressing circumstances of the national emergency, the Border R oad was
divided into five sections. Each of these was assigned to a different
contractor, with the intention that work could be carried out simultaneously
in all of them. Figure 2.2 is the official map prepared by CONAVI,
showing both the road connecting L os Chiles to Delta Colorado as well as
107
Vol 3 , Annex No 28, Executive Decree 36440 -MP, published in the Official Gazette
number 46 of 7 March 2011, Article 1.
108 Ibid, Article 3. 2.33 The Emergency Decree has been the subject of three separate cases
109
before Costa Rica’s Constitutional Court. In every one of these cases, the
Constitutional Court has upheld the Decree as being in accordance with
110
Costa Rica’s Constitution. The road works are thus in full compliance
with Costa Rican law . Due to the national emerg ency precipitated by
Nicaragua’s actions, and consistent with the previous jurisprudence of the
Costa Rican Constitutional Court, 111Costa Rica was not under any domestic
legal obligation to conduct environmental studies or present detailed designs
of the Border Road. Nicaragua’s assertionsto the contrary have no basis. 112
2.34 Under Costa Rican law, the requirement to carry out an
environmental impact assessment before commencing work on a project is
displaced in circumstances where there is an emergency. Costa Rica’s
Constitutional Court has recognised that the urgency brought about by a
state of emergency means that the requirement to carry out an EIA is
excluded. It stated:
“It is therefore not contrary to the Law of the Constitution that the
concerned public institutions are exempted at the proper moment from
the steps and procedures of the ordinary functioning of the
Administration, which in this case refer to the exemption of
environmental regulations, as are, for example, the completion of the
environmental impact assessment or technical reporting by competent
109 Separate cases challenging the constitutionality of the decree were filed by three
individuals.
110
See Vol 3, Annex No 31, Costa Rica, Constitutional Court Judgment No 2012-3266, of
7 March 2012; Vol 3, Annex No 30, Costa Rica, Constitutional Court Judgment No 2012-
Judgment No 2013-008257, of 21 June 2013.o 32, Costa Rica, Constitutional Court
111 See Vol 3, Annex No 21, Costa Rica, Constitutional Court Judgment N o 06322-2003 of
3 July 2003; and Vol , Annex No 24, Costa Rica, Constitutional Court Judgment
No 006336-2006 of 10 May 2006.
112 NM, para. 2.20.
402.33 The Emergency Decree has been the subject of three separate cases
109
before Costa Rica’s Constitutional Court. In every one of these cases, the
Constitutional Court has upheld the Decree as being in accordance with
110
Costa Rica’s Constitution. The road works are thus in full compliance
with Costa Rican law . Due to the national emerg ency precipitated by
Nicaragua’s actions, and consistent with the previous jurisprudence of the
Costa Rican Constitutional Court, 111 Costa Rica was not under any domestic
legal obligation to conduct environmental studies or present detailed designs
of the Border Road. Nicaragua’s assertionsto the contrary have no basis. 112
2.34 Under Costa Rican law, the requirement to carry out an
environmental impact assessment before commencing work on a project is
displaced in circumstances where there is an emergency. Costa Rica’s
Constitutional Court has recognised that the urgency brought about by a
state of emergency means that the requirement to carry out an EIA is
excluded. It stated:
“It is therefore not contrary to the Law of the Constitution that the
concerned public institutions are exempted at the proper moment from
the steps and procedures of the ordinary functioning of the
Administration, which in this case refer to the exemption of
environmental regulations, as are, for example, the completion of the
environmental impact assessment or technical reporting by competent
109 Separate cases challenging the constitutionality of the decree were filed by three
individuals.
110
See Vol 3, Annex No 31, Costa Rica, Constitutional Court Judgment No 2012-3266, of
7 March 2012; Vol 3, Annex No 30, Costa Rica, Constitutional Court Judgment No 2012-
Judgment No 2013-008257, of 21 June 2013.o 32, Costa Rica, Constitutional Court
111 See Vol 3, Annex No 21, Costa Rica, Constitutional Court Judgment N o 06322-2003 of
3 July 2003; and Vol , Annex No 24, Costa Rica, Constitutional Court Judgment
No 006336-2006 of 10 May 2006.
112 NM, para. 2.20. out the Environmental Impact Diagnostic for the Road and it is Annex 10 to
this Counter-Memorial.
2.36 Under Nicaraguan domestic law, the normal requirement to
undertake an EIA may similarly be displaced to permit projects intended to
mitigate disasters or undertaken in the national interest or for national
security reasons in response to situat ions of national emergency. 115 The
domestic law of other countries also has similar exemptions. 116
2.37 Contrary to Nicaragua’s assertion, 117 the construction of the Road is
not a form of unlawful self -help. It was embarked upon in the emergency
circumstances created by Nicaragua, in order to provide essential services to
the population and to enable Costa Rican police to mobilize in the event of a
further armed incursion by Nicaragua, which in the context of Nicaragua’s
repeated provocations appeared to be a very re al risk. It was not taken to
aggravate tensions between the two States, nor to undermine respect for the
judicial process. Rather, Costa Rica’s decision to construct a Road entirely
on its own territory was a reasonable and proportionate response to the ri sk
it perceived at that time.
2.38 Since April 2012, in order to protect the work that has been carried
out so far and to mitigate the effects of the road ( primarily in respect of
Costa Rican territory ), Costa Rica has been carrying out additional
maintenance and remedial works on the Border Road. The maintenance and
115
Vol 3, Annex No 25, Nicaragua, Decree No. 76-2006, approved on 19 December 2006,
published in La Gaceta No. 248 of 2December 2006, Article 12, available at http://
www.ine.gob.ni/DCA/leyes/decreto/Decreto_76-2006_SistemaEvaluacionAmbie… .
116 See, for exampl e, AustraliEnvironment Protection and Biodiversity Conservation
Act 1999 (Cth), in force from16 July 2000, s. 158(5).
117
Cf. NM, para. 5.15.
42out the Environmental Impact Diagnostic for the Road and it is Annex 10 to
this Counter-Memorial.
2.36 Under Nicaraguan domestic law, the normal requirement to
undertake an EIA may similarly be displaced to permit projects intended to
mitigate disasters or undertaken in the national interest or for national
security reasons in response to situat ions of national emergency. 115 The
domestic law of other countries also has similar exemptions. 116
2.37 Contrary to Nicaragua’s assertion, 117 the construction of the Road is
not a form of unlawful self -help. It was embarked upon in the emergency
circumstances created by Nicaragua, in order to provide essential services to
the population and to enable Costa Rican police to mobilize in the event of a
further armed incursion by Nicaragua, which in the context of Nicaragua’s
repeated provocations appeared to be a very re al risk. It was not taken to
aggravate tensions between the two States, nor to undermine respect for the
judicial process. Rather, Costa Rica’s decision to construct a Road entirely
on its own territory was a reasonable and proportionate response to the ri sk
it perceived at that time.
2.38 Since April 2012, in order to protect the work that has been carried
out so far and to mitigate the effects of the road ( primarily in respect of
Costa Rican territory ), Costa Rica has been carrying out additional
maintenance and remedial works on the Border Road. The maintenance and
115
Vol 3, Annex No 25, Nicaragua, Decree No. 76-2006, approved on 19 December 2006,
published in La Gaceta No. 248 of 22December 2006, Article 12, available at http://
www.ine.gob.ni/DCA/leyes/decreto/Decreto_76-2006_SistemaEvaluacionAmbie… .
116 See, for exampl e, AustraliaEnvironment Protection and Biodiversity Conservation
Act 1999 (Cth), in force from16 July 2000, s. 158(5).
117
Cf. NM, para. 5.15. (l) construction of step drains to reduce energy in a concentrated run-off
to prevent gullying;
(m) lining of exit channels to reduce erodibility of channel surfaces;
(n) benching to create stable slopes to prevent landslides;
(o) removal of landslides caused by inadequate slope structure to reduce
erosion of failed materials;
(p) improvement of water passages by putting in place the necessary
infrastructure such as buttress in order to reduce sediment transport
by improved run-off management;
(q) cleaning of drain structures and lined ditches to maintain hydraulic
function;
(r) repairing of bridges to prevent erosion at stream crossings;
(s) removal of debris from channels to maintain hydraulic capacity;and
(t) manual planting of 27,000 trees of native species.
2.39 The photographs below are illustrative of some of the remedial
works that have already been carried out:
44(l) construction of step drains to reduce energy in a concentrated run-off
to prevent gullying;
(m) lining of exit channels to reduce erodibility of channel surfaces;
(n) benching to create stable slopes to prevent landslides;
(o) removal of landslides caused by inadequate slope structure to reduce
erosion of failed materials;
(p) improvement of water passages by putting in place the necessary
infrastructure such as buttress in order to reduce sediment transport
by improved run-off management;
(q) cleaning of drain structures and lined ditches to maintain hydraulic
function;
(r) repairing of bridges to prevent erosion at stream crossings;
(s) removal of debris from channels to maintain hydraulic capacity;and
(t) manual planting of 27,000 trees of native species.
2.39 The photographs below are illustrative of some of the remedial
works that have already been carried out: 121
further 25,000 trees commenced in September 2013. Costa Rica will also
undertake works at seven targeted locations between M arker II and Delta
Costa Rica. Work at three of these locations, between the town of Tiricias
and east of the Infiernito River, and the location of Cur eña River, east of
Boca San Carlos, will be carried out directly by Costa Rica’s Ministry of
Public Works, with its own machinery and personnel. Manual labour will be
used at the other locations in order to avoid using heavy machinery that
might create additional disturbances. The Ministry of the Environment is in
the process of contracting an NGO specializing in this kind of work. These
works will include the stabilization of slopes, building ditches, culverts and
sediment traps, as well as planting of vegetation. Thus Costa Rica’s
remediation work on the Road is continuing.
2.41 Costa Rica will bring the road works to completion for the benefit of
its inhabitants and for the protection of its territory and sovereign rights. In
doing so, it will adhere to high environmental and engineering standards. To
that end, it has commenced a public tendering process for the complete
122
designs of the Road. Costa Rica will also continue to carry out
maintenance and remediation works on the Road, to address any risk of
significant impact.
121
Annex 2, Vol 7 , Report from Ana Lorena Guevara Fernández, Vice-Minister of the
Environment, Costa Rica, to Enrique Castillo Barrantes, Minister of Foreign A ffairs, Costa
Rica, Reference DVM-293-2013, 8 October 2013, p. 2.
122 CR 2013/29, pp. 17-18, para. 17 (Brenes).
46 121
further 25,000 trees commenced in September 2013. Costa Rica will also
undertake works at seven targeted locations between M arker II and Delta
Costa Rica. Work at three of these locations, between the town of Tiricias
and east of the Infiernito River, and the location of Cur eña River, east of
Boca San Carlos, will be carried out directly by Costa Rica’s Ministry of
Public Works, with its own machinery and personnel. Manual labour will be
used at the other locations in order to avoid using heavy machinery that
might create additional disturbances. The Ministry of the Environment is in
the process of contracting an NGO specializing in this kind of work. These
works will include the stabilization of slopes, building ditches, culverts and
sediment traps, as well as planting of vegetation. Thus Costa Rica’s
remediation work on the Road is continuing.
2.41 Costa Rica will bring the road works to completion for the benefit of
its inhabitants and for the protection of its territory and sovereign rights. In
doing so, it will adhere to high environmental and engineering standards. To
that end, it has commenced a public tendering process for the complete
122
designs of the Road. Costa Rica will also continue to carry out
maintenance and remediation works on the Road, to address any risk of
significant impact.
121
Annex 2, Vol 7 , Report from Ana Lorena Guevara Fernández, Vice-Minister of the
Environment, Costa Rica, to Enrique Castillo Barrantes, Minister of Foreign A ffairs, Costa
Rica, Reference DVM-293-2013, 8 October 2013, p. 2.
122 CR 2013/29, pp. 17-18, para. 17 (Brenes). (d) the ecosystem (including aquatic life and fishing), tourism
127
and health.
3.3 Nicaragua’s case rests entirely on the hypothesis that the Road is
contributing massive and harmf ul quantities of additional sediment to the
River. The true picture as to sedimentation is set out in Section B below.
Each of the specific allegations as to adverse impact is addressed in
Section C below. Finally, Nicaragua’s misplaced reliance on the
“Judgment” of the Central American Court of Justice is discussed in
Section D below. Conclusions are listed in Section E.
B. Sedimentation: the True Picture
3.4 At the outset, it must be kept in mind that sediment is not a pollutant.
Rather, the contribution of sediment to a river such as the San Juan is a
natural process, and one which is essential to the life of the River. This
128
process is commonly regarded as beneficial.
3.5 Nicaragua’s allegations of adverse impact are based on the
129
contribution of sediment from the Road to the River. To assess these
allegations it is necessary first to consider the existing sediment load of the
River, in order to establish the baseline from which any impact of additional
sediment may be measured.
127
NM, para. 3.81.
128 See, eg, Vol 3, Annex No 81, GM Kondolf, “Hungry water: Effects of dams and gravel
mining on river channels” 21(4) (1997) Environmental Management 533.
129 See, eg, NM, paras. 1.9, 1.11, 1.12, 1.13, 2.45, 3.2, 3.3, 3.8, 3.14, 3.20, 3.22, 3.24, 3.26,
3.38, 3.41, 3.43, 3.48, 3.49, 3.57, 3.58, 3.59, 3.60, 3.63, 3.67, 3.74, 3.76, 3.78, 3.79, 3.80,
3.81, 3.88, 3.90, 3.92, 3.96, 4.1, 4.13, 4.15, 4.19, 4.32, 4.41 and 6.14.
48 (d) the ecosystem (including aquatic life and fishing), tourism
127
and health.
3.3 Nicaragua’s case rests entirely on the hypothesis that the Road is
contributing massive and harmf ul quantities of additional sediment to the
River. The true picture as to sedimentation is set out in Section B below.
Each of the specific allegations as to adverse impact is addressed in
Section C below. Finally, Nicaragua’s misplaced reliance on the
“Judgment” of the Central American Court of Justice is discussed in
Section D below. Conclusions are listed in Section E.
B. Sedimentation: the True Picture
3.4 At the outset, it must be kept in mind that sediment is not a pollutant.
Rather, the contribution of sediment to a river such as the San Juan is a
natural process, and one which is essential to the life of the River. This
128
process is commonly regarded as beneficial.
3.5 Nicaragua’s allegations of adverse impact are based on the
129
contribution of sediment from the Road to the River. To assess these
allegations it is necessary first to consider the existing sediment load of the
River, in order to establish the baseline from which any impact of additional
sediment may be measured.
127
NM, para. 3.81.
128 See, eg, Vol 3, Annex No 81, GM Kondolf, “Hungry water: Effects of dams and gravel
mining on river channels” 21(4) (1997) Environmental Management 533.
129 See, eg, NM, paras. 1.9, 1.11, 1.12, 1.13, 2.45, 3.2, 3.3, 3.8, 3.14, 3.20, 3.22, 3.24, 3.26,
3.38, 3.41, 3.43, 3.48, 3.49, 3.57, 3.58, 3.59, 3.60, 3.63, 3.67, 3.74, 3.76, 3.78, 3.79, 3.80,
3.81, 3.88, 3.90, 3.92, 3.96, 4.1, 4.13, 4.15, 4.19, 4.32, 4.41 and 6.14. (a) Costa Rican Institute of Electricity (ICE), SBU Projects and
Associated Services, Centre for Basic Engineering Studies,
Department of Hydrology, Report on Hydrology and Sediments for
the Costa Rican River Basins draining to the San Juan River, August
2013 (the ICE Report) (Annex 4; also submitted as Attachment CR-
1 on Nicaragua’s Request for Provisional Measures); 131
(b) University of Costa R ica Centre for Research in Sustainable
Development, Department of Civil Engineering, Report on
Systematic Field monitoring of Erosion and Sediment Yield along
Route 1856, September 2013 (the UCR Report ) (Annex 1; also
submitted as Attachment CR -2 on Nicara gua’s Request for
Provisional Measures); and
(c) Allan Astorga G. and Andreas Mende, Route 1856: analysis of the
change in land use based on satellite images before and after the
construction of the border road, August 2013 (the Land Use
Change Report) (Annex 3; also submitted as Attachment CR-4 on
Nicaragua’s Request for Provisional Measures);
(d) Andreas Mende and Allan Astorga G., Inventory of Slopes and
Water Courses related to the Border Road No 1856 between Mojón
II and Delta Costa Rica, October 2013 (the Inventory of Slopes and
Water Courses) (Annex 6); and
131 The Department of Hydrology of the Costa Rican Institute of Electricity has responsibility
for monitoring of sediment in Costa Rica’s basins and m: see Vol 2, Annex 4,
Costa Rican Institute of Electricity (ICE), SBU Projects and Associated Services, Centre for
Basic Engineering Studies, Department of Hydrology, Report on Hydrology and Sediments
Report), p. 2.Rican River Basins draining to the San JuAugust 2013 (the ICE
50(a) Costa Rican Institute of Electricity (ICE), SBU Projects and
Associated Services, Centre for Basic Engineering Studies,
Department of Hydrology, Report on Hydrology and Sediments for
the Costa Rican River Basins draining to the San Juan River, August
2013 (the ICE Report) (Annex 4; also submitted as Attachment CR-
1 on Nicaragua’s Request for Provisional Measures); 131
(b) University of Costa R ica Centre for Research in Sustainable
Development, Department of Civil Engineering, Report on
Systematic Field monitoring of Erosion and Sediment Yield along
Route 1856, September 2013 (the UCR Report ) (Annex 1; also
submitted as Attachment CR -2 on Nicara gua’s Request for
Provisional Measures); and
(c) Allan Astorga G. and Andreas Mende, Route 1856: analysis of the
change in land use based on satellite images before and after the
construction of the border road, August 2013 (the Land Use
Change Report) (Annex 3; also submitted as Attachment CR-4 on
Nicaragua’s Request for Provisional Measures);
(d) Andreas Mende and Allan Astorga G., Inventory of Slopes and
Water Courses related to the Border Road No 1856 between Mojón
II and Delta Costa Rica, October 2013 (the Inventory of Slopes and
Water Courses) (Annex 6); and
131 The Department of Hydrology of the Costa Rican Institute of Electricity has responsibility
for monitoring of sediment in Costa Rica’s basins and : see Vol 2, Annex 4,
Costa Rican Institute of Electricity (ICE), SBU Projects and Associated Services, Centre for
Basic Engineering Studies, Department of Hydrology, Report on Hydrology and Sediments
Report), p. 2.Rican River Basins draining to the San JAugust 2013 (the ICE which he drove along and/or viewed from air the entire length of the
133
Road.
(1) Impact of the Road on the suspended sediment load of the San
Juan River: before and after
3.10 In order to assess the impact, if any, of the Road, Costa Rica’s
experts first considered the suspended sediment load of the River before and
after construction of the Road. This was done to assess whether, as
Nicaragua asserts, “the increased sediment load resulting from the Road and
134
its construction” has and will cause significant harm to Nicaragua and
whether, as Dr Kondolf asserts, the Road has “increased sediment delivery
135
to the Río San Juan”. As Professor Thorne explains, Costa Rica’s
technical experts:
“… examine[d] measured suspended sediment concentration in the
Río San Juan in order to ascertain whether erosion and sediment
delivery from the Road has significantly increased the sediment load
of the Río San Juan.” 136
3.11 To undertake this comparison, it was necessary first to assess the
baseline of the suspended sediment load of the San Juan River prior to the
construction of Route 1856. For this purpose, recourse was had to available
records in the pr e-construction period, which date from 1974- 1976. The
measurements of Suspended Sediment Concentration in the San Juan made
during this period were recorded jointly by the two parties, and were relied
133 Appendix A, Thorne Report, para. 3.3. See also Chapter 5 of Append, setting out
Professor Thorne’s field observations.
134
NM, para. 1.12.
135 NM, Annex 1, 2012 Kondolf Report, para. 4.11.
136
Appendix A, Thorne Report, para. 8.2.
52which he drove along and/or viewed from air the entire length of the
133
Road.
(1) Impact of the Road on the suspended sediment load of the San
Juan River: before and after
3.10 In order to assess the impact, if any, of the Road, Costa Rica’s
experts first considered the suspended sediment load of the River before and
after construction of the Road. This was done to assess whether, as
Nicaragua asserts, “the increased sediment load resulting from the Road and
134
its construction” has and will cause significant harm to Nicaragua and
whether, as Dr Kondolf asserts, the Road has “increased sediment delivery
135
to the Río San Juan”. As Professor Thorne explains, Costa Rica’s
technical experts:
“… examine[d] measured suspended sediment concentration in the
Río San Juan in order to ascertain whether erosion and sediment
delivery from the Road has significantly increased the sediment load
of the Río San Juan.” 136
3.11 To undertake this comparison, it was necessary first to assess the
baseline of the suspended sediment load of the San Juan River prior to the
construction of Route 1856. For this purpose, recourse was had to available
records in the pr e-construction period, which date from 1974- 1976. The
measurements of Suspended Sediment Concentration in the San Juan made
during this period were recorded jointly by the two parties, and were relied
133 Appendix A, Thorne Report, para. 3.3. See also Chapter 5 of Append, setting out
Professor Thorne’s field observations.
134
NM, para. 1.12.
135 NM, Annex 1, 2012 Kondolf Report, para. 4.11.
136
Appendix A, Thorne Report, para. 8.2. average annual suspended sediment load in the San Juan after construction
of Route 1856. The suspended sediment load for the period after
construction of the Road was calculated using Suspended Sediment
Concentration measurements from the period December 2010 to June 2013.
These measurements were taken from a sediment monitoring station on the
Río Colorado at Delta Colorado, i.e. on Costa Rican territory , and were
recorded by the hydrology department of the Costa Rican Institute of
Electricity, which has responsibility for monitoring of sediment in Costa
142
Rica’s basins and micro basins. The measurements taken at Delta
Colorado are comparable to those take n on the San Juan River at La
Trinidad (in 1974-1976), because about 90% of the flow and sediment that
passes through La Trinidad also passes through Delta Colorado. 143 The
measurements taken at Delta Colorado over the two and a half -year period
from December 2010 to June 2013 indicate that the average annual
suspended sediment load in the Río Colorado was 5,981,000 t y . -1 144The
suspended sediment load measured in the Río Colorado at the Delta
Colorado station may be adjusted to represent that in the Río San J uan
upstream of the Delta by multiplying it by the reciprocal of 0.91. Applying
this adjustment, the average annual suspended sediment load in the Río San
Juan between December 2010 and June 2013 was approximately 6 573 000 t
y . 145
3.14 The two measurements of the average suspended sediment load
(before and after construction of the Road) were then compared. In the
142
See Vol 2, Annex 4, ICE Report, p. 2.
143 Appendix A, Thorne Report, para. 8.3.
144
Ibid, para. 8.8 and Table 10.
145 Ibid, para. 8.10 and Table 10.
54average annual suspended sediment load in the San Juan after construction
of Route 1856. The suspended sediment load for the period after
construction of the Road was calculated using Suspended Sediment
Concentration measurements from the period December 2010 to June 2013.
These measurements were taken from a sediment monitoring station on the
Río Colorado at Delta Colorado, i.e. on Costa Rican territory , and were
recorded by the hydrology department of the Costa Rican Institute of
Electricity, which has responsibility for monitoring of sediment in Costa
142
Rica’s basins and micro basins. The measurements taken at Delta
Colorado are comparable to those take n on the San Juan River at La
Trinidad (in 1974-1976), because about 90% of the flow and sediment that
passes through La Trinidad also passes through Delta Colorado. 143 The
measurements taken at Delta Colorado over the two and a half -year period
from December 2010 to June 2013 indicate that the average annual
suspended sediment load in the Río Colorado was 5,981,000 t y . -1 144The
suspended sediment load measured in the Río Colorado at the Delta
Colorado station may be adjusted to represent that in the Río San J uan
upstream of the Delta by multiplying it by the reciprocal of 0.91. Applying
this adjustment, the average annual suspended sediment load in the Río San
Juan between December 2010 and June 2013 was approximately 6 573 000 t
y . 145
3.14 The two measurements of the average suspended sediment load
(before and after construction of the Road) were then compared. In the
142
See Vol 2, Annex 4, ICE Report, p. 2.
143 Appendix A, Thorne Report, para. 8.3.
144
Ibid, para. 8.8 and Table 10.
145 Ibid, para. 8.10 and Table 10. Figure 27. Mean annual suspended sediment loads in the Río San Juan based on
measurements at La Trinidad (1974 -1976) and D elta Colorado (2010- 2013). Vertical bars
indicate 95% confidence intervals. Note that the loads based on measurements at Delta
Colorado station have been adjusted to represent the Río San Juan on the basis that at the
Delta su147nded load is divided in the same proportion as discharge (from the ICE
Report).
(2) Estimates of sediment eroded from the Road to the River
3.15 In order to confirm whether the Road has had or is having any
adverse impact on the San Juan River, Costa Rica ’s experts then considered
the extent to which the Road is contributing sediment to the River. Based on
his visual observations of the Road from the River and from the air, Dr
Kondolf estimates that cut and fill slopes along the Road are eroding – i.e.
148
the land surface is lowering – at an average rate of 1m per year. He
estimates that erosion at this rate is occurring on 40% to 50% of the slopes
147
Caption taken from Figure 27 to Appendix A, Thorne Report; the same figure is produced
as Figure 5 to Vol 2, Annex 4, ICE Report.
148 NM, Annex 1, 2012 Kondolf Report, p. 46; see also Third Kondolf Report, p. 2.
56Figure 27. Mean annual suspended sediment loads in the Río San Juan based on
measurements at La Trinidad (1974 -1976) and D elta Colorado (2010- 2013). Vertical bars
indicate 95% confidence intervals. Note that the loads based on measurements at Delta
Colorado station have been adjusted to represent the Río San Juan on the basis that at the
Delta su147nded load is divided in the same proportion as discharge (from the ICE
Report).
(2) Estimates of sediment eroded from the Road to the River
3.15 In order to confirm whether the Road has had or is having any
adverse impact on the San Juan River, Costa Rica ’s experts then considered
the extent to which the Road is contributing sediment to the River. Based on
his visual observations of the Road from the River and from the air, Dr
Kondolf estimates that cut and fill slopes along the Road are eroding – i.e.
148
the land surface is lowering – at an average rate of 1m per year. He
estimates that erosion at this rate is occurring on 40% to 50% of the slopes
147
Caption taken from Figure 27 to Appendix A, Thorne Report; the same figure is produced
as Figure 5 to Vol 2, Annex 4, ICE Report.
148 NM, Annex 1, 2012 Kondolf Report, p. 46; see also Third Kondolf Report, p. 2. San Carlos is much flatter, and the Road follows a pre-existing road for a far
greater proportion of its length, passing through areas that have long been
inhabited and developed for pasture, crops, forestry and other uses. 154
3.18 In his 2012 Report, Dr Kondolf states that he “document ed direct
delivery of s ediment from road erosion to the river at 54 sites along the
road.” 155 Dr Kondolf did not provide any indication of the location of these
points, nor did he provide geographic coordinates. In response to a request
by Costa Rica for further information, Nicar agua provided to Costa Rica a
document which listed the geographic coordinates of these 54 sites. Costa
Rica was able to use these coordinates to verify the locations of these sites,
and to assess whether they were in fact sites of sediment delivery from t he
156
Road to the River. Of the 54 sites, seven were found to be in Nicaraguan
157
territory on the left bank of the San Juan. Of the remaining 47, ten were
downstream of Boca San Carlos . These were all examined and analysed by
Costa Rica’s experts. N ine of the ten sites were between Boca San Carlos
and Boca Sarapiquí. Of the nine points, seven were “of trivial significance
158
or unrelated to the road”. The remaining two points refer to the
confluence of the Rio Cureña and a nearby fill slope : as Professor Thorne
notes, these points are downstream of where the Río San Carlos enters the
-1
Río San Juan, contributing in excess of 4.5 million t y . In that context, any
154
Appendix A, Thorne Report, para. 5.7.
155 NM, Annex 1, 2012 Kondolf Report, p. 45.
156
Vol 2, Annex No 5 , Andreas Mende, with Allan Astorga G. and Olivier Chassot, Border
Road No 1856 – Evaluation of the 54 Sites of Purported Direct Sediment Delivery
mentioned by Ph D Mathias Kondolf, September 2013 (54 Sites Report).
157 Appendix A, Thorne Report, para. 5.12; Vol 2, Annex No 5, 54 Sites Report, p. 1.
158
Appendix A, Thorne Report, para. 5.14.
58San Carlos is much flatter, and the Road follows a pre-existing road for a far
greater proportion of its length, passing through areas that have long been
inhabited and developed for pasture, crops, forestry and other uses. 154
3.18 In his 2012 Report, Dr Kondolf states that he “document ed direct
delivery of s ediment from road erosion to the river at 54 sites along the
road.” 155 Dr Kondolf did not provide any indication of the location of these
points, nor did he provide geographic coordinates. In response to a request
by Costa Rica for further information, Nicar agua provided to Costa Rica a
document which listed the geographic coordinates of these 54 sites. Costa
Rica was able to use these coordinates to verify the locations of these sites,
and to assess whether they were in fact sites of sediment delivery from t he
156
Road to the River. Of the 54 sites, seven were found to be in Nicaraguan
157
territory on the left bank of the San Juan. Of the remaining 47, ten were
downstream of Boca San Carlos . These were all examined and analysed by
Costa Rica’s experts. N ine of the ten sites were between Boca San Carlos
and Boca Sarapiquí. Of the nine points, seven were “of trivial significance
158
or unrelated to the road”. The remaining two points refer to the
confluence of the Rio Cureña and a nearby fill slope : as Professor Thorne
notes, these points are downstream of where the Río San Carlos enters the
-1
Río San Juan, contributing in excess of 4.5 million t y . In that context, any
154
Appendix A, Thorne Report, para. 5.7.
155 NM, Annex 1, 2012 Kondolf Report, p. 45.
156
Vol 2, Annex No 5 , Andreas Mende, with Allan Astorga G. and Olivier Chassot, Border
Road No 1856 – Evaluation of the 54 Sites of Purported Direct Sediment Delivery
mentioned by Ph D Mathias Kondolf, September 2013 (54 Sites Report).
157 Appendix A, Thorne Report, para. 5.12; Vol 2, Annex No 5, 54 Sites Report, p. 1.
158
Appendix A, Thorne Report, para. 5.14. landslides; and gullying. 163 Their study focussed on the area between
Marker II and Río Infiernito, which is one of the sections of the Road which
has the most landslides and gullies, and their results are therefore
representative of the erosion which is likely to occur in the 41.6 km stretch
of the Road from Marker II to Boca San Carlos. 164
3.21 Based on the field monitoring done by UCR, the land surface
lowering rates were estimated to be as follows:
(a) For sheet erosion of the road bed and slopes , the land lowering rate
-1 -1 165
varied between 0.061 m y and 0.095 m y . The range in the rates
is attributable to the variation between the dry and wet seasons .
Professor Thorne concludes that it is reasona ble to assume that the
average annual rate of lowering of the land surface due to sheet
erosion along the entire length of the Road is 0.095 m y -1. This
estimate is conservative, for two reasons. First, it reflects the top end
of the range which was derived from monitoring on the parts of the
Road which are the most susceptible to erosion. Secondly, if used as
the base value from which to estimate sheet erosion along the entire
length of the Road, which is the approach which Costa Rica’s
experts have taken, the resulting estimate of sediment delivery from
the Road to the River is further conservative. 166
163
Vol 2, Annex No 1 , University of Costa Rica Centre for Research in Sustainable
Development, Department of Civil Engineering, Report on Systematic Field monitoring of
Erosion and Sediment Yield along Route 1856, September 2013 (the UCR Report );
Appendix A, Thorne Report, para. 8.21.
164 Appendix A, Thorne Report, para. 8.23; cf. Fourth Kondolf Report, pp. 3 and 9.
165 Appendix A, Thorne Report, para. 8.25.
166
Ibid.
60landslides; and gullying. 163 Their study focussed on the area between
Marker II and Río Infiernito, which is one of the sections of the Road which
has the most landslides and gullies, and their results are therefore
representative of the erosion which is likely to occur in the 41.6 km stretch
of the Road from Marker II to Boca San Carlos. 164
3.21 Based on the field monitoring done by UCR, the land surface
lowering rates were estimated to be as follows:
(a) For sheet erosion of the road bed and slopes , the land lowering rate
-1 -1 165
varied between 0.061 m y and 0.095 m y . The range in the rates
is attributable to the variation between the dry and wet seasons .
Professor Thorne concludes that it is reasona ble to assume that the
average annual rate of lowering of the land surface due to sheet
erosion along the entire length of the Road is 0.095 m y -1. This
estimate is conservative, for two reasons. First, it reflects the top end
of the range which was derived from monitoring on the parts of the
Road which are the most susceptible to erosion. Secondly, if used as
the base value from which to estimate sheet erosion along the entire
length of the Road, which is the approach which Costa Rica’s
experts have taken, the resulting estimate of sediment delivery from
the Road to the River is further conservative. 166
163
Vol 2, Annex No 1 , University of Costa Rica Centre for Research in Sustainable
Development, Department of Civil Engineering, Report on Systematic Field monitoring of
Erosion and Sediment Yield along Route 1856, September 2013 (the UCR Report );
Appendix A, Thorne Report, para. 8.21.
164 Appendix A, Thorne Report, para. 8.23; cf. Fourth Kondolf Report, pp. 3 and 9.
165 Appendix A, Thorne Report, para. 8.25.
166
Ibid. the results of the field monitoring indicate that Dr Kondolf’s estimate of
land surface lowering of 1 m per year is probably too high by a factor of five
for the stretch of Road between Marker II and Río Infiernito. With respect to
the entire 108 km of the Road, it is probably too high by a factor of ten. 172
3.23 The field monitoring by UCR, as reviewed and analysed by
Professor Thorne, also indicated that Dr Kondolf’s estimate that this level of
erosion is occurring on 40% to 50% of the relevant area of the Road was a
“significant over-estimate.” 173Professor Thorne concludes:
“In my experience, including my inspections of the Road in
February and May 2012, of land surface lowering due to landslides
and gullies averaging 1 m y -1 is too high and it is unlikely to be
accurate, especially if applied to the entire length of the Road along
the River. Also, the assumption that landslides and gullies cover 40
to 50% of slopes and other disturbed areas overstates the extent of
these features. Conversely, the monitored rates and areas affected as
summarised in [the UCR Report and Table 12 of the Thorne Report]
are consistent with my own observations and, in my opinion, are
likely to be more representative of conditions encountered in general
174
along the Road.”
3.24 In order to assess whether sediment eroded from the Road is having
any impact on the San Juan, ICE analysed the results of the field monitoring
undertaken by UCR. Taking account of the length and steepness of the road
bed, and the areas of cut slopes, fill slopes and other disturbed areas along
the full length of the Road (which were examined and assessed in the
172 Appendix A, Thorne Report, para. 8.34.
173 Ibid, para. 8.35.
174
Ibid, para. 8.36.
62the results of the field monitoring indicate that Dr Kondolf’s estimate of
land surface lowering of 1 m per year is probably too high by a factor of five
for the stretch of Road between Marker II and Río Infiernito. With respect to
the entire 108 km of the Road, it is probably too high by a factor of ten. 172
3.23 The field monitoring by UCR, as reviewed and analysed by
Professor Thorne, also indicated that Dr Kondolf’s estimate that this level of
erosion is occurring on 40% to 50% of the relevant area of the Road was a
“significant over-estimate.” 173 Professor Thorne concludes:
“In my experience, including my inspections of the Road in
February and May 2012, of land surface lowering due to landslides
and gullies averaging 1 m y -1 is too high and it is unlikely to be
accurate, especially if applied to the entire length of the Road along
the River. Also, the assumption that landslides and gullies cover 40
to 50% of slopes and other disturbed areas overstates the extent of
these features. Conversely, the monitored rates and areas affected as
summarised in [the UCR Report and Table 12 of the Thorne Report]
are consistent with my own observations and, in my opinion, are
likely to be more representative of conditions encountered in general
174
along the Road.”
3.24 In order to assess whether sediment eroded from the Road is having
any impact on the San Juan, ICE analysed the results of the field monitoring
undertaken by UCR. Taking account of the length and steepness of the road
bed, and the areas of cut slopes, fill slopes and other disturbed areas along
the full length of the Road (which were examined and assessed in the
172 Appendix A, Thorne Report, para. 8.34.
173 Ibid, para. 8.35.
174
Ibid, para. 8.36. 3.26 ICE’s analysis took account of reach relevant stretch of the 102 km
of the Road. Their detailed results are reported in Table 14 and Figure 31 to
the Thorne Report, reproduced here for convenience:
Table 14. Average annual inputs of Road-derived sediment to the Río San Juan
(from the ICE Report)
3 -1 -1
Road length Input by volume (m yr ) Input by mass* (t yr )
Basin (km) Road Slopes Total Road Slopes Total
Major Costa Rican river basins draining directly to the Río San Juan between Marker II and Delta
Infiernito 38 7 360 16 800 24 160 12 250 28 050 40 300
San Carlos 11 1 240 360 1 600 2 050 600 2 650
Cureña 28 3 140 4 540 7 680 5 200 7 600 12 800
Sarapiquí 3 340 100 440 550 150 700
Chirripó 22 2 460 160 2 620 4 100 250 4 350
Costa Rican area that drains directly to the Río San Juan between Marker II to and Delta Colorado
Total 102 14 540 21 960 36 500 24 150 36 650 60 800
* To convert eroded volumes to masses, a bulk density of 1.67 t massumed. This
value is widely used to represent the bulk density of sil.-sand soils
64 3.26 ICE’s analysis took account of reach relevant stretch of the 102 km
of the Road. Their detailed results are reported in Table 14 and Figure 31 to
the Thorne Report, reproduced here for convenience:
Table 14. Average annual inputs of Road-derived sediment to the Río San Juan
(from the ICE Report)
3 -1 -1
Road length Input by volume (m yr ) Input by mass* (t yr )
Basin (km) Road Slopes Total Road Slopes Total
Major Costa Rican river basins draining directly to the Río San Juan between Marker II and Delta
Infiernito 38 7 360 16 800 24 160 12 250 28 050 40 300
San Carlos 11 1 240 360 1 600 2 050 600 2 650
Cureña 28 3 140 4 540 7 680 5 200 7 600 12 800
Sarapiquí 3 340 100 440 550 150 700
Chirripó 22 2 460 160 2 620 4 100 250 4 350
Costa Rican area that drains directly to the Río San Juan between Marker II to and Delta Colorado
Total 102 14 540 21 960 36 500 24 150 36 650 60 800
* To convert eroded volumes to masses, a bulk density of 1.67 t m assumed. This
value is widely used to represent the bulk density of sil.-sand soils (3) Impact of the sediment eroded from the Road on the total
sediment load of the River
3.27 As noted in paragraph 3.12 above, the total sediment load of a river
is comprised of the suspended sediment load plus the bed load. In the period
between December 2010 and June 2013, 115 bed load samples were
collected by ICE at Delta Colorado and other samples were also collected at
the mouths of the Río San Carlos and the Río Sarapiquí. On the basis of
these samples, and using established methods to generate the bed load rating
curve, ICE was able to estimate the average annual bed load in the Río San
Juan. To the bed load, ICE added the suspended sediment load to estimate
the total load . The results of their analysis are reflected in Table 6 of
Professor Thorne’s Report:
Table 6. Current average annual total loads in the Río San Juan - Colorado
River Suspended load Bed load Total Load
t y-1 t y-1 t y-1
San Juan 6 573 000 2 559 000 9 133 000
Colorado 5 981 000 2 488 000 8 470 000
Lower San Juan 592 000 71 000 663 000
-1
3.28 Thus the total sediment load in the Río San Juan is 9,133,000 t y . In
the Lower San Juan, it is 663,000 t y . -1
3.29 As noted in paragraph 3.25 above, the average input of sediment to
the Road is 60,800 t y -1annually. 183 This represents 0.67% of the total
sediment load of the River. As Professor Thorne explains: “This is
183 Appendix A, Thorne Report, para. 8.45 and Table 14.
66(3) Impact of the sediment eroded from the Road on the total
sediment load of the River
3.27 As noted in paragraph 3.12 above, the total sediment load of a river
is comprised of the suspended sediment load plus the bed load. In the period
between December 2010 and June 2013, 115 bed load samples were
collected by ICE at Delta Colorado and other samples were also collected at
the mouths of the Río San Carlos and the Río Sarapiquí. On the basis of
these samples, and using established methods to generate the bed load rating
curve, ICE was able to estimate the average annual bed load in the Río San
Juan. To the bed load, ICE added the suspended sediment load to estimate
the total load . The results of their analysis are reflected in Table 6 of
Professor Thorne’s Report:
Table 6. Current average annual total loads in the Río San Juan - Colorado
River Suspended load Bed load Total Load
t y-1 t y-1 t y-1
San Juan 6 573 000 2 559 000 9 133 000
Colorado 5 981 000 2 488 000 8 470 000
Lower San Juan 592 000 71 000 663 000
-1
3.28 Thus the total sediment load in the Río San Juan is 9,133,000 t y . In
the Lower San Juan, it is 663,000 t y . -1
3.29 As noted in paragraph 3.25 above, the average input of sediment to
the Road is 60,800 t y -1annually. 183 This represents 0.67% of the total
sediment load of the River. As Professor Thorne explains: “This is
183 Appendix A, Thorne Report, para. 8.45 and Table 14. branches between the Colorado River and the Lower San Juan:
approximately 90% empties into the Colorado; and 10% to the Lower San
Juan.
3.32 As noted in paragraph 3.25 above, the average input of sediment
from the Road to the River is 60,800 t y -1 annually. 187 If 10% of this
sediment enters the Lower San Juan, it would receive 6,080 t y annually.1 188
The Lower Río San Juan has a bed area of 2.7 million m . As Professor
Thorne explains, taking account of the estimate of additional sediment and
the area of the bed:
“Supposing that all of this Road- related sediment were to be
deposited on the bed of the lower Río San Juan (with none at all
deposited on the floodplains and in the wetlands or passing through
to the Caribbean Sea), the average increase in the rate of aggradation
-1 189
of the bed would be less than 0.2 mm y .”
Even this “tiny increase” – which is less than the diameter of a single grain
of sand – is an over-estimate. Because the Río San Juan is a sand bed river,
only the sand fraction of the additional sediment would actually be likely to
be deposited on the bed. Consequently, only 5 to 10% of the additional
sediment would be deposited on the bed. Additional aggradation is therefore
likely to be 0.02 mm y . As Professor Thorne concludes:
“It is immediately obvious that the addition of even the quantity of
additional Road-derived sediment estimated by Dr Kondolf to the
total annual sediment load of the lower Río San Juan could not have
187 Appendix A, Thorne Report, para. 8.45 and Table 14.
188 Ibid, para. 8.58.
189
Ibid, para. 8.59.
68branches between the Colorado River and the Lower San Juan:
approximately 90% empties into the Colorado; and 10% to the Lower San
Juan.
3.32 As noted in paragraph 3.25 above, the average input of sediment
from the Road to the River is 60,800 t y -1 annually. 187 If 10% of this
sediment enters the Lower San Juan, it would receive 6,080 t y annually.-1 188
The Lower Río San Juan has a bed area of 2.7 million m . As Professor
Thorne explains, taking account of the estimate of additional sediment and
the area of the bed:
“Supposing that all of this Road- related sediment were to be
deposited on the bed of the lower Río San Juan (with none at all
deposited on the floodplains and in the wetlands or passing through
to the Caribbean Sea), the average increase in the rate of aggradation
-1 189
of the bed would be less than 0.2 mm y .”
Even this “tiny increase” – which is less than the diameter of a single grain
of sand – is an over-estimate. Because the Río San Juan is a sand bed river,
only the sand fraction of the additional sediment would actually be likely to
be deposited on the bed. Consequently, only 5 to 10% of the additional
sediment would be deposited on the bed. Additional aggradation is therefore
likely to be 0.02 mm y . As Professor Thorne concludes:
“It is immediately obvious that the addition of even the quantity of
additional Road-derived sediment estimated by Dr Kondolf to the
total annual sediment load of the lower Río San Juan could not have
187 Appendix A, Thorne Report, para. 8.45 and Table 14.
188 Ibid, para. 8.58.
189
Ibid, para. 8.59. recorded rainfalls in the in the area proximate to the Road of between 20 and
250 mm (for Hurricane Joan); below 100 mm (for Hurricane Mitch); and
195
between 15 and 150 mm (for Hurricane Stan). Rainfalls in such measures
are unlikely to cause a dramatically increased quantity of sediment to be
delivered to the River. As Professor Thorne explains:
“In my opinion, rainfalls of this magnitude were in each event
unexceptional and unlikely to cause widespread destruction because
the basin of the Río San Juan receives abundant rainfall in most
years and the hydrology, sediment dynamics, morphology and
environment of the River are fully adjusted to the effects of frequent
and heavy rainstorms.” 196
But even if a disastrous hurricane of the sort Nicaragua foretells did impact
the region, the last thing people would be worrying about was sediment
from the road. Likewise, sediment from the entire basin would increase in
the same proportions, and any impact to the river would be caused by the
overall catastrophe, and not by the road alone.
