Reply of Nicaragua

Document Number
18534
Document Type
Date of the Document
Document File
Document

INTERNATIONAL COURT OF JUSTICE

DISPUTE CONCERNING

CONSTRUCTION OF ROAD INCOSTARICA ALONG THSAN JUAN
RIVER

(NICARAGUA V.COSTARICA)

WHICH HAS BEEN JOINED WITH THE CASE CONCERNING

CERTAINA CTIVITICSARRIEDOUT BYNICARAGUA IN THBORDER

AREA

(COSTAR ICA .NICARAGUA)

REPLY
OF THR EPUBLIC ONICARAGUA

V OLUMEI

04 August 2014 TABLE OF CONTENTS

TABLE OF CONTENTS............................................................................. i

LIST OF FIGURES IN VOLUME I........................................................... v

LIST OF ACRONYMS.............................................................................. ix

CHAPTER 1 INTRODUCTION ............................................................... 1

A. Costa Rica’s Counter-Memorial...................................................... 1

B. Summary of the Reply................................................................... 20

CHAPTER 2 HARM TO NICARAGUA ................................................ 21

A. The Road’s Contribution of Sediment to the San Juan River....... 22

1. Worsening Erosion............................................................22

2. Poorly Constructed Stream Crossings...............................26

3. Slopes................................................................................50

B. The Accumulation of Sediment in the River................................. 60

1. Deltas.................................................................................60

2. Sediment Accumulation in the Lower San Juan River .....65

3. Environmental Impact of Sediment from the Road ..........73

4. Visual Impacts and Tourism .............................................86

C. Costa Rica’s Flawed Analysis of Sedimentation .......................... 88

1. Unreasonably Low Erosion Rates in the UCR Report......89

2. The Erroneous Yield Estimates in the Mende and
Astorga Inventory..............................................................95

3. Costa Rica’s Flawed Sediment Load Estimate ...............102 TABLE OF CONTENTS

TABLE OF CONTENTS............................................................................. i

LIST OF FIGURES IN VOLUME I........................................................... v

LIST OF ACRONYMS.............................................................................. ix

CHAPTER 1 INTRODUCTION ............................................................... 1

A. Costa Rica’s Counter-Memorial...................................................... 1

B. Summary of the Reply................................................................... 20

CHAPTER 2 HARM TO NICARAGUA ................................................ 21

A. The Road’s Contribution of Sediment to the San Juan River....... 22

1. Worsening Erosion............................................................22

2. Poorly Constructed Stream Crossings...............................26

3. Slopes................................................................................50

B. The Accumulation of Sediment in the River................................. 60

1. Deltas.................................................................................60

2. Sediment Accumulation in the Lower San Juan River .....65

3. Environmental Impact of Sediment from the Road ..........73

4. Visual Impacts and Tourism .............................................86

C. Costa Rica’s Flawed Analysis of Sedimentation .......................... 88

1. Unreasonably Low Erosion Rates in the UCR Report......89

2. The Erroneous Yield Estimates in the Mende and
Astorga Inventory..............................................................95

3. Costa Rica’s Flawed Sediment Load Estimate ...............102

i D. Conclusion................................................................................... 111

CHAPTER 3 THE RISK OF HARM TO NICARAGUA ..................... 113

A. The Risks Posed by Costa Rica’s Continuing Failure to Comply with
Road Construction Standards...................................................... 113

B. Costa Rica’s Failure To Remediate the Road’s Defects ............. 123

C. The Risk of Toxic Spills.............................................................. 135

D. The Risk Posed by Costa Rican Development............................ 140

E. The Risk Posed by Natural Disasters.......................................... 141

F. Conclusion................................................................................... 148

CHAPTER 4 COSTA RICA’S ERRONEOUS CONCEPTION OF THE
LEGAL REGIME OF THE SAN JUAN RIVER AND OF THE
APPLICABLE LAW................................................................... 149

CHAPTER 5 COSTA RICA’S BREACHES OF THE LEGAL REGIME

OF THE SAN JUAN RIVER...................................................... 159

A. Violation of Nicaragua’s Territorial Sovereignty ....................... 159

B. Breach of Nicaragua’s Right of Navigation and of Other General
Rights .......................................................................................... 170

C. Breaches of the Obligation of Notification................................. 172

CHAPTER 6 COSTA RICA’S BREACHES OF ITS ENVIRONMENTAL
OBLIGATIONS.......................................................................... 179

A. Introduction................................................................................. 179

B. Costa Rica’s Invocation of an “Emergency” Under Its National Law
Does Not Excuse Its Violations of International Law................. 180

C. Costa Rica Breached the Obligation to Prepare, In Advance, an
Environmental Impact Assessment............................................. 191

1. The International Acceptance of the Importance of
Performing an Environmental Impact Assessment.........191

iiD. Conclusion................................................................................... 111

CHAPTER 3 THE RISK OF HARM TO NICARAGUA ..................... 113

A. The Risks Posed by Costa Rica’s Continuing Failure to Comply with
Road Construction Standards...................................................... 113