(6) The Road has had no adverse impact on sediment in the River
3.36 The scientific and independent expert evidence submitted by Costa
Rica demonstrates that the Road has had no adverse or significant impact on
the sediment load of the River. Professor Thorne expresses his opinion as
follows:
“The Road has had no significant impacts on sediment transport and
dynamics in the Rio San Juan because the additional loads of
sediment are tiny (less than 1%) compared to natural loads and are
195 Vol 3, Annex 68 , Letter from the General Director of the Costa Rican National
Meteorological Institute to H.E. Edgar Ugalde Álvarez, 7 November 2013.
196 Appendix A, Thorne Report, para. 6.20.
70recorded rainfalls in the in the area proximate to the Road of between 20 and
250 mm (for Hurricane Joan); below 100 mm (for Hurricane Mitch); and
195
between 15 and 150 mm (for Hurricane Stan). Rainfalls in such measures
are unlikely to cause a dramatically increased quantity of sediment to be
delivered to the River. As Professor Thorne explains:
“In my opinion, rainfalls of this magnitude were in each event
unexceptional and unlikely to cause widespread destruction because
the basin of the Río San Juan receives abundant rainfall in most
years and the hydrology, sediment dynamics, morphology and
environment of the River are fully adjusted to the effects of frequent
and heavy rainstorms.” 196
But even if a disastrous hurricane of the sort Nicaragua foretells did impact
the region, the last thing people would be worrying about was sediment
from the road. Likewise, sediment from the entire basin would increase in
the same proportions, and any impact to the river would be caused by the
overall catastrophe, and not by the road alone.
(6) The Road has had no adverse impact on sediment in the River
3.36 The scientific and independent expert evidence submitted by Costa
Rica demonstrates that the Road has had no adverse or significant impact on
the sediment load of the River. Professor Thorne expresses his opinion as
follows:
“The Road has had no significant impacts on sediment transport and
dynamics in the Rio San Juan because the additional loads of
sediment are tiny (less than 1%) compared to natural loads and are
195 Vol 3, Annex 68 , Letter from the General Director of the Costa Rican National
Meteorological Institute to H.E. Edgar Ugalde Álvarez, 7 November 2013.
196 Appendix A, Thorne Report, para. 6.20. 3.39 Furthermore, while intense concentrated rainstorms are likely to
produce a contrast between local runoff and the receiving water, due to the
River’s natural processes and movement, “the relatively high SCCs decrease
to background levels within a short distance downstream and a short time
after the rainstorm ends, as the plume of local runoff diffuses into the far
203
greater flow in the receiving water.”
3.40 In his Fourth Report, Dr Kondolf altered his position somewhat on
the results of his analysis: he accepted that the concentrations he measured
in the muddy-water plume “were not very high compared to concentrations
measured in the river and its large tributaries du ring high flows”, but
maintained that the measurements “demonstrate the essential fact that
204
sediment from the road is entering the Río San Juan.” But of course that
does not evidence any adverse impact on the San Juan. As Professor Thorne
observes:
“… the central point re mains this: in order to assess whether the
concentrations of suspended sediment measured in runoff from the
Road have harmed or may in future cause harm to life in the River, it
is necessary to consider them within the context of sediment
concentrations that aquatic plants and animals in the river system
experience routinely and to which they are well adapted. The
analysis conducted herein demonstrates that concentrations often
exceed 500 grams per cubic metre and so those measured in May
2013 (364, 459 and 483 grams per cubic metre) have not, and will
not damage life in the River.” 205
3.41 The evidence submitted by Costa Rica further demonstrates that the
Road has had no adverse or significant impact on the lower Río San Juan,
203 Appendix A, Thorne Report, para. 10.6.
204 Fourth Kondolf Report, p. 11.
205 Appendix A, Thorne Report, para. 10.7.
723.39 Furthermore, while intense concentrated rainstorms are likely to
produce a contrast between local runoff and the receiving water, due to the
River’s natural processes and movement, “the relatively high SCCs decrease
to background levels within a short distance downstream and a short time
after the rainstorm ends, as the plume of local runoff diffuses into the far
203
greater flow in the receiving water.”
3.40 In his Fourth Report, Dr Kondolf altered his position somewhat on
the results of his analysis: he accepted that the concentrations he measured
in the muddy-water plume “were not very high compared to concentrations
measured in the river and its large tributaries du ring high flows”, but
maintained that the measurements “demonstrate the essential fact that
204
sediment from the road is entering the Río San Juan.” But of course that
does not evidence any adverse impact on the San Juan. As Professor Thorne
observes:
“… the central point re mains this: in order to assess whether the
concentrations of suspended sediment measured in runoff from the
Road have harmed or may in future cause harm to life in the River, it
is necessary to consider them within the context of sediment
concentrations that aquatic plants and animals in the river system
experience routinely and to which they are well adapted. The
analysis conducted herein demonstrates that concentrations often
exceed 500 grams per cubic metre and so those measured in May
2013 (364, 459 and 483 grams per cubic metre) have not, and will
not damage life in the River.” 205
3.41 The evidence submitted by Costa Rica further demonstrates that the
Road has had no adverse or significant impact on the lower Río San Juan,
203 Appendix A, Thorne Report, para. 10.6.
204 Fourth Kondolf Report, p. 11.
205 Appendix A, Thorne Report, para. 10.7. River, all of which are well -adapted to the heavy load and highly
variable sediment regime of the Río San Juan. 207
C. There is No Risk of Any Other Adverse Impact on the San Juan
River
3.43 Nicaragua claims that the Road has had an adverse impact on the
San Juan River in respect of (1) water quality; (2) channel morphology;
(3) navigation; and (4) ecosystem, tourism and health. The extent to which
the Road is having such an adverse impact on each of these issues will now
be addressed.
3.44 Before doing so, it is necessary to mention Nicaragua’s misplaced
emphasis on the question whether the Road was constructed with strict
adherence to engineering standards. Nicaragua relies heavily on two reports
produced in Costa Rica: a May 2012 report of the National Laboratory of
208
the University of Costa Rica (in its Spanish acronym, LANAMME) and a
June 2012 report of the Costa Rican Federated Association of Engineers and
209
Architects (the CFIA). It alleges that these reports support its claim that
the Road has caused environmental harm to the San Juan River. 210When
reviewed carefully, it is apparent that the reports of LANAMME and the
CFIA do not evidence that environmental harm has or will be caused to the
San Juan River. Both LANAMME and CFIA have confirmed that their
207
Appendix A, Thorne Report, para. 12.7.
208 NCM, Annex 3, National Laboratory of Materials and Structural Models of the University
of Costa Rica, “Report INF -PITRA-014-12: Report from Inspection of Route 1856 - Juan
Rafael Mora PorrasBorder Road,” May 2012.
209
NCM, Annex 4 , Federated Association of Engineers and Architects of Costa 257 Rica,
River CFIA Report,” 8 June 2012.the Border Road, NArea Parallel to the San Juan
210 See, e.g, NM, paras. 2.26, 3.4 -3.5, 3.15-3.18, 3.20, 3.24, 3.26 -3.28, 3.34-3.36, 3.40, 3.43,
3.45-3.46, 3.50, 3.52, 3.55-3.56, 4.15, 5.11, 5.100, 5.106, 6.7, and 6.21.
74 River, all of which are well -adapted to the heavy load and highly
variable sediment regime of the Río San Juan. 207
C. There is No Risk of Any Other Adverse Impact on the San Juan
River
3.43 Nicaragua claims that the Road has had an adverse impact on the
San Juan River in respect of (1) water quality; (2) channel morphology;
(3) navigation; and (4) ecosystem, tourism and health. The extent to which
the Road is having such an adverse impact on each of these issues will now
be addressed.
3.44 Before doing so, it is necessary to mention Nicaragua’s misplaced
emphasis on the question whether the Road was constructed with strict
adherence to engineering standards. Nicaragua relies heavily on two reports
produced in Costa Rica: a May 2012 report of the National Laboratory of
208
the University of Costa Rica (in its Spanish acronym, LANAMME) and a
June 2012 report of the Costa Rican Federated Association of Engineers and
209
Architects (the CFIA). It alleges that these reports support its claim that
the Road has caused environmental harm to the San Juan River. 210When
reviewed carefully, it is apparent that the reports of LANAMME and the
CFIA do not evidence that environmental harm has or will be caused to the
San Juan River. Both LANAMME and CFIA have confirmed that their
207
Appendix A, Thorne Report, para. 12.7.
208 NCM, Annex 3, National Laboratory of Materials and Structural Models of the University
of Costa Rica, “Report INF -PITRA-014-12: Report from Inspection of Route 1856 - Juan
Rafael Mora PorrasBorder Road,” May 2012.
209
NCM, Annex 4 , Federated Association of Engineers and Architects of Costa 257 Rica,
River CFIA Report,” 8 June 2012.the Border Road, NArea Parallel to the San Juan
210 See, e.g, NM, paras. 2.26, 3.4 -3.5, 3.15-3.18, 3.20, 3.24, 3.26 -3.28, 3.34-3.36, 3.40, 3.43,
3.45-3.46, 3.50, 3.52, 3.55-3.56, 4.15, 5.11, 5.100, 5.106, 6.7, and 6.21. misplaced. 212 Nicaragua asserts that this Tribunal confirmed that the Road
had caused environmental harm. 213 This is incorrect. As explained by the
President of the Administrative Tribunal , the file to which the press report
refers is a note signed by a single employee of the technical department of
the Tribunal. It is n ot a decision of the Tribunal . Furthermore, the note in
question states that there was no actual or potential damage to Nicaraguan
territory, so it does not confirm that the Road has caused environmental
harm to Nicaragua. 214
(1) Water quality
3.47 Nicaragua claims that the contribution of sediment from the Road to
the River has adversely impacted the water quality of the River. 215 It relies
on the view expressed by Dr Kondolf that increased sedimentation affects
water quality. 216 Nicaragua claims compensation for the cost of restoring the
water quality of the San Juan. 217
3.48 As Costa Rica has demonstrated, the Road is not delivering
additional sediment to the River in excessive concentration or any
measurable quantity which would cause any harm to the River, including in
respect of water quality. Professor Thorne concludes that “[t]here is
absolutely nothing to suggest that the Road has adversely impacted the
212
NCM, Annex 37, El Pais, Costa Rica, “Environmental Court Confirms Excessive Felling in
the Construction of Trail 1856”, 15 July 2012.
213 NCM, paras. 5.13, 5.19 and 5.21.
214
Vol 3, Annex No 51, Note from President of the TAA to Foreign Minister of Costa Rica,
Reference 200-13-TAA, 9 April 2013.
215 NM, paras. 3.60, 3.81, 3.89 and 3.92.
216 NM, Annex 1, Kondolf 2012 Report, para. 1.3.2.
217
NM, para. 6.33.
76misplaced. 212 Nicaragua asserts that this Tribunal confirmed that the Road
had caused environmental harm. 213 This is incorrect. As explained by the
President of the Administrative Tribunal , the file to which the press report
refers is a note signed by a single employee of the technical department of
the Tribunal. It is n ot a decision of the Tribunal . Furthermore, the note in
question states that there was no actual or potential damage to Nicaraguan
territory, so it does not confirm that the Road has caused environmental
harm to Nicaragua. 214
(1) Water quality
3.47 Nicaragua claims that the contribution of sediment from the Road to
the River has adversely impacted the water quality of the River. 215 It relies
on the view expressed by Dr Kondolf that increased sedimentation affects
water quality. 216Nicaragua claims compensation for the cost of restoring the
water quality of the San Juan. 217
3.48 As Costa Rica has demonstrated, the Road is not delivering
additional sediment to the River in excessive concentration or any
measurable quantity which would cause any harm to the River, including in
respect of water quality. Professor Thorne concludes that “[t]here is
absolutely nothing to suggest that the Road has adversely impacted the
212
NCM, Annex 37, El Pais, Costa Rica, “Environmental Court Confirms Excessive Felling in
the Construction of Trail 1856”, 15 July 2012.
213 NCM, paras. 5.13, 5.19 and 5.21.
214
Vol 3, Annex No 51, Note from President of the TAA to Foreign Minister of Costa Rica,
Reference 200-13-TAA, 9 April 2013.
215 NM, paras. 3.60, 3.81, 3.89 and 3.92.
216 NM, Annex 1, Kondolf 2012 Report, para. 1.3.2.
217
NM, para. 6.33. 223
ecology.” Nicaragua submitted no evidence to support its assertion that
the Road has had or is likely to have an impact on the morphology of the
San Juan River. To the extent that such a n assertion is based on the
contribution of sediment from the River, it has been established by Costa
Rica’s expert evidence and confirmed by Professor Thorne that there has
been no significant impacts on sediment transport and dynamics in the River
because the additional contributions to the sediment load are “tiny” and,
224
within the context of this River, “indiscernible”.
3.50 In his 2012 Report, Dr Kondolf included photographs of sediment
deltas which he says he observed on the C osta Rican side of the River, and
which he attributed to the Road. 225 As Professor Thorne notes, these
photographs do not demonstrate that the Road is having any significant
morphological impact on the River; indeed, they confirm that the Road is
morphologically insignificant. 226 As the Court noted in its Order of 13
December 2013 rejecting Nicaragua’s Request for Provisional Measures in
this case, “the photographic and video evidence submitted by Nicaragua
does nothing to substantiate Nicaragua’s allegations r elating to increased
sedimentation levels.” 227
223 NM, Annex 1, 2012 Kondolf Report, p. 50, para. 5.6 (emphasis added).
224 Appendix A, Thorne Report, para. 12.2.
225
See Appendix A, Thorne Report, Figure 35, reproducing photographs from Appendix B to
2012 Kondolf Report.
226 Appendix A, Thorne Report, para. 9.1.
227
Construction of a Road in Costa Rica Along the San Juan River (Nicaragua v
Costa Rica), Request presented by Nicaragua for the Indication of Provisional
Measures, Order, 13 December 2013, para. 34.
78 223
ecology.” Nicaragua submitted no evidence to support its assertion that
the Road has had or is likely to have an impact on the morphology of the
San Juan River. To the extent that such a n assertion is based on the
contribution of sediment from the River, it has been established by Costa
Rica’s expert evidence and confirmed by Professor Thorne that there has
been no significant impacts on sediment transport and dynamics in the River
because the additional contributions to the sediment load are “tiny” and,
224
within the context of this River, “indiscernible”.
3.50 In his 2012 Report, Dr Kondolf included photographs of sediment
deltas which he says he observed on the C osta Rican side of the River, and
which he attributed to the Road. 225 As Professor Thorne notes, these
photographs do not demonstrate that the Road is having any significant
morphological impact on the River; indeed, they confirm that the Road is
morphologically insignificant. 226 As the Court noted in its Order of 13
December 2013 rejecting Nicaragua’s Request for Provisional Measures in
this case, “the photographic and video evidence submitted by Nicaragua
does nothing to substantiate Nicaragua’s allegations r elating to increased
sedimentation levels.” 227
223 NM, Annex 1, 2012 Kondolf Report, p. 50, para. 5.6 (emphasis added).
224 Appendix A, Thorne Report, para. 12.2.
225
See Appendix A, Thorne Report, Figure 35, reproducing photographs from Appendix B to
2012 Kondolf Report.
226 Appendix A, Thorne Report, para. 9.1.
227
Construction of a Road in Costa Rica Along the San Juan River (Nicaragua v
Costa Rica), Request presented by Nicaragua for the Indication of Provisional
Measures, Order, 13 December 2013, para. 34. 3.52 Professor Thorne concludes that the Road has not posed and will not
pose any risk of harm to the morphology of the River. 231 It follows that
Nicaragua’s claim to the contrary must be dismissed.
(3) Navigation
3.53 Nicaragua claims that the road works have breached Nicaragua’s
232
right of navigation on the San Juan River. In support of this claim
Nicaragua refers to two annexes. The first is the report of Dr Kondolf ,
which in its introduction to Appendix B (which consists of photographs)
states as follows:
“These selected photographs document major deficiencies by Costa
Rica in abiding by international road practices intended to minimize
on-site and off -site impacts to water quality, channel morphology,
233
navigation and riverine ecology…”
Apart from this single reference alleging deficiencies in practices which are
intended to minimize impacts to navigation, there is no further discussion of
any impact on Nicaragua’s ability to navigate on the San Juan in Dr
Kondolf’s lengthy report s. This isolated statement is demonstrably
insufficient to establish that Nicaragua’s ability to navigate on the San Juan
has been impacted at all by the road infrastructure works.
3.54 The second document which N icaragua cites in support of its claim
that Costa Rica has breached Nicaragua’s right of navigation is a note from
Nicaragua’s Minister of Foreign Affairs to the Costa Rican Minister of
231 Appendix A, Thorne Report, para. 12.7.
232 NM, para. 4.41. See also para. 6.15.
233
NM, Annex 1, Appendix B, p 1, referred to in para. 3.6, footnote 112.
803.52 Professor Thorne concludes that the Road has not posed and will not
pose any risk of harm to the morphology of the River. 231 It follows that
Nicaragua’s claim to the contrary must be dismissed.
(3) Navigation
3.53 Nicaragua claims that the road works have breached Nicaragua’s
232
right of navigation on the San Juan River. In support of this claim
Nicaragua refers to two annexes. The first is the report of Dr Kondolf ,
which in its introduction to Appendix B (which consists of photographs)
states as follows:
“These selected photographs document major deficiencies by Costa
Rica in abiding by international road practices intended to minimize
on-site and off -site impacts to water quality, channel morphology,
233
navigation and riverine ecology…”
Apart from this single reference alleging deficiencies in practices which are
intended to minimize impacts to navigation, there is no further discussion of
any impact on Nicaragua’s ability to navigate on the San Juan in Dr
Kondolf’s lengthy report s. This isolated statement is demonstrably
insufficient to establish that Nicaragua’s ability to navigate on the San Juan
has been impacted at all by the road infrastructure works.
3.54 The second document which N icaragua cites in support of its claim
that Costa Rica has breached Nicaragua’s right of navigation is a note from
Nicaragua’s Minister of Foreign Affairs to the Costa Rican Minister of
231 Appendix A, Thorne Report, para. 12.7.
232 NM, para. 4.41. See also para. 6.15.
233
NM, Annex 1, Appendix B, p 1, referred to in para. 3.6, footnote 112. (4) Ecosystem, Tourism and Health
3.56 Nicaragua makes three further claims as to the impact of the road
infrastructure works on the San Juan River, as to adverse effects on the
ecosystem, tourism and health of the riparian communities of the River.
3.57 First, Nicaragua alleges that the Road has harmed the ecosystem of
the River. 238 As a consequence of that harm, Nicaragua claims
compensation for losses allegedly suffered in respect of fishing. 239
Nicaragua’s primary source of evidence for damage to the ecosystem of the
San Juan is the judgment of the Central American Court of Justice. For the
reasons explained in Section D below, the findings of that Court cannot be
relied upon.
3.58 Nicaragua attempts to find support of this claim in the evidence of
Dr Kondolf. He attests that increase sedimentation on a river can cause
significant ecological damage. He notes that “[t]hese effects have been
documented in multiple sites around the globe in a wide range of
240
ecosystems.” While that might be true at an abstract level, Dr Kondolf
does not document any such effects in respect of the San Juan.
3.59 In his Third Report, submitted in support of Nicaragua’s Request for
Provisional Measures, Dr Kondolf reported results of sampling of
241
periphyton done by his colleague, Dr Rios, at nine sites, in May 2013.
The samples collected from the sites on the Costa Rican bank of the River
238 NM, para. 3.93. See also paras. 1.9 -1.10, 5.61 (referring to Nicaragua’s report to the Court
dated 23 July 2012 in the Certain Activities case), and 5.67.
239
NM, para. 6.33.
240 NM, Annex 1, 2012 Kondolf Report, para 3.1.5. See also para 3.1.4.
241
Third Kondolf Report, p. 13.
82(4) Ecosystem, Tourism and Health
3.56 Nicaragua makes three further claims as to the impact of the road
infrastructure works on the San Juan River, as to adverse effects on the
ecosystem, tourism and health of the riparian communities of the River.
3.57 First, Nicaragua alleges that the Road has harmed the ecosystem of
the River. 238 As a consequence of that harm, Nicaragua claims
compensation for losses allegedly suffered in respect of fishing. 239
Nicaragua’s primary source of evidence for damage to the ecosystem of the
San Juan is the judgment of the Central American Court of Justice. For the
reasons explained in Section D below, the findings of that Court cannot be
relied upon.
3.58 Nicaragua attempts to find support of this claim in the evidence of
Dr Kondolf. He attests that increase sedimentation on a river can cause
significant ecological damage. He notes that “[t]hese effects have been
documented in multiple sites around the globe in a wide range of
240
ecosystems.” While that might be true at an abstract level, Dr Kondolf
does not document any such effects in respect of the San Juan.
3.59 In his Third Report, submitted in support of Nicaragua’s Request for
Provisional Measures, Dr Kondolf reported results of sampling of
241
periphyton done by his colleague, Dr Rios, at nine sites, in May 2013.
The samples collected from the sites on the Costa Rican bank of the River
238 NM, para. 3.93. See also paras. 1.9 -1.10, 5.61 (referring to Nicaragua’s report to the Court
dated 23 July 2012 in the Certain Activities case), and 5.67.
239
NM, para. 6.33.
240 NM, Annex 1, 2012 Kondolf Report, para 3.1.5. See also para 3.1.4.
241
Third Kondolf Report, p. 13. endanger such species, and that it has not identified with precision which
species are likely to be affected.” 247
3.60 In the Environmental Diagnostic Asse ssment undertaken by CCT,
the impacts and potential impacts of the Road on terrestrial and aquatic
environments and ecosystems were comprehensively investigated. 248 CCT’s
Report covered the Road’s environmental and ecological impacts on Costa
Rican territory, and concluded that these impacts were irrelevant in five of
eight categories and moderate in the remaining three categories. The
moderate impacts were principally restricted to the stretch of Road between
Marker II and Boca San Carlos, which, as noted in paragraph 3.17 above, is
the only part of the Road of which Dr Kondolf complains. Moderate impacts
were limited to cutting of trees, and increased turbidity and disturbance of
micro-habitats in some Costa Rican water bodies, due to local a nd confined
inputs of sediment. 249
3.61 In respect of impacts on Nicaraguan territory, CCT noted that it was
not permitted to enter Nicaraguan territory to conduct sampling and to
investigate potential impacts. 250 However, based on the field research and
monitoring that CCT was able to undertake, it concluded that “it is not
considered there could be any significant impact on the San Juan river.” 251
In coming to this conclusion, CCT took into account that sediment transport
247 Construction of a Road in Costa Rica Along the San Juan River (Nicaragua v
Costa Rica), Request presented by Nicaragua for the Indication of Provisional
Measures, Order, 13 December 2013, para. 34.
248
See Appendix A, Thorne Report, para. 10.15.
249 Vol 2, Annex No 10, CCT Report, para 6.2.3; Appendix A, Thorne Report, para. 10.15.
250 Vol 2, Annex No 10, CCT Report, p. 13.
251
Ibid, para. 6.3.2.
84endanger such species, and that it has not identified with precision which
species are likely to be affected.” 247
3.60 In the Environmental Diagnostic Asse ssment undertaken by CCT,
the impacts and potential impacts of the Road on terrestrial and aquatic
environments and ecosystems were comprehensively investigated. 248CCT’s
Report covered the Road’s environmental and ecological impacts on Costa
Rican territory, and concluded that these impacts were irrelevant in five of
eight categories and moderate in the remaining three categories. The
moderate impacts were principally restricted to the stretch of Road between
Marker II and Boca San Carlos, which, as noted in paragraph 3.17 above, is
the only part of the Road of which Dr Kondolf complains. Moderate impacts
were limited to cutting of trees, and increased turbidity and disturbance of
micro-habitats in some Costa Rican water bodies, due to local a nd confined
inputs of sediment. 249
3.61 In respect of impacts on Nicaraguan territory, CCT noted that it was
not permitted to enter Nicaraguan territory to conduct sampling and to
investigate potential impacts. 250 However, based on the field research and
monitoring that CCT was able to undertake, it concluded that “it is not
considered there could be any significant impact on the San Juan river.” 251
In coming to this conclusion, CCT took into account that sediment transport
247 Construction of a Road in Costa Rica Along the San Juan River (Nicaragua v
Costa Rica), Request presented by Nicaragua for the Indication of Provisional
Measures, Order, 13 December 2013, para. 34.
248
See Appendix A, Thorne Report, para. 10.15.
249 Vol 2, Annex No 10, CCT Report, para 6.2.3; Appendix A, Thorne Report, para. 10.15.
250 Vol 2, Annex No 10, CCT Report, p. 13.
251
Ibid, para. 6.3.2. 3.64 CCT, in the Environmental Diagnosti c Assessment,
comprehensively considered potential impacts of the Road on tourism and
257
concluded that there were no direct impacts. As noted by CCT and by
258
Professor Thorne, there are no facilities for tourists on either bank of the
River between Marker II and Delta Costa Rica, i.e. adjacent to the 108 km
stretch of the Road along the San Juan River. Furthermore, the potential for
tourism is low, due to lack of accommodation and infrastructure, difficulties
of access and perceptions of instability in the bo rder area. CCT concluded
that “[t]he effect of the construction of Route 1856 has no direct impact on
tourism in recent years.” 259
3.65 Finally, Nicaragua claims that the construction of the Road has
impacted upon the health of the riparians of the River. Although this claim
is not articulated with any particularity, it appears to b e based on the
assertion that adverse impacts on the River will necessarily have an adverse
impact on the health of riparians. 260In its Request for Provisional Measures,
Nicaragua made a similar assertion, that the Road was causing “irreparable
damage” to “the health and wellbeing of the population living along [the]
257 Vol 2, Annex No 10, CCT Report, para. 7.1.3.14.
258
Appendix A, Thorne Report, paras. 10.20-10.21.
259 Vol 2, Annex No 10, CCT Report, p. 148 (conclusion 14).
260 NM, para. 2.14. Nicaragua cites to two sections of Dr Kondolf’s 2012 Report (see NM,
para. 6.33, footnote 609, referring to sections 3.1.4 and2012 Kondolf Report).
However, neither those sections, nor any other part of Dr Kondolf’s Report deal with the
impacts on the Road on human health.
863.64 CCT, in the Environmental Diagnosti c Assessment,
comprehensively considered potential impacts of the Road on tourism and
257
concluded that there were no direct impacts. As noted by CCT and by
258
Professor Thorne, there are no facilities for tourists on either bank of the
River between Marker II and Delta Costa Rica, i.e. adjacent to the 108 km
stretch of the Road along the San Juan River. Furthermore, the potential for
tourism is low, due to lack of accommodation and infrastructure, difficulties
of access and perceptions of instability in the bo rder area. CCT concluded
that “[t]he effect of the construction of Route 1856 has no direct impact on
tourism in recent years.” 259
3.65 Finally, Nicaragua claims that the construction of the Road has
impacted upon the health of the riparians of the River. Although this claim
is not articulated with any particularity, it appears to b e based on the
assertion that adverse impacts on the River will necessarily have an adverse
impact on the health of riparians. 260 In its Request for Provisional Measures,
Nicaragua made a similar assertion, that the Road was causing “irreparable
damage” to “the health and wellbeing of the population living along [the]
257 Vol 2, Annex No 10, CCT Report, para. 7.1.3.14.
258
Appendix A, Thorne Report, paras. 10.20-10.21.
259 Vol 2, Annex No 10, CCT Report, p. 148 (conclusion 14).
260 NM, para. 2.14. Nicaragua cites to two sections of Dr Kondolf’s 2012 Report (see NM,
para. 6.33, footnote 609, referring to sections 3.1.4 and 2012 Kondolf Report).
However, neither those sections, nor any other part of Dr Kondolf’s Report deal with the
impacts on the Road on human health. Central American Integration System. The Central American Integration
System was created in 1991. 264
3.69 It is a fundamental principle of international law that judicial
authority may only be exercised over States with their consent. This
principle is reflected, for example, in Article 36(1) of the Statute of the ICJ,
which provides:
“The jurisdiction of the Court comprises all cases which the parties
refer to it and all matters specially provided for in the Charter of the
United Nations or in treaties and conventions in force.” 265
3.70 Costa Rica is not a party to the Statute of the CACJ. In 1995 Costa
266
Rica’s Parliament voted against ratification of the CACJ Statute. The fact
that Costa Rica is not subject to the jurisdiction of the CACJ was recalled by
267
Costa Rica’s Foreign Minister by note dated 3 0 April 2009. That Costa
Rica is not a party to the CACJ Statute is recorded on the CACJ’s
268
website. Thus the CACJ has no jurisdiction to decide any dispute
involving Costa Rica. In the absence of Costa Rica’s consent, the CACJ ’s
“Judgment” has no effect in relation to Costa Rica.
264 See Tegucigalpa Protocol to the Charter of the Organization of Central American States
(ODECA), Tegucigalpa, 13 December 1991, 1695 UNTS p. 382.
265 Statute of the ICJ, Article 36(1).
266 Vol 3, Annex No 20, Costa Rica, Permanent Commission on Legal Matters, Majority
Negative Vote, Bill for Approval of the Statute of the Central American Court of Justice
signed in Panama City, Panama on 1 December 1992, File Number 11.854, 5 December
1998.
267 Vol 3, Annex No 33 , Note from Foreign Minister, Costa Rica, to CACJ, Reference DM -
AM-306-09, 30 April 2009; see also Vol 3, Annex No 14, Costa Rican Ministry of Foreign
Affairs, Press Release, 5 May 2009.
268
See Vol 3, Annex No 7 3, Extract from CACJ website, “The challenge is having Panama
and Costa Rica join”, available at http://portal.ccj.org.ni/ccj2/Publicar/tabid/88/EntryId/3/-
El-reto-es-que-Panama-y-Costa-Rica-se-integren.aspx .
88Central American Integration System. The Central American Integration
System was created in 1991. 264
3.69 It is a fundamental principle of international law that judicial
authority may only be exercised over States with their consent. This
principle is reflected, for example, in Article 36(1) of the Statute of the ICJ,
which provides:
“The jurisdiction of the Court comprises all cases which the parties
refer to it and all matters specially provided for in the Charter of the
United Nations or in treaties and conventions in force.” 265
3.70 Costa Rica is not a party to the Statute of the CACJ. In 1995 Costa
266
Rica’s Parliament voted against ratification of the CACJ Statute. The fact
that Costa Rica is not subject to the jurisdiction of the CACJ was recalled by
267
Costa Rica’s Foreign Minister by note dated 3 0 April 2009. That Costa
Rica is not a party to the CACJ Statute is recorded on the CACJ’s
268
website. Thus the CACJ has no jurisdiction to decide any dispute
involving Costa Rica. In the absence of Costa Rica’s consent, the CACJ ’s
“Judgment” has no effect in relation to Costa Rica.
264 See Tegucigalpa Protocol to the Charter of the Organization of Central American States
(ODECA), Tegucigalpa, 13 December 1991, 1695 UNTS p. 382.
265 Statute of the ICJ, Article 36(1).
266 Vol 3, Annex No 20, Costa Rica, Permanent Commission on Legal Matters, Majority
Negative Vote, Bill for Approval of the Statute of the Central American Court of Justice
signed in Panama City, Panama on 1 December 1992, File Number 11.854, 5 December
1998.
267 Vol 3, Annex No 33 , Note from Foreign Minister, Costa Rica, to CACJ, Reference DM -
AM-306-09, 30 April 2009; see also Vol 3, Annex No 14, Costa Rican Ministry of Foreign
Affairs, Press Release, 5 May 2009.
268
See Vol 3, Annex No 7 3, Extract from CACJ website, “The challenge is having Panama
and Costa Rica join”, available at http://portal.ccj.org.ni/ccj2/Publicar/tabid/88/EntryId/3/-
El-reto-es-que-Panama-y-Costa-Rica-se-integren.aspx . 272
Government. One of these organizations is headed by Nicaragua’s
Presidential Adviser for the Environment, who has the rank of Minister.
Within two weeks, the President of the Court announced to the Nicaraguan
Press that the Court could make a site visit and issue provisional measures,
and that if Costa Rica failed to comply with the Court’s order, it would be
273
declared in breach. Within a week of the site visit, the CACJ issued a
provisional measures order. 274
3.74 After the provisional measures order, the President of the CACJ
made further public statements that could be seen as encouraging the
claimants to present sufficient evidence to make good the claims against
Costa Rica. The Nicaraguan press recorded that the President “called
Nicaraguan environmental organizati ons to present sufficient evidence so
275
that the Court did not render a judgment … without merit.”
272
Vol 3, Annex No 7 5, Radio La Primerísima, “Central American Court admits lawsuit
against Costa Rica”, 19 December 2011, available at http://www.rlp.com.ni/noticias/
111936/corte-ca-admite-demanda-contra-costa-rica ; Vol 3, Annex No 29, Appointment of
Jaime Incer Barquero as Nicaragua’s President Adviser on the Environment, with rank of
Minister. Presidential Decree 88-2009, of 2 April 2009, published in Nicaragua’s Official
Gazette No. 65, of 3 April 2009.
273
Vol 3, Annex No 75, Radio La Primerísima, “CA Court Admits Complaint Against Costa
Rica”, 19 December 2011, available at http://www.rlp.com.ni/noticias/111936/co-ca-
admite-demanda-contra-costa-rica (“[President of the CACJ] Lobo said that a delegation of
judges of the CACJ could make a visit to the area in which Costa Rica builds its road, to
ascertain the environmental damage that the project could be causing, and thus define the
precautionary measures to be imposed to the neighbouring country . Should Costa Rica
dismiss the decision of the CACJ, [President] Lobo said it could be declared ‘rebel’…”).
274
Referred to in NCM Annex 13, CACJ Judgment, 21 June 2012, p. 10, para. IX.
275 Vol 3, Annex No 76, El Nuevo Diario, “CACJ opens trial to evid ence”, 24 January 2012,
available at http://www.elnuevodiario.com.ni/politica/239562 .
90 272
Government. One of these organizations is headed by Nicaragua’s
Presidential Adviser for the Environment, who has the rank of Minister.
Within two weeks, the President of the Court announced to the Nicaraguan
Press that the Court could make a site visit and issue provisional measures,
and that if Costa Rica failed to comply with the Court’s order, it would be
273
declared in breach. Within a week of the site visit, the CACJ issued a
provisional measures order. 274
3.74 After the provisional measures order, the President of the CACJ
made further public statements that could be seen as encouraging the
claimants to present sufficient evidence to make good the claims against
Costa Rica. The Nicaraguan press recorded that the President “called
Nicaraguan environmental organizati ons to present sufficient evidence so
275
that the Court did not render a judgment … without merit.”
272
Vol 3, Annex No 7 5, Radio La Primerísima, “Central American Court admits lawsuit
against Costa Rica”, 19 December 2011, available at http://www.rlp.com.ni/noticias/
111936/corte-ca-admite-demanda-contra-costa-rica ; Vol 3, Annex No 29, Appointment of
Jaime Incer Barquero as Nicaragua’s President Adviser on the Environment, with rank of
Minister. Presidential Decree 88-2009, of 2 April 2009, published in Nicaragua’s Official
Gazette No. 65, of 3 April 2009.
273
Vol 3, Annex No 75, Radio La Primerísima, “CA Court Admits Complaint Against Costa
Rica”, 19 December 2011, available at http://www.rlp.com.ni/noticias/111936/co-ca-
admite-demanda-contra-costa-rica (“[President of the CACJ] Lobo said that a delegation of
judges of the CACJ could make a visit to the area in which Costa Rica builds its road, to
ascertain the environmental damage that the project could be causing, and thus define the
precautionary measures to be imposed to the neighbouring country . Should Costa Rica
dismiss the decision of the CACJ, [President] Lobo said it could be declared ‘rebel’…”).
274
Referred to in NCM Annex 13, CACJ Judgment, 21 June 2012, p. 10, para. IX.
275 Vol 3, Annex No 76, El Nuevo Diario, “CACJ opens trial to evid ence”, 24 January 2012,
available at http://www.elnuevodiario.com.ni/politica/239562 . E. Conclusion
3.76 Nicaragua’s claims of significant harm rest on its assumption that
the Road is contributing sediment to the River in quantities which cause
damage. Costa Rica’s evidence demonstrates that this is not the case. In
particular,
(a) The sediment load carried by the San Juan in the period since
construction of the Road is actually lower than it was before the
Road was constructed. Hence, there is no evidence that construction
of the Road has increased the suspended sediment load carried by
the San Juan.
(b) The field monitoring undertaken by Costa Rica’s experts indicates
that the average input of sediment from the Road to the River is
60,800 t y -1 annually. This represents 0.67% of the total sediment
load of the River , and is obviously too small a proportion to have
any significant or adverse impact on the River . This is consistent
with the Court’s conclusion in its Order of 13 December 2013
rejecting Nicaragua’s Request for Provisional Measures, in which it
noted that a contribution of sediment in the range of 1 to 2 per cent
of the total sediment load of the San Juan River “seems too small a
proportion to have a significant impact on the river in the immediate
future.”277
277 Construction of a Road in Costa Rica Along the San Juan River (Nicaragua v
Costa Rica), Request presented by Nicaragua for the Indication of Provisional
Measures, Order, 13 December 2013, para. 34.
92(c) At Delta Colorado, 10% of the San Juan enters to the Lower San
Juan River. It is reasonable to assume that 10% of the additi onal
sediment would enter the Lower San Juan (i.e 6,080 t y -1 per year).
Taking account of the bed area of the Lower San Juan, the average
increase in the rate of aggradation of the bed would be less than
-1
0.02 mm y – less than the diameter of a single gr ain of sand. This
could not have impacted navigation or caused Nicaragua to have to
dredge the River. As the Court noted in its Order of 13 December
2013, the Court has not been presented “with evidence as to any
long-term effect on the river by aggradatio ns of the river channel
allegedly caused by additional sediment from the construction on the
278
road.”
(d) As the Road is not delivering additional sediment to the River in
excessive concentration or any measurable quantity which would
cause any harm to the River, there is no evidence to suggest that
there has been any adverse impact on the water quality of the San
Juan.
(e) There has been no harm to the River in terms of channel
morphology.
(f) There is no evidence of any adverse impact on the ecosystem, nor on
tourism or health of riparians.
278 Construction of a Road in Costa Rica Along the San Juan River (Nicaragua v
Costa Rica), Request presented by Nicaragua for the Indication of Provisional
Measures, Order, 13 December 2013, para. 34.
9394 Chapter 4
The Treaty of Limits has no Bearing on the Present Proceedings
A. Introduction
4.1 In its Memorial, Nicaragua lists the 1858 Treaty of Limits, and the
arbitral awards and judicial decisions that have interpreted and applied it, as
the main applicable law to the present dispute. It devotes the first of two
chapters dealing with the alleged violations of international and domestic
law by Costa Rica – Chapter 4 of its Memorial – to these instruments, under
the rubric “Breaches of the Legal Regime of the San Juan de Nicaragua
River”. Indeed, Chapter 4 is presented as analysing “the law applicable to
279
the case”, the lex specialis prevailing over other obligations under general
international law, although these are also said to be relevant to the present
proceedings.
4.2 Obviously the 1858 Treaty of Limits is fundamental to the relations
between the Parties in the matter of the River; but that does not mean that it
deals with issues that it does not deal with. In truth, nothing in the 1858
Treaty of Limits, nor in its interpretation and application by different
adjudicative bodies, prevents Costa Rica from carrying out works on its
road infrastructure on its own territory. Contrary to what Nicaragua asserts,
undertaking road infrastructure works on Costa Rican terri tory in no way
violates Nicaraguan territorial sovereignty, nor prevents or impairs the right
to navigation by Nicaragua to the San Juan. Costa Rica’s position is that the
1858 Treaty of Limits has no bearing on the present proceedings.
Nicaragua’s real purpose of invoking the 1858 Treaty in this case appears to
279 NM, para. 1.13.
95 be to invent a purported justification for it to continue to impede Costa Rica
from exercising its free and perpetual right of navigation established by the
Treaty. 280
4.3 The present chapter will focus o n Nicaraguan efforts to construct
obligations purportedly stemming from the 1858 Treaty of Limits that are
said to have been “violated” by Costa Rica in undertaking the road works. It
will be shown that the instrument which Nicaragua considers the lex
specialis in this case has no bearing on the present proceedings.
4.4 The cardinal point is that the 1858 Treaty does not regulate road
infrastructure works on Costa Rican territory. Rather, it sets out limitations
to Nicaragua’s sovereignty over the waters of the San Juan River,
particularly the Costa Rican perpetual right of free navigation for purposes
of commerce and any planned canalisation. 281 It also establishes co -
imperium over the two bays in the border area in both oceans, and provides
for the common defence of the San Juan River. Beyond this, it is silent with
regard to the activities that Costa Rica may perform on its own territory.
B. Nothing in the 1858 Treaty of Limits prevents Costa Rica from
undertaking Road Infrastructure Works
4.5 It is true that the 1858 Treaty of Limits is not only a boundary
agreement: it also regulates different aspects of the conduct of the Parties in
280 See NM, paras. 6.35-6.42.
281
Further limitations were established by the 1888 Cleveland Award, including in respect of
works of improvement on the River: see NM, Vol. II, Annex 6, Award of the Arbitrator, the
President of the United States, upon the validity of the Treaty of Limits of 1858 between
Nicaragua and Costa Rica, reprinted in United Nations, Reports of International Arbitral
Awards, Vol. XXVIII (2006) pp. 207-211. The Award was given in English.
96be to invent a purported justification for it to continue to impede Costa Rica
from exercising its free and perpetual right of navigation established by the
Treaty. 280
4.3 The present chapter will focus o n Nicaraguan efforts to construct
obligations purportedly stemming from the 1858 Treaty of Limits that are
said to have been “violated” by Costa Rica in undertaking the road works. It
will be shown that the instrument which Nicaragua considers the lex
specialis in this case has no bearing on the present proceedings.
4.4 The cardinal point is that the 1858 Treaty does not regulate road
infrastructure works on Costa Rican territory. Rather, it sets out limitations
to Nicaragua’s sovereignty over the waters of the San Juan River,
particularly the Costa Rican perpetual right of free navigation for purposes
of commerce and any planned canalisation. 281 It also establishes co -
imperium over the two bays in the border area in both oceans, and provides
for the common defence of the San Juan River. Beyond this, it is silent with
regard to the activities that Costa Rica may perform on its own territory.
B. Nothing in the 1858 Treaty of Limits prevents Costa Rica from
undertaking Road Infrastructure Works
4.5 It is true that the 1858 Treaty of Limits is not only a boundary
agreement: it also regulates different aspects of the conduct of the Parties in
280 See NM, paras. 6.35-6.42.
281
Further limitations were established by the 1888 Cleveland Award, including in respect of
works of improvement on the River: see NM, Vol. II, Annex 6, Award of the Arbitrator, the
President of the United States, upon the validity of the Treaty of Limits of 1858 between
Nicaragua and Costa Rica, reprinted in United Nations, Reports of International Arbitral
Awards, Vol. XXVIII (2006) pp. 207-211. The Award was given in English. judgments prevents Costa Rica from constructing a road on its own
territory, or provides any other basis for Nicaragua’s claims here. Nicaragua
has not identified a sing le sentence either in the 1858 Treaty or in the
relevant arbitral awards or judgments that suggests the contrary.
(i) The alleged violation of Nicaraguan territorial sovereignty
4.7 Nicaragua refers in general terms to an alleged “violation of
Nicaraguan terr itorial sovereignty” or “to the fundamental principle of
territorial integrity of Nicaragua”. 286 Nicaragua’s submissions refer to the
“obligation not to violate the integrity of Nicaragua’s territory as delimited
by the 1858 Treaty of Limits, the Cleveland A ward of 1888 and the five
Awards of the Umpire EP Alexander of 30 September 1897, 20 December
287
1897, 22 March 1898, 26 July 1899 and 10 March 1900”. But Nicaragua
goes even further , referring to an alleged “invasion of Nicaraguan
territory”. 288These “invasions” and “assaults” were also referred to during
the hearings on the request for provisional measures made by Nicaragua. 289
4.8 The Memorial offers only a brief explanation why the road works on
Costa Rican territory constitute a violation of the territorial sovereignty or
integrity of Nicaragua, even an invasion of its territory. After quoting Max
Huber’s celebrated notion of territorial sovereignty in the Island of Palmas
arbitration, Nicaragua contends:
286 See NM, para. 4.28 and subtitle 1, p. 232, para. 6.14
287
NM, p. 251, Submission 1 (i).
288 NM, para. 4.13.
289
CR 2013/28, p. 24, para. 1 (McCaffrey); p. 28, par. 15 (McCaffrey); CR 2013/30, p. 16,
para. 2 (McCaffrey).