B. Costa Rica’s Failure To Remediate the Road’s Defects ............. 123

C. The Risk of Toxic Spills.............................................................. 135

D. The Risk Posed by Costa Rican Development............................ 140

E. The Risk Posed by Natural Disasters.......................................... 141

F. Conclusion................................................................................... 148

CHAPTER 4 COSTA RICA’S ERRONEOUS CONCEPTION OF THE
LEGAL REGIME OF THE SAN JUAN RIVER AND OF THE
APPLICABLE LAW................................................................... 149

CHAPTER 5 COSTA RICA’S BREACHES OF THE LEGAL REGIME

OF THE SAN JUAN RIVER...................................................... 159

A. Violation of Nicaragua’s Territorial Sovereignty ....................... 159

B. Breach of Nicaragua’s Right of Navigation and of Other General
Rights .......................................................................................... 170

C. Breaches of the Obligation of Notification................................. 172

CHAPTER 6 COSTA RICA’S BREACHES OF ITS ENVIRONMENTAL
OBLIGATIONS.......................................................................... 179

A. Introduction................................................................................. 179

B. Costa Rica’s Invocation of an “Emergency” Under Its National Law
Does Not Excuse Its Violations of International Law................. 180

C. Costa Rica Breached the Obligation to Prepare, In Advance, an
Environmental Impact Assessment............................................. 191

1. The International Acceptance of the Importance of
Performing an Environmental Impact Assessment.........191 3. Declaratory Relief...........................................................267

(a) A Declaration Concerning the Violations of
Costa Rica’s Obligations vis-à-vis Nicaragua.....268

(b) A Declaration that Costa Rica is Bound to

Prepare an Appropriate EIA................................269

(c) A Declaration that Costa Rica Must Refrain from
Using Route 1856 to Transport Hazardous
Material ...............................................................273

(d) A Declaration that Nicaragua is Entitled to
Dredge the San Juan de Nicaragua River............277

SUBMISSIONS ...................................................................................... 281

CERTIFICATION................................................................................... 285

LIST OF ANNEXES VOLUME II......................................................... 287

iv 3. Declaratory Relief...........................................................267

(a) A Declaration Concerning the Violations of Figure 1.1.
Costa Rica’s Obligations vis-à-vis Nicaragua.....268

(b) A Declaration that Costa Rica is Bound to

Prepare an Appropriate EIA................................269

(c) A Declaration that Costa Rica Must Refrain from Figure 2.1.
Using Route 1856 to Transport Hazardous
Material ...............................................................273

(d) A Declaration that Nicaragua is Entitled to
Dredge the San Juan de Nicaragua River............277
Figure 2.2.

SUBMISSIONS ...................................................................................... 281
Figure 2.3.
CERTIFICATION................................................................................... 285

LIST OF ANNEXES VOLUME II......................................................... 287
Figure 2.4.

Figure 2.5.

Figure 2.6.

Figure 2.7.

Figure 2.8.

Figure 2.9.

Figure 2.10

Figure 2.11. Figure 2.12. Helicopter and satellite imagery of failed fill crossing on flat land
20.3 km downstream of Mojon II.

Figure 2.13. Broken culvert pipes and fill mat erial extending into the San Juan
River at location of stream crossing failure on flat land. Photograph
from March 31, 2014.

Figure 2.14. Fill placed in channel with no culvert to provide temporary

crossing, allowing water to flow over the fill. Photog raph from
March 31, 2014.

Figure 2.15. Severely Eroding Site 8.1, 16.1 km downstream of Mojon II.
Oblique aerial view from October 2012.

Figure 2.16. Severely Eroding Site 8.1, 16.1 km downstream of Mojon II.
High-resolution satellite image of December 2013.

Figure 2.17. Severely Eroding Site 8.1, 16.1 km downstream of Mojon II.
Oblique aerial view from May 2014.

Figure 2.18. Severely Eroding Site 8.2, 16.2 km downstream of Mojon II.
Oblique aerial view from October 2012.

Figure 2.19. Severely E roding Site 8.2, 16.2 km downstream of Mojon II.
High-resolution satellite image of December 2013.

Figure 2.20. Severely Eroding Site 8.2, 16.2 km downstream of Mojon II.
Oblique aerial view from May 2014.

Figure 2.21. Delta deposit below Severely Ero ding Site 9.6. Photographs and

measurements from March 30, 2014.

Figure 2.22. Delta deposit below Severely Eroding Site 9.4. Photograph from
March 30, 2014.

Figure 2.23. Delta deposit below Severely Eroding Site 9.4. Photograph from

March 30, 2014.

Figure 2.24. Delta deposit from fill material of failed crossing 20.3 km
downstream of Mojon 2 extending into the San Juan River.
Photograph from March 31, 2014.

viFigure 2.12. Helicopter and satellite imagery of failed fill crossing on flat land
20.3 km downstream of Mojon II.

Figure 2.13. Broken culvert pipes and fill mat erial extending into the San Juan
River at location of stream crossing failure on flat land. Photograph
from March 31, 2014.