98judgments prevents Costa Rica from constructing a road on its own
territory, or provides any other basis for Nicaragua’s claims here. Nicaragua
has not identified a sing le sentence either in the 1858 Treaty or in the
relevant arbitral awards or judgments that suggests the contrary.
(i) The alleged violation of Nicaraguan territorial sovereignty
4.7 Nicaragua refers in general terms to an alleged “violation of
Nicaraguan terr itorial sovereignty” or “to the fundamental principle of
territorial integrity of Nicaragua”. 286 Nicaragua’s submissions refer to the
“obligation not to violate the integrity of Nicaragua’s territory as delimited
by the 1858 Treaty of Limits, the Cleveland A ward of 1888 and the five
Awards of the Umpire EP Alexander of 30 September 1897, 20 December
287
1897, 22 March 1898, 26 July 1899 and 10 March 1900”. But Nicaragua
goes even further , referring to an alleged “invasion of Nicaraguan
territory”.288 These “invasions” and “assaults” were also referred to during
the hearings on the request for provisional measures made by Nicaragua. 289
4.8 The Memorial offers only a brief explanation why the road works on
Costa Rican territory constitute a violation of the territorial sovereignty or
integrity of Nicaragua, even an invasion of its territory. After quoting Max
Huber’s celebrated notion of territorial sovereignty in the Island of Palmas
arbitration, Nicaragua contends:
286 See NM, para. 4.28 and subtitle 1, p. 232, para. 6.14
287
NM, p. 251, Submission 1 (i).
288 NM, para. 4.13.
289
CR 2013/28, p. 24, para. 1 (McCaffrey); p. 28, par. 15 (McCaffrey); CR 2013/30, p. 16,
para. 2 (McCaffrey). in Nicaragua’s final submissions. Indeed, in the relevant sub-section, the
alleged “breach of Nicaragua’s right of navigation” is merely described in
the following manner: “ The w orks for the construction of road 1856
constitute a serious threat on the navigation on the river – and not only in
293
the short term”.
4.11 A g reat leap of imagination is required to follow Nicaragua’s
assertion that the road works constitute a violation of the navigational rights
of Nicaragua over the San Juan River emanating from the 1858 Treaty of
Limits. Indeed, what Nicaragua first categorized as a “breach” became soon
just a “threat”. On Nicaragua’s own case, there has been no impediment by
Costa Rica to th e navigation of the San Juan. In fact, there is not even the
slightest “threat”, by action or by implication, to navigation. As explained in
Chapter 3 of this Counter-Memorial, the construction works and use of the
road in no way impact upon the navigational conditions of the River.
4.12 During the hearings on Nicaragua’s request for provisional
measures, it submitted evidence that “[t]he San Juan River MARENA
Delegation implements monthly waterway patrolling on the San Juan River
with the participation of MAREN A forest rangers and technical specialists
accompanied by the Army of Nicaragua” .294 At no time has Nicaragua
contended that this regular patrolling has been rendered more difficult, or
indeed affected in any way, by the alleged “catastrophic” effects of the
293
NM, para. 4.15 (emphasis added).
294 Vol 3 , Annex No 18, Nicaragua, Ministry of Environment and Natural Resources
(MARENA), San Juan River Territorial Delegation, Technical Waterway Patrol on the San
Juan River on October, 27 2013, annexed to the Letter to the Registrar of the Court from
His Excellency Carlos Argüello Gomez, Agent of the Republic of Nicaragua, Reference
HOL-EMB-220, 31 October 2013, p. 1.
100in Nicaragua’s final submissions. Indeed, in the relevant sub-section, the
alleged “breach of Nicaragua’s right of navigation” is merely described in
the following manner: “ The w orks for the construction of road 1856
constitute a serious threat on the navigation on the river – and not only in
293
the short term”.
4.11 A g reat leap of imagination is required to follow Nicaragua’s
assertion that the road works constitute a violation of the navigational rights
of Nicaragua over the San Juan River emanating from the 1858 Treaty of
Limits. Indeed, what Nicaragua first categorized as a “breach” became soon
just a “threat”. On Nicaragua’s own case, there has been no impediment by
Costa Rica to th e navigation of the San Juan. In fact, there is not even the
slightest “threat”, by action or by implication, to navigation. As explained in
Chapter 3 of this Counter-Memorial, the construction works and use of the
road in no way impact upon the navigational conditions of the River.
4.12 During the hearings on Nicaragua’s request for provisional
measures, it submitted evidence that “[t]he San Juan River MARENA
Delegation implements monthly waterway patrolling on the San Juan River
with the participation of MAREN A forest rangers and technical specialists
accompanied by the Army of Nicaragua” .294 At no time has Nicaragua
contended that this regular patrolling has been rendered more difficult, or
indeed affected in any way, by the alleged “catastrophic” effects of the
293
NM, para. 4.15 (emphasis added).
294 Vol 3 , Annex No 18, Nicaragua, Ministry of Environment and Natural Resources
(MARENA), San Juan River Territorial Delegation, Technical Waterway Patrol on the San
Juan River on October, 27 2013, annexed to the Letter to the Registrar of the Court from
His Excellency Carlos Argüello Gomez, Agent of the Republic of Nicaragua, Reference
HOL-EMB-220, 31 October 2013, p. 1. navigation, Nicaragua failed to refer to the first part of the Court’s analysis,
which reads:
“The Treaty imposes no express general obligation on either
of the Parties to notify the other about measures it i s taking
relating to navigation on the river. It contains a requirement of
agreement in Article VI and a requirement of consultation in
Article VIII which imply prior contact between the Parties.
Under Article VI the two Parties are required to agree if they
wish to impose any taxes in the situation contemplated by that
provision. Under Article VIII, if the Government of
Nicaragua is proposing to enter into an arrangement for
canalization or transit on the San Juan, it must first consult
with the Government of Costa Rica about the disadvantages
the project might occasion between the two Parties.” 296
Hence, the Treaty contains precise provisions related to different levels of
mutual conduct with regard to different topics, ranging from contact and
consultation to agreement. None of these refers to activities such as the road
infrastructure projects on Costa Rican territory.
4.16 Third, in spite of the absence of any specific provision in the Treaty,
the Court found that an obligation to notify exists on the basis of three
factors:
• the 1956 Agreement to facilitate and expedite traffic on the Pan
American Highway and on the San Juan River;
• the very subject-matter of regulation: “navigation on a river in which
two States have rights” and “the practical necessities of navigation
296 Dispute regarding Navigatio nal and Related Rights (Costa Rica v Nicaragua), Judgment,
I C J Reports 2009, p. 251, para. 93.
102navigation, Nicaragua failed to refer to the first part of the Court’s analysis,
which reads:
“The Treaty imposes no express general obligation on either
of the Parties to notify the other about measures it i s taking
relating to navigation on the river. It contains a requirement of
agreement in Article VI and a requirement of consultation in
Article VIII which imply prior contact between the Parties.
Under Article VI the two Parties are required to agree if they
wish to impose any taxes in the situation contemplated by that
provision. Under Article VIII, if the Government of
Nicaragua is proposing to enter into an arrangement for
canalization or transit on the San Juan, it must first consult
with the Government of Costa Rica about the disadvantages
the project might occasion between the two Parties.” 296
Hence, the Treaty contains precise provisions related to different levels of
mutual conduct with regard to different topics, ranging from contact and
consultation to agreement. None of these refers to activities such as the road
infrastructure projects on Costa Rican territory.
4.16 Third, in spite of the absence of any specific provision in the Treaty,
the Court found that an obligation to notify exists on the basis of three
factors:
• the 1956 Agreement to facilitate and expedite traffic on the Pan
American Highway and on the San Juan River;
• the very subject-matter of regulation: “navigation on a river in which
two States have rights” and “the practical necessities of navigation
296 Dispute regarding Navigatio nal and Related Rights (Costa Rica v Nicaragua), Judgment,
I C J Reports 2009, p. 251, para. 93. 4.19 In its submissions Nicaragua “only” requests the Court to allow it to
299
“suspend” Costa Rica’s perpetual right of free navigation. But whether it
takes the form of loss or suspension of rights, the substance is much the
same: Nicaragua’s claim entails a substantial rejection of one of the
essential bases of the fundamental instrument between the two countries.
The condition for Costa Rica’s acceptance of Nicaraguan sovereignty over
the entire waters of the San Juan River was precisely recognition of Costa
Rica’s perpetual right of free navigation for commercial purposes. Such a
claim is unfounded both in law and in fact.
D. Conclusions
4.20 To summarize:
(a) the road infrastructure works carried out on undisputed Costa Rican
territory in no way infringe the boundary delimited by the 1858
Treaty of Limits, let alone Nicaraguan sovereignty or territorial
integrity;
(b) the road infrastructure works undertaken by Costa Rica on Costa
Rican territory in no way impede or otherwise impact upon the
exercise of any navigational rights of Nicaragua stemming from the
1858 Treaty or otherwise;
(c) there is no obligation on Costa Rica to notify road infrastructure
works undertaken on its territory by virtue of the 1858 Treaty of
Limits; and
299 NM, p. 252, Submission 3(i).
1044.19 In its submissions Nicaragua “only” requests the Court to allow it to
299
“suspend” Costa Rica’s perpetual right of free navigation. But whether it
takes the form of loss or suspension of rights, the substance is much the
same: Nicaragua’s claim entails a substantial rejection of one of the
essential bases of the fundamental instrument between the two countries.
The condition for Costa Rica’s acceptance of Nicaraguan sovereignty over
the entire waters of the San Juan River was precisely recognition of Costa
Rica’s perpetual right of free navigation for commercial purposes. Such a
claim is unfounded both in law and in fact.
D. Conclusions
4.20 To summarize:
(a) the road infrastructure works carried out on undisputed Costa Rican
territory in no way infringe the boundary delimited by the 1858
Treaty of Limits, let alone Nicaraguan sovereignty or territorial
integrity;
(b) the road infrastructure works undertaken by Costa Rica on Costa
Rican territory in no way impede or otherwise impact upon the
exercise of any navigational rights of Nicaragua stemming from the
1858 Treaty or otherwise;
(c) there is no obligation on Costa Rica to notify road infrastructure
works undertaken on its territory by virtue of the 1858 Treaty of
Limits; and
299 NM, p. 252, Submission 3(i).106 Chapter 5
Alleged Breaches of Obligations in respect of the Environment
A. Introduction
5.1 Chapter 5 of Nic aragua’s Memorial is devoted to alleged Costa
Rican breaches of its environmental obligations , namely the obligations “to
assess the environmental impact o f the road, on both the na tional and
transboundary level”, “to provide prior notification to Nicaragua” and “not
to cause significant transboundary harm”. In this context, Costa Rica is said
to have breached a broad range of treaties and international instruments
through the construction of the Road.
5.2 This C hapter will show that none of the alleged breaches are
grounded in law or in fact . Before turning to the details, Costa Rica makes
four observations of an introductory kind.
5.3 First, Nicaragua has not contested the fact that the work carried out
by Costa Rica to improve its road infrastructure in the border area has been
conducted exclusively within Costa Rica’s territory. In this respect, the
decision to undertake road infrastructure work on its own terri tory is a
sovereign decision of any State. Thus, the starting point in terms of
considering the alleged breaches is that Costa Rica, as any other State, is
free to make its own appraisal of its own security and communicational
needs, and the best means to implement those needs within its territory. The
reasons for improving infrastructure, as a sovereign decision, need not be
explained or justified at the international level, and still less to a
neighbouring State that has recently occupied and claimed part of Costa
107 Rica’s territory, as established by a treaty (the Treaty of Limits) that has
been in force for more than one and a half centuries.
5.4 Secondly, and following on from the above, Nicaragua’s case is not
assisted by allegations that the construction wo rks on the Road were poorly
planned or implemented or had adverse impacts to the environment on
300
Costa Rican territory. Even if correct, those are matters internal to Costa
Rica.
5.5 Thirdly, underlying the rules relating to transboundary
environmental harm t here is a general principle relating to cooperation
between neighbouring countries. Given that the current claim is to be heard
alongside the Certain Activities case, Costa Rica makes the point that
Nicaragua is currently relying on a series of obligationsthat it has ignored in
the context of Certain Activities . Far from cooperating there, Nicaragua
undertook activities in the border area (in a river over which Costa Rica
possesses rights) not only likely to produce significant adverse
transboundary effects on Costa Rican territory, particularly on the Colorado
River, but with the very intention of doing so. Far from cooperating with its
neighbour, Nicaragua entered onto Costa Rican territory and carried out
works in order to transform the river basin, by unlawfully constructing an
artificial caño across Costa Rican territory in 2010, and (as the Court has
now confirmed) two more artificial caños in 2013.
5.6 Finally, and notwithstanding Nicaragua’s discrepant conduct, when
it comes to the key legal principles that apply in respect of actual or
potential transboundary environmental impact, t here appears to be little if
300
Cf. NM, paras. 5.11-5.13.
108Rica’s territory, as established by a treaty (the Treaty of Limits) that has
been in force for more than one and a half centuries.
5.4 Secondly, and following on from the above, Nicaragua’s case is not
assisted by allegations that the construction wo rks on the Road were poorly
planned or implemented or had adverse impacts to the environment on
300
Costa Rican territory. Even if correct, those are matters internal to Costa
Rica.
5.5 Thirdly, underlying the rules relating to transboundary
environmental harm t here is a general principle relating to cooperation
between neighbouring countries. Given that the current claim is to be heard
alongside the Certain Activities case, Costa Rica makes the point that
Nicaragua is currently relying on a series of obligationsthat it has ignored in
the context of Certain Activities . Far from cooperating there, Nicaragua
undertook activities in the border area (in a river over which Costa Rica
possesses rights) not only likely to produce significant adverse
transboundary effects on Costa Rican territory, particularly on the Colorado
River, but with the very intention of doing so. Far from cooperating with its
neighbour, Nicaragua entered onto Costa Rican territory and carried out
works in order to transform the river basin, by unlawfully constructing an
artificial caño across Costa Rican territory in 2010, and (as the Court has
now confirmed) two more artificial caños in 2013.
5.6 Finally, and notwithstanding Nicaragua’s discrepant conduct, when
it comes to the key legal principles that apply in respect of actual or
potential transboundary environmental impact, t here appears to be little if
300
Cf. NM, paras. 5.11-5.13. (1) Threshold requirements in respect of the obligation to conduct an
environmental impact assessment
5.8 It is recalled that, pursuant to Article 14(1) of the Convention on
Biological Diversity:
“Each Contracting Party, as far as possible and as appropriate, shall:
(a) Introduce appropriate procedures requiring environmental
impact assessment of its proposed projects that are likely to have
significant adverse effects on biological diversity with a view to
avoiding or minimizing such effe cts and, where appropriate, allow
for public participation in such procedures; …”
5.9 The obligation under Article 14(1) is thus qualified in various ways,
and notably applies only in respect of “ proposed projects that are likely to
have significant adverse ef fect”. There is thus a threshold of likelihood of
significant adverse effect that applies.
5.10 To similar effect, the Court in the Pulp Mills case stated that:
“ … it may now be considered a requirement under general
international law to undertake an environm ental impact assessment
where there is a risk that the proposed industrial activity may have a
significant adverse impact in a transboundary context , in particular,
on a shared resource. Moreover, due diligence, and the duty of
vigilance and prevention whi ch it implies, would not be considered
to have been exercised, if a party planning works liable to affect the
régime of the river or the quality of its waters did not undertake an
environm305al impact assessment on the potential effects of such
works.” (Emphasis added.)
305
Pulp Mills on the River Uruguay (Argentina v Uruguay), Judgment, I C J Reports
2010, p. 83, para. 204.
110(1) Threshold requirements in respect of the obligation to conduct an
environmental impact assessment
5.8 It is recalled that, pursuant to Article 14(1) of the Convention on
Biological Diversity:
“Each Contracting Party, as far as possible and as appropriate, shall:
(a) Introduce appropriate procedures requiring environmental
impact assessment of its proposed projects that are likely to have
significant adverse effects on biological diversity with a view to
avoiding or minimizing such effe cts and, where appropriate, allow
for public participation in such procedures; …”
5.9 The obligation under Article 14(1) is thus qualified in various ways,
and notably applies only in respect of “ proposed projects that are likely to
have significant adverse ef fect”. There is thus a threshold of likelihood of
significant adverse effect that applies.
5.10 To similar effect, the Court in the Pulp Mills case stated that:
“ … it may now be considered a requirement under general
international law to undertake an environm ental impact assessment
where there is a risk that the proposed industrial activity may have a
significant adverse impact in a transboundary context , in particular,
on a shared resource. Moreover, due diligence, and the duty of
vigilance and prevention whi ch it implies, would not be considered
to have been exercised, if a party planning works liable to affect the
régime of the river or the quality of its waters did not undertake an
environm305al impact assessment on the potential effects of such
works.” (Emphasis added.)
305
Pulp Mills on the River Uruguay (Argentina v Uruguay), Judgment, I C J Reports
2010, p. 83, para. 204. (2) Environmental impact assessment in the particular context of an
emergency
5.13 The Pulp Mills case does not address directly the issue of conduct of
an environmental impact assessment in the context of an emergency.
However, as follows from the general principles as reflected in Pulp Mills ,
this issue must be approached by reference to the domestic law of t he State
concerned. In this respect, the Court stated:
“… it is the view of the Court that it is for each State to determine in
its domestic legislation or in the authorization process for the
project, the specific content of the environmental impact assessment
required in each case, having regard to the nature and magnitude of
the proposed development and its likely adverse impact on the
environment as well as to the need to exercise due diligence in
conducting such an assessment. The Court also considers that an
environmental impact assessment must be conducted prior to the
implementation of a project. Moreover, once operations have started
and, where necessary, throughout the life of the project, continuous
307
monitoring of its effects on the environment shall be undertaken.”
5.14 It is thus left to domestic law to define the specific content of the
assessment that is required in each individual case. Consistent with this and
with the qualifications in the wording of Article 14(1) of the Convention on
Biological Diversity (“ as far as possible and as appropriate ”), where in an
exceptional case domestic law establishes that there is no requirement to
carry out an assessment because of an emergency, general international law
must likewise recognise th is aspect of domestic law. It is not a requirement
of international law that a pro forma environmental impact assessment be
307 Pulp Mills on the River Uruguay (Argentina v Uruguay), Judgment, I C J Reports
2010, pp. 83-84, para. 205.
112(2) Environmental impact assessment in the particular context of an
emergency
5.13 The Pulp Mills case does not address directly the issue of conduct of
an environmental impact assessment in the context of an emergency.
However, as follows from the general principles as reflected in Pulp Mills ,
this issue must be approached by reference to the domestic law of t he State
concerned. In this respect, the Court stated:
“… it is the view of the Court that it is for each State to determine in
its domestic legislation or in the authorization process for the
project, the specific content of the environmental impact assessment
required in each case, having regard to the nature and magnitude of
the proposed development and its likely adverse impact on the
environment as well as to the need to exercise due diligence in
conducting such an assessment. The Court also considers that an
environmental impact assessment must be conducted prior to the
implementation of a project. Moreover, once operations have started
and, where necessary, throughout the life of the project, continuous
307
monitoring of its effects on the environment shall be undertaken.”
5.14 It is thus left to domestic law to define the specific content of the
assessment that is required in each individual case. Consistent with this and
with the qualifications in the wording of Article 14(1) of the Convention on
Biological Diversity (“ as far as possible and as appropriate ”), where in an
exceptional case domestic law establishes that there is no requirement to
carry out an assessment because of an emergency, general international law
must likewise recognise th is aspect of domestic law. It is not a requirement
of international law that a pro forma environmental impact assessment be
307 Pulp Mills on the River Uruguay (Argentina v Uruguay), Judgment, I C J Reports
2010, pp. 83-84, para. 205. explained in Chapter 3 above, Costa Rica has carried out the Environmental
Diagnostic Assessment (Annex 10 hereto), a lengthy and detailed report that
has identified impacts and risks associated with construction of the Road,
and that has also recommended env ironmental control measures necessary
to prevent or to mitigate such impacts and risks . If, which is not accepted,
there is any form of international law obligation to conduct an
environmental impact assessment on the very particular facts of this case,
that obligation has been satisfied by complet ion of the Environmental
Diagnostic Assessment.
5.17 Finally, it is to be recalled that this case is all the more exceptional in
light of the fact that it is the State complaining of the lack of an
environmental impac t assessment that, through its own unlawful acts,
created the emergency leading to the very activities that are said to be
unlawful due to the lack of assessment.
5.18 On Nicaragua’s view of the law, a State precipitating an emergency
(or what is reasonably pe rceived as such) is to be accorded important
elements of control over the response to that emergency – through the
affected State having to delay its response in order to conduct an
environmental impact assessment as well as engaging in alleged obligations
of notification and consultation. On the particular facts of this case, this
would amount to Nicaragua seeking to rely on an alleged breach that stems
from its own wrong (cf. ex turpi causa non oritur actio). 312
312
Cf. Gabčíkovo/Nagymaros Project (Hungary/Slovakia), Judgment, I C J Reports
1997, p. 67, para. 110.
114explained in Chapter 3 above, Costa Rica has carried out the Environmental
Diagnostic Assessment (Annex 10 hereto), a lengthy and detailed report that
has identified impacts and risks associated with construction of the Road,
and that has also recommended env ironmental control measures necessary
to prevent or to mitigate such impacts and risks . If, which is not accepted,
there is any form of international law obligation to conduct an
environmental impact assessment on the very particular facts of this case,
that obligation has been satisfied by complet ion of the Environmental
Diagnostic Assessment.
5.17 Finally, it is to be recalled that this case is all the more exceptional in
light of the fact that it is the State complaining of the lack of an
environmental impac t assessment that, through its own unlawful acts,
created the emergency leading to the very activities that are said to be
unlawful due to the lack of assessment.
5.18 On Nicaragua’s view of the law, a State precipitating an emergency
(or what is reasonably pe rceived as such) is to be accorded important
elements of control over the response to that emergency – through the
affected State having to delay its response in order to conduct an
environmental impact assessment as well as engaging in alleged obligations
of notification and consultation. On the particular facts of this case, this
would amount to Nicaragua seeking to rely on an alleged breach that stems
from its own wrong (cf. ex turpi causa non oritur actio). 312
312
Cf. Gabčíkovo/Nagymaros Project (Hungary/Slovakia), Judgment, I C J Reports
1997, p. 67, para. 110. C. Notification
5.20 Nicaragua’s case on breach of an alleged obligation of notification
315
fails for the same basic reasons, i.e. the relevant threshold is not met . In
any event the alleged obligation does not apply in a context where the State
claiming a right to be notified has itself precipitated an emergency that is
being responded to.
5.21 In addition, in this context, Nicaragua relies on materials that are
irrelevant, i.e. the ILC’s draft A rticles on Prevention of Transboundary
Harm from Hazardous Activities, 316 or inapplicable even on Nicaragua’s
submissions, i.e. the 1997 United Nations Convention on the Non -
Navigational Uses of International Waterways . 317The latter is relied upon
merely on the basis that its articles “provide an indication of how the
318
notification should properly unfold”, and not on the basis that these
reflect customary international law. It is not explained how rules that are
intended to apply under general circumstances are to be applied in very
particular circumstances where it was Nicaragua itself, the other riparian of
International Court of Justice, Reference ECRPB -052-13, 7 August 2013; Vol 3,
Annex No 60, Letter from Registrar of the International Court of Justice to Agent
of Costa Rica, Reference 142331, 8 August 2013; Vol 3, Annex No 64 , Letter
from Agent of Nicaragua to Registrar of the International Court of Justice,
Reference HOL-EMB-167, 30 August 2013; Vol 3, Annex No 65, Letter from Co-
Agent of Costa Rica to Registrar of the International Court of Justice, Reference
ECRPB-63-2013, 27 September 2013; and Vol 3, Annex No 6 6, Letter from
Registrar of the International Court of Justice to Agent of Costa Rica, Reference
142549, 27 September 2013.
315 Cf. NM, para. 5.45 (relying on Principle 19 of the 1992 Rio Declaration), and
para. 5.46 (relying on Article 3 of the Espoo Convention).
316 NM, para. 5.47.
317
NM, para. 5.48.
318 Ibid.
116 C. Notification
5.20 Nicaragua’s case on breach of an alleged obligation of notification
315
fails for the same basic reasons, i.e. the relevant threshold is not met . In
any event the alleged obligation does not apply in a context where the State
claiming a right to be notified has itself precipitated an emergency that is
being responded to.
5.21 In addition, in this context, Nicaragua relies on materials that are
irrelevant, i.e. the ILC’s draft A rticles on Prevention of Transboundary
Harm from Hazardous Activities, 316 or inapplicable even on Nicaragua’s
submissions, i.e. the 1997 United Nations Convention on the Non -
Navigational Uses of International Waterways . 317The latter is relied upon
merely on the basis that its articles “provide an indication of how the
318
notification should properly unfold”, and not on the basis that these
reflect customary international law. It is not explained how rules that are
intended to apply under general circumstances are to be applied in very
particular circumstances where it was Nicaragua itself, the other riparian of
International Court of Justice, Reference ECRPB -052-13, 7 August 2013; Vol 3,
Annex No 60, Letter from Registrar of the International Court of Justice to Agent
of Costa Rica, Reference 142331, 8 August 2013; Vol 3, Annex No 64 , Letter
from Agent of Nicaragua to Registrar of the International Court of Justice,
Reference HOL-EMB-167, 30 August 2013; Vol 3, Annex No 65, Letter from Co-
Agent of Costa Rica to Registrar of the International Court of Justice, Reference
ECRPB-63-2013, 27 September 2013; and Vol 3, Annex No 6 6, Letter from
Registrar of the International Court of Justice to Agent of Costa Rica, Reference
142549, 27 September 2013.
315 Cf. NM, para. 5.45 (relying on Principle 19 of the 1992 Rio Declaration), and
para. 5.46 (relying on Article 3 of the Espoo Convention).
316 NM, para. 5.47.
317
NM, para. 5.48.
318 Ibid. 320
significant harm. The difficulty with this is that, as follows from Chapter
3 above, Nicaragua c omes nowhere near establishing breach of either of
those provisions.
5.24 It is also to be noted that the alleged failure is purely formalistic in
nature. At the same time as alleging a failure to notify, Nicaragua states that
it was well aware of construction of the Road (on this point at least, it can
readily be believed, given the highly militarised ch aracter of Nicaragua’s
321
presence along the River). To similar effect, it complains of the failure to
provide “any environmental impact assessment” while at the same time
322
saying that none existed. It is as if the provisions of the 1997 Convention
had been developed to enable a point-scoring exercise.
D. Alleged significant transboundary harm
5.25 The allegation of significant transboundary harm is not made out on
the evidence, and it is notable that , as follows from C hapter 3 above, the
allegation was made without the detailed consideration of impact on the Río
San Juan’s existing sediment load that constitutes the obvious prerequisite
to any serious case on harm. It is also notable that the high water mark of
Nicaragua’s case here is the CACJ “J udgment” of 21 June 2012, 323 despite
this being a case made by a court without jurisdiction, without reference to
scientific evidence, and without of course Costa Rica before it.
320 NM, para. 5.48.
321 NM, para. 5.50.
322
NM, para. 5.49.
323 NM, para. 5.62.
118 320
significant harm. The difficulty with this is that, as follows from Chapter
3 above, Nicaragua c omes nowhere near establishing breach of either of
those provisions.
5.24 It is also to be noted that the alleged failure is purely formalistic in
nature. At the same time as alleging a failure to notify, Nicaragua states that
it was well aware of construction of the Road (on this point at least, it can
readily be believed, given the highly militarised ch aracter of Nicaragua’s
321
presence along the River). To similar effect, it complains of the failure to
provide “any environmental impact assessment” while at the same time
322
saying that none existed. It is as if the provisions of the 1997 Convention
had been developed to enable a point-scoring exercise.
D. Alleged significant transboundary harm
5.25 The allegation of significant transboundary harm is not made out on
the evidence, and it is notable that , as follows from C hapter 3 above, the
allegation was made without the detailed consideration of impact on the Río
San Juan’s existing sediment load that constitutes the obvious prerequisite
to any serious case on harm. It is also notable that the high water mark of
Nicaragua’s case here is the CACJ “J udgment” of 21 June 2012, 323 despite
this being a case made by a court without jurisdiction, without reference to
scientific evidence, and without of course Costa Rica before it.
320 NM, para. 5.48.
321 NM, para. 5.50.
322
NM, para. 5.49.
323 NM, para. 5.62. 5.29 As to Article 14(1), Nicaragua relies on sub- articles (a) to (c ),27
which are as follows:
“1. Each Contracting Party, as far as possible and as appropriate,
shall:
(a) Introduce appropriate proce dures requiring environmental
impact assessment of its proposed projects that are likely to have
significant adverse effects on biological diversity with a view to
avoiding or minimizing such effects and, where appropriate, allow
for public participation in such procedures;
(b) Introduce appropriate arrangements to ensure that the
environmental consequences of its programmes and policies that are
likely to have significant adverse impacts on biological diversity are
duly taken into account;
(c) Promote, on the basis of reciprocity, notification, exchange
of information and consultation on activities under their jurisdiction
or control which are likely to significantly affect adversely the
biological diversity of other States or areas beyond the jurisdiction ,
by encouraging the conclusion of bilateral, regional or multilateral
arrangements, as appropriate;”.
5.30 There has been no breach of general international law obligations
with respect to conduct of an environmental impact assessment, as
established in Section B above. As to specific obligations that might be seen
to arise under Article 14 (a) and (b) , these provisions concern the
introduction of appropriate procedures and arrangements with respect to
proposed projects , programmes and policies that are likely t o have
(e) Promote environmentally sound and sustainable development in areas adjacent
to protected areas with a view to furthering protection of these areas;
(f) Rehabilitate and restore degraded ecosystems and prome the recovery of
threatened species, inter alia, through the development and implementation of
plans or other management strategies; …”
327
NM, paras. 5.71-5.72.
1205.29 As to Article 14(1), Nicaragua relies on sub- articles (a) to (c ),27
which are as follows:
“1. Each Contracting Party, as far as possible and as appropriate,
shall:
(a) Introduce appropriate proce dures requiring environmental
impact assessment of its proposed projects that are likely to have
significant adverse effects on biological diversity with a view to
avoiding or minimizing such effects and, where appropriate, allow
for public participation in such procedures;
(b) Introduce appropriate arrangements to ensure that the
environmental consequences of its programmes and policies that are
likely to have significant adverse impacts on biological diversity are
duly taken into account;
(c) Promote, on the basis of reciprocity, notification, exchange
of information and consultation on activities under their jurisdiction
or control which are likely to significantly affect adversely the
biological diversity of other States or areas beyond the jurisdiction ,
by encouraging the conclusion of bilateral, regional or multilateral
arrangements, as appropriate;”.
5.30 There has been no breach of general international law obligations
with respect to conduct of an environmental impact assessment, as
established in Section B above. As to specific obligations that might be seen
to arise under Article 14 (a) and (b) , these provisions concern the
introduction of appropriate procedures and arrangements with respect to
proposed projects , programmes and policies that are likely t o have
(e) Promote environmentally sound and sustainable development in areas adjacent
to protected areas with a view to furthering protection of these areas;
(f) Rehabilitate and restore degraded ecosystems and promoe the recovery of
threatened species, inter alia, through the development and implementation of
plans or other management strategies; …”
327
NM, paras. 5.71-5.72. wetlands falling within the Ramsar Convention, while it leads to no ri sk of
significant harm to the Río San Juan, let alone protected wetlands i n
Nicaragua. For this reason, Nicaragua’s reliance on this Convention in the
present case is misconceived.
5.33 For completeness, it is noted that a 22 km section of the Road is
constructed on a site declared by Costa Rica as a protected wetland. Costa
Rica has consequently notified the Secretariat of the Ramsar Convention. 329
(3) Alleged breaches of the Central American Convention for the
Protection of the Environment and other regional instruments
5.34 Nicaragua contends that construction of the Road is incompatibl e
with the “regional system of cooperation for the optimal and rational use of
the region’s natural resources” that is established by Article I of the Central
American Convention for the P rotection of Envir onment, and “flies in the
face” of the objectives of that system of cooperation, which are as spelled
330
out in Article II of that Convention.
5.35 This Convention is of no relevance to the present dispute, as is
reflected by Nicaragua’s failure to set out and detail alleged breaches of any
specific provision. Rather, Nicaragua makes the unsubstantiated assertions
summarised above. The Memorial also refers to the establishment of the
329 Vol 3, Annex No 43, Note from Minister of Foreign Relations and Worship, Costa
Rica, to Secretary General of the Ramsar Convention, Reference DM- 110-12, 28
February 2012; Vol 3, Annex No 44 , Note from Secretary General of the Ramsar
Convention to the Minister of Foreign Relations and Worship, Costa Rica, 6 June
2012.
330 NM, paras. 5.81 -5.84. See e.g. Article II(a) of the Convention, establishheg t
objective: “To instil respect for and protect the region’s natural heritage, which is
characterized by its high level of biological and ecological diversity.”
122wetlands falling within the Ramsar Convention, while it leads to no ri sk of
significant harm to the Río San Juan, let alone protected wetlands i n
Nicaragua. For this reason, Nicaragua’s reliance on this Convention in the
present case is misconceived.
5.33 For completeness, it is noted that a 22 km section of the Road is
constructed on a site declared by Costa Rica as a protected wetland. Costa
Rica has consequently notified the Secretariat of the Ramsar Convention. 329
(3) Alleged breaches of the Central American Convention for the
Protection of the Environment and other regional instruments
5.34 Nicaragua contends that construction of the Road is incompatibl e
with the “regional system of cooperation for the optimal and rational use of
the region’s natural resources” that is established by Article I of the Central
American Convention for the P rotection of Envir onment, and “flies in the
face” of the objectives of that system of cooperation, which are as spelled
330
out in Article II of that Convention.
5.35 This Convention is of no relevance to the present dispute, as is
reflected by Nicaragua’s failure to set out and detail alleged breaches of any
specific provision. Rather, Nicaragua makes the unsubstantiated assertions
summarised above. The Memorial also refers to the establishment of the
329 Vol 3, Annex No 43, Note from Minister of Foreign Relations and Worship, Costa
Rica, to Secretary General of the Ramsar Convention, Reference DM- 110-12, 28
February 2012; Vol 3, Annex No 44 , Note from Secretary General of the Ramsar
Convention to the Minister of Foreign Relations and Worship, Costa Rica, 6 June
2012.
330 NM, paras. 5.81 -5.84. See e.g. Article II(a) of the Convention, establishheg t
objective: “To instil respect for and protect the region’s natural heritage, which is
characterized by its high level of biological and ecological diversity.” “The phased, specific and progressive nature of the process of
economic integration, based on harmonious and balanced regional
development, with special treatment for relatively less developed
Member States, and on equi ty and reciprocity, and the Central
American Exception Clause.”
333
That principle is evidently of no relevance to the current claim.
5.37 There is likewise no tenable basis to the assertion that works on the
Road are contrary to Article 6 of the Protocol on the basis that they “may
endanger the attainment of the objectives and compliance with the
fundamental principles of the Central American Integration System”. 334
Such assertions are frivolous.
5.38 Nicaragua alleges breach of obligations of no harm, cooperation and
conservation said to arise under the 1992 Convention for the Conservation
of Biodiversity and the Protection of Wilderness Areas in Central
America. 335 To the extent that the provisions relied on by Nicaragua impose
obligations on Costa Rica, Nicaragua’s cas e under this Convention fails for
equivalent reasons to those identified above in relation to the Convention on
Biological Diversity and the Ramsar Convention.
333 Nicaragua also refers to Article 4(h) of the Protocol, which establishes as a
fundamental principle: “Good faith on the part of the Member States in the
discharge of their obligations; Member States shall abstain from establishing,
agreeing to or adopting any measure that contravenes the provisions of this
instrument or that impedes compliance with the fundamental principles of the
Central American Integration System or the attainment of its objectives.” See NM,
para. 5.88. It is unclear what Nicaragua seeks to derive from this.
334 Pursuant to Article 6 of the Protocol:The Members of the Central American
Integration System shall be those Central American States that fully accept the
obligations set forth in this Charter by means of their approval or ratification
thereof or accession hereto, and that implement this Charter in accordance with the
provisions of article 36 hereof.”
335 NM, paras. 5.93-5.98.
124 “The phased, specific and progressive nature of the process of
economic integration, based on harmonious and balanced regional
development, with special treatment for relatively less developed
Member States, and on equi ty and reciprocity, and the Central
American Exception Clause.”
333
That principle is evidently of no relevance to the current claim.
5.37 There is likewise no tenable basis to the assertion that works on the
Road are contrary to Article 6 of the Protocol on the basis that they “may
endanger the attainment of the objectives and compliance with the
fundamental principles of the Central American Integration System”. 334
Such assertions are frivolous.
5.38 Nicaragua alleges breach of obligations of no harm, cooperation and
conservation said to arise under the 1992 Convention for the Conservation
of Biodiversity and the Protection of Wilderness Areas in Central
America. 335 To the extent that the provisions relied on by Nicaragua impose
obligations on Costa Rica, Nicaragua’s cas e under this Convention fails for
equivalent reasons to those identified above in relation to the Convention on
Biological Diversity and the Ramsar Convention.
333 Nicaragua also refers to Article 4(h) of the Protocol, which establishes as a
fundamental principle: “Good faith on the part of the Member States in the
discharge of their obligations; Member States shall abstain from establishing,
agreeing to or adopting any measure that contravenes the provisions of this
instrument or that impedes compliance with the fundamental principles of the
Central American Integration System or the attainment of its objectives.” See NM,
para. 5.88. It is unclear what Nicaragua seeks to derive from this.
334 Pursuant to Article 6 of the Protocol:The Members of the Central American
Integration System shall be those Central American States that fully accept the
obligations set forth in this Charter by means of their approval or ratification
thereof or accession hereto, and that implement this Charter in accordance with the
provisions of article 36 hereof.”
335 NM, paras. 5.93-5.98. F. Conclusions
5.41 To summarize:
(a) Costa Rica has not breached any obligation to carry out an
environmental impact assessment. The threshold requirement of
significant adverse impact is not met, and therefore there is n o
obligation to carry out any such assessment. Moreover, Nicaragua’s
argument to the contrary ignores the pressing circumstances in
which the Road was constructed which, under Costa Rican law (as to
which see the renvoi under international law), exempted C osta Rica
from having to carry out an impact assessment in advance.
(b) Costa Rica has not breached any obligation to notify Nicaragua.
Again, the threshold requirement of significant adverse impact is not
met and therefore Costa Rica was not obliged to notif y Nicaragua.
Nicaragua relies on instruments that are either irrelevant or
inapplicable, and again it ignores the emergency circumstances in
which the Road was constructed.
(c) Nicaragua has failed to demonstrate that the Road has caused any
significant transboundary harm, or that there is any potential for any
such significant harm.
(d) Costa Rica has not breached any obligations under any other treaty
invoked by Nicaragua (including the Convention on Biological
Diversity, the Ramsar Convention, the Central American Convention
for the Protection of the Environment, and the SI -A-PAZ
Agreement).
126 F. Conclusions
5.41 To summarize:
(a) Costa Rica has not breached any obligation to carry out an
environmental impact assessment. The threshold requirement of
significant adverse impact is not met, and therefore there is n o
obligation to carry out any such assessment. Moreover, Nicaragua’s
argument to the contrary ignores the pressing circumstances in
which the Road was constructed which, under Costa Rican law (as to
which see the renvoi under international law), exempted C osta Rica
from having to carry out an impact assessment in advance.
(b) Costa Rica has not breached any obligation to notify Nicaragua.
Again, the threshold requirement of significant adverse impact is not
met and therefore Costa Rica was not obliged to notif y Nicaragua.
Nicaragua relies on instruments that are either irrelevant or
inapplicable, and again it ignores the emergency circumstances in
which the Road was constructed.
(c) Nicaragua has failed to demonstrate that the Road has caused any
significant transboundary harm, or that there is any potential for any
such significant harm.
(d) Costa Rica has not breached any obligations under any other treaty
invoked by Nicaragua (including the Convention on Biological
Diversity, the Ramsar Convention, the Central American Convention
for the Protection of the Environment, and the SI -A-PAZ
Agreement). proprio motu. Nicaragua explicitly declined to make a formal request in
342
accordance with the requirements of the Rules.
6.3 Nicaragua’s request for provisional measures was summarily
343
rejected by the Court on 11 March 2013. Nicaragua’s submission
requesting the Court “to order Costa Rica to immediately take … emergency
344
measures” has therefore already been rejected by the Court.
6.4 On 14 June 2013, in response to Costa Rica’s request for
modification of the provisional measures indicated in the Certain Activities
case, Nicaragua requested the Court to modify its O rder of 8 March 2011 in
the Certain Activities case, to indicate that the Parties refrain from conduct
which might aggravate or exten d the dispute before the Court to the two
joined cases, i.e. to the Construction of a Road case. The Court definitively
rejected this request in its Order of 16 July 2013, recalling that it had
already rejected Nicaragua’s request for provisional measures on 11 March
345
2013. The Court stated that Nicaragua’s request “does not have any
bearing on the situation addressed in [the Order of 8 March 2011]” and that
the joinder of proceedings
“… is a procedural step which does not have the effect of
rendering applicable ipso facto, to the facts underlying the
[Construction of a Road case], the measures prescribed with
342 NM, para. 6.6. See Articles 73(1), 73(2) and 74(3) of the Rules of the Court.
343
Vol 3, Annex No 50 , Letter from the International Court of Justice to Costa Rica,
Reference 141641, 11 March 2013.
344
NM, Submissions, para 4, pp 252-253.
345 Certain Activities Carried out by Nicaragua in the Border Area (Costa Rica v
Nicaragua); Construction of a Road in Costa Rica along the San Juan River
(Nicaragua v Costa Rica), Requests for the Modification of the Order of 8 March
2011 indicating Provisional Measures, Order , 16 July 2013, paras. 26-29.
128proprio motu. Nicaragua explicitly declined to make a formal request in
342
accordance with the requirements of the Rules.
6.3 Nicaragua’s request for provisional measures was summarily
343
rejected by the Court on 11 March 2013. Nicaragua’s submission
requesting the Court “to order Costa Rica to immediately take … emergency
344
measures” has therefore already been rejected by the Court.
6.4 On 14 June 2013, in response to Costa Rica’s request for
modification of the provisional measures indicated in the Certain Activities
case, Nicaragua requested the Court to modify its O rder of 8 March 2011 in
the Certain Activities case, to indicate that the Parties refrain from conduct
which might aggravate or exten d the dispute before the Court to the two
joined cases, i.e. to the Construction of a Road case. The Court definitively
rejected this request in its Order of 16 July 2013, recalling that it had
already rejected Nicaragua’s request for provisional measures on 11 March
345
2013. The Court stated that Nicaragua’s request “does not have any
bearing on the situation addressed in [the Order of 8 March 2011]” and that
the joinder of proceedings
“… is a procedural step which does not have the effect of
rendering applicable ipso facto, to the facts underlying the
[Construction of a Road case], the measures prescribed with
342 NM, para. 6.6. See Articles 73(1), 73(2) and 74(3) of the Rules of the Court.
343
Vol 3, Annex No 50 , Letter from the International Court of Justice to Costa Rica,
Reference 141641, 11 March 2013.
344
NM, Submissions, para 4, pp 252-253.
345 Certain Activities Carried out by Nicaragua in the Border Area (Costa Rica v
Nicaragua); Construction of a Road in Costa Rica along the San Juan River
(Nicaragua v Costa Rica), Requests for the Modification of the Order of 8 March
2011 indicating Provisional Measures, Order , 16 July 2013, paras. 26-29. Thus Nicaragua contended, before the United Nations, that the Court’s
Order of 8 March 2011 in the Certain Activities case was rendered
applicable to the Construction of the Road case, by the Court’s Order of 16
July 2013. This is incorrect . The Court rejected Nicar agua’s request for
modification in no uncertain terms, noting that “joinder is a procedural step
which does not have the effect of rendering applicable ipso facto, to the
facts underlying the Nicaragua v Costa Rica case, the measures prescribed
with respect to a specific and separate situation in the Costa Rica v
Nicaragua case.” 348 By responsive letter dated 7 August 2013, Costa Rica
explained Nicaragua’s misrepresentations to the United Nations, 349 and
informed the Court by separate letter dated 26 August 2013. 350
6.6 On Friday 11 October 2013 Nicaragua presented a Request for
Provisional Measures in this case. It asked the Court to hear its Request
concurrently with Costa Rica’s Request for New Provisional Measures in
the Certain Activities Case. 351The Court declined to do so, and set dates for
a hearing of Nicaragua’s Request from 5 t o 8 November 2013. On 13
December 2013, the Court unanimously rejected Nicaragua’s Request for
348
Certain Activities Carried out by Nicaragua in the Border Area (Costa Rica v
Nicaragua); Cons truction of a Road in Costa Rica along the San Juan River
(Nicaragua v Costa Rica), Requests for the Modification of the Order of 8 March
2011 indicating Provisional Measures, Order , 16 July 2013, para. 28.
349
Vol 3, Annex No 58, Letter from Permanent Mis sion of Costa Rica to the United
Nations to the Permanent and Observer Missions of the United Nations, Reference
MCRONU-458-13, 7 August 2013, attaching Position of Costa Rica in relation to
a Press Release dated 1 August 2013 circulated by the Permanent M ission of
Nicaragua to all Permanent and Observer Missions to the United Nations on
5 August 2013, 7 August 2013
350 Vol 3, Annex No 6 2, Letter from Costa Rica to the I nternational Court of Justice,
Reference ECRPB-055-13, 26 August 2013.
351
Vol 3, Annex No 67, Letter from Nicaragua to the ICJ, Reference HOL-EMB-
196, 11 October 2013.
130Thus Nicaragua contended, before the United Nations, that the Court’s
Order of 8 March 2011 in the Certain Activities case was rendered
applicable to the Construction of the Road case, by the Court’s Order of 16
July 2013. This is incorrect . The Court rejected Nicar agua’s request for
modification in no uncertain terms, noting that “joinder is a procedural step
which does not have the effect of rendering applicable ipso facto, to the
facts underlying the Nicaragua v Costa Rica case, the measures prescribed
with respect to a specific and separate situation in the Costa Rica v
Nicaragua case.” 348By responsive letter dated 7 August 2013, Costa Rica
explained Nicaragua’s misrepresentations to the United Nations, 349 and
informed the Court by separate letter dated 26 August 2013. 350
6.6 On Friday 11 October 2013 Nicaragua presented a Request for
Provisional Measures in this case. It asked the Court to hear its Request
concurrently with Costa Rica’s Request for New Provisional Measures in
the Certain Activities Case. 351The Court declined to do so, and set dates for
a hearing of Nicaragua’s Request from 5 t o 8 November 2013. On 13
December 2013, the Court unanimously rejected Nicaragua’s Request for
348
Certain Activities Carried out by Nicaragua in the Border Area (Costa Rica v
Nicaragua); Cons truction of a Road in Costa Rica along the San Juan River
(Nicaragua v Costa Rica), Requests for the Modification of the Order of 8 March
2011 indicating Provisional Measures, Order , 16 July 2013, para. 28.
349
Vol 3, Annex No 58, Letter from Permanent Mis sion of Costa Rica to the United
Nations to the Permanent and Observer Missions of the United Nations, Reference
MCRONU-458-13, 7 August 2013, attaching Position of Costa Rica in relation to
a Press Release dated 1 August 2013 circulated by the Permanent M ission of
Nicaragua to all Permanent and Observer Missions to the United Nations on
5 August 2013, 7 August 2013
350 Vol 3, Annex No 6 2, Letter from Costa Rica to the I nternational Court of Justice,
Reference ECRPB-055-13, 26 August 2013.
351
Vol 3, Annex No 67, Letter from Nicaragua to the ICJ, Reference HOL-EMB-
196, 11 October 2013. follows that there is no extant request for Provisional Measures that the
Court need address in this case.
C. Nicaragua’s requests for declaratory relief
6.7 In Chapter 6 of its Memorial, and in its submissions, Nicaragua sets
out a catalogue of claims toforms of reparation, including:
(a) a declaration of unlawful conduct and responsibility;
(b) an order requiring Costa Rica to cease its unlawful conduct,
and an order that Costa Rica is required to perform its
obligations;
(c) assurances and guarantees of non-repetition; and
(d) a declaration that Costa Rica is not entitled to continue or
undertake further development in its territory without an
appropriate transboundary Environmental Impact
Assessment which is provided to Nicaragua.
6.8 Each of these claims is premised on an internationally wron gful act
or acts having been committed by Costa Rica. For r easons explained in
Chapters 3, 4 and 5 above, Nicaragua has not demonstrated that any such
internationally wrongful acts have occurred.
6.9 Furthermore, Costa Rica has submitted with this Counter Memorial
the “Environmental Diagnostic Assessment” for the Road. As explained in
Chapter 2 above, this Environmental Diagnostic Assessment has been
completed in accordance with the guidelines of Costa Rica’s administrative
regulations for a project which has already been constructed, including
132follows that there is no extant request for Provisional Measures that the
Court need address in this case.
C. Nicaragua’s requests for declaratory relief
6.7 In Chapter 6 of its Memorial, and in its submissions, Nicaragua sets
out a catalogue of claims toforms of reparation, including:
(a) a declaration of unlawful conduct and responsibility;
(b) an order requiring Costa Rica to cease its unlawful conduct,
and an order that Costa Rica is required to perform its
obligations;
(c) assurances and guarantees of non-repetition; and
(d) a declaration that Costa Rica is not entitled to continue or
undertake further development in its territory without an
appropriate transboundary Environmental Impact
Assessment which is provided to Nicaragua.
6.8 Each of these claims is premised on an internationally wron gful act
or acts having been committed by Costa Rica. For r easons explained in
Chapters 3, 4 and 5 above, Nicaragua has not demonstrated that any such
internationally wrongful acts have occurred.
6.9 Furthermore, Costa Rica has submitted with this Counter Memorial
the “Environmental Diagnostic Assessment” for the Road. As explained in
Chapter 2 above, this Environmental Diagnostic Assessment has been
completed in accordance with the guidelines of Costa Rica’s administrative
regulations for a project which has already been constructed, including the same reasons, Nicaragua’s requests for these declarations should be
rejected.
D. Nicaragua’s Remedial Claims
359
6.12 Nicaragua also claims monetary compensation. To satisfy a claim
for compensation, a State must (1) specify the head of damage and quantify
360
the harm, and (2) establish a sufficient causal connection between the
361
harm and an internationally wrongful act. Nicaragua claims reparation in
the form of pecuniary compensation. This claim must be dismissed.
Nicaragua has not demonstrated that it has suffered or will suffer any
compensable loss, nor that any such loss is the result of an internationally
wrongful act by Costa Rica . Nicaragua alleges that it has suffered
financially assessable loss for the following:
(a) costs of “cleaning of the San Juan de Nicaragua (the removal
of soil, trees and other vegetation as well as the restoration of
the quality of the water of the San Juan River)”;
(b) “additional costs” for dredging; and
359
NM, para. 6.33.
360 Fisheries Jurisdiction (Federal Republic of Germany v Iceland), I C J Reports
1974, p. 204, para. 76.
361 Military and Paramilitary Activities in and against Nicaragua (Nicaragua v
United States of America), Merits, Judgment, I C J Reports 1986, pp. 142143,
para. 284. See also International Law Commission, Articles on the Responsibility
of States for Internationally Wrongful Acts [2001-II(2)] Yearbook of the
International Law Commission 26, Article 36.
134the same reasons, Nicaragua’s requests for these declarations should be
rejected.
D. Nicaragua’s Remedial Claims
359
6.12 Nicaragua also claims monetary compensation. To satisfy a claim
for compensation, a State must (1) specify the head of damage and quantify
360
the harm, and (2) establish a sufficient causal connection between the
361
harm and an internationally wrongful act. Nicaragua claims reparation in
the form of pecuniary compensation. This claim must be dismissed.
Nicaragua has not demonstrated that it has suffered or will suffer any
compensable loss, nor that any such loss is the result of an internationally
wrongful act by Costa Rica . Nicaragua alleges that it has suffered
financially assessable loss for the following:
(a) costs of “cleaning of the San Juan de Nicaragua (the removal
of soil, trees and other vegetation as well as the restoration of
the quality of the water of the San Juan River)”;
(b) “additional costs” for dredging; and
359
NM, para. 6.33.
360 Fisheries Jurisdiction (Federal Republic of Germany v Iceland), I C J Reports
1974, p. 204, para. 76.
361 Military and Paramilitary Activities in and against Nicaragua (Nicaragua v
United States of America), Merits, Judgment, I C J Reports 1986, pp. 142143,
para. 284. See also International Law Commission, Articles on the Responsibility
of States for Internationally Wrongful Acts [2001-II(2)] Yearbook of the
International Law Commission 26, Article 36. which asserts that “tourists make faces when they see the
364
road.” This is insufficient to support a claim. So far as
concerns fishing and public health, as explained in Chapter 3
above, Nicaragua has not provided any evidence of har m
which would sustain a claim for breach, and then to
compensation for such breach.
6.14 For the reasons explained in Chapters 3, 4 and 5 above, Nicaragua
has failed to discharge its burden to demonstrate that the road infrastructure
works are in breach of any international obligation binding on Costa Rica,
and that they ha ve caused any actual harm to the San Juan River or to
Nicaragua. Nor has it demonstrated that it has incurred any compensable
loss as the result of that alleged harm. It follows that Nicaragua’s request for
compensation must be dismissed.
E. Nicaragua’s Request to Suspend Costa Rica’s Perpetual Right of
Free Navigation
6.15 Nicaragua claims that “[t]he prejudice to Nicaragua’s territory
affects the navigational rights granted by the 1858 Treaty to Costa Rica”. 365
This appears to be an ill -disguised and impermissible attempt to re -litigate
the Court’s 2009 judgment in Navigational Rights . 366It is in reality another
in a series of attempts by Nicaragua to eliminate Costa Rica’s navigational
rights on the San Juan River. In the first instance, Nicaragua refused to
recognize the existence and scope of Costa Rica’s right, in the Navigational
364 NM, Vol II, Annex No 26, La Prensa, Nicaragua, “Surrounding Damage Could not
be Hidden”, 14 January 2012, p. 448.
365
NM, p. 244 (heading 5).
366 Dispute Regarding Navigational and Relat ed Rights (Costa Rica v Nicaragua),
Judgment, I C J Reports 2009, p. 213.
136 which asserts that “tourists make faces when they see the
364
road.” This is insufficient to support a claim. So far as
concerns fishing and public health, as explained in Chapter 3
above, Nicaragua has not provided any evidence of har m
which would sustain a claim for breach, and then to
compensation for such breach.
6.14 For the reasons explained in Chapters 3, 4 and 5 above, Nicaragua
has failed to discharge its burden to demonstrate that the road infrastructure
works are in breach of any international obligation binding on Costa Rica,
and that they ha ve caused any actual harm to the San Juan River or to
Nicaragua. Nor has it demonstrated that it has incurred any compensable
loss as the result of that alleged harm. It follows that Nicaragua’s request for
compensation must be dismissed.
E. Nicaragua’s Request to Suspend Costa Rica’s Perpetual Right of
Free Navigation
6.15 Nicaragua claims that “[t]he prejudice to Nicaragua’s territory
affects the navigational rights granted by the 1858 Treaty to Costa Rica”. 365
This appears to be an ill -disguised and impermissible attempt to re -litigate
the Court’s 2009 judgment in Navigational Rights . 366It is in reality another
in a series of attempts by Nicaragua to eliminate Costa Rica’s navigational
rights on the San Juan River. In the first instance, Nicaragua refused to
recognize the existence and scope of Costa Rica’s right, in the Navigational
364 NM, Vol II, Annex No 26, La Prensa, Nicaragua, “Surrounding Damage Could not
be Hidden”, 14 January 2012, p. 448.
365
NM, p. 244 (heading 5).
366 Dispute Regarding Navigational and Relat ed Rights (Costa Rica v Nicaragua),
Judgment, I C J Reports 2009, p. 213. waters between the m outh of the river and a point located three
English miles below Castillo Viejo …” 368
6.17 As the Court made clear in its 2009 Judgment, the 1858 Treaty does
not establish any hierarchy between Nicaragua’s sovereignty and Costa
Rica’s right of free navigation: each of them co-exist:
“A simple reading of Article VI shows that the Parties did not intend
to establish any hierarchy between Nicaragua’s sovereignty over the
river and Costa Rica’s right of free navigation, characterized as
“perpetual”, with each of these affirmations counter -balancing the
other. Nicaragua’s sovereignty is affirmed only to the extent that it
does not prejudice the substance of Costa Rica’s right of free
navigation in its domain, the establishment of which is precisely the
point at issue; the right of free navigation, albeit “perpetual”, is
granted only on condition that it does not prejudice the key
369
prerogatives of territorial sovereignty.”
6.18 Nicaragua quotes selectively from this paragraph of the Court’s 2009
Judgment, suggesting that Costa Rica has “prejudiced ‘the key prerogatives
of [Nicaraguan] territorial sovereignty’” and is therefore “no more entitled
to claim its ‘perpetual’ but conditional right of free navigation”. 370 This
assertion is without basis. Nicaragua’s sovereignty , and Costa Rica’s right
of free navigation are each of them subject to the other.
6.19 In any event, as explained in Chapter 3 above, Nicaragua has not
demonstrated that Costa Rica has in fact caused any actual harm to the San
Juan River, let alone significant harm. There is therefore no evidence that
368
1858 Treaty, as quoted in Case Concerning the Dispute Regarding Navigational
and Related Rights (Costa Rica v Nicaragua), Judgment, I C J Reports 2009 ,
p. 236, para. 44.
369 Dispute Regarding Navigational and Related Rights (Costa Rica v Nicaragua),
Judgment, I C J Reports 2009, p. 237, para. 48.
370 NM, para. 6.36.
138 waters between the m outh of the river and a point located three
English miles below Castillo Viejo …” 368
6.17 As the Court made clear in its 2009 Judgment, the 1858 Treaty does
not establish any hierarchy between Nicaragua’s sovereignty and Costa
Rica’s right of free navigation: each of them co-exist:
“A simple reading of Article VI shows that the Parties did not intend
to establish any hierarchy between Nicaragua’s sovereignty over the
river and Costa Rica’s right of free navigation, characterized as
“perpetual”, with each of these affirmations counter -balancing the
other. Nicaragua’s sovereignty is affirmed only to the extent that it
does not prejudice the substance of Costa Rica’s right of free
navigation in its domain, the establishment of which is precisely the
point at issue; the right of free navigation, albeit “perpetual”, is
granted only on condition that it does not prejudice the key
369
prerogatives of territorial sovereignty.”
6.18 Nicaragua quotes selectively from this paragraph of the Court’s 2009
Judgment, suggesting that Costa Rica has “prejudiced ‘the key prerogatives
of [Nicaraguan] territorial sovereignty’” and is therefore “no more entitled
to claim its ‘perpetual’ but conditional right of free navigation”. 370 This
assertion is without basis. Nicaragua’s sovereignty , and Costa Rica’s right
of free navigation are each of them subject to the other.
6.19 In any event, as explained in Chapter 3 above, Nicaragua has not
demonstrated that Costa Rica has in fact caused any actual harm to the San
Juan River, let alone significant harm. There is therefore no evidence that
368
1858 Treaty, as quoted in Case Concerning the Dispute Regarding Navigational
and Related Rights (Costa Rica v Nicaragua), Judgment, I C J Reports 2009 ,
p. 236, para. 44.
369 Dispute Regarding Navigational and Related Rights (Costa Rica v Nicaragua),
Judgment, I C J Reports 2009, p. 237, para. 48.
370 NM, para. 6.36. further contests Nicaragua’s misconceived and self serving interpretation of
the 1858 Treaty of Limits. As explained in Chapter 4, the k ey provisions of
this Treaty concern the establishment of a permanent and final boundary. No
provision of this Treaty is relevant to Costa Rica's Road infrastructure works
entirely within its own sovereign territory.
6.22 For the reasons given above, these Nicaraguan arguments must be
rejected. Costa Rica’s right of navigation is not hierarchically inferior to
Nicaragua’s sovereignty: the y are co-existent. Costa Rica’s right of
navigation cannot be suspended on the basis of breaches of the 1858 Treaty,
which is a treaty establishing boundaries: since Costa Rica’s perpetual right
of free navigation is intrinsically linked to Nicaraguan sovereignty over the
waters of the San Juan, neither sovereignty nor the perpetual right of free
navigation may be suspended. Both Nicaragua’s sovereign rights and Costas
Rica’s rights of navigation form part of the boundary regime, and that
regime is subject to the fundamental principle of stability of boundaries. As
the Court affirmed in Gabč íkovo-Nagymaros, a treaty which establishes a
territorial régime – including in respect of rights of navigation on rivers – is
subject to the principle of stability as reflected for example in Article 12 of
the Vienna Convention on Succession of States in Respect of Treaties. 378
The 1858 Treaty establishes such territorial régime and is therefore subject
to the principle of stability of boundaries. 379 It may not be suspended.
378 Gabčíkovo-Nagymaros Project (Hungar y/Slovakia), Judgment, I C J Reports
1997, p. 72, para. 123, referring to Vienna Convention on Succession of States in
Respect of Treaties, 23 August 1978 (entry into force 6 November 1996), 1946
UNTS 3, Article 12.
379
See, eg, Case concerning the Temple of Preah Vihear (Cambodia v Thailand),
Merits, Judgment, I C J Reports 1962, p. 34 (“In general, when two countries
140further contests Nicaragua’s misconceived and self serving interpretation of
the 1858 Treaty of Limits. As explained in Chapter 4, the k ey provisions of
this Treaty concern the establishment of a permanent and final boundary. No
provision of this Treaty is relevant to Costa Rica's Road infrastructure works
entirely within its own sovereign territory.
6.22 For the reasons given above, these Nicaraguan arguments must be
rejected. Costa Rica’s right of navigation is not hierarchically inferior to
Nicaragua’s sovereignty: the y are co-existent. Costa Rica’s right of
navigation cannot be suspended on the basis of breaches of the 1858 Treaty,
which is a treaty establishing boundaries: since Costa Rica’s perpetual right
of free navigation is intrinsically linked to Nicaraguan sovereignty over the
waters of the San Juan, neither sovereignty nor the perpetual right of free
navigation may be suspended. Both Nicaragua’s sovereign rights and Costas
Rica’s rights of navigation form part of the boundary regime, and that
regime is subject to the fundamental principle of stability of boundaries. As
the Court affirmed in Gabč íkovo-Nagymaros, a treaty which establishes a
territorial régime – including in respect of rights of navigation on rivers – is
subject to the principle of stability as reflected for example in Article 12 of
the Vienna Convention on Succession of States in Respect of Treaties. 378
The 1858 Treaty establishes such territorial régime and is therefore subject
to the principle of stability of boundaries. 379 It may not be suspended.
378 Gabčíkovo-Nagymaros Project (Hungar y/Slovakia), Judgment, I C J Reports
1997, p. 72, para. 123, referring to Vienna Convention on Succession of States in
Respect of Treaties, 23 August 1978 (entry into force 6 November 1996), 1946
UNTS 3, Article 12.
379
See, eg, Case concerning the Temple of Preah Vihear (Cambodia v Thailand),
Merits, Judgment, I C J Reports 1962, p. 34 (“In general, when two countries 6.26 It follows that Nicaragua’s request that the Court suspend Costa
Rica’s perpetual right of free navigation on the basis that Nicaragua is
entitled to do so as a lawful countermeasure should be dismissed.
142 Submissions
For these reasons, and reserving the right to supplement, amplify or amend
the present submissions, Costa Rica requests the Court to dismiss all of
Nicaragua’s claimsin this proceeding.
Jorge Urbina Ortega
Co-Agent of Costa Rica
19 December 2013
143144 APPENDIX A
Professor Colin Thorne
Assessment of the Impact of the Construction of the Border Road in Costa Rica on the San
Juan River
November 2013
145146 Appendix A
DISPUTE CONCERNING
C ONSTRUCTION OF AR OAD INCOSTA RICA ALONG THES ANJUAN R IVER
(NICARAGUA V COSTA RICA)
Assessment of the Impact of the Construction of the Border Road in Costa
Rica on the San Juan River
Prepared by
Colin Thorne
Nottingham, UK
Professor and Chair of Physical Geography
University of Nottingham
December 2013
147 Table of Contents
List of Figures ................................ ................................ ................................ ....................... 5
List of Tables ................................ ................................ ................................ ........................ 8
1. Introduction ................................ ................................ ................................ ............ 9
2. My Qualifications ................................ ................................ ................................ .10
3. Terms of Reference and Methodo logy................................ .......................... 11
A. Terms of Reference ................................ ................................ ................................ ...11
B. Methodology ................................ ................................ ................................ ................11
4. Nicaragua’s statements concerning adverse impacts of the Road on
the Río San Juan ................................ ................................ ................................ ....14
A. Statements in Nicaragua's Memorial ................................ ............................... 14
B. Statements in the 2012 Kondolf Report ................................ ........................... 15
C. Geographical Extent of the Statements ................................ ........................... 16
5. My Field Observations of the Road ................................ ................................ 18
A. Field Observations in February and May, 2013 ................................ ............18
B. My observations and Dr Kondolf's decision to limit his quantitative
analysis to the upstream 41.6 km of the Road ................................ ..............18
6. Characteristics of the Río San Juan ................................ ................................ 27
A. Introduction................................ ................................ ................................ .................27
B. Geologic, Tectonic and Topographic Controls on the Río San Juan .....27
C. Channel morphology and classification ................................ .......................... 32
D. Catchment Hydrology ................................ ................................ .............................. 36
(1) Rainfall Distribution ................................ ................................ .................36
(2) Gauging stations and records ................................ ............................... 39
(3) Mean Annual Discharge Regime of the Rio San Juan - Colorado
System ................................ ................................ ................................ .............40
E. Sediment Regime ................................ ................................ ................................ .......43
(1) Suspended sediment gauging stations and records .................... 43
(2) Measured and calculated bed load in the Rio San Juan -
Colorado ................................ ................................ ................................ .........46
(3) Average annual total sediment loads in the Río San Juan –
Colorado ................................ ................................ ................................ .........48
148 2 F. Contrasts between the Río San Juan and rivers in the Pacific
Northwest ................................ ................................ ................................ ..................... 48
G. Appearance of the Río San Juan in 2009 in Figures 4 and 5 of the
Kondolf Report................................ ................................ ................................ ............52
7. Has Route 1856 altered the hydrology of the Río San Juan? .................56
A. Overview................................ ................................ ................................ ........................ 56
B. Increases in impermeable areas due to construction of Route 1856 ..56
C. Hydrologic modelling Costa Rican micro -basins draining to the Rio
San Juan between Marker II and the Delta with and without Route
1856 ................................ ................................ ................................ ................................ 59
D. Discharges from all Costa Rican basins draining to the Rio San Juan
between Marker II and the Delta with and without Route 1856 ..........61
E. Conclusions................................ ................................ ................................ ...................64
8. Has sediment from Route 1856 had any significant impact on the Río
San Juan? ................................ ................................ ................................ .................65
A. Introduction................................ ................................ ................................ .................65
B. Has the Road significantly impacted suspended sediment
concentrations or loads in the Río San Juan? ................................ ................65
-1
C. Is the 1 m y rate of land lowering used in the 2012 Kondolf Report
reasonable? ................................ ................................ ................................ ..................70
D. Potential for Road -derived sediment to have a significant impact on
the Río San Juan ................................ ................................ ................................ .........82
(1) Introduction................................ ................................ ................................ ..82
(2) Estimated annual load of Road -related sediment supplied to
the Río San Juan ................................ ................................ .......................... 82
(3) Comparison of the additional Road -derived sediment to the
average annual sedim ent load in the lower Río San Juan since
December 2010 ................................ ................................ ........................... 83
(4) Relative input of Road -derived sediment to the Río San Juan .84
(5) Inputs of Road -derived sediment are not just insignificant,
they are undetectable ................................ ................................ ...............85
E. Sediment budget of the Río San Juan and the possibility of reach -scale
sediment impacts ................................ ................................ ................................ .......86
3 149 9. Has construction of the Road had any significant impacts on channel
morphology in the Río San Juan? ................................ ................................ ....95
A. Sediment deltas observed in the Río San Juan following construction
of Route 1856 ................................ ................................ ................................ ..............95
10. Has the Road impacted the Ecology or Fishery of the Río San Juan, or
had any effect on Tourism? ................................ ................................ ........... 103
11. Mitigation Works ................................ ................................ .............................. 109
A. Observations of the Mitigation Works in May 2013 ................................ 109
B. Mitigation of future erosion risks and a permanent solution to erosion
issues associated with the Road ................................ ................................ .......116
12. Conclusions ................................ ................................ ................................ .........119
13. References ................................ ................................ ................................ ........... 121
14. Statement of Independence and Truth ................................ ...................... 123
List of Attachments ................................ ................................ ................................ .......125
150 4 List of Figures
Figure 1. Photographs representative of conditions observed by the author along the Road
between Boca San Carlos and Boca Sarapiquí on the ground on February 16, 2013. ..............21
Figure 2. Photographs representative of conditions observed by the author along the Road
between Boca Sarapiquí and the Delta on the ground on February 16, 2013. ......................... 22
Figure 3. Photographs representative of conditions along the Road between Boca San Carlos
and Boca Sarapiquí observed from the air by the autho r on February 16, 2013 ...................... 23
Figure 4. Photographs representative of conditions along the Road between Boca Sarapiquí
and the Delta observed from the air by the author on February 16, 2013. .............................. 24
Figure 5. Geological-tectonic map of the Caribbean Region with enlargement showing the
area in and around the basin of the Río San Juan ................................ ................................ ....28
Figure 6. Digital Elevation Model (DEM) of area around the Río San Juan downstream of Lake
Nicaragua ................................ ................................ ................................ ................................ .29
Figure 7. (a) Long profile of the Río San Juan between Lake Nicaragua and the D elta showing
reach limits mentioned in Table 1 and locations of rapids caused by bed rock outcrops in the
bed (see Figure 9 for an example) (b) DEM and (c) topographic map with five river reaches
indicated ................................ ................................ ................................ ................................ ...31
Figure 8. Long profile of the Río San Juan ................................ ................................ ................ 32
Figure 9. Example of rapids that control the bed elevation and long -stream slope of the Río
San Juan between the confluence with the Río Pocosol and Boca San Carlos ......................... 33
Figure 10. Typical river long profile from source to sea ................................ ........................... 33
Figure 11. Schematic represen tation of downstream trends in relative sediment transport
capacity (Qc) and sediment supply (Qs) in mountain rivers ................................ ..................... 35
Figure 12. Designation of reaches of the Rio San Juan according to the M ontgomery-
Buffington classification ................................ ................................ ................................ ...........36
Figure 13. (a) Topographic map and (b) Distribution of mean annual rainfall in the catchment
of the Río San Juan downstream of Lake Nicaragua ................................ ................................ .37
Figure 14. Monthly mean discharges measured in the Río San Juan main stream at Station 01 -
03, La Trinidad ................................ ................................ ................................ .......................... 37
Figure 15. Historical hurri cane tracks according to NOAA ................................ ........................ 38
Figure 16. Gauging stations in the Rio San Juan basin ................................ .............................. 41
Figure 17. Discharge regime of the Río San Juan - Colorado system ................................ ........43
Figure 18. Suspended sediment concentration as a function of discharge for 2 409 samples
taken from the Río Colorado, Río San Juan and its Costa Rican tributarie s.............................. 45
Figure 19. Frequency distribution of the sand percentages in all bed load samples ................ 46
Figure 20. Bed load sediment rating cu rve for sand calculated by calibrating and applying the
Einstein function to measured data from the Delta Colorado station (11 -04) ......................... 47
Figure 21. (a) Figure 4 from page 18 of the 2012 Kondolf R eport. (b) Rapideye image of areas
around Isla Reloj – Palo Seco in 2009 supplied to Nicaragua by Spatial Solutions and in Figure
4 of the 2012 Kondolf Report ................................ ................................ ................................ ...54
5 151 Figure 22. (a) Figure 5 from p age 18 of the 2012 Kondolf Report. (b) Rapideye image of area
around 2.3 km downstream from Boca San Carlos and across from the mouth of Quebrada
Guapote in 2009, supplied to Nicaragua by Spatial Solutions and used in Figure 5 of the 2012
Kondolf Report ................................ ................................ ................................ ......................... 55
Figure 23. Major tributary basins and micro -basins (highlighted in grey) draining from Costa
Rica to the Río San Juan between Marker II and the Delta ................................ ....................... 57
Figure 24. Mean monthly discharges from micro -basins draining to the Río San Juan with and
without Route 1856 ................................ ................................ ................................ .................. 61
Figure 25. Monthly average stream flows for all Costa Rican tributary basins (micro and
macro) draining to the Río San Juan under Pre - and Post-Route 1956 conditions ................... 63
Figure 26. Measured suspended sediment concentrations, rating curves and 95% confidence
intervals for pre -Road [La Trinidad (01 -03), January 1974 to March 1976] and post -Road
[Delta Colorado (11 -04), December 2010 to June 2013] periods ................................ .............66
Figure 27. Mean annual suspen ded sediment loads in the Río San Juan based on
measurements at La Trinidad (1974 -1976) and Delta Colorado (2010 -2013) .......................... 68
Figure 28. Location of monitored sites ................................ ................................ ..................... 71
Figure 29. Sediment trap #2 on (a) 8 June and (b) 22 July 2013 ................................ ...............72
Figure 30. Rill erosion monitoring site on a cut slope, with rills numbered and 1 metre gr id
overlaid for scale ................................ ................................ ................................ ...................... 72
Figure 31. (a) Map showing the major tributary basins between Lake Nicaragua and Delta
Costa Rica. (b) Length of Road and estimated annual average inputs of sediment t o the Rio
San Juan from erosion of the road and cut/fill slopes in basins CR3 (Infiernito) to CR7
(Chirripó) between Marker II and the Delta ................................ ................................ .............80
Figure 32. Sediment budget for the Río San Juan including inputs from the Road .................. 92
Figure 33. Sediment budget for the Río San Juan excluding inputs from the Road .................. 93
Figure 34. Sediment budget for the Rio San Juan – Colorado system highlighting the
contribution due to construction of Route 1856 from each major tributary basin .................. 94
Figure 35. Photographs reproduced direc tly from Appendix B of the Kondolf Report .............95
Figure 36. Prominent sediment delta observed in the Río San Juan from a helicopter in Costa
Rican airspace on 7 May 2013 (a) close up and (b) wide angle view showing clearly that this
delta is on the left (Nicaraguan) bank of the River ................................ ................................ ...98
Figure 37. Sediment delta observed in the Río San Juan from a helicopter in Costa Rican
airspace on 7 May 2013 (a) close up. (b) wide angle view showing clearly that this delta is also
on the far (Nicaraguan) bank of the River ................................ ................................ ................ 99
Figure 38. Photographs taken from Costa Rican air space on 7 M ay 2013............................. 101
Figure 39. The Road near Marker II (a) prior to mitigation work on 15 February 2013 and (b)
on 7 May 2013 with mitigation measures in place ................................ ................................ .111
Figure 40. View down a large gully in a fill prism created by concentrated runoff from the
Road draining to Costa Rican territory to the west of Marker II (a) in February when it was
actively eroding and (b) in May when the gull y had been back -filled and stabilized using a
culverted cross -drain and concrete drainage channel, with coconut matting used to protect
the surrounding fill slope from sheet and rill erosion ................................ ............................ 111
152 6Figure 41. Road at East 497867, North 325463 about 6.4 km east of Marker II (a) on 15
February when failure of geotextile slope protection had allowed concentrated out -board
runoff from the Road to create two gullies and in -board runoff was undercutting a cut slope
(b) on 7 May 2013 after construction of concrete -lined out-board and in board ditches ......112
Figure 42. Road at East 498072, North 325345, about 6.6 km east of Marker II (a) on 15
February 2013 showing a network of gullies on an outboard slope and sediment accumulated
as a run-out deposit on the flat terrace surface separating the foot of the slope from the bank
of the Río San Juan (b) on 7 May 2013 showing mitigation works in the for m of concrete
channels and drop structures to convey runoff from the road bed, and silt fences to protect
the slope from sheet and rill erosion, lined out -board and prevent road -derived sediment
reaching the terrace ................................ ................................ ................................ ...............113
Figure 43. Road at East 502480, North 321561, close to the Río Infiernito (a) on 15 February
when surface unmanaged runoff from the road bed and surrounding slopes disturbed during
construction had caused sheet and rill erosion of bare soil surfaces. (b) The same stretch of
road on 7 May 2013 after protection of the road surface using crushed rock, installation of silt
fences to prevent sheet and rill erosion while directing down -slope surface runoff into
concrete-lined outboard and inboard ditches ................................ ................................ ........114
Figure 44. Path cleared for the Road near Crucitas, just east of the Rio Infiernito (a) on 15
February when unmanaged runoff from the path cleared in preparation for co nstruction of
the road bed had caused sheet and rill erosion. (b) The same area on 7 May 2013 after
installation integrated measures to manage runoff involving regrading, silt fences, and
concrete-lined outboard ditch ................................ ................................ ................................ 115
Figure 45. Relationship between sediment production per cm of rainfall and time elapsed
since the road was constructed (or regarded) for a constant average road slope ................. 116
7 153 List of Tables
Table 1. Geologically defined reaches of the Río San Juan ................................ ....................... 30
Table 2. Gauging stations on the Río San Juan - Colorado system and its Costa Rican
tributaries................................ ................................ ................................ ................................ .40
Table 3. Discharge Regime of the Rio San Juan ................................ ................................ ........42
Table 4. Suspended sediment ga uging stations along the main stream Rio San Juan and in
Costa Rican tributary basins ................................ ................................ ................................ .....44
Table 5. Current average annual bed loads in the ................................ ................................ ....48
Table 6. Current average annual total loads in the ................................ ................................ ..48
Table 7. Maximum possible increases in impermeable area due to construction of Route 1856
within micro-basins and major tribu tary basins draining from Costa Rica to the Río San Juan 58
Table 8. Average monthly stream flows from micro -basins draining to the Río San Juan,
predicted using a HEC -HMS model simulation fro m 1976 to 2013 for conditions with and
without Route 1856 ................................ ................................ ................................ .................. 60
Table 9. Monthly average stream flows for all basins (micro and macro) draining to the Río
San Juan ................................ ................................ ................................ ................................ ...63
Table 10. Suspended sediment records for the Río San Juan – Colorado................................ .66
Table 11. Mean annual suspended sediment loads in the Río San Juan – Colorado ................ 69
Table 12. Summary of erosion monitoring results ................................ ................................ ...75
Table 13. Estimated average annual erosion rates ................................ ................................ ..79
Table 14. Average annual inputs of Road -derived sediment to the Río San Juan .................... 80
Table 15. Annual sediment inputs (suspended and bed loads) to the Río San Ju an from Lake
Nicaragua and its tributary basins based on CALCITE modelling ................................ ..............89
Table 16. Annual sediment inputs (suspended and bed loads) to the Río San Juan from Lake
Nicaragua and its tributa ry basins adjusted to obtain balance the sediment budget ..............91
154 8 1. Introduction
1.1. I am Colin Thorne, Professor of Physical Geography at the University of
Nottingham. I have been requested by Costa Rica to prepare an independent
expert report for the International Court of Justice (the Court) in connection with
the claim brought against Costa Rica by Nicaragua concerning the construction of
a road in Costa Rica near the San Juan River (the Road).
1.2. I am instructed to form an independe nt expert opinion on the matters set
out in the Terms of Reference below.
1.3. I have reviewed the following documents:
(a) Report prepared by G. Mathias Kondolf entitled, Environmental Impacts of
Juan Rafael Mora Porras Route 1856, Costa Rica, on the Río San Juan,
Nicaragua, December 2012 (the 2012 Kondolf Report), which is Annex 1
to Nicaragua’s Memorial in the Road Case;
(b) Nicaragua’s Memorial of 19 December 2012 in the Road Case;
(c) G. Mathias Kondolf, Confirmation of Urgent Measures to Mitigate Erosion &
Sediment De livery from Rte 1856, Costa Rica, into the Río San Juan,
Nicaragua, a report by Dr Kondolf dated 12 October 2013 (the Second
Kondolf Report );
(d) G. Mathias Kondolf, Continued Impacts of Erosion from Rte 1856, Costa
Rica to the Río San Juan, Nicaragua, a furth er report by Dr Kondolf dated
30 October 2013 ( the Third Kondolf Report );
(e) G. Mathias Kondolf, Selected Photographs of Depositional Features along
the Río San Juan de Nicaragua caused by Costa Rican Route 1856
Construction, Poor Design and Lack of Maintenan ce. Photos taken May 20 -
22, 2013 (Appendix A), which accompanies the Third Kondolf Report; and
(f) G. Mathias Kondolf, Comments on Costa Rican Submissions of November
2013, 6 November 2013 (the Fourth Kondolf Report ).
9 155 2. My Qualifications
2.1. Since 1990, I have held the Chair of Physical Geography at the University of
Nottingham, United Kingdom (UK). I hold BSc (1974) and PhD (1978) degrees in
Environmental Science from the University of East Anglia, UK. I have over 37
years of professional experience, including appo intments at Colorado State
University; the University of London; the U. S. Army Corps of Engineers,
Waterways Experiment Station; and the U. S. Department of Agriculture,
Agricultural Research Service, National Sedimentation Laboratory. I have
published ov er 200 journal papers, conference papers and book chapters;
authored two books; and edited a further seven . My research concentrates on
fluvial and sediment processes in natural, modified, and managed rivers,
particularly with respect to the implications f or river erosion, sedimentation, and
flood risk. I have performed original research and consultancy in the UK, USA,
Argentina, Bangladesh, China, Ethiopia, Laos, and New Zealand, particularly
involving large rivers and their coastal deltas.
2.2. My curriculum v itae is included as Attachment 1 to this Report.
156 10 3. Terms of Reference and Methodology
A. Terms of Reference
3.1. I have been asked to provide an independent expert opinion on the
environmental impacts of the Road on Nicaragua on the Río San Juan. In this
context, I have been asked to review and assess the information and opinions
given by Professor Kondolf in the reports listed in paragraph 1.3 above and the
claims made by Nicaragua in Construction of a Road case relating to harm or
potential harm to Nicaraguan territory.
3.2. I have been instructed to consider the potential environmental impacts of
the Road on Nicaragua . Therefore, I have not addressed any impacts of the Road
within Costa Rican territory.
B. Methodology
3.3. In preparing this Report , my approach has been as follows:
(a) I have reviewed the 2012 Kondolf Report , and the Second, Third and
Fourth Kondolf Reports, and Nicaragua’s Memorial insofar as it deals with
harm or potential harm to the San Juan River and makes statements that
rely on the 2012 Kondolf Report . I have also reviewed additional materials
provided by Nicaragua in July 2013, including information relating to
Professor Kondolf’s estimates of annual rates of lowering of the land
surface due to erosion associated with constructio n of the Road, delivery of
some portion of the eroded sediment to the Río San Juan , and the
coordinates of 54 “sediment input points” referred to on page 42 of the
2012 Kondolf Report.
(b) I have conducted a review of published academic literature on the
hydrological, sediment and environmental impacts of road construction on
rivers, including rivers in the Pacific Northwest of the United States of
America that are mentioned in the Kondolf Report .
11 157 (c) I have participated in two site visits to the Road, on 15 and 16 February,
and 7 May 2013. On the first occasion I drove along and/or viewed from
the air the entire length of the Road. On the second occasion I drove to and
reviewed from the air the first 41 km of the Road between Marker II and
Boca San Carlos. During b oth site visits I undertook field observations,
spoke to engineers and scientists engaged in mitigation works and took
ground and aerial photographs;
(d) I have requested, formulated and supervised scientific and technical
studies performed by qualified Costa Rican scientists and engineers, to
elicit the data and information needed to evaluate the potential for
construction of the R oad to impact the Río San Juan;
(e) I have participated in technical meetings with the team of scientists and
engineers on February 14 and 17, May 6 and 9 -10, and July 30 -31, during
which we discussed approaches and methodologies to be employed in
performing the work, reviewed progress and discussed the results of
archive-based, field, remote -sensing, GIS -based research, and computer
modelling; and
(f) I have reviewed the preliminary findings of the team , requesting additional
analyses where appropriate.
(g) The technical reports have been produced and provided to me as the
outcomes of this supervised research process are:
Astorga, A. and Mende, A ., Route 1856: analysis of the change in land
use based on satellite images before and after the construction of the
border road , August 2013 (Land Use Change Report ), Annex 3 to
Costa Rica’s Counter -Memorial;
Mende, A. and Astorga, A. , Inventory of Slopes and Water Courses
related to the Border Road Nº 1856 between Mojón II and Delta Costa
Rica, October 2013 (Inventory of Slopes and Water Courses ), Annex
6 to Costa Rica’s Counter -Memorial;
Mende, A., As torga, A. and Chassot, O. , Evaluation of the 54 Sites of
Purported Direct Sediment Delivery mentioned by Ph.D. Mathias
Kondolf, September 2013 (54 Sites Report ), Annex 5 to Costa Rica’s
Counter-Memorial;
158 12 Costa Rican Institute of Electricity (ICE) , SBC Projects and Associated
Services, Centre for Basic Enginee ring Studies, Department of
Hydrology, Report on Hydrology and Sediments for the Costa Rican
River Basins draining to the San Juan River , August 2013 (ICE Report),
Annex 4 to Costa Rica’s Counter -Memorial; and
University of Costa Rica Centre for Research in Sustainable
Development, Department of Civil Engineering, Report on Systematic
Field monitoring of Erosion and Sediment Yield along Route 1856 ,
September 2013 (UCR Report ), Annex 1 to Costa Rica’s Counter -
Memorial
3.4. I have also reviewed the Environmental Diagnostic Assessment (Ecological
Component) performed by the Tropical Science Center (CCT Report), Annex 10 to
Costa Rica’s Counter -Memorial. I am instructed that this Environmental
Diagnostic Assessment was prepared pursuant to applicable requirements of
Costa Rican law.
3.5. Where I rely on information and data contained in these reports and
studies, or any other reports prepared in the course of the investigations and
activities referred to in paragraphs 3.3 and 3.4 above, I indicate that I am doing so.
13 159 4. Nicaragua’s statements concerning adverse impacts of the Road
on the Río San Juan
A. Statements in Nicaragua's Memorial
4.1. In its Memorial, Nicaragua claim s that:
“it is evident that the construction of the road se riously affects the
environment and the rights of Nicaragua. If the project is not ceased
it would have irreversible and transcendental ecological and
environmental consequences. Among the many consequences that
can be highlighted are the following :
1. Dumping of trees and soil along the route of the road into the
river flow, making more difficult and risking the navigation in its
waters, over which Nicaragua has the dominion and sovereign
jurisdiction based on the Treaty of 15th April 1858 and the Cleveland
Award of 22nd March 1888.
2. Removal and sedimentation of fragile soils resulting in an
increased and excessive sedimentation of the waters of the
Nicaraguan river.
3. Impact over the hydrological resources, particularly
affecting fishing in t he river because of the changes in the quality of
the water.
4. Destruction of the natural habitat of the bank by removing
the immediate vegetation to the river flow for the construction of the
road, affecting the tree diversity around it.
5. Interception of the natural flow of the waters that flow
through the south basin to the San Juan River by modifying the
drainage of the surrounding wetlands at the lower San Juan and its
delta.
6. Erosion of the soil banks in places where a certain slope
exists and res ulting in the sedimentation of clay soils to the San Juan
of Nicaragua River.
7. Decrease or alteration of the aquatic life due to the water
cloudiness resulting from the sediments of the road construction.
160 14 8. Destruction of the inherent scenic values and eco-tourism
potential of the river course.”1
B. Statements in the 2012 Kondolf Report
4.2. In his 2012 R eport, Dr Kondolf sets out the grounds for these claims by
reference to the literature on the impacts of roads on rivers, expands upon the
claims in detail and presents photographs, sketches and estimates of sediment
volumes eroded and delivered to the Río San Juan annually (based on GIS analysis
and opinion) to support the claims. He does not, however, provide any evidence to
support claims of damage to ecosyste ms, navigability or ecotourism specific to the
Río San Juan.
4.3. In summary, Dr Kondolf as serts that construction of the R oad has already:
(a) decreased infiltration, increased surface runoff and distorted/diverted
drainage in water courses and wetlands draining t o the Río San Juan from
the southern part of the basin, to disturb the natural hydrological regime of
the river;
(b) delivered around 87,000 to 109,000 m 3 y-1 of additional sediment to the
Río San Juan;
(c) increased significantly sediment concentrations and loads in the Río San
Juan compared to pre-Road values, with adverse impacts on water quality,
turbidity, morphology and the river environment both locally and
downstream;
(d) caused significant damage to aquatic and wetland environments and
navigability of the lower Río San Juan through causing excessive
sedimentation.
1
NM, para. 2.31, quoting Diplomatic Note from the Minister of Foreign Affairs of Nicaragua,
to the Minister of Foreign Affairs of Costa Rica, Ref: MRE/DVS/VJW/0685/12/11, 10
December, 2011, NM, Annex 16.
15 161 4.4. In his 2012 report, Dr Kondolf, predicts that, unless the measures he
recommends to stabilise the road are taken, damage to the Río San Juan is certain
to continue, accelerating by a factor of ten should a hurricane strike the area . In
the conclusion to his report , Dr Kondolf states,
“Importantly, the erosion and sediment delivery to the Río San Juan
documented to date represent only a small fraction of the amount
that is certain to occur during a hurricane or other large storm.” 2
4.5. Dr Kondolf’s statement indicates that he believes the potential for erosion
and sediment delivery to be much greater than any erosion and sediment delivery
that has actually occurred since the Road was constructed. In essence he
acknowledges that relatively little erosion and sediment delivery has occurred to
date. Dr Kondolf attributes this to the fact that the pe riod since construction of the
Road has been drier than expected.
C. Geographical E xtent of the Statements
4.6. It is cle ar from the statements made by Nicaragua (reproduced in
paragraph 4.1 above) that the “transcendental ” adverse ecological and
environmental impacts referred to above would not be limited to the 108 km
length of the Road where i t is close to and parallels the Río San Juan, but would
extend downstream throughout the basin. Conversely, the 2012 Kondolf Report
focuses almost exclusively on the 41.6 km stretch of Road between Marker II and
Boca San Carlos. The only reference to sedim ent delivery to the Río San Juan
outside this stretch is oblique: Dr Kondolf reports observing sediment to have
entered or be entering the Río San Juan at a total of 54 sites, 43 of which were
located between Marker II and Boca San Carlos , but 11 of which were located in
the longer (66.4 km) reach between Boca San Carlos and the Delta . 3
2 2012 Kondolf Report, p. 51.
3 In his 2012 Report, Dr Kondolf referred to 54 sites where he says he observed direct
delivery of sediment to the San Juan (see 2012 Kondolf Report, p. 7, paraand p. 42,
lines 3 and 4 ). Dr Kondolf did not identify the exact locations of these 54 sites in his 2012
Report. In response to a request for information, Nicaragua provided the coordinates of
these 54 sites. They have been identified and analysed in the 54 Sites Report .
162 164.7. In investigating whether there is actual evidence to support the se claims of
transcendental harm to the Río San Juan it is , therefore, essential to match the
scope of the i nvestigation to that of the claims. In this context , my Report
considers the possibility of damage at both the river reach and river system
scales. However, before doing so, I report in the next section my initial
conclusions regarding the geographical sco pe of the 2012 Kondolf Report (and his
further reports) and the extent of significant erosion issues along the Road , based
on my own field observations in February and May of this year.
17 163 5. My Field Observations of the Road
A. Field Observations in February and May, 2013
5.1. As reported in the Introduction, I have visited the Road on two occasions
this year. In this chapter , I report my over -arching impressions of the Road,
especially in the context of Dr Kondolf’s narrative, based on his inspection of that
part of the Road that runs parallel to the border, which were made from a boat on
the Río San Juan and a helicopter in Nicaragu an air space in October 2012. 4I also
observed some of the mitigation works , which are dealt w ith in Chapter 12.
B. My observations and Dr Kondolf's decision to limit his quantitative
analysis to the upstream 41 .6 km of the Road
5.2. Dr Kondolf has made several visits to the Rio San Juan i n the vicinity of the
Road, but as early as on Page 9 of his 2012 R eport, Dr Kondolf introduces and
explains hi s decision to limit assessment of road -related erosion and sediment
delivery to the 41.6 km stretch of the Río San Juan between Marker 2 and its
confluence of the with the Río San Carlos:
“Due to time constraints, we completed this analysis only for the
upstream 41 km of the road, upstream from the Río San Carlos
confluence.”
5.3. On the same page, h e further notes that;
“We treated this section with priority because it has the steepest
topography overall. ”
5.4. In the event , Dr Kondolf not only prioritised this po rtion of the Road for
analysis, he considered it exclusively. Dr Kondolf appears to have had insufficient
time to estimate potential erosion rates and delivery ratios along the remaining
66.4 km of the Road between Boca San Carlos and Delta Costa Rica . Had he done
so, he would have discovered that the steep topography in this area is unusual
and contrasts markedly with that of what is much the longer part of the Road that
4 2012 Kondolf Report, p. 1, para. 1.1; see also Third Kondolf Report, p. 1.
164 18he was unable or chose not to analyse in detail. As a result, Dr Kondolf’s 2012
Report delivers an unrepresentative and potentially misleading impression of:
(a) the propensity for and extent of road -related erosion,
(b) the potential for road -derived sediment to be delivered to the Río San Juan,
and
(c) the possibility that road -derived sediment cou ld have adverse impacts on
water quality, sediment loads, morphology, environment , ecology or
navigation in either the Río San Juan or the lower Río San Juan .
5.5. I base this conclusion on having viewed the entire length of the Road from
the air plus having in spected the entire length of the Road along the Río San Juan
(except for those stretches that either do not exist or are in accessible by four
wheel drive vehicle) during field v isits made in February and May 2013.
5.6. Based on my first hand inspection of the R oad on the ground it is clear that
the erosion rates and sedimen t delivery ratios based on the 41.6 km of the road,
upstream from the Río San Carlos confluence are unrepresentative of conditions
along the remainder of the Road, where erosion rates are likely to be much lower
and probably close to those extant p rior to January 2011 , and sediment delivery
ratios are also likely to be lower than that suggested by Dr Kondolf.
5.7. This is the case not only because the terrain that the Road downstream of
Boca San Ca rlos traverses is flatter, but also because construction of the Road
followed a pre -existing road for a much greater proportion of its length, passing
through areas that have long been inhabited and developed for pasture, crops,
forestry and other uses wit h non -zero sediment yields . To support this
conclusion, it is only necessary first to look at typical views from the air and the
ground, demonstrated in photographs I took during my field visits ( Figures 1 and
2) and, second, to examine the detailed maps o f land use along a 1 km wide
corridor around Route 1856 that were produced in a Geographical Information
System (GIS) , based on satellite images, aerial photographs and ground -truthing,
by Astorga and Mende in the Land Use Change Report . In this context th e
19 165 quantitative results of Astorga and Mende’s spatial analysis and conclusions
based on those results are relevant.
5.8. According to their analysis, the area occupied by Route 1856 between
Marker 2 and Delta Costa Rica is 350.2 ha, which represents 3.3% of the
10 447.2 ha area of a one kilometre wide corridor around the Road between
Marker 2 and Delta Costa Rica.
5.9. Nearly three quarters (72.4% or 253.5 ha) of the area lost to the Road was
used for pasture p rior to construction of Route 1856 and so that land had a lready
been cleared of natural vegetatio n and developed for agriculture .
5.10. Based on the detailed mapping, field work and spatial analyse s performed
in producing the maps presented in the Land Use Change Report , I conclude that
the land use impacts of Route 1 856 downstream of Boca San Carlos and outside
the upstream 41 .6 km that features prominently in each of Kondolf’s Reports
(2012 Kondolf Report, and Second, Third and Fourth Kondolf Reports) are mainly
confined to low relief, pasture lands.
166 20Figure 1. Photographs representative of conditions observed by the author along the Road
between Boca San Carlos and Boca Sarapiqu í on the ground on February 16, 2013 .
21 167 Figure 2. Photographs representative of conditions observed by the authothe Road
between Boca Sarapiquí and the Delta on the ground on February 16, 2013 .
5.11. When viewed from the air, it is apparent that the cut slopes and fill prisms
referred to frequently (and featured in many of the photographs) in the 2012
Kondolf Report as b eing significant areas of erosion are rare along the Road
between Boca San Carlos and Boca Sarapiquí and are almost entirely absent
between Boca Sarapiquí and the Delta (Figures 3 and 4). This personal
observation is entirely consistent with the results re corded in the Inventory of
Slopes and Water Courses by Mende and Astorga (2013), which is based on
exhaustive field work combined with examination of satellite images, land -use
change maps and helicopter overflights.
168 22 Figure 3. Photographs representative of conditions along the Road between Boca San Carlos
and Boca Sarapiquí observed from the air by the author on February 16, 2013 . The only slopes
observed along the Road are in the catchment of the Río Cureña.
23 169 Figure 4. Photographs representative of conditions along the Road between Boca Sarapiquí
and the Delta observed from the air by the author on February 16, 2013 .
5.12. With regard to sediment input to the River , in his 2012 Report, Dr Kondolf
reports having observed sediment eroded from the Road to have entered, or to be
entering, the R ío San Juan at 54 sites. 5In response to a request from Costa Rica,
5 2012 Kondolf Report, p. 7, para. 1.3.6 and page 42, lines 3 and 4 .
170 24Nicaragua later provided coordinates for these 54 sites. This allowed the Costa
Rican technical team to establish the precise lo cations of the 54 sites. Of the 54
sites, the majority (42) were found actually to be upstream of Boca San Carlos,
with just 12 locations where road -derived sediment appeared to have entered or
be entering the Río San Juan along the entire 66.4 km stretch extending
downstream from Boca San Carlos to the Delta. The analysis undertaken by the
Costa Rican team is reported in the 54 Sites Report by Mende et al. (2013). This
report further establishes that the coordinates of 7 of the 54 sites place them in
Nicaraguan territory on the opposite side of the River to the Road. I take it that
either these coordinates are blunders, or that they refer to the location of the
helicopter rather than the point being observed. With respect to the Road
downstream of Boca San Carlos, points 48 and 51 are in Nicaragua, leaving just 10
points of interest, only one of which is downstream of Boca Sarapiquí.
5.13. All of the points identified by Dr Kondolf which are on Costa Rican
territory were investigated through field work and inspec ted using helicopter
over flights during summer 2013. The complete results are available in the 54
Sites Report by Mende et al. (2013), but the most salient findings are reported
here for completeness .
5.14. Turning first to the 9 points listed by D r Kondolf that lie between Boca San
Carlos and Boca Sarapiqu í on closer inspection , 7 of these appear to be of trivial
significance or unrelated to the Road . The non- trivial points (49 and 50) refer to
the confluence of the Rio Cureña and a nearby fill slope, respecti vely. As listed in
Tables 13 and 14, and illustrated in Figure 31 below, the Inventory of Slopes and
Water Courses and the ICE Report both indicate that the Cureña basin probably
does contribute sediment to the River, but this reach is located downstream o f the
massive input of sediment from the Río San Carlos (estimated in Table 14 as being
-1
in excess of 4.5 million t y ), meaning that in comparison to the average annual
sediment load of the R ío San Juan in this reach (which is nearly 8 million tonnes ).
For the reasons explained in the subsequent sections of this report) , these inputs
of Road -derived sediment between Boca San Carlos and Boca Sarapiqu í are
insignificant.
25 171 5.15. Only one of Dr Kondolf’s sites is located downstream of Boca Sarapiqu í, at
the mouth of the Caño Negro (C-109 in Medne and Asorga’s 2013 Inventory). This
crossing is stable, there are no cut or fill slopes in the vicinity and there is no
evidence of even trivial delivery of sediment to the River. The River at this
location (downstream of the major inputs from both the Rio San Carlos and Rio
Sarapiquí), carries nearly 9 million tonnes of sediment annually (see Table 16
below). If Road-derived sediment does enter the R ío San Juan via the Caño Negro
it does so in quantities that are small in abs olute terms and negligible in relative
terms.
5.16. Based on my visits to and observations of the Road, backed up by detailed
investigation of the 54 sites of sediment delivery referred to in the 2012 Kondolf
Report by the Costa Rican technical team , I conclude that the Kondolf Report s say
nothing about the Road downstream of Boca San Carlos because, with respect to
the actual and potential delivery of road -derived sediment to the Río San Juan,
there is nothing to say.
172 26 6. Characteristics of the Río San Juan
A. Introduction
6.1. The statements made by Nicaragua (summarised above in paragraph 4.1 )
and supported in the 2012 Kondolf Report (summarised above in paragraph 4.2)
as well as the Second, Third and Fourth Kondolf Reports , suggest that the impacts
of the Road on the Río San Juan extend to its hydrology, sediment concentrations
and loads, morphology, environment and ecology. To assess whether there is
evidence to support these statements, it is first necessary to examine and
establish the characteristics of the Río San Juan with respect to each of these
aspects of its form and process. That is the purpose of this Chapter of my Report.
B. Geologic, Tectonic and T opographic Controls on the Río San Juan
6.2. The natural characteristics of the catchment and drainage system of the
Río San Juan are controlled by the geology and climate of its basin. Hence, this
examination of those characteristics must start by reference to the structure and
tectonics of the region. The account presented here is based on original and
background resear ch performed by Dr. Allan Astorga as part of technical studies
related to preparation on my 2011 Report in the Certain Activities Case. The
complete account of regional geology is presented in detail in a report to the Costa
Rican Government ( Astorga, 2011 b). The material presented here is consistent
with my précis in Thorne (2011), but i t differs in that this summary covers the
entire length of the River between Lake Nicaragua and the Caribbean Sea,
whereas c overage in Thorne (2011) focused solely on geolo gical control s on the
bifurcation of the Río San Juan into the lower Río San Juan and the Río Colorado at
Delta Costa Rica , and the effects of neotectonics on the gradient of the lower Río
San Juan.
6.3. The geological -tectonic map of the Caribbean region publ ished by Case and
Holcombe (1980), shows that the basin of the Río San Juan consists of contrasting
geologies separated by active fault lines (Figure 5).
27 173 Figure 5. Geological-tectonic map of the Caribbean Region with enlarg ement showing the
area in and around the basin of the Río San Juan (box in lower right of map) .
6.4. The effects of geology and tectonics are evident in the regional terrain, as
illustrated clearly in the Digital Elevation Mod el (DEM) reproduced in Figure 6 .
Based on the contrasting types and varying degrees of geologic and tectonic
control exerted on the River, its channel and its floodplain, the Río San Juan may
be divided into five, distinctly different reaches, described in detail in Tabl e 1 and
illustrated in Figure 7 , which shows the five geologically -tectonically -
topographically controlled reaches (including bed rock outcrops) superimposed
on the long profile of the River, together with the DEM and a topographic map of
the region.
6.5. It is vital to recognise and understand the significance of geology, tectonics
and topography in influencing, and in some reaches constraining, fluvial
processes and morphological responses to changes in the sediment supply in the
Río San Juan, as will be explained in the remaining sections of this C hapter of my
report.
174 28(supplied by A. Astorga).
ragua
order is marked in red.
and the b
29
and other major rivers are marked in blue
Río San Juan
The courses of the
.igital Elevation Model (DEM) of area around the Río San Juan downstream of Lake Nica
Figure 6
175 -
long the
. Hesof the
the
s (see long maintailock, which
The sediment
rapid vial (that is: selfediment from
allu Río San Juan and,
. The elevation,
is controlled by the first
Hess Fault. As explained in
- channel tending to silt and
logical basin that contains Lakeck outcropfloodplain is wider and more
discontinuous, being alternatebounded by high terrain
long profileonfluence. closer to beingThere arealluvial. outcrops in the
Río active . -
valley
and its semi
, :here are no flows north across the Chortis B
steeper and
bounded on both sides by steep terrain formed in
that are naturally resistant to fluvial San Juan to continue rising, while that to the south continues
Description
changes because it comes under the control ofagainst the prevailing, neotectonic
. The alluvial floodplain is thrault zone to the soRioplain
9 Río
are controlled by bedrock outcrops that form of the fault
etention rn Lake Nicaragua and lafluvial processes) and theaining
t has a very low gradient of the of the River
Rive
colluvial slope materials
of the directionRiver flowsthe channel 30
-xistent as the river is and the channel encounters hard rock and colluvium slopes lesslos.Elena
rock or responsive too the north and
Consequently, i and
and slope and hich are for land north
steep basins.
Geologically defined reaches of the Río San Juan being uplifted
1. In thiarrlgadriIlRtvrprotflrthIrovanlryarffsrlolIhirylcuebrtilisttebmisrsdefricndu,wtrelr(stcrplncneittd,rRctyufetiiistawcrn
Table
Slo(m/m) 0.007 0.008 0.010 0.010 0.009
(m)
6.5 7.7 6.9 3.8 5
Fall in
Elevation
(km)
Length 52.86 52.67 39.86 22.04 32.35
- -
–
–
o –
Reach ri
RíoRFío PocosolRíoRíocSoasnolCaRíoRSanSaCralisuí RíoDSealapiquí Deltaribbean Sea
176 .
s indicated
(c)
river reache
five
wth
topographic map
(a) showing reach limits31entioned in Table 1 and locations of rapids caused by bed rock
(b) DEM
for an example)
en Lake Nicaragua and the Delta
(see Figure 9
ed
(b) San Juan betwe
Río
outcrops in the b
Locations of bedrock outcrops that form rapids
Long profile of the
(a)
7
Figure
177 C. Channel morphology and classification
6.6. The fact that the Río San Juan is not a conventional, alluvial stream has
long been recognised. For example, in the 19 thcentury, engineers surveying the
River in exploratory investigations for a Trans -Oceanic Canal noted that the long -
profile was almost uniform and that the bed upstream of Boca San Carlos featured
multiple rapids associated with bed rock shoals that made the River difficult to
navigate and canalize (Figure 8).
Figure 8. Long profile of the Río San Juan (from: Aguirre-Sacasa, Franciso 2002. “Un Atlas
Histórico de Nicaragua”, Colección Cultural de Centroamérica ).
6.7. I observed several of these rapids during my field inspections in Febr uary
and May 2013 (see Figure 9 for one example) and can confirm that they control
both bed elevations and the long -stream gradient of the River in the reach
between the tributary junctions of the R ío Pocosol and Río San Carlos.
178 32 Figure 9. Example of rapids that control the bed elevation and long -stream slope of the Río
San Juan between the confluence with the Río Pocosol and Boca San Carlos . These particular
rapids are located just downstream of Río Inf iernito tributary conflue nce.
6.8. It is only necessary to compare the long profi le of the Rio San Juan
(Figures 7a and 8 ) to th at in a typica l river (Figure 10 ) for the main difference to
become obvious.
Source Transport Response
Figure 10. Typical river long profile from so urce to sea. Note the concave shape with a
gradient that is steep in the upper course, gentle in the middle course and low in the lower
course. Annotations represent the Montgomery-Buffington (1997) stream classes based on
channel type and the ratio between sediment transport capacity and supply (see Figure 11).
Modified from Montgomery and Buffington (1997).
6.9. In the case of the Río San Juan, the river is missing its steep, headwater
‘Source’ zone of hillslopes, hollows and colluvial reaches and the course
downstream of Lake Nicaragua comprise s only of ‘Transport’ and ‘Response’
33 179 reaches. This is because what would be the ‘Source’ zone of the Rio San Juan main
stream is isolated from the River by Lake Nicaragua. The de facto sediment
‘Source’ zones are actually the headwaters of the major Costa Rican tributaries
(and especially the Río San Carlos) , as explained in the following sections of this
chapter.
6.10. Montgomery and Buffington (1997) explain that the sensitivity of any
reach to changes in the supply of sedime nt depends on the ratio between its
capacity to transport sediment and the supply of sediment from upstream and
local sources:
q = Q /Q
r c s
where, qr = capacity/supply ratio, Q c = sediment transport capacity
and Q = sediment supply from upstream and local s ources.
s
6.11. Transport reaches are morphologically resilient channels in which q r > 1
and the actual rate of sediment transport is limited by the available supply rather
than the capacity of the flow to carry sediment. Supply -limited conditions mean
that the ri ver has unfilled capacity to transport more sediment if it becomes
available, giving the reach the capability to rapidly convey increased sediment
loads downstream with little or no morphological response . Transport reaches
typically featu re a cascade of b edrock-controlled rapids or a step -pool bed
controlled by large , rarely mobilized boulders.
6.12. Response reaches are morphologically sensitive channels in which q r < 1
and the actual rate of sediment transport is limited by the capacity to transport
sediment rather than the supply from upstream and local sources. Transport -
limited conditions mean that the river has no unfilled capacity to transport
additional sediment and morphologic adjustment s are likely to occur in response
to changes in sediment supply. Response reaches typically have alluvial beds
featuring plane -bed, pool -riffle, or dune -ripple bedforms depending on whether
the dominant bed material s are in the cobble, gravel or sand size ranges
(Figure 11).
180 34 Figure 11. Schematic representation of downst ream trends in relative sediment transport
capacity (Qc) and sediment supply (Qs) in mountain rivers . From Montgomery and Buffington
(1997).
6.13. My application of the Montgomery -Buffington classification to the Rio San
Juan indicates that the first and second reaches (between Lake Nicaragua , Río
Pocosol and Boca San Carlos) are Transport reaches (Figure 12) because the River
in these reaches is controlled by a series of rapids ( i.e. it is a cascade -type channel
according to Figure s 10 and 11 ). These reaches hav e ample sediment transport
capacity to carry the relatively limited supplies of sediment from Lake Nicaragua
and tributaries drain ing relatively small, low relief catchments with relatively low
sediment yields.
6.14. The third and fourth reaches (between Boca S an Carlos , Boca Sarapiqu í
and the Delta ) are Response reaches (Figure 12). They are characterised by dune-
ripple beds formed in mobile sand and high rates of sediment supply from large
Costa Rican tributaries draining steep basins with active volcanoes . These inputs
are roughly in balance with the high transport capacity of the River, though with a
slight tendency for net deposition rat her than erosion (see Figures 10 and 11 ).
6.15. The fifth reach is the lower Río San Juan below the Delta. This is a Response
reach (Figure 12 ) in which the channel has a dune -ripple bed. Regional,
neotectonic uplift of the Chortis Block (which lies to the north of the Santa Elena -
Hess Fault) dictates that the transport capacity of the lower Río San Juan naturally
decreases gradua lly through time, to drive a lon g-term depositional trend (see
35 181 section II.2.1 of Thorne (2011) for a fuller explanation of this trend). According to
my application of the Montgomery -Buffington classification, the Rio Colorado also
constitutes a dune -ripple, Response reach, although regional tectonic subsidence
south of the Santa Elena - Hess Fault means that the sediment transport capacity
of the Rio Colorado naturally increases gradually through time.
Locations of bedrock outcrops with rapids
Transport Response
Figure 12. Designation of reac hes of the Rio San Juan according to the Montgomery -
Buffington classification .
D. Catchment Hydrology
(1) Rainfall Distribution
6.16. The climate of the region is dominated by atmospheric circulation in the
Inter-tropic Convergence Zone (ICZ). The spatial distribution of rainfall in the Río
San Juan basin exhibits the impacts of strong orographic effects associated with
high mountains and volcanic peaks located along the s outhern margin of the
catchment in the headwaters of large, northeast -flowing tributaries such as t he
Río San Carlos and the Río Sarapiquí (Figure 13 a).
182 36 Figure 13. (a) Topographic map and (b) Distribution of mean annual rainfall in the catchment
of the Río San Juan downstream of Lake Nicaragua . Note coincidence of heaviest rainfall with
area of high relief along the southern margin of the basin in the headwaters of ío San
Carlos and Rio Sarapiquí (maps from 2013 ICE Report).
6.17. As a result, annual precipitation in the mountainous headwaters of rivers
like the R ío San Carlos and R ío Sarapiquí is se veral times greater than that
recorded close to and along the main stream Río San Juan in the vi cinity of the
Road (Figure 13 b).
6.18. Seasonal effects influence the temporal distributions of both rainfall and
runoff with the latter characteristically being hig h between July and December
and low between March and May (Figure 14 ). Further details of regional climate
and rainfall may be found in the ICE Report and the CCT Report.
Figure 14. Monthly mean discharges measured in the R ío San Juan main stream at Stat ion 01-
03, La Trinidad (from 2013 ICE Report).
6.19. In the 2012 Kondolf Report, Dr Kondolf refers on several occasions to the
certainty that erosion from the Road will increase tenfold during the next
hurricane or tropical storm. For example, on page 44, he states:
37 183 ‘The intense rains that will inevitably occur during the next hurricane or
other major storm will produce vastly greater erosion, mass wasting, and
sediment delivery to the river. ”
And this dire prediction is repeated on page 4 of the Third Kondolf Report:
“There is no question that when intense rains associated with
tropical storms and hurricanes occur, the damage will be widespread
and severe.”
6.20. However, it is not inevitable or unquestionable that the Río San Juan will
be struck by a hurricane or tro pical storm . In fact, this would actually be
unprecedented and it is therefore highly unlikely. According to the United States
National Oceanographic and Atmospheric Administration website, there is no
record of Costa Rica ever having been struck by a hurr icane or tropical storm
(Figure 15).
Figure 15. Historical hurricane tracks according to NOAA (from
http://csc.noaa.gov/hurricanes/# ).
It is true that Costa Rica has been affected in the past by hurricanes passing to the
north of the country, For example, in respect of three relatively recent events, the
Costa Rican National Meteorological Institute recorded rainfalls in the Rio San
184 38Juan basin (in the area proximate to the Road) of between 20 and 250 mm (f or
Hurricane Joan); below 100 mm (for Hurricane Mitch); and between 15 and 150
mm (for Hurricane Stan). 6 In my opinion, rainfalls of this magnitude were in each
event unexceptional and unlikely to cause widespread destruction because the
basin of the Río S an Juan receives abundant rainfall in most years and the
hydrology, sediment dynamics, morphology and environment of the River are
fully adjusted to the effects of frequent and heavy rain storms.
6.21. On the other hand , if a hurricane or tropical storm were to strike the basin
directly, there would likely be damage on a massive scale, including flooding and
landslides affect ing the entire region . In such a case, damage would be severe and
extensive whether or not the Road existed.
6.22. But such an event would be unprecedented and, rather than being a
certainty, the chance that a hurricane might cause significant erosion and
sediment delivery from the Road is actually very small.
(2) Gauging stations and records
6.23. Gauged discharges for different periods of record are avail able for three
gauging stations on the Río San Juan main stream and twelve stations distributed
between the basins of the Ríos Frío, San Carlos and Sarapiquí in Costa Rica . In
December 2010, a further station was established o n the Río Colorado just
downstream of the bifurcation , at Delta Costa Rica (Figure 16, Table 2).
6
Letter from the General Director of the Costa Rican National Meteorological Institute to
H.E. Edgar Ugalde Alvarez, 7 November 2013, Annex [xx] to Costa Rica’s Counter-
Memorial.
39 185 Table 2. Gauging stations on the Río San Juan - Colorado system and its Costa Rican
tributaries (from ICE Report).
Mean
Drainage
Station Station Name River Basin Area Period of Annual Active to
code 2 Record Discharge date
(km ) (m s )1
01-01a San Carlos San Juan San Juan 30 306 c 1965-1986 c 297 c No
01-02a El Castillo San Juan San Juan 32 819d 1971-1981 422 b No
1997-1998 b
e e
01-03 La Trinidad San Juan San Juan 38 730 1973-1976 1123 No
11-04 Delta Colorado Colorado San Juan - 2010-2013 1026 Yes
12-03 Puerto Viejo Sarapiquí Sarapiquí 845 1968-1999 113 No
12-04 Veracruz Toro Sarapiquí 191 1971-2013 26 Yes
12-05 Bajos del Toro Toro Sarapiquí 73 1985-1996 6.7 No
12-06 Toro Toro Sarapiquí 41 1993-2013 4.4 Yes
12-11 San Miguel Volcán Sarapiquí 59 1998-2002 11 Yes
2010-2013
12-13 Río Segundo Segundo Sarapiquí 17 1999-2013 2.7 Yes
14-02 Jabillos San San Carlos 552 1963-2013 51 Yes
Carlos
14-04 Terrón Colorado San San Carlos 1556 1968-2008 166 No
Carlos
f
14-05 Peñas Blancas Peñas San Carlos 293 1968-2013 35 Yes
Blancas
14-20 Pocosol Peñas San Carlos 124 1980-2013 19 Yes
Blancas
16-02 Guatuso Frío Frío 253 1969-2013 28 Yes
16-05 Santa Lucía Venado Frío 34 1982-2013 3.9 Yes
a b
Stations install ed, coded and operated by the INETER of Nicaragua. INETER (2001).
cINETER (2002). INETER (2006). ICE (1973). Since 2002 the discharges are regulated by the
Peñas Blancas hydropower plant.
(3) Mean Annual Discharge Regime of the Rio San Juan - Colorado System
6.24. The mean annual discharge regime of the Rio San Juan - Colorado system
was established based on accounting for inputs from Lake Nicaragua and the main
tributaries in Costa Rica and Nicaragua. This was achieved using the gauged data
listed in Table 2 fo r the three main stream gauging stations, together with
186 40discharges calculated using the Area -Precipitation method for each of the Costa
Rican tributaries.
Figure 16. Gauging stations in the Rio San Juan basin (from ICE Report).
6.25. The Area -Precipitation me thod is a standard approach used by
hydrologists t o estimate discharges from un -gauged locations and catchments ,
based on synthetic rainfall -runoff relationships for data from gauging stations
nearby. It was necessary to apply the A rea-Precipitation method because the
tributary gauging stations are located at varying distance s upstream of the ir
confluences with the main River, so that the gauged records are not directly
equivalent to the discharges supplied to the Río San Juan, while other tributaries
are entirely un-gauged.
6.26. The discharge balance was closed by estimating the mean annual
discharge to the River from Lake Nicaragua as the difference between the
discharge of Río San Juan measured at the San Carlos station (INETER, 2002) and
the mean annual disc harge of the Río Frío (ICE, 2010). The mean annual discharge
input by Nicaraguan tributaries was estimated as the difference between the
measured discharge of Río San Juan at La Trinidad station (ICE, 2011) and the
41 187 sum of the inputs from Lake Nicaragua and all the Costa Rican tributaries ( see
Table 3 and Figure 17 ). As elements of the discharge regime have had to be
obtained based the differences between gauged discharges, the figures in Table 3
are only indicative. They are still reasonable approximations, however, quite
sufficient for the purposes of this Report.
Table 3. Discharge Regime of the Rio San Juan (from ICE Report).
Mean Annual Relative contribution (%)
Source Discharge
-1 Including Lake Excluding Lake
(m³ s ) Nicaragua Nicaragua
a
Lake Nicaragu a 185 16 -
Costa Rican basins 783 70 83
b
Nicaraguan basins 155 14 17
Total 1123 100 100
aEstimated as the difference between the discharge of San Juan River at San Carlos station
b
(INETER, 2002) and the input from the Frío River basin (ICE, 2010). Estimated as the
difference between the discharge of San Juan River at La Trinidad station (ICE, 2011) and the
sum of inputs from Lake Nicaragua and all the Costa Rican river basins
188 42 Figure 17. Discharge regime of the Río San Juan - Colorado system .
E. Sediment Regime
(1) Suspended sediment gauging stations and records
6.27. Suspended S ediment Concentration (SSC) has been measured using
standard sampling procedures for different periods of record at thirteen stations
operated by ICE and within the Río San Juan River drain age network in Costa Rica
(Table 4). The values of average annual Suspended Sediment Load (SSL) listed in
column 7 of Table 4 have been calculated by combining the SSC record with the
average annual hydrograph for each station.
43 189 Table 4. Suspended sediment gauging stations along the main stream Rio San Juan and in
Costa Rican tributary basins (from the ICE Report ).
Ave. Annual
Station No. Sampling Suspended
Name Basin River sample
code s period load
(t yr )
01-03 La Trinidad San Juan San Juan 12 1974-1976 7 995 000
a
11-04 Delta Colorado San Juan Colorado 31 2010-2013 5 981 000
12-03 Puerto Viejo Sarapiquí Sarapiquí 264 1970-1998 165 500
12-04 Veracruz Sarapiquí Toro 285 1972-2012 101 000
12-05 Bajos del Toro Sarapiquí Toro 137 1985-2001 50 000
12-06 Toro Sarapiquí Toro 117 1995-2010 20 500
12-11 San Miguel Sarapiquí Volcán 47 1998-2010 23 000
12-13 Río Segundo Sarapiquí Segundo 25 1999-2009 1 800
14-02 Jabillos San Carlos San Carlos 338 1967-2011 600 000
14-04 Terrón Colorado San Carlos San Carlos 53 1998-2009 1 300 000
14-05 Peñas Blancas San Carlos Peñas 308 1970-2011 157 000
Blancas
14-20 Pocosol San Carlos Peñas 278 1980-2012 358 000
Blancas
16-02 Guatuso Frío Frío 361 1970-2012 60 800
16-05 Santa Lucía Frío Venado 153 1984-2011 8 100
a
Note: this is the average annual suspended load of the Río Colorado downstream of the
Delta.
6.28. However, the only SSC record available for the Río San Juan main stream is
that from La Trinidad (Station 01 -03) between January 1974 and March 1976
(Line one in Table 4 ). I am instructed that these measurements were made jointly
by Costa Rica and Nicaragua and their source is:
Governments of Nicaragua and Costa Rica (1977). Central American
Hydrological Project [PHCA), with the assistance of the United
Nations Developme nt Programme, San Juan River Hydroelectric and
Navigation Project, December 1977, vol. 1, p. 69.
6.29. These data were cited in Nicaragua's Counter Memorial in the Navigational
Rights Case, where Nicaragua said: “the sediment load immediately downstream
190 44from the Sarapiquí River, measured at the beginning of the seventies, was 10.2
7
million metric tons per year.” Given their provenance, and the fact that the data
extend over more than a two year period, I conclude that they provide a
reasonable indication of SSCs in the Río San Juan prior to construction of the
Road.
6.30. The records reported in Table 4 include 2 409 individual measurements of
suspended sediment concentration and these are plotted below in Figure 18 .
Figure 18. Suspended sediment concentration as a function of discharge for 2 409 samples
taken from the Río Colorado, Río San Juan and its Costa Rican tributa. Note: Station 14 -01
in the legend refers to Delta Colorado (Station 11 -04) in Table 4 (from the 2013 ICE Report).
6.31. SSCs measured in this large data set vary from less than 10 parts per
million to more than 10 000 parts per million. This clearly illustrates the extreme
natural variability in sediment concentrations, and associa ted levels of turbidity,
characteristic of rivers in the Río San Juan – Colorado system. It should be noted
that the wide range of SSCs is not an environmental or water quality problem – as
7
See Nicaragua Counter -Memorial, Navigational Rights Case , para. 1.1.8.
45 191 demonstrated in the CCT Report, it is a long -standing fact of life to which the
River’s aquatic and riparian ecosystem is fully adapted.
(2) Measured and calculated bed load in the Rio San Juan - Colorado
6.32. Bed load is not routinely measured at most gauging stations, but 115 bed
load samples were collected between December 201 0 and June 2013 at the Delta
Colorado station (11 -04) and seven samples were also collected at the mouths of
Río San Carlos and Río Sarapiquí. Details of the samples, including their particle
size distributions , are reported in the ICE Report . The results demonstrate that
bed load in Río San Juan – Colorado system is almost entirely composed of sand
(Figure 19) confirming that the bed of the Río San Juan downstream of Boca San
Carlos is formed in mobile, sand -sized sediment.
Figure 19. Frequency distribu tion of the sand percentage s in all bed load samples, indicating
that downstream of Bo ca San Carlos 90% of the bed of the Río San Juan is formed in mobile
sand.
6.33. The measured bed load data are in themselves insufficient to estimate the
average annual bed lo ad of the Río San Juan, but it is well established that the
Einstein bed load function can be used to contruct reliable bed load rating curves,
provided that the equation is calibrated using measured data. Hence, the Einstein
function was applied to produc e a calibrated bed load rating curve for sand (that
is particles larger than 0.063 mm) at the Río Colorado Station (11 -04), using the
115 bed load measurements, the sampled median bed sediment size (D 65 =
0.584 mm) and the hydraulic parameters relevant to a wide range of discharges
(Figure 20).
192 466.34. The calculations are reported in the ICE Report.
Figure 20. Bed load sediment rating curve for sand calculated by calibrating and applying the
Einstein function to measured data from the Delta Colorado s tation (11-04) (from ICE 2013).
6.35. The average annual bed load transported by the Río Colorado was then
calculated by combining the bed load rating curve with the hydrograph
established by stream gauging at Station 11 -04 between December 2010 and June
2013. The calculations are reported in detail in the ICE Report.
6.36. Using this method, the best estimate of the average annual bed load
-1
transported by the Río Colorado is 2 488 000 t y . Given the uncertainties in the
data, th e 95% confidence interval on this best estimate is 2 340 000 to
2 595 000 t yr -1.
6.37. The bed load rating curve for the lower Río San Juan just downstream of
the Delta should be similar to that in the nearby by Río Colorado, and with this
reasonable assumption, an average annual bed load of 71 000 t yr was calculated
for the Lower Río San Juan, with a 95% confidence interval of 66 600
to 73 800 t yr .1
6.38. Applying the law of sediment continuity, the average annual rate at which
bed load is transported by flow in the Río San Juan approaching the Delta must
match the sum of the loads calculated for the Colorado and Lower San Juan,
suggesting that the average annual bed load in the main stream Río San Juan
47 193 should be about 2 559 000 t yr -, with a 95% confidence interval of 2 406 600 to
2 668 800 t yr -.
6.39. Estimated average annual bed loads in the Río San Juan – Colorado system
are summarised in below, in Table 5.
Table 5. Current average annual bed loads in the Río San Juan – Colorado
(compiled from the ICE Report)
Average Annual Bed Load (t yr -)
River Period
Best Estimate Upper and lower bounds
Río San Juan 2010 - 2013 2 559 000 2 406 600 – 2 668 800
Río Colorado 2010 - 2013 2 488 000 2 340 000 – 2 595 000
Lower Río San Juan 2010 - 2013 71 000 66 600 – 73 800
(3) Average annual total sediment loads in the Río San Juan – Colorado
6.40. The suspended and bed loads calculated in sections E (1) and E (2) above
for the period December 2010 to June 2013 may be added to indicate the total
sediment load s in the rivers of the Río San Juan – Colorado system. The resu lts are
listed below, in Table 6 .
Table 6. Current average annual total loads in the Río San Juan – Colorado
(compiled from data presented in the ICE Report)
River Suspended load Bed load Total Load
t y1 t y-1 t y1
San Juan 6 573 000 2 559 000 9 133 000
Colorado 5 981 000 2 488 000 8 470 000
lower San Juan 592 000 71 000 663 000
F. Contrasts between the Río San Juan and rivers in the Pacific Northwest
6.41. In the literature review in section 3.1.4 of the 2012 Kondolf Report, the
adverse impacts o f roads on rivers are illustrated primarily by use of examples
from the West coast of the USA. Dr Kondolf cites and quotes from a considerable
body of literature in explaining how road building in the twentieth century
supplied massive amounts of sediment to water courses such as the Quinault
194 48River, Clearwater River, and Redwood Creek, leading to reduced water quality,
unprecedented sedimentation, and deterioration in aquatic and benthic habitats
that led to the collapse of the salmon populations in these w ater courses.
However, as I will demonstrate below, there are some caveats to the simple
message he delivers that road building in northern California, Oregon and
Washington drove salmon to the point of extinction and, in any case, what
happened in these r ivers has no relevance to the Río San Juan, because (as is clear
from the CCT Report) , there are no salmon in the Río San Juan.
6.42. Without trying to defend the totally inappropriate actions taken and
damage done to rivers in the Pacific Northwest, which were indeed regrettable, it
is worth citing some further literature and making counter -points on road
construction and near extinction of the ‘King of Fish’.
6.43. The first point is that the scale of road building in the catchments
mentioned by Dr Kondolf was exten sive – far more so than in the case of the Road
constructed by Costa Rica. According to Montgomery (1994a; 1994b ), in many
catchments in the P acific Northwest the road density resulting from the 20 th
century forest road building campaign rivaled in extent the length of the stream
network itself, with as much as 60% of the newly constructed roads being directly
connected to the stream networks within the basins affected . The effect was for
road construction to increase drainage density by 50% or more , with the
understandably marked impacts on catchment hydrology and sediment yields
noted earlier by Reid and Dunne (1984) , which are cited by Dr Kondolf in his
Third Report . By contrast, the total length of Route 1856 is a tiny fraction of the
length of the exten sive channel networks in the Costa Rican tributary basins, and
is infinitesimal in the context of the drainage network of the Río San Juan itself.
6.44. A further comparison that explains why the impacts of road building
observed in the examples cited by Dr Kond olf cannot be compared to those in the
Río San Juan is to consider the paper published by Cedarholm et al. (1982) , who
found that roads covering 4% of the overall surface area of the Clearwater River
increased sediment production and delivery to channels b y 400%. This is indeed
a massive increase and one that would be expected to have significant impacts on
49 195 the receiving waters. However, if we apply that same proportionality to Route
1856, a different outcome emerges. Let us assume that, as in the case of t he
Clearwater River, covering 1% of a basin in roads increases sediment delivery by
100%. The basin area of the Rio San Juan is close to 40 000 km while, according
to the mapping performed by Astorga and Mende in the Land Use Change Report ,
the area of the Road (including cut slopes, fill slopes and all other disturbed areas)
is about 3.5 km 2. The Road therefore covers only 0.00875% of the area of the
basin. It follows, that in the case of the Road along the Rio San Juan, the expected
increase in sediment delivery to the Río San Juan should be around 1%. As I show
later in paragraph 8.56 of this report, that estimate is actually very close to the
mark. Yet the measured data reported a bove in section 6.E establish that natural
variability in the sediment loa d is around +/-20%: that is, far greater than 1%, so
such an increase would have no impact whatsoever and would, in fact, be
undetectable. If the example of road building in the Clearwater River has value as
comparator to construction of Route 1856 , that v alue lies not in portending
similarly damaging impacts in the Río San Juan but reassuring us that any
increase in sediment load due to construction of is bound be tiny.
6.45. Another major difference between tropical rivers in Central America and
the examples u sed by Dr Kondolf is that the Pacific North West rivers are cold -
water streams with naturally low concentrations of Total Suspended Solids ( TSS).
Between storm runoff events turbidity in these rivers is minimal - hence names
like the "Clearwater River" . In contrast, the Río San Juan is a warm -water stream
with high naturally high concentrations of suspended sediment and organic
material that persist even during base flow. The high TSS concentration is what
makes the water turbid and gives the River the characteristic green-brown colour
that is evident i n true colour photographs and satellite images . Fish and other
aquatic organisms in the Río San Juan do not find high turbidity problematic
because they are fully adapted to it. On the contrary , a reduction in turbidity
would be more likely damage the aquatic ecosystem of the Río San Juan through,
for example, unnaturally revealing to predators the location of prey species .
196 506.46. The final point that is unclear from Dr Kondolf’s literature review is that
road buildi ng was just one of multiple factors responsible for the decline of
salmon in the rivers of the Pacific North West .
6.47. First, loss of Large Woody Debris due to clean ing of stream channels and
catchment forest clear cutting was far more important as a fundamen tal driver of
environmental change in Pacific North West rivers than was road construction , in
all but the areas with the steepest terrains . Loss of Large Woody Debris leads to
extensive impacts on river morphology and habitat complexity (e.g. wetted
channel area, size, number and depth of pools, number of side channels etc. ). It is
now generally recognis ed that changes in habitat character, loss of key habitats
(e.g. pools) and reduction in habitat diversity and floodplain connectivity were
primary causes the decline in salmon (Montgomery et al. 1995, Collins and
Montgomery 2002, Collins et al. 2002, Collins et al. 2012) .
6.48. Second, Chapman (1988) and Lisle (1989) established that increased f ine
sediment infiltration into previously clean river bed gravels adversely affects
salmon survival because their eggs incubate within the gravel. But the fish species
that inhabit the Río San Juan do not bury their eggs in clean gravel beds .
Therefore, t his mechanism by which the salmon fishery in California, Oregon and
Washington was damaged is completely irrelevant.
6.49. Third, salmon are anadromous – meaning that they migrate between the
river and the ocean, actually spending most of their lives at sea. Pess et al. (2002)
showed that changes in the river environment accounted for only about half of
inter-annual variability in Coho salmon abundance in the Snohomish River, with
factors related to that part of the fish’s life cycle dependent on ocean conditions
accounting for the other half. Hence, the decline of salmon in the Pacific
Northwest is probably related as much to pressures on the population at sea
(climate change and over -fishing) as it is to changes in river environments.
6.50. Finally, perhaps the biggest single cause of the decline of pacific salmon has
been dam buildin g - which blocks the passage of anadromous fish between their
headwater spawning streams and the sea; an impact which f ish ladders have
failed to alleviate and fish hatcheries seem to have compounded.
51 197 6.51. In summary, road building was a leading contributor to the decline of
salmon in the Pacific North West only in some very steep drainage basins where
road construction was particularly extensive, such as in the Clearwater and
Quinault basins quoted by Dr Kondolf . In most American west coast rivers the
decline of salmon must be blamed primarily on dam construction, overfishing,
hatcheries, hydrological changes due to urban expansion, and loss of Large
Woody Debris due to stream cleaning and basin-wide forest clear cutting
(Nehlsen et al. 1991, Montgomery 2003, esp. Chapters 1 -3, 10 and 11 ). These
factors are simply irrelevant to assessment of the impact of the Border Road on
the Río San Juan.
G. Appearance of the Río San Juan in 2009 in Figures 4 and 5 of the
Kondolf Report
6.52. In the 2012 Kondolf Report, it is stated on page 7 that,
“Spatial Solutions of Bend, Oregon USA) supplied the following
imagery of the river and road corridor through the study area:
Pleaides Satellite pan -sharpened multi -spectral imagery with 50cm
resolution for September -October 2012; and
RapidEye Satellite multi -spectral imagery with 5m re solution
acquired December 2009.”
6.53. Selected parts of these images were used in Figures 4 and 5 (on page 18 of
the 2012 Kondolf Report) to illustrate conditions before (2009) and after (2012)
construction of th e Road. Figures 4 and 5 from the 2012 Kondolf are reproduc ed
below as Figures 21(a) and 22(a ), respectively.
6.54. In June 2013, on Nicar agua’s suggestion, 8I requested from Jeff Campbell of
Spatial Solutions, Bend Oregon, duplicate copies of the December 2009 RapidEye
satellite images supplied to Nicaragua in 2012 . Mr Campbell attest ed that the
images supplied to me are identical to those supplied to Nicaragua. They ar e
8 Costa Rica requested copies of the satellite imagery used in the 2012 Kondolf Report.
Nicaragua refused to provide thbut indicated that these could be obtained from the
commercial vendor, Spatial Solutions.
198 52reproduced in Figures 21 (b) and 22 (b) (below Figures 4 and 5 of the 2012
Kondolf Report) fo r comparison.
6.55. When the images depicting pre -Road conditions in 2009 in Figures 4 and 5
from the 2012 Kondolf Report (Figures 21 (a) and 22(a)) are compared with the
true colour satellite images supplied by Spatial Solutions (Figures 21 (b) and
22(b)) this reveals that the hue in Figures 4 and 5 of the 2012 Kondolf Report
depicting pre -Road conditions differs from that in the original images. This is
especially evident in the colour of the pre -existing road ( marked in both Figures 4
and 5) and that of the Rive r itself. In December, at the height of the wet season,
the Río San J uan River is high (see Figure 14 , above) and characteristically brown
– as it appears in the original RapidEye images.
53 199 (a)
(b)
Figure 21. (a) Figure 4 from page 18 of the 2012 Kondolf Report. (b) Rapideye image of areas
around Isla Reloj – Palo Seco in 2009 supplied to Nicaragua by Spatial Solutions and in Figure
4 of the 2012 Kondolf Report . Red box indicates the area depicted in the left (2009) image in
Figure 4 of the 2012 Kondolf Report. I obtained this image from Spatial Solutions in June
2013. Mr Jeff Campbell of Spatial Solutions supplied both images and he attest ed to me that
the image in (b) is an exact duplicate, identical to the image he supplied to Nicaragua in 2012
- which was used to produce the left hand (2009, pre -Road) image in (a) .
200 54 (a)
(b)
Figure 22. (a) Figure 5 from page 18 of the 2012 Kondolf Report. (b) Rapideye image of area
around 2.3 km downstream from Boca San Carlos and across from the mouth of Quebrada
Guapote in 2009, supplied to Nicaragua by Spatial Solutions and used in Figure 5 of th2012
Kondolf Report . Red box indicates the area depicted in the lef t (2009) image in Figure 5 of the
2012 Kondolf Report. I obtained this image from Spatial Solutions in June 2013. Mr Jeff
Campbell of Spatial Solutions supplied both images and he attest ed to me that the image in
(b) is an exact duplicate, identical to the image he supplied to Nicaragua in 2012 - which was
used to produce the left hand (2009, pre -Road) image in (a) .
55 201 7. Has Route 1856 altered the hydrology of the Río San Juan?
A. Overview
7.1. This Chapter reports the results of analyses performed to ascertain
whether constru ction for Route 1856 has impacted the hydrology of the Río San
Juan. The necessary analyses were performed by Costa Rican hydrologists and
engineers at ICE and are reported in the ICE Report . The investigation was
undertaken in two stages. First, the incre ase in impermeable area within each of
the major and micro -basins draining from Costa Rica to the Rio San Juan was
measured using a GIS. Second, the hydrological regimes of the basins prior to and
following construction of Route 1856 were simulated using h ydrologic modelling.
B. Increases in impermeable areas due to construction of Route 1856
7.2. In performing this analysis , consideration of the hydrology of Costa Rican
basins draining to the Rio San Juan was extended to include not only the seven
major tributari es reported in Section 6 D[2] but also eighty micro -basins draining
to the Río San Juan between Marker II and Delta Costa Rica that would, in practice,
be most likely to exhibit the hydrological impacts of the Road , if there were any.
The major and micro -basins (highlighted in grey) are shown in Figure 23 and
their parameters are listed in Table 7.
202 56Figure 23. Major tributary basins and micro-basins (highlighted in grey) draining from Costa
Rica to the Río San Juan between Marker II and the Delta .
57 203 Table 7. Maximum possible increases in impermeable area due to construction of Route 1856
within micro-basins and major tributary basins draining from Costa Rica to the Río San Juan
(from 2013 ICE Report).
Area Impermeable Change Area Impermeable Change
Basin (km ) Area (km ) (%) Basin (km ) Area (km ) (%)
Micro-basins between Marker II and Delta C.R. Micro-basins between marker II and Delta C.R.
Basin 01 2.00 0.109 5.40 Basin 46 0.88 0.012 1.33
Basin 02 1.05 0.067 6.40 Basin 47 0.42 0.005 1.25
Basin 03 0.41 0.014 3.30 Basin 48 0.70 0.006 0.80
Basin 04 1.05 0.047 4.50 Basin 49 0.39 0.001 0.36
Basin 05 1.45 0.019 1.30 Basin 50 1.68 0.030 1.76
Basin 06 2.20 0.030 1.40 Basin 51 0.61 0.020 3.33
Basin 07 0.93 0.006 0.60 Basin 52 1.57 0.011 0.69
Basin 08 3.30 0.124 3.70 Basin 53 0.50 0.007 1.47
Basin 09 2.68 0.033 1.20 Basin 54 0.92 0.011 1.20
Basin 10 0.40 0.021 5.30 Basin 55 0.56 0.005 0.96
Basin 11 1.69 0.078 4.60 Basin 56 4.93 0.080 1.63
Basin 12 1.12 0.122 10.90 Basin 57 1.66 0.034 2.08
Basin 13 0.69 0.097 14.00 Basin 58 1.60 0.033 2.07
Basin 14 0.61 0.073 12.10 Basin 59 1.16 0.037 3.16
Basin 15 8.12 0.117 1.40 Basin 60 1.47 0.028 1.88
Basin 16 1.01 0.025 2.40 Basin 61 1.70 0.092 5.42
Basin 17 0.83 0.025 3.00 Basin 62 0.76 0.029 3.78
Basin 18 1.08 0.067 6.20 Basin 63 0.40 0.013 3.26
Basin 19 9.77 0.081 0.80 Basin 64 3.53 0.035 0.98
Basin 20 0.68 0.076 11.30 Basin 65 2.83 0.093 3.29
Basin 21 5.24 0.055 1.00 Basin 66 2.43 0.051 2.10
Basin 22 0.68 0.050 7.40 Basin 67 0.38 0.016 4.34
Basin 23 2.09 0.052 2.50 Basin 68 1.26 0.067 5.31
Basin 24 0.86 0.009 1.00 Basin 69 0.68 0.029 4.24
Basin 25 0.63 0.010 1.60 Basin 70 1.49 0.004 0.30
Basin 26 5.50 0.018 0.30 Basin 71 1.58 0.055 3.47
Basin 27 10.27 0.006 0.10 Basin 72 1.48 0.064 4.32
Basin 28 0.91 0.040 4.40 Basin 73 2.08 0.016 0.77
Basin 29 9.12 0.035 0.40 Basin 74 1.62 0.006 0.35
Basin 30 1.65 0.109 6.60 Basin 75 2.63 0.100 3.80
Basin 31 4.37 0.040 0.90 Basin 76 0.40 0.006 1.56
Basin 32 1.49 0.017 1.20 Basin 77 2.21 0.005 0.23
Basin 33 0.56 0.005 0.87 Basin 78 0.58 0.003 0.47
Basin 34 0.87 0.033 3.84 Basin 79 0.69 0.040 5.74
Basin 35 0.76 0.036 4.70 Basin 80 1.32 0.025 1.91
Basin 36 0.44 0.028 6.35 Major Costa Rican basins along San Juan River
Basin 37 1.71 0.063 3.70 Frío 1 746 0.00 0.00
Basin 38 1.14 0.039 3.45 Pocosol 1 224 0.93 0.08
Basin 39 1.07 0.031 2.92 Infiernito 609 1.99 0.33
Basin 40 0.71 0.041 5.72 San Carlos 2 644 0.34 0.01
Basin 41 1.88 0.051 2.73 Cureña 343 0.76 0.22
Basin 42 0.97 0.020 2.03 Sarapiquí 2 743 0.06 0.00
Basin 43 0.51 0.034 6.63 Chirripó 255 0.41 0.16
Basin 44 1.15 0.009 0.77 All Costa Rican basins draining to Rio San Juan
Basin 45 0.40 0.003 0.74 Totals 9564 4.50 0.05
204 587.3. The areas of impermeable surface introduced by construction of the Road
listed in Table 7 were measured from the digital polygons used to represent
Route 1856 in the GIS used by Astorga and Mende to create the land use change
maps included in the Land Use Change Report . These areas inclu de not only the
road bed itself, but also the entire right -of-way and, bearing in mind that the
surface of the road bed is either bare soil or crushed rock – neither of which are
entirely impermeable, these areas are highly conservative, upper -bound values.
7.4. The results lis ted in Table 8 reveal that in 65 of the 80 micro -basins, the
Road increases the impermeable area by less than 5% of the total drainage area,
while in more than half the micro -basins the increase is less than 2.5%. The
impermeable area of the Road comprise s more than 10% of the drainage area in
just four micro-basins, with the highest single figure being 14%.
7.5. These findings establish with a high degree of confidence that the
possibility of local impacts due to reductions in the catchment p ermeability
following construction of the Road is limited to four of the smallest micro -basins,
which have drainage areas of about 1 km 2 or less. With respect to the main stream
Río San Juan itself, it is inconc eivable that an increase of 0.05% in the
impermeable area within the tributary basins draining to the River from Costa
Rica could have any discernible hydrological impact, let alone cause any damage
whatsoever to the river, its environment or its ecosystem.
C. Hydrologic modelling Costa Rican micro -basins draining to the Rio San
Juan between Marker II and the Delta with and without Route 1856
7.6. The HEC -HMS hydrological model developed by the US Army Corps of
Engineers was used to simulate the hydrology of each micro -basin prior to and
following constructi on of Route -1856. This model is designed to simulate rainfall -
runoff processes in a wide range of geographic areas , for solving a wide range of
problems (http://www.hec.usace.army.mil/software /hec-hms/). The 38 -year
record of daily precipitation measured at the nearby El Bum hydrometric Station
(station 69-578) between 1976 and 2013 provided the rainfall input to the model.
59 205 7.7. Appropriate Soil Conservation Service ( SCS) Curve Numbers were used t o
represent infiltration in each micro -basin prior to and following construction of
Route 1856, based on the land use change maps provided by Astorga and Mende
in their 2013 Report and the increases in impermeable areas listed in Table 7. SCS
Curve numbers are routinely used by the Natural Resources Conservation Service
(NRCS) of the US Department of Agriculture to simulate increases in impermeable
areas in urbanizing catchments
(https://engineering.purdue.edu/mapserve/sedspec/doc/tr55.pdf ).
7.8. Antecedent moisture condition II, corresponding to average conditions,
was selected to represent moisture levels at the beginning of each simulation. For
each micro -basin initial abstractions (Ia) and time of concentration (tc) were
calculated based on Curve Numbers representative of pre - and post-Route 1856
conditions and appropriate morphometric parameters for each micro -basin
(drainage area, average slope, length of the longest flow path, et c.). The lag time
(tg) was assumed to be 60% of the time to concentration, as indicated by the SCS
Lag Time equation. The results are listed in Table 8 and shown in Fig ure 24.
Table 8. Average monthly stream flows from micro-basins draining to the Río San Juan,
predicted using a HEC-HMS model simulation from 1976 to 2013 for conditions with and
without Route 1856 (from the 2013 ICE Report ).
Runoff without Road (m s ) -1 Runoff with Road (m s )-1 Difference
Month
Mean Error margin Mean value Error margin (m s )1
January 16.46 1.13 16.47 1.42 3.81 x 10-3
February 11.63 0.81 11.63 1.20 6.39 x 10-4
March 8.06 0.64 8.06 1.01 1.45 x 10-4
-4
April 8.87 0.76 8.87 1.16 1.03 x 10
-4
May 13.70 0.86 13.70 1.01 1.38 x 10
-4
June 20.46 1.23 20.46 1.43 1.37 x 10
-4
July 25.84 1.31 25.84 1.59 1.69 x 10
-5
August 20.05 1.10 20.05 1.33 5.51 x 10
-5
September 15.04 0.90 15.04 1.35 3.76 x 10
October 17.05 1.02 17.05 1.20 2.72 x 10-5
November 24.45 1.32 24.45 1.46 2.76 x 10-5
December 23.09 1.35 23.09 1.54 1.50 x 10-5
206 60 Figure 24. Mean monthly discharges from micro-basins draining to the Río San Juan with and
without Route 1856 . Bars indicate error margins (from 2013 ICE Report).
7.9. The first point to note in Table 8 and Figure 24 is that monthly average
discharges fr om all the micro -basins combined are very small compared to the
annual average discharge in the Río San Juan (which is 442 m 3 s-1 at El Castillo
(Station 01 -02), which is located near Marker II, rising to 1 123 m 3 s-1 at La
Trinidad (Station 01 -03): see monthly distribution of flow at La Trinidad i n Figure
20 and Map in Figure 16 above). Consequently, even substantial changes in
discharges input to the Río San Juan from the micro -basins would have little or no
impact on the far larger flows in the main stre am. However, the Road’s impacts on
monthly average discharges from the micro -basins are actually miniscule: they
are visually undetectable in Figure 24 and fall well within the error margins for
the expected discharges listed in Table 8 and shown as error bars in Figure 24 .
D. Discharges from all Costa Rican basins draining to the Rio San Juan
between Marker II and the Delta with and without Route 1856
7.10. Although discharges to the R ío San Juan from the micro -basins are very
small compared to those in the main st ream River, the same cannot be said for the
seven major Costa Rican tributaries. However, in the catchment contexts of the
main tributary basins, the increases in impermeable areas due to construction are
even smaller than those in the micro -basins. The findings listed in Table 8 reveal
that the Road has not increased the impermeable area in any of the major tributary
basin by mo re than a third of one per cent while, when all Costa Rican basins are
61 207 considered together , the overall increase in impermeable ar ea draining to the Río San
Juan amounts to a miniscule 0.05%.
7.11. To examine the possible hydrological impacts of the Road in the context of
runoff from the Costa Rican basins as a whole, it was necessary to synthesise the
pre- and post -Route 1856 discharge r egimes for all the basins (main and micro)
as a whole.
7.12. Derivation of the mean annual discharges input to the Río San Juan from
the seven major tributary basins prior to constructi on of the Road is described in
Sections 6.D(2) and 6.D(3) and the results are indicated in Figure 17 . These much
larger basins incorporate the eighty micro-basins mapped in Figure 23 .
7.13. The next stage was to break the average annual discharges down into
average monthly discharges using the Area -Precipitation method and t he
discharge balance presented in Section 6.D(3). In these calculations, the records
used to represent the main tributary basins came from 1971 to 2006 (which is
prior to construction of the Road) for the three gauged basins: Fr ío (Guatuso
Station 16-02), San Carlos ( Terrón Colorado Station 14 -04), and Sarapiquí (Puerto
Viejo Station 12-03 and Veracruz Station 12 -04).
7.14. At the larger scales of these major basins, increases in impermeable area
due to construction of Route 1856 were all less than one third of 1% (see Tabl e
8), which is too small for there to exist even the possibility of a measurable impact
average monthly discharges. Consequently, hydrological analysis of the seven
major tributaries was not repeated for conditions with the Road. Instead, monthly
average d ischarges to the Rio San Juan under post -Route 1856 conditions were
calculated by adding the absolute differences in discharges modeled for the
micro-basins (as listed in Table 8) to the average monthly values calculated for
the pre -Road period, 1971 to 20 06. The results are listed below in Table 9 and
illustrated in Figure 25 .
208 62 Table 9. Monthly average stream flows for all basins (micro and macro) draining to the Río
San Juan. Time series generated from 1971 to 2006 for Pre - and Post-Route 1956 conditions
(from 2013 ICE Report).
Stream flow (m s )3 -1 Absolute
Relative
Month difference difference (%)
Pre-Route Post-Route Error margin (m s )-1
January 765.30 765.44 103.7 3.81 x 10-3 4.97 x 10 -4
February 535.56 535.59 54.8 6.39 x 10-4 1.19 x 10 -4
March 400.64 400.64 34.9 1.45 x 10-4 3.62 x 10 -5
April 360.78 360.79 40.2 1.03 x 10-4 2.86 x 10 -5
-4 -5
May 561.09 561.09 76.8 1.38 x 10 2.45 x 10
-4 -5
June 781.79 781.80 59.2 1.37 x 10 1.75 x 10
-4 -5
July 1000.46 1000.47 60.5 1.69 x 10 1.69 x 10
-5 -6
August 1001.94 1001.94 53.0 5.51 x 10 5.50 x 10
-5 -6
September 894.23 894.23 35.9 3.76 x 10 4.21 x 10
-5 -6
October 974.93 974.93 54.3 2.72 x 10 2.79 x 10
November 1069.41 1069.41 100.4 2.76 x 10-5 2.58 x 10 -6
December 1043.77 1043.78 118.6 1.50 x 10-5 1.44 x 10 -6
Figure 25. Monthly average stream flows for all Costa Rican tributary basins (micro and
macro) draining to the Río San Juan under Pre- and Post-Route 1956 conditions . Times series
generated from 1971 to 2006. Bars indicate error margins (from 2013 ICE Rep ort).
7.15. In the context of the far larger catchments of the seven main Costa Rican
tributaries, which drain a combined area of 9 198 km 2, the Road’s impacts on
monthly average discharges are minute, being visually undetectable in Figur e 25
63 209 and entirely neglig ible compared to the error margins for the expect ed discharges
listed in Table 9 and shown as error bars in Figure 25 . The drainage area of the
Río San Juan in the vicinity of the Road increases from 32 819 km 2at El Castillo
(Station 01 -02) to 38 730 km 2 at La Trinidad (Station 01 -03), making it 3 to 4
times larger than that of the Costa Rican tributary basins combined. In this
context, the hydrological impact of the Road must be infinitesimal and, most
certainly, scientifically undetectable.
E. Conclusions
7.16. The results of spatial analyses using GIS, runoff simulations using well
established hydrologic models , and discharge calculations based on the records of
long established rainfall and discharge measuring stations demonstrate
unequivocally that construction of Route 1856 could not possibly be responsible
for any discernible differences in discharges supplied to the R ío San Juan from
seven large basins and 80 micro-basins draining to the River from Costa Rica.
7.17. The drainage area of the basin of the Río San Ju an at La Trinidad (Station
01-03) is 38 730 km 2 – which is around four times that of the Costa Rican
2
tributary basins combined (9 709 km ). Hence, the already tiny impacts of the
Road on the hydrology of the Costa Rican basins will be further diminished in the
context of the far larger drainage area of the basin of the Río San Juan . The
inescapable conclusion must be that there is no possibility that the Road has had,
will have, or indeed could ever have any measurable impact on the hydrology of
the Río San Juan.
210 64 8. Has sediment from Route 1856 had any significant impact on
the Río San Juan?
A. Introduction
8.1. This chapter reports the results of analyses performed to ascertain
whether sediment eroded from road bed, cut slopes, fill slopes and other areas
disturbed by construction of Route 1856 has had significant impacts on the Río
San Juan. This was addressed through analysis of existing records of recent and
historical suspended sediment concentrations (reported in the 2013 ICE Report),
application of land use ch ange maps provided by Astorga and Mende (the Land
Use Change Report ), uptake of the inventory of slopes and water courses, field and
remote sensing provided in the 2013 Inventory of Slopes and Water Courses
Report by Mende and Astorga , and the results of f ield monitoring of rates of
erosion and land surface lowering delivered in the 2013 UCR Report.
B. Has the Road significantly impacted s uspended sediment
concentration s or loads in the Río San Juan?
8.2. The aim of this part of the sediment study was to examine m easured
suspended sediment concentrations in the Río San Juan in order to ascertain
whether erosion and sediment delivery from the Road has significantly increased
the sediment load of the River. To do this I examined the available records of
measured Susp ended Sediment Concentration ( SSC) prior to and following
construction of the Road. As no historical records of bed load exist, it was not
possible to extend this analysis of existing, measured data to the coarse fraction of
the sediment load.
8.3. As noted in Section 6.E above , SSC records from Station 01 -03 at
La Trinidad between January 1974 and March 1976, and Station 11 -04 at Delta
Colorado, bet ween December 2010 and June 2013 are suitable for this purpose as
they represent periods before and after construction of the Road. SSCs measured
at these two stations should be comparable because over 90% of the flow and
sediment that passes through the La Trinidad also passes through the Delta
65 211 Colorado Station. Station locations are mapped above in Figure 16 and th eir
records are listed in Table 10, below (which is extracted from Table 4) .
Table 10. Suspended sediment records for the Río San Juan – Colorado (data taken from
Table 4 above).
Average Annual
Station Name River No. of Sampling Suspended load
code samples period -1
(t yr )
01-03 La Trinidad San Juan 12 1974-1976 7 995 000
a
11-04 Delta Colorado Colorado 31 2010-2013 5 981 000
aNote: this is the average annual suspended load in the Río Colorado.
8.4. For comparison, the recorded data are plotted together on a single graph,
with rating curves for SSC as a function of discharge for each station and period
added using regression in Figure 26.
Figure 26. Measured suspended sediment concentrations, rating curves and 95% confidence
intervals for pre -Road [La Trinidad (01-03), January 1974 to March 1976] and post -Road
[Delta Colorado (11 -04), December 2010 to June 2013] periods . Continuous lines are SSC
Rating Curves (based on best -fit regression). Dotted lines indicate the 95% confidence
intervals (from the 2013 ICE Report).
8.5. If additional sediment from the Road had caused an increase in the rate of
sediment transport in the Río San Juan, this would reflect in Figure 26 through
increases in the SSCs measured since 2010 and a corresponding upward shift in
the 2010-2013 suspended sediment rating curve compared to that for 1974 -1976.
212 66It is clear from Figure 26 that this is not the case. On the contrary, the highest
measured concentration (SSC > 600 mg l -1) was actually observed during the
period before construction of t he Road and the distribution of 27 of the 31 post -
Road measured concentrations in Figure 24 coincides with that of the pre -Road
data. Not only is there no statistically significant difference between the pre - and
post-Road suspended sediment rating curves, but Figure 26 reveals them to be
practically identical. This suggests that any differences between pre - and post -
Road SSCs measured at these stations are the result of random chance.
8.6. Additionally, the high degree of natural variability in the relationshi p
between discharge and SSC means that the 95% confidence intervals on the rating
curves are wide apart. Not only is natural variability similar during the pre - and
post-road periods, but the two uncertainty bands are also close to coinciding. This
illustrates that variability in measured SSCs has not changed significantly
between pre - and post -Road periods and that differences between measured
values are probably due to random chance.
8.7. Based on these two findings, the answer to the question of whether
construction of the Road has increased sediment concentrations in the Río San
Juan is an emphatic No.
8.8. As discharge is measured on a semi -continuous basis at both these
hydrometric stations, the suspended sediment rating curve can be integrated with
the dischar ge recor d to calculate the mean annual Suspended Sediment L oad
(SSL). This approach was used to calculate the mean annual SSL’s transported by
the Río San Juan at La Trinidad between 1974 and 1976 and by the Río Colorado
at Delta Colorado between 2010 and 2013, which are around 7 995 000 and 5 981
-1
000 t y , respectively (as listed in Table 10).
8.9. The average discharges measured at the La Trinidad and Delta Colorado
3 -1 3 -1
stations listed in Table 4 are 1 123 m s and 1 026 m s , respectively. This
suggests that, on average, roughly 90 % of the discharge in the Río San Juan
approaching Delta Costa Rica passes to the Río Colorado, while roughly 10 %
passes to the lower Río San Juan. As the suspended load is distributed throughout
the River’s flow, it is reasonable to assume that the SSL is similarly divided.
67 213 8.10. On this basis the SSL measured in the Río Colorado at the Delta Colorado
station may be adjusted to represent that in the Río San Juan upstream of the
Delta by multiplying it by the reciprocal of 0.91. Applying this adjustment, the
average annual SSL in the Río San Juan between December 2010 and June 2013
-1
was approximately 6 573 000 t y . It follows that the mean annual SSL in the
-1
lower Río San Juan during this period was about 592 000 t y .
8.11. In considering the se figures, it must be borne in mind that they are based
on small numbers of samples made over short (two to three -year) periods of
observation. The 95% confidence intervals of the regression relationships used to
generate the suspended sediment rating cur ves reflect not only uncertainty due to
the small number of data points, but also the high degree natural variability
inherent to the way that SSCs vary with discharge in the Río San Juan. Recognising
this, uncertainty analyses were performed on the data f or both stations to
produce 95% confidence intervals for the calculated mean annual SSL’s in the Río
San Juan. The results are illustrated below in Figure 27 and listed in Table 11.
1 )
-
1974 – 1976
2010 - 2013
AnnuaLoad in the San Juan River (t y
La Trinidad Delta Colorado
Figure 27. Mean annual suspended sediment lo ads in the Río San Juan based on
measurements at La Trinidad (1974 -1976) and Delta Colorado (2010 -2013). Vertical bars
indicate 95% confidence intervals. Note that the loads based on measurements at Delta
Colorado station have been adjusted to represent th e Río San Juan on the basis that at the
Delta suspended load is divided in the same proportion as discharge (from the ICE Report).
214 68 Table 11. Mean annual suspended sediment loads in the Río San Juan – Colorado
(from the ICE Report)
River Period Mean Annua l Suspended Sediment Load (t yr -)
Best Estimate 95% Confidence Interval
San Juan 1974 - 1976 7 995 000 5 405 000 - 10 585 000
San Juan 2010 - 2013 6 573 000 5 181 000 - 7 966 000
Colorado 2010 - 2013 5 981 000 --
lower San Juan 2010 - 2013 592 000 --
8.12. In comparing the suspended sediment loads transported annually by the
River during the two periods of observation, the first point to note is that the best
estimate of the mean for 2010 -2013 is noticeably lower than that for 1974 -1976.
This is unsurpr ising, because the post -Road period has been drier than usual. For
example, measured data for the hydrometric El Bum station (69 -578) indicate
that mean annual rainfall in the hydrological year 1975 -1976 was 3 651 mm,
compared to only 2 267 mm in the hydro logical year 2011 -2012. Lower rainfall
produces less catchment runoff that generates less erosion and, therefore, a
smaller SSL.
8.13. This result demonstrates that construction of the Road has not led to a
significant increase in the SSL carried by the Río San Juan.
8.14. However, it is instructive to consider that the difference between the mean
annual suspended loads falls within the confidence intervals on those means
(listed in Table 11). As the over -lapping 95% confidence intervals in Figure 27
confirm, the high levels of measurement uncertainty and natural variability in
annual SSL’s mean that there is no statistically significant difference between
mean annual SSL’s for periods prior to and following construction of the Road.
8.15. The point is that, notwithstanding the difference in calculated SSL’s,
analysis of the measured data indicates that they are not significantly different.
Statistically, there is a 95% probability that the two sample means come from the
same population of annual SSL’s, a population that is c haracterised by a very high
degree of inter -annual variability. It must, therefore, be concluded that the
difference between them is statistically insignificant.
69 215 8.16. These data reveal that measurement uncertainty, together with natural
fluctuations in rainfal l, discharges, catchment sediment yields and SSC ’s, mean
that SSL’s are likely to vary inter -annually between about 5 and 10.5 million
tonnes. Using longer measurement records with more measurements might
reduce the confidence interval on the mean annual SSL somewhat, but the range
of expected value s would remain wide because high natural variability is a
property characteristic of the River, not the data .
8.17. The significance of this finding is that it while it shows that the Road has
had no significant impac t on SSL in the River, it also demonstrates that no
possibility exists for using measured loads to estimate how much sediment
derived from erosion of the Road has been added to the Río San Juan, due to the
very high natural variability in those loads .
-1
C. Is the 1 m y rate of land lowering used in the 2012 Kondolf Report
reasonable?
8.18. In the 2012 Kondolf Report, Dr Kondolf estimates on page 46 that,
“landslide/gully erosion averages 1 m deep (i.e., lowering of the land
surface by 1 m on average ”.
8.19. This estimat e is not based on monitoring or measurement, but on visual
observation of the Road from the air and the River in October 2012. On the same
page of the 2012 Report, Dr Kondolf estimates the proportion of eroded soil that
is input to the Río San Juan is 40% 9.
8.20. Using these estimates for erosion and sediment delivery ratio , Dr Kondolf
estimates that the annual input of sediment from the Road to the River is in the
3 -1
range of 87 000 to 109 000 m y (2012 Kondolf Report, page 46). This estimate
is repeated in his Third Report (on page 2). It is an estimate for all sediment
delivered from slopes and other disturbed areas along the Road to the River,
whether by mass wasting or gullying. In the 2012 Kondolf Report erosion of the
9 2012 Kondolf Report, pp. 45 -46, para. 4.12.
216 70road bed itself is dismissed as being l ess than 10% of that from slopes and in his
Second Report Dr Kondolf n otes that most of the road bed ha s now been covered
in gravel, which will further reduce erosion of the road itself, especially in relation
to that from cut and fill slopes.
8.21. To establish whether the rate at which the land surface is being lowered by
erosion of cut slopes, fill slopes and other disturbed areas along the Road adopted
-1
in the 2012 Kondolf Report ( 1 m y ) is conservative, or reasonable, a team from
the University of Costa Ri ca has, since 8 June 2013, been monitoring erosion at
nine of the most active sites for sheet erosion, rill (micro -channel) erosion,
landslides and gullying in a study reach location in the steepest stretch of Road,
which is between Marker II and the Río Infiernito (Figure 28). Their results are
reported in the 2013 UCR Report.
Figure 28. Location of monitored sites (from the UCR Report).
8.22. The monitoring results reported in the 2013 UCR Report and used here
come from the two largest rotational landslides observed along the Road in the
study area ; the three large gullies; the slope which displayed most intense rill
(micro-channel) erosion; and a sediment trap that collects sediment eroded from
a steep stretch of road bed and cut slope which only experiences sheet erosion
(Figures 29 and 30).
71 217 (a)
(b)
Figure 29. Sediment trap #2 on (a) 8 June and (b) 22 July 2013 (from the UCR Report).
Figure 30. Rill erosion monitoring site on a cut slope, with rills number ed and 1 metre grid
overlaid for scale (from the UCR Report).
218 728.23. In the Fourth Kondolf Report, Dr Kondolf asserts that the sites monitored
by UCR “excluded the most seriously eroding sites” .10Having viewed the entire
length of the Road, I consider that the s ites which were monitored by UCR were
representative of the characteristics of the geology and terrain in the first 41.6 km
of the Road downstream from Marker II , and on that basis the erosion they
monitored provide s a representative indication of the eros ion likely to have
occurred along the entire length of that stretch of the Road. I also consider that
the sites monitored by UCR were in a section of the Road with the greatest
number of landslides and gullies. For these reasons, the results of UCR’s
monitoring can be taken to be representative of erosion along the first 41.6 km of
the Road alongside the River, which is the only part of the Road about which Dr
Kondolf is concerned .
8.24. Erosion and mass wasting rates along the other 66.4 km of the Road that
parallels the Río San Juan downstream of Boca San Carlos are certainly much
lower than they are in the area studied by UCR between Marker II and the Río
Infiernito, for the reasons set out above in Section 5.A. This finding is confirmed
by the results present ed by Mende and Astorga (2013) in the Inventory of Slopes
and Water Courses Report. It is therefore reasonable to assume first, that the
recorded rates of land surface lowering approach ‘worst case’ scenarios for Road -
related erosion to date and, second, t hat their application in calculating erosion
and mass wasting along the entire 108 km length of the Road where it parallels
the River between Marker II and Delta Costa Rica is highly conservative.
8.25. Based on field measurements, the rate of land surface lowe ring due to
sheet erosion of the road bed and cut slo pes varies between about 0.061 m y -1and
-1
0.095 m y . The range in the rates is due to differences in the amount of soil lost
between re -surveys of features made during relatively dry (June - July) and
relatively wet (July - August) periods in 2013. Based on these direct
measurements it is concluded that using 0.095 m y -1as the basis for estimating
10 Fourth Kondolf Report, p. 3. See also p. 9.
73 219 the average annual rate of lowering of the land surface due to sheet erosion along
the entire length of the Road is conservative.
8.26. On th ose monitored cut slopes where landslides were observed, they
occupied 10% to 13% of the overall area of the slope and had lowered the land
surface in those areas by between 0.11 and 0.38 metres. These slopes were
created when th e Road was under construction in 2011 and they have therefore
existed for at least two years. This implies average rates of lowering of the land
-1
surface due to landslides of between 0.06 and 0.19 m y when averaged over the
entire areas of the slopes affe cted.
8.27. Gullies on cut slopes were the rarest erosion feature observed by UCR
along the Road between Marker II and the Río Infiernito, while rills were the most
common. The worst gully monitored in the study had a maximum depth of 3
metres and a surface area of 13.1 m 2, meaning it covered only just over 2% of the
slope in which it had formed. The total volume of soil eroded to create this gully
was approximately 6 m . When this volume is divided by the total area of the
slope, the average lowering of the land surface due to erosion by this gully is
0.01 m. If it is again assumed that the slope was created when the Road was under
construction in 2011, this implies a rate of lowering of the land surface due to
gullying is 0.005 m y -, when averaged over the enti re area of the slope affected.
8.28. The majority of slopes along the Road between Marker II and the Río
Infiernito were observed to experience rill (micro-channel) erosion. At the rill
study site, there were 26 rills, the largest of which had a maximum width of
0.3 metres and a maximum depth of 0.6 metres. Based on spatial analysis of all the
rills in the sample area, and with the conservative assumption that they all had
widths and depths equal to that of the largest rill, UCR concluded that rill erosion
has lowered the land surface of the slop e by an average of 0.12 metres since the
Road was constructed , which implies an average rate of lowering of the land
surface due to rilling of around 0.06 m y -1when averaged over the entire area of
the slope.
8.29. Fill slopes in the studied area do not feature erosion due to deep
landslides, with mass wasting limited to much less damaging shallow slips and
220 74soil falls. Rill erosion wa s observed on fill slopes with intensities broadly similar
to those observed on cut slopes. Con sequently, the rate monitored on the most
-1
intensively rilled cut slope (0.06 m y ) may be conservatively used also to
represent rill erosion of fill slopes .
8.30. Gully erosion on fill slopes was observed by UCR to cover about 4% to 10%
of the monitored fills, lowering the surface of these slopes by between 0.06 and
0.10 m when averaged over the area of fill slope affected. In contrast to erosion of
road cuts, the monitored gullies had formed in about the last six months.
Therefore, the estimated average annual rate of land surface lowering due to gully
erosion of fill slopes is higher than that for cut slopes, being between 0.12 and
0.20 m y -1.
8.31. Table 12 below summarises the observed average erosion depths and
average a nnual rates of land surface lowering reported above. As this summary
lists the highest values of eroded area/area of feature, average eroded depth, and
average annual rates of land surface lowering for each erosion type, the data
listed are likely to over -estimate actual average values for the Road between
Marker II and the Delta and, in this respect, they are conservative.
Table 12. Summary of erosion monitoring results (from the 2013 UCR Report).
Eroded Average Average rate of land
Type of Erosion Area/Area of erosion depth surface lowering
feature type -1
Feature (%) (m) (m y )
Cut Slope Landslide 13 0.38 0.19
Cut Slope Gully 2 0.01 0.005
Cut Slope* Rill 50 0.12 0.06
Road bed and
Cut Slope Sheet 100 0.02 0.095
Fill Slope Gully 9 0.10 0.20
*these findings may also be conservatively applied to rills on fill slopes.
8.32. In the 2013 UCR Report, the authors recommend using average erosion
depths for landslides, gullies and rills on cut slopes in place of estimated annual
rates of erosion when calculating average annual rates of land surface lowering
along the Road . Doing so is even more conservative because the erosion depths
75 221 probably represent the amount of land surface lowering over two years , rather
than annually . For sheet erosion, the maximum rate observ ed (i.e. 0.095 m y -1
during the wet season) is recommended. Finally, 0.20 m y -1 is the most
conservative value for gullies in road fills and UCR suggests that this should be
used. These rates should all over -estimate actual average erosion rates to date,
but considering that the last two years have been drier than average, they could
be exceeded in future. This will only be the case if erosion risks are unmitigated,
leaving the slopes exposed to potentially heavier rainfall. However, a s I observed
in May 2013 (discussed below in Chapter 12) and as reported in the 2013 Reports
by CONAVI and Codeforsa, work to mitigate erosion risks has begun and I
understand that it is projected to continue .
8.33. In the 2012 Kondolf Report, rates of land surface lowering due to e rosion
were estimated using visual observations of the Road made at a distance from the
air and from a boat during a single, two -day visit to the area in October 2012,
together with consideration of published studies of sediment budgets in the
Pacific Nort hwest of North America and the team’s observations of road -related
erosional impacts elsewhere (2012 Kondolf Repo rt, page 46). In his 2012 Report,
Dr Kondolf states that,
“we conservatively estimated that that landslide and gully erosion is
occurring on 4 0-50% of the steep disturbed land (21.8 to 27.3 ha)
and that this landslide/gully erosion averages 1 m deep (i.e., lowering
the land surface by 1 m on average) .”
8.34. Monitoring of landslide and gully erosion reported by UCR above suggests
that the rate of land surface lowering estimated in the 2012 Kondolf Report is
probably too high by a factor of five for the stretch of Road between Marker II and
the Río Infiernito. With respect to the 108 km length of the Road where it parallels
the Río San Juan, an average annual rate of land lowering of 1 m y -1is definitely
much too high, probably by a factor of ten .
8.35. Further, UCR field monitoring indicates that landslides and gullies on
average cover around 10 to 15% of the slopes with these features observed
between Marke r II and the Río Infiernito. Consequently, the estimate that
landslides and gullies occupy 40 to 50% of the area of cut and fill slopes along the
222 76Road, which is made in the 2012 Kondolf Report, would also appear to be a
significant over-estimate.
8.36. In my exp erience, including my inspections of the Road in February and
May 2013, of land surface lowering due to landslides and gullies averaging 1 m y -1
is too high and it is unlikely to be accurate , especially if applied to the entire
length of the Road alongside the River . Also, the assumption that landslides and
gullies cover 40 to 50% of slopes and other disturbed areas overstates the extent
of these features. Conversely, the monitored rates and areas affected as
summarised in Table 12 are consistent with my ow n observations and, in my
opinion, are likely to be more representative of conditions encountered in general
along the Road .
8.37. Recognising this, the average annual volume of sediment eroded from the
Road between Marker II and Boca San Carlos (i.e. the upstre am 41.6 km of the
Road that runs adjacent to the River) estimated by Dr Kondolf (reported on page
46 of the 2012 Kondolf Report) of 218 400 to 273 000 m 3 y-1 is likely to be
significantly too high.
8.38. In his Third Report Dr Kondolf emphasizes the impact of ‘mass wasting’
which he describes as involving ,
“the movement of larger volumes of earth by gravity, often along
failure plains determined by differences in material, such as the
boundary between a volume of fill material and the existing s lope
upon which it was placed.”
I agree in principle with this description.
8.39. Dr Kondolf also states that, on his inspection in October 2013,
“[s]ignificant cutslope and fillslope mass w asting as also locally
evident”. 11
8.40. However, the ‘mass wasting’ Dr Kondolf is said to ha ve observed in
October 2013 has not caused him to revisit his 2012 estimates of erosion from the
11 Third Kondolf Report, p. 14.
77 223 Road, which, as noted in paragraph 8.20 above, already includes all sediment
input, whether from mass wasting or gullies.
8.41. All form s of mass wasting (including landslides) are driven by gravity. In
short the weight of the slope becomes greater than its strength and it falls down.
Failure may be triggered by any of the processes listed as triggering landslides on
page 14 of the 2013 UCR Report . Essentially, there is a range of mechanisms by
which slopes retreat due to mass wasting, with landslides being the largest in
scale and shallow slides being the smallest. In the studies reported in the 2013
Reports by UCR and ICE, which yield the estimates for sediment input described
in Table 12 above, all mass wasting is treated as being by landslides. As a result,
the estimates for sediment input are conservative, because landslides are the
largest in scale of the potential events which result in mass wasting. Furthermore,
it is clear that these estimates take account of all potential sediment input from
the Road to the River, including by mass wasting.
8.42. To investigate whether sediment eroded from the Road could pose any
risk to the Río San Juan , the 2013 ICE Report took up the results reported in the
2013 Reports by UCR and Mende and Astorga (The Inventory of Slopes and Water
Courses Report) and used them to estimate sediment delivery rates from the Road
to the River. The work was per formed in t wo steps. First, the average volume of
sediment eroded from the Road, cut slopes, fill slopes and other disturbed areas
was estimated. For the road bed the higher of the two rates of erosion reported in
the 2013 UCR Report (0.095 m y -1, as listed in Table 12) was accepted. ICE then
used the length , area and steepness of the road bed and adjacent disturbed
ground within each of the major tributary basins draining to the River between
Marker II and Delta Costa Rica to estimate the average annual volume of sed iment
eroded from the road bed in each tributary basin .
8.43. For cut and fill slopes, ICE accepted the Mende and Astorga’s estimates (in
the Inventory of Slopes and Water Courses Report) for the average annual volumes
of erosion by landslides and gullies along the Road in each of the tributary basins,
which are based on areas recorded in their 2013 inventory of slopes and
224 78 application of the erosion depths reported in the 2013 UCR Report (as listed in
Table 12).
8.44. The five main river basins draining from Costa Ri ca to the Río San Juan
between Marker II and Delta Costa Rica are mapped below in Figure 31 (a), and
the eroded volumes compiled by ICE are listed for each basin in Table 13.
Table 13. Estimated average annual erosion rates (from the 2013 ICE Report).
3 -1 -1
Road Annual rate by volume (m y ) Annual rate by mass* (t y )
Basin length
Road Slopes Total Road Slopes Total
(km)
Major Costa Rican river basins draining directly to the Río San Juan between Marker II and Delta
Infiernito 38 12 260 28 000 40 260 20 450 46 750 67 250
San Carlos 11 2 060 600 2 660 3 450 1 000 4 450
Cureña 28 5 220 7 560 12 780 8 700 12 650 21 350
Sarapiquí 3 560 160 720 950 250 1 200
Chirripó 22 4 100 260 4 360 6 850 450 7 300
Costa Rican area that drains directly to the San Juan River between Marker II to and Delta
Colorado
Total 102 24 200 36 580 60 780 40 400 61 100 101 550
-3
* To convert eroded volumes to masses, a bulk density of 1.67 t m was assumed. This value
is widely used to represent the bulk density of silt-sand soils.
8.45. Second, ICE applied a sediment delivery ratio to estimate the proportion of
the eroded sediment reaching the Río San Juan. Dr Kondolf estimated this delivery
ratio to be 40% (2012 Kondolf Report, page 46). However, considering the small
size of many of the micro -basins draining either directly to the Río San Juan or to
the five major Costa Rican tributaries, the large number of crossings identified in
the Inventory of Slopes and Water Courses Report by Mende and Astorga, and
bearing in min d the relatively fine grain size of most of the eroded sediment
(found to be mostly silt – see Table 5 in the 2013 UCR Report), ICE concluded that
Dr Kondolf’s estimate was probably low and they instead used a considerably
higher estimate of 60%. I concur with ICE’s selection of 60% as being reasonable
but more conservative than Dr Kondolf’s assumption of 40%. The results of
applying this higher delivery ratio are listed in Table 14 and shown in Figure
31(b).
79 225 Table 14. Average annual inputs of Road -derived sediment to the Río San Juan
(from the ICE Report)
3 -1 -1
Road length Input by volume (m yr ) Input by mass* (t yr )
Basin (km) Road Slopes Total Road Slopes Total
Major Costa Rican river basins draining directly to the Río San Juan between Marker II and Delta
Infiernito 38 7 360 16 800 24 160 12 250 28 050 40 300
San Carlos 11 1 240 360 1 600 2 050 600 2 650
Cureña 28 3 140 4 540 7 680 5 200 7 600 12 800
Sarapiquí 3 340 100 440 550 150 700
Chirripó 22 2 460 160 2 620 4 100 250 4 350
Costa Rican area that drains directly to the Río San Juan between Marker II to and Delta Colorado
Total 102 14 540 21 960 36 500 24 150 36 650 60 800
-3
* To convert eroded volumes to masses, a bulk density of 1.67 t m was assumed. This value
is widely used to represent the bulk density of silt -sand soils.
(a)
(b)
Figure 31. (a) Map showing the major tributary basins between Lake Nicaragua and Delta
Costa Rica. (b) Length of Road and estimated annual average inputs of sediment to the Rio
San Juan from ero sion of the road and cut/fill slopes in basins CR3 (Infiernito) to CR7
(Chirripó) between Marker II and the Delta (from 2013 ICE Report).
226 808.46. The results plotted in Figure 31 above indicate that delivery of sediment
eroded from slopes along the Road in the San Carlos, Sarapiquí and Chirrip ó
reaches of the Río San Juan is negligible. Input of the slope -derived sediment in
the Infiernito stretch of the Road is higher, which is consistent with Dr Kondolf’s
decision to focus his attention on that stretch in the 201 2 Kondolf Report , a
decision he did not revisit in his Second, Third and Fourth Reports.
8.47. However, the estimated average annual input sediment eroded from the
Infiernito reach of the Road is around 24 000 m 3 y , which is only a third to a
quarter of that estimated by Dr Kondolf for the first 41.6 km of the Road between
3 -1
Marker II and Boca San Carlos (87 000 – 109 000 m y ). Indeed, the estimated
input for the entire length of the Road alongside the River between Marker II and
3 -1
Delta Costa Rica (36 500 m y ) is only a third to a half of that estimated on page
46 of the 2012 Kondolf Report.
8.48. The average annual rates of additional sediment delivery listed in Table 14
and graphed in Figure 31(b) represent conditions since December 2010 and up to
June 2013. Th ese results indicate that during this period additional sediment
eroded from the Road w as delivered to the Río San Juan in the Infiernito reach
and, to a lesser degree, the Cureña reach, but at rates insufficient to have any
significant impact on the River or its surrounding environment. Lack of significant
impact is due to : (i) the large discharge of the Río San Juan (see Section 6.D ,
above), (ii) the River’s inherent capacity to transport very large and highly
variable amounts of sediment (see Section 8.B above), and (iii) its capacity to
transport varying sediment loads without perturbing either reach-scale channel
morphology, which is geologically -controlled (see Sections 6.B and 6.C above), or
in-stream and ri parian habitats and ecosystems, which are we ll adapted to high
and variable sediment loads (see Section 10, below and, for details, the 2013 CCT
Report).
8.49. In the ICE Report ( based on application of detailed field measurements
reported in the UCR Report and Mende and Astorga Inventory of Slopes and Water
Courses), construction of the Road is estimated to have added, at most, 36 500 m 3
y-1(60,800 t y ) of sediment to the load of the Río San Juan. I am confident that
81 227 this figure is more reliable than the much highe r estimate of 87 000 to
109 000 m 3y (145 290 and 182 030 t y ) made by Dr Kondolf, which is based on
observations from a boat and a helicopter made over two days in October 2012
and which was not revisited or revised in his second, third or fourth Reports.
D. Potential for Road -derived sedime nt to have a significant impact on the
Río San Juan
(1) Introduction
8.50. The purpose of this Section is to use the e vidence provided in Sections 8.B
and 8.C above to examine whether the additional Road -derived sediment supplied
to the Río San Juan could damage the River and its environment and whether the
additional sediment derived from Road could have caused aggradation in the
lower Rio San Juan sufficient to require Nicaragua to dredge the River to maintain
navigation and flow in that watercourse . In summary, t he evidence does not
support either of these propositions.
(2) Estimated annual load of Road -related sediment supplied to the Río
San Juan
8.51. According to the estimate s made in the 2012 Kondolf Report ( on page 46),
the average total quantity of sediment supplied to the Río San Juan by the Road
3 -1
annually is 87 000 to 109 000 m y . As explained in Section 8.C above, this
estimate includes all potential sources of sediment along the Road considered
significant in the 2012 Kondolf Report (a finding not revisited in Dr Kondolf’s
Third Report), including gullies and mass wasting.
8.52. It should be noted that Dr Kondolf’s figure is derived from observations
referenced only to the first 41.6 km of the Road between M arker II and Boca San
Carlos. Dr Kondolf made no estimate of e rosion from the remaining 66.4 km
between Boca San Carlos and Delta Costa Rica. As noted above in paragraph 4.6
according to Dr Kondolf, 42 of the 54 locations where he says that he observed
Road-derived sediment to have entered or to be entering the Río S an Juan are
located within the first 41.6 km, with only 1 1 along the remaining length of the
228 82Road. On this basis, the upper bound of Dr Kondolf’s estimated range seems likely
to be close to what he would have estimated for the entire Road.
8.53. As reported in Section 8.C above, ICE’s estimate for the total quantity of
Road-derived sediment delivered to the River is 36 500 m y , which is only a
third of the upper bound of the range estimated by Dr Kondolf. For the reasons
-1
stated earlier, my view is that Dr Kon dolf’s use of 1 m y as the average rate of
lowering of the land surface due to landsliding and gullying between Marker II
and Boca San Carlos is almost certainly an over -estimate. My observations along
the entire length of the Road likewise indicate to m e that Dr Kondolf’s estimate is
far too high to be representative of erosion along the 66.4 km stretch between
Boca San Carlos and Delta Costa Rica. Likewise, I believe that his assumption that
40 to 50% of slopes are covered by landslides and gullies is a lso an over-estimate.
8.54. Notwithstanding this, in examining whether the input of Road -derived
sediment could significantly impact the Río San Juan or impede navigation in the
lower Río San Juan to the degree necessary to require dredging, in my November
2013 Report submitted to the Court in response to Nicaragua’s request for the
indication of provisional measures in the Construction of a Road Case , I was
instructed to proceed on the basis of Dr Kondolf’s estimate of average annual
sediment delivery of road -derived sediment . This exercise did not imply
acceptance of Dr Kondolf’s estimate, which, for the reasons I have expla ined, I
consider to be a significant over -estimate. In the comparison below I revert to the
more reliable estimates made by ICE in their 201 3 Report , based on the field
monitoring carried out by Costa Rica’s technical teams .
(3) Comparison of the additional Road -derived sediment to the a verage
annual sediment load in the lower Río San Juan since December 2010
8.55. Sediment loads in the River are expr essed by mass (tonnes) rather than
volume (cubic metres). As noted in Tables 13 and 14 above, a cubic metre of
sediment has a mass of about 1.67 tonnes. This is typical for closely -packed,
quartz sand grains, though it may be a little high for soil (which has a higher
porosity). Hence, it is conservative. Assuming that each cubic metre of soil has a
mass of 1.67 tonnes, the average annual load of Road -related sedime nt input to
83 229 the Río San Juan is (as listed above in Table 14 , based on field monitoring ),
-1
60 800 t y .
8.56. As explained in Section 6.E and listed in Table 6 above , the average annual
total sediment load (that is suspended load plus bed load) carried by the Río San
Juan between December 2010 and Jun e 2013 was around 9 133 000 t y -1, of which
around 8 470 000 t y -1passes to the Río Colorado and 663 000 t y -1to the lower
Río San Juan.
(4) Relative input of Road-derived sediment to the Río San Juan
8.57. If 60 800 t y -1enters the Río San Juan this would make up less than 1% of
the total sediment load carried by the Río San Juan , which is 9 133 000 t y -. This
is obviously too small a proportion to have an y significant impact s on the River.
As noted in paragraph 8.49 above, Dr Kondolf’s estimate of a range of sediment
delivered annually from the Road to the River (145 290 and 182 030 t y -1) is
significantly overstated. But even if it were an accurate assessment, which Costa
Rica does not accept, it would represent only 1.6% to 2% of the total annual
sediment load of the Río San Juan. A contributi on of sediment in t his range would
still be far too small to have any adverse impact on the River.
8.58. Assuming that 10% of the additional sediment from the Road enters the
lower Río San Juan , this suggests that the average annual input of Road -derived
-1
sediment to the lower Río San Juan is 6 080 t y , which constitutes less than 1% of
-1
the 663 000 t y total load in the lower Río San Juan downstream of the Delta.
8.59. The lower Río San Juan is approximately 30 km long and it has an average
2
channel width around 90 m, giving it a bed a rea of about 2.7 million m . The
-1 3 -1
6 080 t y input of Road -derived sediment is equivalent to 3 650 m y in
volumetric terms. Supposing that all of this Road-related sediment were
deposited on the bed of the lower Río San Juan (with none at all deposited on the
floodplains and in the wetlands or passing through to the Caribbean Sea), the
average increase in the rate of aggradation of the bed would be less than
0.2 mm y .-1
230 848.60. Even this tiny increase in sedimentation is actually an over -estimate. As
illustrated in Figure 19 above, the Río San Juan is a sand bed river. Consequently,
in practice it is likely that only the sand fraction of the additional sediment
derived from erosion of the Road would be deposited on the bed of the River. On
page 44 of his 2012 Rep ort, Dr Kondolf notes that,
“The cones of sand and gravel we sampled probably represent less
than 5% of the total amount of sediment that passed at those points
into the river. ”
The particle size analyses performed UCR and reported in their 2013 Report,
support this conclusion : on average, sand made up less than 10% of the Road -
derived sediment they sampled. It follows that probably only 5 to 10% of the
additional sediment derived from the Road (i.e. the sand fraction) would be
deposited on the bed of the lower Río San Juan – perhaps 200 to 400 m 3y . This
is consistent with Dr Kondolf’s estimate above and further reinforces that any
additional sedimentation due to construction of the Road would be indiscernible.
8.61. It is immediately obvious that the additio n of Road -derived sediment to
the annual sediment load of the lower Río San Juan could not have impeded
navigation or required Nicaragua to dredge the River for this of any other
purpose.
(5) Inputs of Road -derived sediment are not just insignificant, they are
undetectable
8.62. As established in Section 8.B , the annual load of the Río San Juan is not
constant year -on-year but is different every year because it responds to natural
variability in rainfall, runoff, erosion and channel evolution. Analysis of
suspended sediment records in the Río Colorado immediately downstream of the
Delta between 2010 and 2013 indicates that while the average annual suspended
sediment load is currently 5 981 000 t y -, the 95% confidence interval on th at
-1
average value is 5 181 000 to 10 585 000 t y due to uncertainty and natural
variability in the measured data. This means that there is a 95% probability that
the SSL carried in any year will be between 5 181 000 and 10 585 000 t, but there
is a 5% chance that it could be still higher or lower than this. Variability in annual
85 231 bedload is unknown, but is likely to be similar or greater than that in the
suspended sediment load. It follows that using variability in SSL to represent that
in total load (i.e. suspended sediment plus bed loads) is conservative.
8.63. These figures reveal that the annual total sediment load of the Río
Colorado will probably be within about +/ - 20% of the mean value , 95% of the
time. As around 90% of the discharge in the Río San Juan passes to the Río
Colorado, it follo ws that the 95% confidence interval on the mean annual
sediment load of Río San Juan must also be around +/ - 20%. Similarly, as 100% of
the discharge passing through the lower Río San Juan comes from the Río San
Juan, the 95% confidence interval on its ann ual sediment loads is also likely to be
about +/- 20%.
8.64. In this context, t he increase of less than 1% predicted based on ICE’s
analysis for delivery of road -derived sediment to the Río San Juan falls well within
the range of natural variability of sediment loads in the River represented by a
confidence interval of +/ - 20%, meaning that even if such a change in load were to
occur it would be practically indiscernible and statistically undetectable in
records of measured loads. This would still be the case if Dr Kondolf’s estimate
were accepted, which it is not.
8.65. The bed of the lower Río San Juan is formed in mobile sand, self -organised
into ripples and dunes with amplitudes ranging from centimetres up to a metre or
more, respectively. The bed also features natural scour pools and depositional
bars that cause in -channel depths to vary locally by one to several metres . It
follows that a change in the rate of sedimentation by less than 0.2 mm y -1 (which
is less than the diameter of a single sand grain) or even 100 times this (that is 2 0
mm y , which is less than the amplitude of a ripple bedform) would be
imperceptible in the field and immeasurable using a conventional echo-sounder.
E. Sediment budget of the Río San Juan and the possibility of reach -scale
sediment impacts
8.66. On page 8 (paragraph 3) of his Third Report , Dr Kondolf alludes to the
finding reported by Reid and Dunne (2003) that ,
232 86 “road-related sediment can dominate the sediment budget in many
rivers.”
8.67. As a general proposition and in the abstract, I agree w ith this statement.
But Reid and Dunne were not referring to the Río San Juan. In Sections 8.B and 8.D
above, it is explained that even accepting Dr Kondolf’s upper -bound estimate of
the contribution of sediment from the Road to the Río San Juan (182 030 t y ),-1
this constitutes only about 2% of the annual sediment budget for this specific
River. Road-related sediment may dominate the sediment budget in many rivers,
but the Río San Juan is not one of them.
8.68. Notwithstanding this, there is more to the sediment budget of a river than
the average annual load measured downstream in the system , and it could be
argued that while the contribution of Road -related sediment is tiny in comparison
to the average annual load measured downstream at La Trinidad or the Delta, it
might be significant when compared to the average annual load carried by the
River in the immediate vicinity of the Road, which is someway upstream. To
examine whether this could be the case, it was necessary to construct a spatially
referenced sedimen t budget in the manner pioneered by Dr Stan Trimble for Coon
Creek, Wisconsin (Trimble 1983).
8.69. The starting point for construction of such a sediment budget is Table 6,
which sets out the average annual loads of suspended, bed and total loads in the
Río San Juan, Río Colorado and lower Río San Juan. This Table is reproduced here
for ease of reference.
Table 6. Current average annual total loads in the Rio San Juan - Colorado
River Suspended load Bed load Total Load
t y1 t y-1 t y-1
San Juan 6 573 000 2 559 000 9 133 000
Colorado 5 981 000 2 488 000 8 470 000
Lower San Juan 592 000 71 000 663 000
8.70. Unfortunately, the spatial distribution and periods of record for which
sediment transport data are available at other points along the mainstream and in
the m ajor tributaries are insufficient to support construction of a sediment
87 233 budget. Therefore it is necessary to estimate the sediment yields from the major
Costa Rican and Nicaraguan tributary basins , and then use the available measured
data to balance the se diment budget. These estimates are based on rigorous use of
appropriate sediment models, and their application benefitted from the insight
and sound judgment of the engineers at ICE, who are highly experienced in
construction of reliable sediment budgets f or Costa Rican rivers in the context of
their work in designing sustainable hydropower dams and reservoirs .
8.71. Tributary sediment yields due to sheet and rill erosion in basins draining
from Costa Rica (Frío, Pocosol, Infiernito, San Carlos, Cureña, Sarapiqu í and
Chirripó) and Nicaragua (Melchora, Sábalos, Santa Cruz, Bartola, Caño Machado
and Caño Las Banderas) were estimated using the Calibrated Simulation of
Transported Erosion (CALSITE) model (Bradbury et al., 1993). This model
employs the Universal Soil Loss Equation (USLE) which is by far the most widely
applied method for predicting land surface erosion by surface runoff, worldwide
(Wischmeier and Smith, 1960). When calibrated (as in this application) the USLE
works well, though it is important that the person responsible for its application
has experience in avoiding potential pitfalls that can lead to unreliable results.
The modelling at ICE was led by Federico Gómez Delgado, who has over a decade
of experience in us ing the USLE and CALCITE models. Application of the CALSITE
model in the management of multiple hydropower development and catchment
management plans (Gómez -Delgado, 2002 and 2004; Gómez -Delgado et al., 2011;
Marchamalo et al., 2007 and 2012), has demonstrated the coherence and
reliability o f this model for determining the sheet and rill component of the basin
sediment yield in the Río San Juan (and other) basins. Full details of the mode lling
may be found in section 5 and Appendix H of the 2013 ICE Report. For these
reasons, I consider the c riticism made by Dr Kondolf in his Fourth Report that the
estimates derived from the USLE are “notoriously inaccurate” to have no
relevance to the ICE Report.
8.72. However, CALCITE does not account for the input of coarse sediment
moving through the tributaries as bed load. Measurements of suspended and bed
loads at the Delta Colorado station indicate that the suspended load of the Río San
Juan is about 2.5 times larger than bed load. On this basis, the bed load
234 88contributions of the major basins were approximate d as being 40% of the
suspended load. With respect to bed load , it was assumed that the Lake Nicaragua
does not provide significant bed load to the Río San Juan due to its large size and
high trap efficiency for coarse sediment .
8.73. The results of CALCITE mode lling and estimation of bed load inputs based
on the predicted suspended sediment loads in the tributaries to the Rio San Juan
are summarised below, in Table 15.
Table 15. Annual sediment inputs (suspended and bed loads) to the R ío San Juan from Lake
Nicaragua and its tributary basins based on CALCITE modelling (from 2013 ICE Report).
Basin Suspended load Bed load Total load
(t yr ) (t yr ) (t yr )
Major Costa Rican basins draining directly to the R ío San Juan
Frío 269 000 108 000 377 000
Pocosol 49 000 20 000 69 000
Infiernito 78 000 31 000 109 000
San Carlos 1 824 000 730 000 2 554 000
Cureña 23 000 9 000 32 000
Sarapiquí 458 000 183 000 641 000
Chirripó 27 000 11 000 38 000
Major Nicaraguan basins (inc. Lake Nicaragua) draining directl y to the Río San
Juan
Melchora 278 000 111 000 389 000
Sábalos 366 000 146 000 512 000
Santa Cruz 244 000 98 000 342 000
Bartola 23 000 9 000 32 000
Machado 44 000 17 000 61 000
Las Banderas 31 000 12 000 43 000
Lake Nicaragua 365 000 - 365 000
Summary for R ío San Juan - Colorado system
Total 4 079 000 1 485 000 5 556 000
8.74. The total sediment load in Table 15, based on application of CALCITE and
the assumption that bed load is about 40% of the suspended load, is
5 556 000 t y . This is lower than the total load estimated for the Río San Juan -
89 235 Colorado system based on measured loads at the Delta Colorado station, which is
9 133 000 t y -1. The difference is easily explained by the fact that the CALSITE
model accounts only for sheet and rill er osion; it does not predict the basin
sediment yield due to larger scale erosion processes such as mass wasting and
gully erosion , which are processes observed to occur throughout the region.
8.75. To balance the budget, the deficit (3 567 000 t y -) may be attr ibuted to
landslide and gully erosion. This suggests that surface erosion (sheet and rill) and
mass wasting/gullying contribute approximately equally to the yield of fine
sediment from the tributary basins, which is not an unreasonable finding. Also,
problems occur when components of a sediment budget are small numbers
estimated based on the difference between two large numbers. This is not the
case here as the contributions of surface erosion and mass wasting/gullying are
commensurate in size. For these re asons, closing the budget in this way is
acceptable. The balanced sediment budget is listed below in Table 16.
236 90 Table 16. Annual sediment inputs (suspended and bed loads) to the Río San Juan from Lake
Nicaragua and its tributary basins adjusted to obtain b alance the sediment budget
(from 2013 ICE Report).
Suspended
Bed load Total load
Basin load -1 -1
(t yr ) (t yr ) (t yr )
Major Costa Rican basins draining directly to the R ío San Juan
Frío 433 000 185 000 618 000
Pocosol 79 000 34 000 113 000
Infiernito 126 000 54 000 180 000
San Carlos 2 939 000 1 257 000 4 196 000
Cureña 37 000 16 000 53 000
Sarapiquí 738 000 316 000 1 054 000
Chirripó 44 000 19 000 63 000
Major Nicaraguan basins draining directly to the R ío San Juan
Melchora 448 000 192 000 640 000
Sábalos 590 000 252 000 842 000
Santa Cruz 393 000 168 000 561 000
Bartola 37 000 16 000 53 000
Machado 71 000 30 000 101 000
Las Banderas 50 000 21 000 71 000
Lake Nicaragua 588 000 - 588 000
Totals for Río San Juan - Colorado system
Río San Juan 6 573 000 2 559 000 9 133 000
Río Colorado 5 981 000 2 489 000 8 470 000
lower Río San 592 000 71 000 663 000
Juan
8.76. The sediment budget set out in Table 16 is shown graphically in Figure 32 .
In this diagram, the average annual supply of sediment from each tributary is
labelled (in tonnes) and represented by an inward arrow, the width of which is
proportional to the magnitude of th e average annual sediment input. T he average
annual supplies of sediment to the Río Colorado and lower Río San Juan
downstream are also labelled (in tonnes) and represented by outward arrows
that are similarly scaled on the relevant sediment loads. The legend and map in
Figure 24 define the tributary rivers and locations of their basins, respectively. It
91 237 follows that in Figure 24, the width of the body of the diagram, which represents
the average annual load transported by the Río San Juan, increases left to right as
the tributary inputs add to that load.
Legend
Total Sediment Load (t y )1
Figure 32. Sediment budget fo r the Río San Juan including inputs from the Road
(from 2013 ICE Report). Labels indicate average annual inputs and outputs in tonnes.
8.77. The sediment budget set out in Table 15 and illustrated in Figure 32
corresponds to the period December 2010 to June 2013 , which means it reflects
conditions following construction of Route 1856. In Section 8.C above the average
annual inputs of sediment eroded from the Road (including the road bed, cut
slopes, fill slopes and other disturbed areas) by all relevant processes (including
sheet erosion, rill erosion, landslides and gullies) were calculated for each of the
five major basins draining to the Rio San Juan along the entire length of the Road
that parallels the River between marker II and the Delta. The results were l isted in
Table 14 and plotted in Figure 31 .
238 928.78. A sediment budget for conditions that would have pertained had the Road
not been constructed was obtained by subtracting the estimated inputs of
sediment from the Road in each of the major basins (as listed in T able 14) from
the relevant rows in the sediment budget in Table 15. The sediment budget for
conditions without the Road is shown graphically in Figure 3 3.
Legend
Total Sediment Load (t y )1
Figure 33. Sediment budget for the Río San Juan excluding inputs from t he Road (from 2013
ICE Report). Labels indicate average annual inputs and outputs in tonnes.
8.79. Finally, the contribution s made to the sediment budget from each of the
five major basins draining to the Río San Juan along its length can be illustrated by
the differences between the sediment budgets in Figures 32 and 33, and these are
shown graphically in Figure 34 . The narrow width s of the red band s in Figure 34
are correctly scaled and accurately portray that sediment inputs from Route 1856
in each reach are s o small relative to natural loads in those reaches that they are
not only difficult to see but inconsequential and practically undetectable .
93 239 Legend
Sediment Input to the Rio San Juan
from the Road (t y )-1
Sediment budget excluding the Road Sediment contributed by the Road
Figure 34. Sediment budget for the Rio San Juan – Colorado system highlighting the
contribution due to construction of Route 1856 from each major tributary basin . Inputs of
road-derived sediment are as labelled: for example, the largest input to the San Juan River is
+40 300 t y-1 from CR5 (the Infiernito Basin). The narrow widths of red ba nds are correctly
scaled and accurately portray that sediment inputs from Route 1856 in each reach are so
small relative to natural loads that they are not only difficult to see but inconsequential and
practically undetectable (from the 2013 ICE Report).
8.80. Based on this exhaustive investigation and the sediment budget that has
been constructed , it is abundantly clear that the addition of sediment eroded from
the Road is insufficient to significantly impact the sediment budget not only at the
system scale, but also in Río San Juan in the vicinity of the Road .
240 94 9. Has construction of the Road had any significant impacts on
channel morphology in the Río San Juan?
A. Sediment deltas observed in the Río San Juan following construction of
Route 1856
9.1. The 2012 Kondolf Repo rt makes reference to deltas of sediment eroded
from the Road that were observed along the right (Costa Rican) bank of the River
in October 2012. The few photographs are included in that report to il lustrate
these del tas do not demonstrate that the Road wa s having a significant
morphological impact on the Río San Juan. Four of the photographs from the 2012
Kondolf Report are reproduced here to illustrate the small dimensions and
morphological insignificance of the deltas observed in October 2012 .
Figure 35. Photographs reproduced directly from Appendix B of the Kondolf Report . Dr
Kondolf presumably selected them to be representative of the deltas of Road-derived he
observed in October 2010 . If so, the deltas he observed appear small and inconsequen tial in
the context of this large River .
95 241 9.2. On page of his Third Report (paragraph two), Dr Kondolf reports further
observations related to the morphological impacts of the Road, reporting that
during his May 2013 field visit he ,
“documented multiple ‘deltas’ of sediment eroded from the road, and
carried by local streams or newly eroded gullies into the river.”
9.3. On this occasion, he supported his textual account with a large number of
photographs, included in Appendix A to the Third Report .
9.4. In my 2013 Report su bmitted in response to Nicar agua’s request for the
indication of Provisional Measures in the Construction of Road Case, I opined that I
was unsure of the basis on which Dr Kondolf could be certain that all of the deltas
documented in the photographs in Appendix A were composed entirely or even
predominantly of ‘sediment eroded from the road’ . In a subsequent written
response (the Fourth Kondolf Report) , Dr Kondolf agreed that the source of the
sediment in the photographs was not always clear and that in man y of them it was
impossible to see a link to the Road that was obvious in the field. He also drew
attention to the fact that the existence of the deltas could be causally linked to
erosion of the Road because the sediment comprising them was more angular
than that sourced higher in the catchment, delivered by tributary streams and
rounded in the process. This is an argument I understand and accept , at least for
particles of gravel size or larger.
9.5. Having accepted that, I remain convinced that by no means al l the
sediment deltas observed by D r Kondolf along the right bank of the Río San Juan
between Marker II and Boca San Carlos in May 2013 exist solely because of the
addition to the River of sediment eroded from the Road.
9.6. As noted in paragraph 3.3 above, I also participated in an overflight of the
Road in May 2013, and I also noticed multiple deltas of sediment. However, many
of the deltas I noticed were along the left bank line of the Río San Juan , on the
Nicaraguan side . And s everal of them appeared larger and considerably more
prominent than those documented in Appendix A (Figures 36 to 38 show
examples). These deltas are composed of sediment eroded from Nicaraguan
242 96territory and deposited in the Río San Juan by Nicaraguan tribu taries. They cannot
be deltas of sediment eroded from the Road.
97 243 (a)
(b)
Figure 36. Prominent sediment delta observed in the Río San Juan from a helicopter in Costa
Rican airspace on 7 May 2013 (a) close up and (b) wide angle view showing clearly that this
delta is on the left (Nicaraguan) bank of the River . Route 1856 is clearly visible on the right
(Costa Rican) side of the River (both photographs by author).
244 98 (a)
(b)
Figure 37. Sediment delta observed in the Río San Juan from a helicopter in Costa Rican
airspace on 7 May 2013 (a) close up . (b) wide angle view showing clearly that this delta is also
on the far (Nicaraguan) bank of the River . Route 1856 is clea rly visible on the near (Costa
Rican) side of the River (both photographs by author).
99 245246 100 Figure 38. Photographs taken from Costa Rican air space on 7 May 2013 . These show that
deltas of sediment occur at most of the left bank tributarie s of the Río San Juan between
Marker II and Boca San Carlos . The deltas are unrelated to the Road and are formed by
sediment delivered to the Río San Juan by streams drain ing catchments entirely within
Nicaraguan territory.
9.7. Without speculat ing on the orig ins of the sediment that builds deltas at
tributary mouths along the Nicaraguan bank of the Río San Juan and whether
these are natural or anthropogenic sources, the presence of multiple deltas that
cannot be composed of sediment eroded from the Road demonstrates that deltas
in this River are not exclusively or even predominantly caused by deposition of
additional sediment eroded from the Road.
9.8. On the contrary, deltas are part of the natural sediment transfer system
along the channel of the Río San Juan . They form when local rainstorms produce
sediment-laden runoff from tributaries, the coarse fraction of which is deposited
in the lower course of the tributary channel and around the tributary ’s confluence
with the Río San Juan. As Dr Kondolf notes, that depo sition is temporary – deltaic
sediments are re -eroded and transported downstream, diffusing into the
101 247 receiving river’s sediment load during the next significant sediment transport
event in the main river.
9.9. In any case, t he limited size and relatively wide spacing of the tributary
deltas I observed along both banks of the Río San Juan in May 2013 means that
they do not harm the River. Indeed, to the contrary, tributary bars and deltas are
beneficial to the aquatic and riparian ecosystems because, for example , they
provide fresh habitats and open niches for pioneer plant species – for example, as
illustrated in photographs 1018, 1043 and 1046 in Dr Kondolf’s 2013 Appendix A
(to his Third Report) .
9.10. The potential for any other morphological responses to changes in the
sediment supply to the Río San Juan upstream of Boca San Carlos is effectively
zero because (for the reasons set out in Section 6.C) the River between Lake
Nicaragua and the Rio San Carlos is composed of a series of three transport
reaches, in which channel form, elevation and slope are controlled geologically.
Downstream of Boca San Carlos, the River is composed of response reaches within
which channel form is controlled by the sediment regime (as des cribed in Section
6.C). However, that regime is d ominated by high and variable sediment inputs
from the San Carlos and Sarapiqu í basins, which supply the vast majority of
sediment carried by the River. The contribution from the Road is far too small to
have any discernible impacts.
248 102 10. Has the Road impacted the Ecology or Fishery of the Río San
Juan, or had any effect on Tourism?
10.1. In addition to the statements made in Nicaragua’s Memorial and the 2012
Kondolf Report, in his Third Report Dr Kondolf makes further reference to the
impacts of road construction in rivers other than the Río San Juan. For example,
on page 7 (paragraph 2) of his Third Report , he writes that ecological impacts
stem from,
“The combination of hydrological effects and increased erosion and
sedimentation from road construction that result in significant
increases of sediment loading to rivers and streams, which in turn,
have been documented to cause a range of serious environmental
problems.”
10.2. And in paragraph 5 on page 7,
‘The delivery of massive volumes of sediment to rivers has resulted in
significant ecological damage. ”
10.3. These statements are entirely general in their terms and are only relevant
to road construction that delivers increases in sediment loading that may
justifiably be described as massive or at the very least significant. As explained in
Chapters 6, 7, 8 and 9 above, hydrologic impacts of the Road on the Río San Juan
are infinitesimal ; its sediment impacts are undetectable , its impacts on navigation
are non -existent; and its morphological impacts (in building deltas that
temporarily store coarse sediment) are insignificant, and in any case not
necessarily adverse . In no sense can any of the Road’s impacts be described as
massive or even significant. Considering uncertainty in the hydrology, sediment
load and in-channel storag e of sediment associated with natural variability in the
annual load the impacts of the Road are not only negligible, they are indiscernible.
10.4. On page 11 (paragraph 2) of his Third Report , Dr Kondolf reports
suspended sediment concentrations in three sampl es of muddy -water in plumes
in the River, which had e ntered the River following a 15 -minute downpour. The
samples had SSCs of 364, 459 and 483 grams per cubic metre. Dr Kondolf
describes these SSCs as ‘ high’. He also took two samples of River water, both o f
which had SSCs of 8 grams per cubic metre. Section 6.E(1) of this Report includes
103 249 data from not five SSC samples, but 2 409. Table 4 lists the sources of SSC data for
the Río San Juan and its Costa Rican tributaries and these data were graphed in
Figure 18.
10.5. The SSCs measured in this larger data set vary from less than 10 ppm (or
grams per cubic metre – the two measures of SSC are equivalent) to more than 10
000 ppm. While the background SSC in the River as measured by Dr Kondolf was
indeed low, the conce ntrations in the plume of muddy -water are not high in the
context of SSC s routinely observed in runoff draining to the Río San Juan, or even
in the River itself.
10.6. I am not surprised that a 15 -minute rainstorm in May produced a striking
contrast between SSC s in local runoff and the receiving water because under
these circumstances the source of sediment is localised to the area of the
rainstorm while discharge and background SSCs in the River (which in May is at
its lowest (base flow) discharge – see Figure 14 above) are at their lowest.
However, the volume of muddy water is a tiny fraction of even the lowest
discharge in the Río San Juan and turbulent mixing would ensure that the
relatively high SSC decreases to background levels within a short distance
downstream and a short time after the rainstorm ends, as the plume of local
runoff diffuses into the far greater flow in the receiving water.
10.7. In his Fourth Report, Dr Kondolf accepted that the sediment
concentrations he measured in the muddy plume , “were not very high compared
to concentrations measured in the river and its large tributaries during high
flows.”12 In doing so, he e ffectively retracts the statement in his Third Report that
these measurements showed , “that the runoff from the road carried high
suspended sediment contributions” . 13Dr Kondolf went on to state in his Fourth
Report that the measurements , “demonstrate the essential fact that sediment
from the road is entering the Rio San Juan.” 14I agree , but the central point
12
Fourth Kondolf Report, p. 11.
13 Third Kondolf Report, p. 11.
14 Fourth Kondolf Report, p. 11.
250 104remains this: in order to assess the whether the concentration s of suspended
sediment measured in runoff from the Road have harmed or may in future cause
harm to life in the River , it is necessary to consider them within the context of
sediment concentrations that aquatic plants and animals in the river system
experience routinely and to which they are well adapted. The analysis condu cted
herein demonstrates that concentrations often exceed 500 grams per cubic metre
and so th ose measured in May 2013 ( 364, 459 and 483 grams per cubic metre)
have not, and will not damage life in the River .
10.8. With two exceptions, the Third Kondolf Report adopts a descriptive
approach in presenting a literature review of the impacts of road building on
rivers other than the Río San Juan (much of which is s imilar or even identical to
material presented previously in the 2012 Kondolf Report), together with textual
commentary and a virtual tour of the Río San Juan, both of which (as in October
2012) extend only to 41 .6 km of the Road between Marker II and Boca San Carlos.
The five suspended sediment samples measured in the muddy plume constitute
one exception to this approach.
10.9. The second exception is the reported results of research done by Dr
Kondolf’s colleague, Dr Rios, who sampled the periphyton at nine si tes, in late May
2013. On page 13 (paragraph 1) of the Third Kondolf Report , Dr Kondolf explains
that four samples came from the deltas assumed to be composed of sediment
eroded from the Road on the south (Costa Rican) bank of the River. The text is less
clear concerning the nature of the sample sites on the north (Nicaraguan) bank.
Dr Kondolf states that these were “five sites draining rel atively undisturbed
landscapes.”
10.10. What the text does not make clear is whether those sites were on any of
the multiple deltas I observed at the Nicaraguan side of the River earlier that
month (as illustrated in Figures 36-38 above). If they were, then it would be a fair
to compare them to deltas at the south bank ; if they were not then the comparison
between these samples taken at the north and south banks is inapt.
10.11. In the concluding part of paragraph 4 on page 2 of his Third Report , Dr
Kondolf makes reference to irreversible harm done to salmon by massive mining
105 251 in California and extensive logging in the Pacific Northwest . This contrasts with
statements in the 2012 Kondolf Report that attribute the demise of pacific salmon
populations in the USA to road building alone, which (as pointed out in
Section 6 F) was not the case. But , as explained in the CCT Report , there are no
salmon in the Río San Juan and in any case construction of a Road that increases
the impermeable area in the Costa Rican basins draining to the Rio San Juan by
0.05% cannot be compared to the catchment -wide practices of hydraulic mining
and clear-cut forestry that occurred in California and the Pacific Northwest.
10.12. Putting the evidence together, I can find nothing to support the statement
made in paragraph 4 on page 2 of the Third Kondolf Report that Dr Kondolf and
his team, “already see extensive, severe e nvironmental damage .”
10.13. With regard to the possibility that the Road has significantly damaged the
Río San Juan, this statement seems inconsistent with the photographs in the 2012
Kondolf Report and the Third Kondolf Report , let alone the evidence provided
throughout this report, which is supported by data, mapping and modeling
provided in the accompanying reports mentioned in paragraph 3.3.
10.14. Nevertheless, it is still appropriate to précis some of the key findings of the
2013 CCT Report, as they pertain to th e premise that there has already been
‘extensive, severe environmental damage’ to the Río San Juan.
10.15. In their comprehensive investigation, CCT examined the impacts of the
Road on terrestrial and aquatic environments with complex ecosystems and food
webs. T hey employed field work that included scientific sampling and analysis,
together with over flights and application of the maps of land use change and
inventories of slopes and watercourse provided in the 2013 Land Use Change
Report and Inventory of Slopes and Water Courses , respectively . However, the
great majority of the observations, data, analyses and conclusions in the CCT
Report pertain to the Road’s environmental and ecological impacts within Costa
Rica. These impacts are assessed as being irrelevant in five of eight categories and
moderate in three. Moderate impacts were mostly confined to the stretch of the
Road between Marker II and Boca San Carlos, with a few micro -basins between
Boca San Carlos and Boca Sarapiqu í being moderately impacted. There w ere no
252 106impacts at all between Boca Sarapiquí and the Delta. Moderate impacts were
limited to tree cutting in previously disturbed primary and secondary forests
(along about 25% of the Road) , and increased turbidity and disturbance of micro -
habitats in some water bodies , due to localized sedimentation. These findings are
important in helping to inform on -going planning and implementation of
mitigation works (as described in Section 11, below) . However, they are of no
relevance to the Río San Juan, and so are not mentioned again herein .
10.16. CCT were prevented from evaluating environmental and ecological
conditions in the Río San Juan itself because,
“the Government of Nicaragua did not allow the scientists that
conducted this study to enter Nicaraguan territory along the San Juan
15
River in order to conduct sampling.”
10.17. Although it was not possible to prepare a matrix of potential impacts based
on field data, for the reasons set out below, CCT concluded that,
‘”it is not considered there could be any significant imp act on the San
Juan river.”16
10.18. CCT concluded that the Road has not had any significant, adverse impacts
on the Río San Juan for the following reasons:
(a) Sediment transport and sedimentation are natural processes that play
important roles in the aquatic environ ments of lowland, tropical water
bodies, wetlands and rivers like those in this region.
(b) In lowland tropical rivers with high and variable sediment loads, resident
species of macro -invertebrates and fish have adapted to conditions of high
sedimentation, gi ving them a high tolerance over prolonged periods (see,
for example, Connolly and Pearson , 2007).
15 CCT Report, p. 139, para. 3.
16
CCT Report, p. 139, para. 4.
107 253 (c) The Environmental Diagnostic Assessment indicated that impacts would
not be expected in the Río San Juan even at an irrelevant (insignificant)
level, due to the much larger volume of water this watercourse conveys, its
greater depth and the high degree of adaptation of aquatic organisms that
inhabit the River.
10.19. These findings extend to the potential for the Road to have adversely
impacted the fishery in the Río San Juan. Potential impacts on sport fishing are
dealt with below in paragraph 10.21 on Tourism. CCT identified no commercial
fishing activities along the R iver in the study area. Fishing activities from Mark er
II to Delta Cost a Rica consitute sporadic, subsistence fishing and there is no
evidence that they have been adversely impacted by construction of the Road .
10.20. On page 110 and in conclusions 12 and 13 on page 156, CCT point out that
it is currently impossible for any scientif ic study to demonstrate the possibility of
there being adverse ecological impacts on the Río San Juan due to construction of
the Road. This is because to do so would require the establishment of threshold
levels for tolerance, morbidity and mortality of ke y species in the River with
regard to sediment and sedimentation, a process that has not been undertaken to
date and which would take several years to complete.
10.21. CCT’s conclusions with respect to the possible impacts of the Road on
tourism are unequivocal. First, it is important to note that there are no facilities
for tourists on either bank of the Río San Juan between Marker II and Delta Costa
Rica. The potential for international tourism (including sport fishing) is low due to
lack of appropriate accommod ation and infrastructur e, poor access, and the
perception of insecurity generated by press reports of border disputes between
Costa Rica and Nicaragu a. CCT were unable to find any evidence of a reduction in
visitor numbers that could be attributed to const ruction of the Road and conclude
in conclusion 14 on page 158 that,
“The effect of the construction of Route 1856 has no direct impact on
tourism in recent years. ”
254 108 11. Mitigation Works
A. Observations of the Mitigation Works in May 2013
11.1. During my first visit to the Route 1856 in February 2013, I inspected
mitigation works under construction at several points along the Road between
Marker II and the Río Infiernito. At one site I spoke to senior engineers from
CONAVI ( http://www.conavi.go.cr/ ), who were supervising construction of an
inboard drainage channel. We discussed proposals for further mitigation works
and I was impressed by their appreciation of the challenges posed by erosion
control, their wide experience in succes sfully meeting the challenges along roads
in other parts of Costa Rica, their resolve to stabilize cut and fill slopes and
manage runoff from them and the road bed along Route 1856, and their
confidence that they knew how to achieve these goals. An enginee r from MECO
(the lead contractor: http://constructorameco.com ) was present, as was an
engineer with Durman (the contractor responsible for materials:
http://www.durma n.com/inicio.htm). Each of these individuals thoroughly
understood the need to mitigate erosion at specific locations along the Road and
they demonstrated a deep knowledge of both the materials (woven biodegradable
geofabrics, coconut matting, silt fences , rock, concrete) and infrastructure (in -
board and out -board drainage channels, culverted cross -drains etc.) appropriate
to the site.
11.2. During my second visit to the Road in May 2013, I focused particularly on
the 41 km stretch between Marker II and Boca San Carlos and, especially, on
inspection of mitigation work performed by MECO and Durman under
supervision by CONAVI since my February visit. I did so based on the focus on this
stretch in the Kondolf Report, my own observations of eroding cut and fill slope s
in this stretch in February 2013, and my conclusion that there were few eroding
slopes along the Road between Boca San Carlos and the Delta. I was accompanied
in the field by Mr Carlos Pereira who was at that time leading the mitigation effort
on behalf of CONAVI. I also took the opportunity to inspect sites proposed for
erosion monitoring by a team of experts from the Departments of Geology and
109 255 Civil Engineering at the University of Costa Rica (see the UCR Report for a full
account of the erosion monitor ing programme).
11.3. The first site I inspected was near Marker II, where the Road approaches
the Río San Juan from the west. In February 2013 the Road corridor featured
extensive areas of bare soil and a developing gully along the inboard edge (Figure
39a). In May the area had been transformed by recently completed erosion
mitigation measures including a concrete -lined, in -board ditch to convey water
draining off a relatively steeply sloping stretch of the road while preventing
concentrated flow erosion, and c oconut matting to protect the bare soil areas
from raindrop, sheet and rill erosion, while allowing it t o re -vegetate naturally
Figure 39b.
11.4. On 15 February 2013 I observed a gully eroding into a fill prism located to
the west of Marker II. This gully had fo rmed due to concentrated runoff that
between 2011 and May 2013 flowed across Route 1856 from a micro -basin that
had been blocked temporarily during co nstruction of the Road (Figure 40 a). I
noted at the time that the gully was draining to Costa Rican territ ory, and well
away from the Río San Juan. When I revisited the same site on 7 May 2013 the
gully was no longer there. A culvert had been installed to convey runoff from the
micro-basin beneath the road and a concrete -lined channel had been constructed
to carry it to the base of the fill slope. The surrounding fill slope surface had been
protected from raindrop impact, sheet and rill erosion by extensive deployment of
coconut matting, which is well suited to this purpose (Figure 40 b).
256 110 Figure 39. The Road near Marker II (a) prior to mitigation work on 15 February 2013 and (b)
on 7 May 2013 with mitigation measures in place : note in-board drainage channel and
extensive biodegradable, erosion control matting. Photographs by author.
Figure 40. View down a large gully in a fill prism created by concentrated runoff from the
Road draining to Costa Rican territory to the west of Marker II (a) in February when it was
actively eroding and (b) in May when the gully had been back -filled and stabilized using a
culverted cross -drain and concrete drainage channel, with coconut matting used to protect
the surrounding fill slope from sheet and rill erosion . Photographs by the author.
11.5. The next location where erosion had been noted during the February field
visit was about 6.4 km east of Marker II. At this stretch of road, runoff from a
relatively steep stretch of road had created two gullies on the out -board slope and
initial attempts at erosion control using geofabric had been unsuccessful. Also,
runoff was eroding th e unlined in -board ditch. If left untreated, there was a risk
that scour in the inboard ditch might undercut the toe of a cut slope at the top of
hill to trigger a landslide (Figure 41a). During the May visit I observed that
extensive concrete drainage cha nnels had been constructed to convey both out -
board and inboard runoff down the steeply s loping stretch of road (Figure 41 b).
The channels were functioning as intended and there had been no further toe
111 257 erosion of the cut slope, which appeared to be stable and unchanged from
February.
Figure 41. Road at East 497867, North 325463 about 6.4 km east of MarkeII (a) on 15
February when failure of geotextile slope protection had allowed concentrated -board
runoff from the Road to create two gullies and i n-board runoff was undercutting a cut slope
(b) on 7 May 2013 after construction of concrete -lined out-board and in board ditches .
Photographs by author.
11.6. In February I observed a network of rills and gullies on an outboard slope
about 6.6 km east of Marker II that extended from the edge of the road bed down
slope to the rear edge of a terrace separating the slope from the ba nk of the Río
San Juan (Figure 42 a). Soil eroded from the gullies had accumulated on the
terrace surface as a run -out deposit, though n o flow, erosion or sediment
transport was occurring on February 15 and I could not see evidence of Road -
related sediment having reached either the bank or the river. When I returned on
7 May, there had been extensive mitiga tion work at this site (Figure 42 b). The
gullies had been replaced by an engineered drainage system consisting of
concrete channels connected by drop structures and silt fences had been installed
to prevent overland flow from driving sheet and rill erosion of the steepest parts
of the out board slope (Figure 42 b). Further silt fencing and a sediment trap had
been constructed at the base of the outboard slope, to prevent sediment eroded
from the road bed or outboard slope from reaching the terrace separating the
slope from the river bank.
258 112 Figure 42. Road at East 498072, North 32534 5, about 6.6 km east of Marker II (a) on 15
February 2013 showing a network of gullies on an outboard slope and sediment accumulated
as a run-out deposit on the flat terrace surface separating the foot of slope from the bank
of the Río San Juan (b) on 7 May 2013 showing mitigation works in the form of concrete
channels and drop structures to convey runoff from the road bed, and silt fences to protect
the slope from sheet and rill erosion, lined out -board and prevent road -derived sediment
reaching the terrace. A sediment trap had also been constructed at the downstream
termination of the gully system to prevent sediment reaching the River, though this cannot be
easily identified in the photograph. Photographs by author.
11.7. In February, I observed evidence of sheet and rill erosion adjacent to the
road bed on a relatively steeply sloping stretch of the Road close to the Río
Infiernito (Figure 43a). Although the lower part of the rilled area was re -
vegetating natur ally, I was concerned that this may not happen quickly enough to
stabilize the slope during the 2013 summer wet season. In the event, the risk of
serious future erosion at this site was reduced through a multi -element,
engineering solution designed to mana ge surface water runoff from the road bed
and adjacent disturbed slopes i n an integrated manner (Figure 43 b).
113 259 Figure 43. Road at East 502480, North 321561, close to the Río Infiernito (a) on 15 February
when surface unmanaged runoff from the road bed and surrounding slopes disturbed during
construction had caused sheet and rill erosion of bare soil surfaces. (b) The same stretch of
road on 7 May 2013 after protection of the road surface using crushed rock, installation of silt
fences to prevent sheet a nd rill erosion while directing down -slope surface runoff into
concrete-lined outboard and inboard ditches . Photographs by author.
11.8. The final site in the stretch of road between Marker II and Boca San Carlos
visited on the ground on 15 February was at a pro montory featuring a monument
to slain police officers at Crucitas just east of the crossing on the Río Infiernito.
This is currently as far as Route 1856 is accessible by conventional 4 -wheel drive
vehicle. From this vantage point it was possible to observ e the path cleared in
preparation for construction of the Road to the east. The exposed soil surface was
subject to sheet and rill erosion by unmanaged down -slope runoff (Figure 44a).
On 7 May 2013, it was clear that erosion had been addressed using an int egrated
system of runoff management measures (Figure 44b) that featured regarding of
the slope profile that removed the more erodible surficial soils, installation of silt
fences across the slope to reduce the effective length of down -slope overland flow
and direct runoff into a concrete -lined, outboard ditch.
260 114 Figure 44. Path cleared for the Road near Crucitas, just east of the Rio Infiernito (a) on 15
February when unmanaged runoff from the path cleared in preparation for construction of
the road bed had caused sheet and rill erosion. (b) The same area on 7 May 2013 after
installation integrated measures to manage runoff involving regrading, silt fences, and
concrete-lined outboard ditch . Photographs by author .
11.9. Based on the observations of th e Road on 15 February and 7 May 2013
that are reported above it may be concluded that, during the intervening period,
significant and substantial engineering works were carried out at multiple
locations along the Road between Marker II and the Rio Infiernito, inclu ding but
not limited to those illustrated in Figures 39 to 44.
11.10. Further, it may be predicted that the rate of erosion of the Road will
decrease further in future compared to that reported in the UCR Report and that
the Road will become increasingly insensit ive to heavier rainfall as time passes.
This prediction is based on measurements of sediment production from newly
constructed, unpaved roads on the island of St John in the Caribbean reported by
Ramos-Scharron and MacDonald (2005) . These measurements indicate that
sediment production declines with time since construction of the road surface
because runoff preferentially removes easily eroded particles, leaving behind
larger and less erodible ones so that the surface progressively ‘armours’ itself to
become less erodible through time. (See Figure 45 below.)
115 261 Figure 45. Relationship between sediment production per cm of rainfall and time elapsed
since the road was constructed (or regarded) for a constant average road slope (from Ramos -
Scharron and MacDonald, 2005).
11.11. Finally, the susceptibility to erosion of the Road will further decrease as
extent to which its surface is covered by crushed rock increases.
11.12. For all these reasons, it seems certain that the future risks of erosion from
the Road during heavier rai nfall will decrease compared to those that pertained
when construction of the Road was suspended .
B. Mitigation of future erosion risks and a permanent solution to erosion
issues associated with the Road
11.13. In addition to the works I observed during my field vis its, described in
Section A immediately above, I am instructed that work is continuing to mitigate
future erosion risks and to find a permanent solution to erosion issues a ssociated
with the Road. I note that the findings of the Environmental Diagnostic
Assessment performed by CCT, which are included in their 2013 Report, indicate
that further measures are necessary to control erosion from the Road in the
future, in order to avoid environmental impacts within Costa Rica . In establishing
whether appropriate plans are in place to achieve this, I have reviewed the
following reports:
262 116(a) Consejo Nacional de Vialidad (CONAVI), Program for the Consolidation and
Continued Improvement of Route No 1856 , Reference DIE -02-13-3107,
25 October 2013 (Annex [xx] to Costa Rica’s Counter-Memorial);
(b) Report from Ana Lorena Guevara Fernández, Vice -Minister of the
Environment, Costa Rica, to Enrique Castillo Barrantes, Minister of Foreign
Affairs, Costa Rica, Reference DVM -293-2013, 8 October 2013 (Annex [xx]
to Costa Rica’s Counter -Memorial); and
(c) Comisión de Desarrollo Forestal de San Carlos (CODEFORSA), Consulting
Services for the Development and Implementation of an Environmental Plan
for the Juan Rafael Mora Porras Border Road, Report of Activities to the
Ministry of Foreign Aff airs of the Republic of Costa Rica , January 2013
(Annex [xx] to Costa Rica’s Counter -Memorial).
11.14. These reports detail the continuing work to reduce erosion risks presented
by the Road in the immediate and near future, i.e. the next one or two years.
11.15. I do not agree with the recommendation in the opening sentence of
paragraph 4 on page 2 of the Third Kondolf Report that,
“If work continues on Rte 1856, its impact will be devastating to
areas directly affected and to downstream receiving waters .”
11.16. On the contrary, I agree with the recommendations in the 2013 CCT Report
that it is important that mitigation work continue s in order to minimise the risk of
future erosion and ecological impacts within some Costa Rican micro -basins,
should heavier rainfall occur.
11.17. Based on my experience with engineered and biotechnical erosion
mitigation works in other areas experiencing heavy rainfall, including Ethiopia,
Bangladesh and the USA, my opinion is that the measures taken by Costa Rica
have reduced and will continue to re duce the risk that significant erosion might
occur during heavy rainstorms, compared to conditions immediately following
construction of the Road. Consequently, I do not agree with the conclusion drawn
in paragraph 3 on page 2 of the Third Kondolf Report that “erosion control and
drainage works have been ineffective .”
117 263 11.18. It is my understanding that the measures I observed in May 2013 are part
of ongoing efforts intended to reduce erosion risks stemming from the way the
Road was constructed in 2011 and that the y are not intended to provide a
permanent solution to erosion issues. Given that, my experience suggests that
with appropriate inspection and, where necessary, maintenance or repair, the
mitigation works will significantly reduce local erosion rates for th e next year or
two, allowing time for the work necessary to design, contract and build
permanent works to progress.
11.19. However, these are temporary works that mitigate but do not permanently
solve erosion problems , and a permanent solution will not be achieve d until
design, planning and construction of Road are completed. In my opinion, the
necessary work should proceed as soon as possible, with the work expedited to
the greatest degree , and consistently with Costa Rican legal and contracting
practices.
264 118 12. Conclusions
12.1. Based on the scientific and technical studies reported herein, I conclude
that the Road has had no significant impact on the hydrology of the Rio San Juan.
At the micro -basin scale, changes in the permeability and hydrology of previously
unmanaged b asins are tiny and even when accumulated for all the affected basins
there can be no impact on the Río San Juan. Around three quarters of the change
in land use actually affects pasture rather than primary or secondary forest, so
minimal hydrological impac ts would be expected in any case.
12.2. The Road has had no significant impacts on sediment transport and
dynamics in the Rio San Juan because the additional loads of sediment are tiny
(less than 1 %) compared to natural loads and are well within the ranges of
natural variability (+/ -20%) characteristic of this River, meaning they are in
practice indiscerni ble.
12.3. In the reach upstream of Boca San Carlos the morphology of the Rio San
Juan is insensitive to changes in the sediment load because it is a transport reach
whose morphology is controlled by bed rock outcrops that form a cascade of
rapids that fix the channel form, bed elevation, long profile and slope . This
restricts morphological responses to changes in sediment input to the deposition
and re -entrainment of the coarse fraction of the incoming load in temporary
sediment deltas . My observations suggest that t hese deltas are actually larger and
more frequent on the Nicaraguan side of the River. Downstream of Boca San
Carlos, the Rio San Juan is a dune-ripple type river with a channel that is
responsive to changes in sediment supply , but the sediment regime is completely
dominated by naturally high inputs f rom the San Carlos and Sarapiqu í basins.
12.4. There is absolutely nothing to suggest that t he Road has adversely
impacted the water quality, ecology or the fishery of the River . B iotic impacts
would in any case be highly unlikely given that the abiotic impacts of the Road are
insignificant. There is similarly nothing to suggest that there has been any impact
on tourism.
119 265 12.5. There is no scientific justification for ‘active efforts, including dredging, to
maintain the capacity and quantity of the river’s waters ’ in the lower Río San Juan
on the pretext of having to remove Road -derived sediment. Sediment transfer and
deposition calculations based on measured data and conservativ e assumptions
demonstrate that the additional amount of Road -derived sediment entering the
lower Río San Juan is probably less than 1% of its total sediment load.
12.6. Sediment continuity dictates that eve n if all of this sediment were to be
deposited on the bed of the channel, it would on average raise the bed of the river
by less than 0.2 mm per year. In fact, deposition is spread over a much wider area
of floodplain, wetlands and wash lands and an unknow n but significant
percentage of the load is discharged to the Caribbean Sea. Also, as the River has a
sand bed, it is likely that only the sand fraction (which makes up 5 to 10% of the
Road-derived sediment delivered to the River) would actually be deposit ed on the
bed. Hence the estimates of increase sediment load and bed deposition in the
lower Río San Juan are necessarily over -estimates. They are in any case well
within the error margin for sediment measurements and calculations, and are
small in compari son to inter-annual fluctuations in that are the product of natural
variability.
12.7. Due to very small relative contribution of sediment in comparison to the
heavy and highly variable sediment load in this River, the Road has not and will
not in future pose a risk of harm to the hydrology, sediments, morphology,
environment, or ecology of the River , all of which are well -adapted to the heavy
load and highly variable sediment regime of the Río San Juan. That said,
construction of the Route 1856 should be complet ed to the highest standards and
as quickly as possible to provide a permanent solution to erosion issues along the
Road.
266 120 13. References
Aguirre Sacasa, F. X. (2002). Un Atlas Histórico de Nicaragua. First Edition, Mapas ,
col. Colección Cultural de Centro Amé rica Serie Histórica, No 15, Managua,
Nicaragua: Fundación Vida, 250 p.; on CD ROM.
Astorga, A. G. 2011b. Geology, Sedimentology and Tectonics within the
Surroundings of the San Juan River and Calero Island. Report to Government of
Costa Rica, 25 p.
Case, J. E. and Holcombe, T. L. 1980. Geologic-tectonic Map of the CaribbeanRegion,
Scale 1:2.500.000. Prepared in cooperation with the U. S. Naval Oceanographic
Office and U. S. Naval Ocean Research and Development Activity.
Cedarhold, C. J., Reid, L. M., Edie , B. G., and Salo, E. O., 1982. Effects of forest road
erosion on salmonid spawning gravel composition and populations of the
Clearwater River, Washington, In, Habitat Disturbance and Recovery , California
Trout, Inc.: San Francisco, pp. 1 -17.
Chapman, D. W. 1988. Critical review of variables used to define effects of fines in
redds of large salmonids, Transactions of the American Fisheries Society , 117, pp.
1-21.
Collins, B . D. and Montgomery, D. R. 2002. Forest development, log jams, and the
restoration of floodplain rivers in the Puget Lowland, Restoration Ecology , 10, pp.
237-247.
Collins, B. D., Montgomery, D. R. and Haas, A. 2002. Historic changes in the
distribution and functions of large woody debris in Puget Lowland rivers,
Canadian Journal of Fish eries and Aquatic Sciences , 59, pp. 66-76.
Collins, B. D., Mo ntgomery, D. R., Fetherston, K. and Abbe, T. B. 2012. The wood
cycle in structuring forested floodplains in the Pacific Northwest,
Geomorpohology, 139-140, pp. 460-470.
Connolly, N. and Pearson, R. 2007. The effect of fine s edimentation on tropical
stream macroinvertebrate assemblages: a comparison using flow -through
artificial stream channels and recirculating mesocosms. Hydrobiologia 592: 423–
438.
Gómez-Delgado, F. 2002 . Evaluation of the poten tial erosion and sediment yield in
three basins of Costa Rica (Thesis). University of Costa Rica, San José, Costa Rica.
Gómez-Delgado, F. 2004. Report on the spatial distribution of the potential
erosion and sediments production in the basin defined for th e Peñas Blancas
Hydroelectric Plant. Volume B1. ICE, San José, Costa Rica.
Gómez-Delgado, F., Marchamalo -Sacristán, M. and Laporte -Molina, S. 2011.
Calibrating a distributed model to estimate the sediment input rate to the Peñas
Blancas reservoir in Costa Rica. In: J. D. Brea and F. Balocchi (e ds.), Erosion -
Sedimentation Processes in rivers and basins . Technical Document No. 28.
Montevideo, Uruguay: IHP -LAC, UNESCO.
Lisle, T. 1989. Sediment transport and resulting deposition in spawning gravels,
North Coastal California, Water Resources Research , 25, pp. 1301-1319.
121 267 Marchamalo, M., Gómez -Delgado, F. and Gonzalez, B. 2007. Quantification of soil
and water conservation potencial based on territorial analisys of the catchment :
Birris basin case study . Technical Report. Turrialba, Costa Rica: CATIE -UICN.
Marchamalo, M., Vignola, R., Gómez -Delgado, F. and González -Rodrigo, B. 2012.
Quantifying Services and Identifying Watershed Priority Areas for Soil and Water
Conservation Programs. In , B. Rapidel, F. DeClerk, J .F. Le Coq and J. Beer,
Ecosystem Services from A griculture and Agroforestry: Measurement and Payment .
London: Earthscan.
Montgomery, D. R. 1994 a. Influences of road construction in natural landscapes,
Congressional Record, Department of the Interior and R elated Agencies
Appropriations for 1995, Part 6: Testimony of Public Witnesses for Natural
Resources Management Programs, pp. 858 -861.
Montgomery, D. R. 1994 b. Road surface drainage, channel initiation, and slope
stability, Water Resources Research , 30, pp. 1925-1932,
Montgomery, D. R. 2003. King of fish: the thousand -year run of salmon . Westview
Press, Boulder CO .
Montgomery, D. R. and Buffington, J. M. 1997. Channel -reach morphology in
mountain drainage basins. Geological Society of America Bulletin , 109(5), 596-611.
Montgomery, D. R., Buffington, J. M., Smith, R., Schmidt, K., and Pess, G. 1995. Pool
spacing in forest channels, Water Resources Research , 31, pp. 1097 -1105.
Nehlsen, W. , Williams, J. E. and Lichatowich , J. A . 1991. Pacific salmon at the
crossroads: stocks at risk from California, Oregon, Idaho, and Washington,
Fisheries, 16.2, pp. 4-21.
Pess, G. R., Montgomery, D. R., Bilby, R. E., Steel, A. E., Feist, B. E. and Greenberg, H.
M. 2002. Landscape characteristics, land use, and coho salmon ( Oncorhynchus
kisutch) abundance, Snohomish River, Washington State, USA, Canadian Journal of
Fisheries and Aquatic Sciences , 59, pp. 613-623.
Ramos-Scharron C. E. and MacDonald L . H. 2005. Measurement and prediction of
sediment production from unpaved roads, St John, US Virgin Islands. Earth
Surface Processes and Landforms , 30, pp. 1283–1304.
Reid, L. M., and Dunne, T. 1984, Sediment production from forest road surfaces,
Water Resources Research , 20, pp. 1753-1761.
Thorne, C. R. (2011) Assessment of the phys ical impact of works of carried out by
Nicaragua since October 2010 on the geomorphology, hydrology and sediment
dynamics of the San Juan River and the environmental impacts on Costa Rican
territory. Report prepared for the Certain Activities Case , Notting ham University
Consultants, UK.
Trimble, S. W. 1983. A sediment budget for Coon Creek basin in the Driftless Area,
Wisconsin, 1853 -1977. American Journal of Science, 283(5), pp. 454-474.
Wischmeier, W. H. and D. D. Smith, 1960. A universal soil -loss equat ion to gu ide
conservation farm planning. Trans. 7th Int. Congr ess Soil Sci ence (Belgium), p p.
418-425.
268 122 14. Statement of I ndependence and Truth
14.1. The opinions I have expressed in this Report represent my true and
complete professional opinion. Where I have reli ed on the outputs of field and
analytical work performed under my supervision by the technical team or facts
supplied to me by those instructing me, I have noted this in my Report.
14.2. I understand that my overriding duty is to the Court, both in preparing thi s
Report and in giving oral evidence, if required to give such evidence . I have
complied and will continue to comply with that duty.
14.3. I have set out in my Report what I understand from those instructing me to
be the questions in respect of which my opinion as an expert is required. I have
done my best, in preparing this Report, to be accurate and complete. I have
mentioned all matters that I regard as relevant to the opinions that I have
expressed. I consider that all the matters on which I have expressed an opinion
are within my field of expertise. I have drawn the attention of the Court to all
matters, of which I am aware, which might adversely affect my opinion.
14.4. In preparing this Report, I am not aware of any conflict of interest actual or
potential which might impact upon my ability to provide an independent expert
opinion.
14.5. I confirm that I have not entered into any arrangement where the amount
or payment of my fees is in any way dependent on the outcome of this proceeding.
14.6. In respect of matters referred to which are not within my personal
knowledge, I have indicated the source of such information.
14.7. I have not, without forming an independent view, included anything which
has been suggested to me by others, including the technical team and those
instructing me.
14.8. At the time of signing this Report I consider it to be complete and accurate
subject to any qualifications noted herein. I will notify those instructing me if, for
123 269 any reason, I subsequently consider that the Report requires any material
correction or qualification.
14.9. I understand that this Report will be the evidence that I will give, if
required, under oath, subject to any correction or qualification I may make before
swearing to its veracity.
14.10. The substance of all facts and instructions given to me wich are material
to the opinions expressed in this Report or upon which those opinions are based
are reflected in my Report.
14.11. I confirm that I have made clear which facts and matters referred to in this
Report are within my own knowledge and which are not. Those that are within
my own knowledge I confirm to be true. The opinions I have expressed represent
my true and complete professional opinion.
………………………………………
Professor Colin Thorne
2 Parker Gardens
Nottingham
NG9 8QG
UK
December 2013
270 124 List of Attachments
Attachment 1 Curriculum Vitae of Professor Colin Thorne
125 271 Attachment 1
Curriculum Vitae - Colin Reginald Thorne
PERSONAL DETAILS
Home Address 2 Parker Gardens, Nottingham, NG9 8QG, UK
Nationality UK
DEGREES
1974 BSc (Honours) Environmental Scien ces, Univ. of East Anglia Class: First
1978 PhD Environmental Sciences, Univ. of East Anglia
AWARDS
1983 Faculty Award for Academic Excellence, Colorado State University
1986 Collingwood Prize, American Society of Civil Engineers
CAREER TO DATE
1977-79 Senior Research Associate, University of East Anglia, Norwich
1979-80 Visiting Scientist, USDA Sedimentation Lab., Oxford, Mississippi, USA
1980-81 Senior Research Associate, University of East Anglia, Norwich
1982-84 Associate Professor, Department of Civl Engineering, Colorado State University,
Fort Collins, Colorado 80523
1984-2010 Affiliate Professor, Engineering Research Ce nter, Colorado State University
1984-89 Lecturer, Department of Geography, Queen Mar y College, University of London
1989-90 Reader, Department of Geography, Queen Mar y College, University of London
1990- Professor, Department of Geog raphy, University of Nottingham
1993-96 Head of Department, Department of Geography, University of Nottingham
1998 Visiting Professor, Dept. Geography, University o f Canterbury, Christchurch, NZ
1998-2001 Dean, Faculty of Law and Social Sciences , University of Nottingham
2001- Concurrent Professor, Department of Geogr aphy, Nanjing University, China
2008 Visiting Scientist, NOAA Fisheries, Santa Rosa, California
2012- Affiliate Professor, School of Geography, Portland State University, Oregon
REFEREED PUBLICATIONS
1975-2013 Seven authored and eight edited books, 175 refereed publications including
journal papers (72), proceedings papers (61) and book chapters (47), plus
272 126 over 130 re search reports, 20 journal and published conference discussions,
and numerous non -refereed papers, reports, book reviews and conference
contributions.
PROFESSIONAL SOCIETIES AND SERVICE
American Geophysical Union (since 1980)
American Society of Civil E ngineers (Affiliate) (since 1982)
British Society for Geomorphology (since 1974)
Trustee – Papplewick Trust and Water Education Trust (since 2008)
Member of Editorial Panel for the Geographical Journal (since 1999)
CURRENT RESEARCH STUDENTSHIPS, CONTRACTS AND GRANTS
Engineering and Physical Sciences Research Council , UK
Evaluating and delivering multiple flood risk benefits in B-Green Cities (2013 -2016)
Three-year, multi-disciplinary research project to co -lead a consortium of universities in a
UK£2 million research project concerned with improved management of urban flood risk .
Blue-Green Cities are those that manage the urban water cycle holistically while
integrating the design and management floodways and green spaces. The consortium led
by Notting ham includes Cambridge, London, Leeds, Newcastle, He Ríot-Watt, West of
England and Cranfield Universities. Work packages deal with: Effective stakeholder
engagement and communications; Hydraulic, geomorphic and citizen modelling; Options
appraisal for floo d risk management, Multi -criteria evaluation of flood risk benefits, and; a
Case study.
Economic and Social Research Council, UK
Water Literacy, citizenship and sustainable schools strategy: transition education f or
environmental sustainability (2010-13)
CASE studentship with Severn -Trent Water Ltd. and the Papplewick Trust.
Environment Agency -Department for Environment Joint Research Programme, UK
River Sediments and Habitats: Channel Mai ntenance and Habitats (2005 -13)
Production of a Channel Managemen t Handbook based on the results of a multi -year
study to monitor a series of field investigations of the impacts of different river maintenance
regimes on in -stream and riparian habitats.The Handbook uses findings from 5 field sites
and maintenance practi ces covered include desilting, dredging, vegetation clearance and
gravel extraction.
Mekong River Commission
127 273 PRíor Notification, P Ríor Consultation and Agreement Process for Xayaburi Dam (2010 -2013)
Leading Sediment Expert Group responsible for reviewin g documents provided by
proponent of the proposed dam and advising MRCS on preparation of reports to the
Mekong River Joint Committee with respect to potential impacts of dam on Sediments,
Morphology and Nutrient Balance.
Nottingham University, School of Geography (with Cascades Volcano Observatory, US
Geological Survey and Portland District US Army Corps of Engineers)
Landscape Evolution Modeling of the Debris Avalanche generated by the 1980 Eruption of
Mount St Helens, Washington (2010 -13)
3-year stud entship to support collaborative research with the US Geological Survey and
US Army Corps of Engineers on future evolution of the drainage system of the North Fork
Toutle River and consequential flood risks and their management in the Cowlitz River.
US Army Corps of Engineers (Portland District)
Geomorphic Assessment Evaluation of Island Building Structures on the SRS Sediment Plain,
NF Toutle River
Assessment, evaluation and visualization of the morphological, sediment and ecological
performance of fourt een large Engineered Log Jams (ELJ’s) designed to promote grade
building and create habitat on the sediment plain upstream of the Sediment Retention
Structure on the North Fork Toutle River.
Republic of Costa Rica
Certain activities carried out by N icaragua in the border ar ea (Costa Rica v.Nicaragua ) (2010-)
Expert witness input on a case filed with the International Court of Justice, The Hague.
Construcción de un camino en Costa Rica a lo largo del Río San Juan ( Nicaragua v. Costa
Rica) (2012-)
Expert wi tness input on a second case filed with the International Court of Justice, The
Hague.
CURRENT TEACHING
Module Year Details
Earth and Environmental Dynamics yr 1 Core Module (Convenor)
River Channel Forms and Dynamics yr 2 Option Module (Conv enor)
River Channel Dynamics yr 2 Option Module (Convenor)
River Channel Management & Restoration yr 3/MSc Option Module (Convenor)
Environmental Management in Practice MSc/MA Core Module (Contributor)
Foundations of Environmental Management MSc/MA Core Module (Contributor)
Professional GIS MSc Core Module (Contributor)
274 128East Midlands Consortium Mphil/PhD Research Training (Contributor)
CURRENT DOCTORAL SUPERVISION
Student Topic
Liphapang Khaba Modelling Soil Erosion and Sediment Transport for the Nqoe River
Catchment , Lesotho (International Studentship)
Shaun Maskrey Networks of Influence: Improving the Evaluation of Innovative Flo-Risk
Solutions (EPSRC Studentship)
Tim Meadows Landscape Evolution Model ing at Mount St Helens (Nottingham Univ ersity
Studentship)
Oladipo Olafino Impact of the Floods and Water Act (2010) on Future FRM in the UK (se-f
funded)
Georgina Wood Water Literacy, citizenship and sustainable schools strategy: transition
education f or environmental sustainability (ESRC Stud entship)
Liam Clark Measuring and Evaluating River width using Remote -sensing (University
Studentship)
PAST DOCTORAL SUPERVISION
40 PhDs supervised to successful completion, to date.
CURRENT ADMINISTRATIVE DUTIES
2009- Undergraduate Admissions Tutor responsible for:
UCAS Code Degree Title and Intake
F800 BSc Geography (79)
F630 BSc Environmental Geoscience (20)
L700 BA Geography (79)
L7N1 BA Geography with Business (21)
L7T1 BA Geography with Chinese Studies (9)
PAST ADMINISTRATIVE DUTIES
Dates Position
1993-96 Head of Department, Department of Geography, University of Nottingham.
1998-2001 Dean, Faculty of Law and Social Sciences, University of Nottingham.
2011-12 Deputy Head, School of Geography, University of Nottingham
129 275 PAST PROFESSI ONAL COMMITTEES
Journal of Geography in Higher Education: Editorial Board 19-1993
British Geomorphological Research Group: Executive Committee Member 1989 -92
Earth Surface Processes and Landforms: Guest Editor ‘Geomorphology at Work’ Edition, 1995
American Society of Civil Engineers: Chair, Task Committee on Hydraulics, Soil Mechanics
and Modelling of River Width Adjustment 1993 -1998
Earth Surface Processes and Landforms: Guest Editor, IAG Special Edition 1999
British Geomorphological Research Group: Awar ds Committee 2001 -2004
Geomorphology : Member of Editorial Panel 1992 -2010
276 130 CERTIFICATION
I have the honour to certify that the documents annexed to this
Counter-memorial are true copies and conform to the original
documents and that the translations into English made by Costa Rica
are accurate translations.
Jorge Urbina
Co-Agent of Costa Rica
277278 LIST OF ANNEXES
Vol II: Technical and Environmental Reports
Vol III: Treaties, Official Documents, National Legislation and
Jurisprudence, Diplomatic (or Other) Correspondence, Media Re-
ports andAcademic articles.
VOLUME II
TECHNICALAND ENVIROMENTAL REPORTS
No. DOCUMENT Page
1 University of Costa Rica Centre for Research in Sustainable 1
Development, Department of Civil Engineering, Report on
Systematic Field monitoring of Erosion and Sediment Yield
along Route 1856, September 2013
2 Comisión de Desarrollo Forestal de San Carlos (CODEFORSA), 29
Consulting Services for the Development and Implementation
of an Environmental Plan for the Juan Rafael Mora Porras
Border Road, Report of Activities to the Ministry of Foreign
Affairs of the Republic of Costa Rica, January 2013
English Translation
AllanAstorga G. andAndreas Mende, Route 1856:Analysis of
3 103
the Change in Land use Based on Satellite Images Before and
After the Construction of the Border Road,August 2013
279 4 Costa Rican Institute of Electricity (ICE), SBU Projects and 133
Associated Services, Centre for Basic Engineering Studies,
Department of Hydrology, Report on Hydrology and Sediments
for the Costa Rican River Basins draining to the San Juan River,
August 2013
5 Andreas Mende, with Allan Astorga G. and Olivier Chassot, 291
Border Road No 1856 – Evaluation of the 54 Sites of Purported
Direct Sediment Delivery mentioned by Ph.D. Mathias Kondolf,
September 2013
6 Dr.Andreas Mende and Dr.AllanAstorga, Inventory of Slopes 369
and Water Courses related to the Border Road Nº 1856 between
Mojón II and Delta Costa Rica, September 2013
Report from Ana Lorena Guevara Fernández, Vice-Minister
7 409
of the Environment, Costa Rica, to Enrique Castillo Barrantes,
Minister of ForeignAffairs, Costa Rica, Reference DVM-293-
2013, 8 October 2013
English Translation
8 Consejo Nacional de Vialidad (CONAVI), Program for the 421
Consolidation and Continued Improvement of Route No 1856,
Reference DIE-02-13-3107, 25 October 2013
English Translation
9 Professor Colin Thorne, Report on the Risk of Irreversible 453
Harm to the Río San Juan relating to the Construction of the
Border Road in Costa Rica, 4 November 2013
10 Costa Rica, Centro Científico Tropical, Environmental 499
DiagnosticAssessment (EDA), Route 1856 Project – Ecological
Component, November 2013
280 VOLUME III
TREATIES
No. DOCUMENT Page
11 Costa Rica-Nicaragua Treaty of Limits (Cañas-Jerez),English 1
Translation: Costa Rican version submitted to Cleveland
Source: P.Pérez Zeledón, Argument on the question of
the Validity of Limits between Costa Rica and Nicaragua
(Washington D.C., Gibson Bros Printers and Book
binders 1887). Document No 1. pp 185-190,San José,
15 April 1858
PHOTOGRAPHS AND MAPS
12 Photographs of transport of passengers and other Nicaraguan 11
navigation on the San Juan River
13 United States National Oceanic and Atmospheric 17
Administration, Map of Historical Hurricane Tracks, available
at http://csc.noaa.gov/hurricanes
OFFICIAL DOCUMENTS
14 Press Release, Ministry of Foreign Affairs and Worship Costa 21
Rica stating its official position about the Central American
Court of Justice Jurisdiction, 5 May 2009
English Translation and Spanish Original
281 15 Costa Rica, Minute of the National Security Council Ordinary 29
Session No. 3 of 24 November 2010
English Translation and Spanish Original
16 Nicaragua, ‘Inaugural Lesson of the Academic Year 2011, 33
6 April 2011’, transcript of public speech delivered by
President Ortega, available at http://www.presidencia.gob.
ni/index.php?option=com_content&view=article&id=358:l
eccion-inaugural-del-ano-academico-2011&catid=84:abril-
2011&Itemid=54&showall=1
English Translation and Spanish Original
17 Costa Rica, Statement given under oath by Mr. José María 39
Tijerino, Minister of Public Security of Costa Rica, before
the Permanent Special Commission for the Control of Public
Revenue and Expenses, Minutes of Extraordinary Session
N° 50, (Extract) 29 January 2013
English Translation
18 Nicaragua, Ministry of Environment and Natural Resources 43
(MARENA), San Juan River Territorial Delegation, Technical
Waterway Patrol on the San Juan River on October, 27 2013 ,
annexed to the Letter to the Registrar of the Court from His
Excellency CarlosArgüello Gomez,Agent of the Republic of
Nicaragua, Reference HOL-EMB-220, 31 October 2013
English translation
NATIONAL LEGISLATIONAND JURISPRUDENCE
19 Costa Rica, Constitutional Court Judgment No 1992-3410, 51
(Extract) 10 November 1992
English Translation
28220 Costa Rica, Permanent Commission on Legal Matters, Majority 55
Negative Vote, Bill for Approval of the Statute of the Central
American Court of Justice signed in Panama City, Panama on
1 December 1992, File Number 11.854, 5 December 1998
English Translation
21 Costa Rica, Constitutional Court Judgment No 2003-6322, 61
(Extract) 3 July 2003
English Translation
22 Costa Rica, Constitutional Court Judgment No 2005-8675, 65
(Extract)1 July 2005
English Translation
23 Costa Rica, National Law of Emergencies and Risk Prevention, 69
Law No. 8488 of 11 January 2006,Article 4
English extract
24 Costa Rica, Constitutional Court Judgment No 2006-6336, 73
(Extract)10 May 2006
English Translation
25 Nicaragua, Decree No 76-2006, ‘Environmental Evaluation 77
System’approved on 19 December 2006, published in La
Gaceta No 248 of 22 December 2006, Article 12, available at
http://www.ine.gob.ni/DCA/leyes/decreto/Decreto_76-2006_
SistemaEvaluacionAmbiental.pdf
English extract
26 Nicaragua, Executive Decree No 79-2009 of 24 September 2009, 81
‘Creation of the Inter-institutional Commission to Develop and
Implement the Regulations Regarding Navigation on the San
Juan River, specifically where the International Court of Justice
Grants Limited Navigation Rights to the Republic of Costa
Rica’, (Extract) published in the Gazette of 1 October 2009
English Translation
283 27 Costa Rica, Ministerial Resolution 02572 of 2009, Technical 101
Guide for an Environmental Diagnostic – EDA, 2 November
2009 (Extract)
English Translation and Spanish Original
28 Costa Rica, Emergency Decree No. 36440-MP,published in the 107
Official Gazette number 46 of March 2011
English Translation and Spanish Original
29 Nicaragua, Presidential Decrees Number 88-2009 of 2 April 117
2009 and Number 01-2012 of 10 January 2012 (Extracts),
Appointment of Dr Jaime Incer Barquero as Presidential
Advisor for Enviromental Issues and Natural Resources with
the Rank of Minister
English Translations
Costa Rica, Constitutional Court Judgment No 2012-8420,
30 121
(Extract) 22 June 2012
English Translation
31 Costa Rica, Constitutional Court Judgment No 2012-3266, 125
(Extract) 7 March 2012
English Translation
32 Costa Rica, Constitutional Court Judgment No 2013-008257, 129
(Extract) 21 June 2013
English Translation
CORRESPONDENCE
33 Note from the Minister of ForeignAffairs and Worship of Costa 133
Rica to the CentralAmerican Court of Justice, Reference DM-
AM-306-09, 30April 2009
English Translation and Spanish Original
28434 Note from the Minister of ForeignAffairs and Worship of Costa 137
Rica to the Minister of ForeignAffairs of Nicaragua, Reference
DM-AM-816-09, 20 November 2009
English Translation and Spanish Original
35 Note from the Minister of ForeignAffairs of Nicaragua, to the 163
Minister of ForeignAffairs and Worship of Costa Rica , Costa
Rica, Reference MRE/AJST/297/3/2010, 25 March 2010
English Translation and Spanish Original
36 Note from the Minister of ForeignAffairs and Worship of Costa 167
Rica to the Minister of ForeignAffairs of Nicaragua, Reference
DM-AM-327-10, 22April 2010
English Translation and Spanish Original
37 Letter from the Minister of Public Security of Costa Rica to 171
the Minister of Public Works and Transportation of Costa Rica,
Reference 2278-2010, 1 December 2010
English Translation and Spanish Original
38 Note from the Minister of ForeignAffairs and Worship of Costa 175
Rica to the Minister of ForeignAffairs of Nicaragua, Reference
DM-059-11, 2 February 2011
English Translation and Spanish Original
39 Note from the Minister of ForeignAffairs and Worship of Costa 179
Rica to the Minister of Foreign Affairs of Nicaragua, Ref DM-
601-11, 29 November 2011
English Translation and Spanish Original
40 Note from the Minister of ForeignAffairs and Worship of Costa 183
Rica to the Secretary General of the United Nations, Ref: DM-
AM-663-11, 14 December 2011.
English Translation and Spanish Original
41 Note from the Viceminister of Foreign Affairs of Costa Rica to 189
the Minister of ForeignAffairs of Nicaragua, Reference DVM-
AM-286-11, 20 December, 2011
English Translation and Spanish Original
285 42 Note from the Minister of ForeignAffairs and Worship of Costa 195
Rica to the Minister of ForeignAffairs of Nicaragua, Reference
DM-AM-045-12, 26 January 2012
English Translation and Spanish Original
43 Note from the Minister of Foreign Affairs and Worship of 199
Costa Rica to the Secretary General of the Ramsar Convention,
Reference DM-110-12, 28 February 2012
English Translation and Spanish Original
44 Note from the Secretary General of the Ramsar Convention to 205
the Minister of Foreign Affairs and Worship of Costa Rica,
6 June 2012
English Translation and Spanish Original
Letter from the Agent of Nicaragua to the Registrar of the
45 209
International Court of Justice, Reference 02-19-12-2012,
19 December 2012
46 Note from the Minister of ForeignAffairs and Worship of Costa 213
Rica to the Minister of ForeignAffairs of Nicaragua, Ref. DM-
AM-063-13, 6 February 2013
English Translation and Spanish Original
47 Letter from the Co-Agent of Costa Rica to the Registrar of 219
the International Court of Justice, Reference ECRPB-005-13,
7 February 2013.
48 Note from the Minister of ForeignAffairs of Nicaragua to the 227
Minister of ForeignAffairs and Worship of Costa Rica, Costa
Rica, Reference MRE/DM-AJ/129/03/13, 5 March 2013
English Translation and Spanish Original
49 Letter from the Co-Agent of Costa Rica to the Registrar of the 233
International Court of JusticeReference ECRPB-013-2013,
7 March 2013
28650 Letter from the Registrar of the International Court of Justice239
to theAgent of Costa Rica, Reference 141641, 11 March 2013
51 Note from the President of the Environmental Administrative 243
Tribunal of Costa Rica to the Minister of Foreign Affairs and
Worship of Costa Rica, Reference 200-13-TAA, 9April 2013
English Translation and Spanish Original
52 Letter from the Co-Agent of Costa Rica to the Registrar of 255
the International Court of JusticeReference ECRPB-26-13,
24 May 2013
53 Letter from the Co-Agent of Costa Rica to the Registrar of 259
the International Court of JusticeReference ECRPB-31-13,
13 June 2013
54 Letter from the Agent of Nicaragua to the Registrar of the 265
International Court of Justice, Reference HOL-EMB-108,
14 June 2013
55 Letter from the Co-Agent of Costa Rica to the Registrar of 273
the International Court of Justice, Reference ECRPB-036-13,
24 June 2013
56 Letter from the Minister of ForeignAffairs and Worship of Costa283
Rica to the Director General National Laboratory of Materials
and Structures of the University of Costa Rica ,Reference DM-
AM-389, 15 July 2013
57 Note of the Permanent Mission of Nicaragua to the Permanent 287
and Observer Mission to the United Nations, 5 August 2013,
attaching Official Statement to the Press by the Government
of Nicaragua, 1August 2013, Reference MINIC-MIS-114-13,
5 August 2013
287 58 Note from the Permanent Mission of Costa Rica to the United 299
Nations to the Permanent and Observer Missions to the
United Nations, attaching Position of Costa Rica in relation
to a Press Release dated 1 August 2013 circulated by the
Permanent Mission of Nicaragua to all permanent and Observer
Missions to the United Nations on 5 August 2013, Reference
MCRONU-458-13, 7August 2013
59 Letter from the Co-Agent of Costa Rica to the Registrar of 305
the International Court of Justice, Reference ECRPB-052-13,
7 August 2013
60 Letter from the Registrar of the International Court of Justice 309
to theAgent of Costa Rica, Reference 142331, 8August 2013
Letter from the Director General of the National Laboratory
61 313
of Materials and Structures of the University of Costa Rica
to the Minister of ForeignAffairs and Worship of Costa Rica,
Reference LM-IC-D-0914-2013, 14August 2013
English Translation and Spanish Original
62 Letter from the Co-Agent of Costa Rica to the Registrar of 323
the International Court of Justice, Reference ECRPB-055-13,
26 August 2013
63 Letter from the President of theAssociation of Engineers and 327
Architects of Costa Rica to the Minister of Foreign Affairs
and Worship of Costa Rica, Reference 034-2012-2013-PRES,
28 August 2013
English Translation and Spanish Original
64 Letter from the Agent of Nicaragua to the Registrar of the 359
International Court of Justice, Reference HOL-EMB-167,
30 August 2013
28865 Letter from the Co-Agent of Costa Rica to the Registrar of the 367
International Court of Justice, Reference ECRPB-63-2013,
27 September 2013
66 Letter from the Registrar of the International Court of Justice371
to the Agent of Costa Rica, Reference 142549, 27 September
2013
67 Letter from the Agent of Nicaragua to the Registrar of the 375
International Court of Justice, Reference HOL-EMB-196,
11 October 2013
68 Letter from the General Director of the Costa Rican National 383
Meteorological Institute to H.E. Edgar Ugalde Álvarez,
7 November 2013
English Translation and Spanish Original
MEDIAREPORTS
69 La Nación (Costa Rica), ‘Nicaraguan immigration denies 389
entry to journalists through San Juan River’, 22 October 2010,
available at http://wfnode01.nacion.com/2010-10-22/ElPais/
UltimaHora/ElPais2564695.aspx?Page=3English Translation
and Spanish Original
70 La Nación (Costa Rica), ‘Nicaragua Reinforces Troops at the 393
Border’, 24 October 2010, available athttp://www.nacion.com/
sucesos/Nicaragua-refuerza-tropas-frontera_0_1154884554.
html
English Translation and Spanish Original
289 71 El 19 (Nicaragua), ‘Nicaragua will request before the ICJ 399
Navigation through Río Colorado’, 13 November 2010, available
at http://www.el19digital.com/index.php?option=com_co
ntent&view=article&id=18149:nicaragua-pedira-ante-cij-
navegacion-por-rio-colorado&catid=23:nacionales&Item
id=12
72 La Prensa (Nicaragua), ‘Nicas want Peace and Dialogue with 405
Costa Rica’, 14 De cember 2010, available at http://www.
laprensa.com.ni/2010/12/14/nacionales/46366
English Translation and Spanish Original
73 CACJ (Managua), transcript of interview with CACJ judges 413
Acevedo Peralta a nd Dario Lobo, ‘The challenge is having
Panama and Costa Rica join’, available at http://portal.ccj.org.
ni/ccj2/Publicar/tabid/88/EntryId/3/-El-reto-es-que-Panama-y-
Costa-Rica-se-integren.aspx
English Translation and Spanish Original
74 El Nuevo Diario (Nicaragua), ‘Stop the Road’, 30 November 421
2011, available at http://www.elnuevodiario.com.ni/
nacionales/234697-paren-carretera
English Translation and Spanish Original
75 La Gente, Radio la Primerísima (Nicaragua), ‘CentralAmerican 429
Court admits lawsuit against Costa Rica’, 19 December 2011,
available at http://www.rlp.com.ni/noticias/111936/corte-ca-
admite-demanda-contra-costa-rica
English Translation and Spanish Original
76 El Nuevo Diario (Nicaragua), ‘CACJ opens trial to evidence’, 433
24 January 2012, available at http://www.elnuevodiario.com.
ni/politica/239562
English Translation and Spanish Original
29077 El 19 Digital (Nicaragua), ‘Nicaragua advances in picking up 441
evidence for case against Costa Rica at the Hague’, 10 February
2012, available at http://www.canal15.com.ni/noticia/34739 or
http://www.lavozdelsandinismo.com/nicaragua/2012-02-10/
nicaragua-trabaja-en-recopilacion-de-pruebas-sobre-danos-de-
costa-rica-al-rio-san-juan/
English Translation and Spanish Original
78 La Prensa (Nicaragua), ‘CACJ Judgment will go to case at The 447
Hague’, available at http://www.laprensa.com.ni/2012/07/03/
ambito/107181-fallo-ccj-a-al
English Translation and Spanish Original
79 LaPrensa(Nicaragua),‘Damagestotheriverwillbequantified’, 453
3 November 2013, available at http://www.laprensa.com.
ni/2013/11/03/poderes/168532-cuantificaran-danos-al-rio
English Translation and Spanish Original
80 El 19 (Nicaragua), ‘33rd Anniversary of the Naval Force’, 459
14August 2013, available at http://www.el19digital.com/index.
php/discurso/ver/12213/33-aniversario-de-la-fuerza-naval-
English Translation and Spanish Original
ACADEMIC ARTICLES
81 G.M. Kondolf, ‘Hungry water: Effects of dams and gravel 481
mining on river channels’ 21(4) (1997) Environmental
Management 533
291
Counter-Memorial of Costa Rica