Figure 2.14. Fill placed in channel with no culvert to provide temporary

crossing, allowing water to flow over the fill. Photog raph from
March 31, 2014.

Figure 2.15. Severely Eroding Site 8.1, 16.1 km downstream of Mojon II.
Oblique aerial view from October 2012.

Figure 2.16. Severely Eroding Site 8.1, 16.1 km downstream of Mojon II.
High-resolution satellite image of December 2013.

Figure 2.17. Severely Eroding Site 8.1, 16.1 km downstream of Mojon II.
Oblique aerial view from May 2014.

Figure 2.18. Severely Eroding Site 8.2, 16.2 km downstream of Mojon II.
Oblique aerial view from October 2012.

Figure 2.19. Severely E roding Site 8.2, 16.2 km downstream of Mojon II.
High-resolution satellite image of December 2013.

Figure 2.20. Severely Eroding Site 8.2, 16.2 km downstream of Mojon II.
Oblique aerial view from May 2014.

Figure 2.21. Delta deposit below Severely Ero ding Site 9.6. Photographs and

measurements from March 30, 2014.

Figure 2.22. Delta deposit below Severely Eroding Site 9.4. Photograph from
March 30, 2014.

Figure 2.23. Delta deposit below Severely Eroding Site 9.4. Photograph from

March 30, 2014.

Figure 2.24. Delta deposit from fill material of failed crossing 20.3 km
downstream of Mojon 2 extending into the San Juan River.
Photograph from March 31, 2014. Figure 2.39. Costa Rica’s Sketch Map 4 from the Counter -Memorial: “Transport

Network in the Area After Construction of Route 1856,” with
access roads indicated in red.

Figure 3.1. Failing geotextile approximately 10.0 km downstream from Mojon

II.

Figure 3.2. Failing geotextiles approximately 6.8 km downstream from Mojon

II.

Figure 3.3. May 2013 photograph of road runoff directed from drainage
structure into fill.

Figure 3.4. May 2014 p hotograph of erosion resulting from direct drainage
from road onto fill.

Figure 5.1. Severely Eroding Site 4.1, located 8.2-8.7 km downstream of Mojon

II.

Figure 5.2. Delta deposit below Severely Eroding Site 9.4. Photograph from

March 30, 2014.

Figure 5.3. Delta deposit below Severely Eroding Site 9.4. Photograph from
March 30, 2014.

Figure 5.4. Delta deposit from fill material of failed crossing 20.3 km
downstream of Mojon 2 extending into the San Juan River.

Photograph from March 31, 2014.

Figure 5.5. Delta deposit from Severely Eroding Site 9.7. Photograph from
March 30, 2014.

viiiFigure 2.39. Costa Rica’s Sketch Map 4 from the Counter -Memorial: “Transport

Network in the Area After Construction of Route 1856,” with
access roads indicated in red.

Figure 3.1. Failing geotextile approximately 10.0 km downstream from Mojon

II.

Figure 3.2. Failing geotextiles approximately 6.8 km downstream from Mojon

II.

Figure 3.3. May 2013 photograph of road runoff directed from drainage
structure into fill.

Figure 3.4. May 2014 p hotograph of erosion resulting from direct drainage
from road onto fill.

Figure 5.1. Severely Eroding Site 4.1, located 8.2-8.7 km downstream of Mojon

II.

Figure 5.2. Delta deposit below Severely Eroding Site 9.4. Photograph from

March 30, 2014.

Figure 5.3. Delta deposit below Severely Eroding Site 9.4. Photograph from
March 30, 2014.

Figure 5.4. Delta deposit from fill material of failed crossing 20.3 km
downstream of Mojon 2 extending into the San Juan River.

Photograph from March 31, 2014.

Figure 5.5. Delta deposit from Severely Eroding Site 9.7. Photograph from
March 30, 2014.x CHAPTER 1

INTRODUCTION

1.1 This Reply is filed pursuant to the Order of the Court of

03 February 2014 that directed the Republic of Nicaragua to submit a Reply in the

case concerning the Construction of a Road in Costa Rica along the San Juan

River (Nicaragua v. Costa Rica), which has been joined with the case concerning

Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v.

Nicaragua) and fixed 04 August 2014 as the time limit for the filing of this

pleading. It addresses questions r aised in the Counter-Memorial of Costa Rica

filed on 19 December 2013.

A. COSTA RICA’S COUNTER-MEMORIAL

1.2 In Chapter 2 of its Counter -Memorial, Costa Rica addresses the

“Circumstances leading to the Construction of the Road.” In it, Costa Rica throws

out an ar ray of unrelated “circumstances” that it tries to use to explain the

inexplicable: its ill-considered decision to unleash at least thirty -five different

construction companies 1 with no plans – or, it seems, even forethought – with

instructions to bulldoze a 160 -km-long road along its northern border, some

110-120 km of which follows the right bank of the San Juan River. The only

prior “planning” revealed by Costa Rica was to divide the prospective “Border

1 Crhoy.com, Costa Rica “Path construction supervisors informed problems and the lack of
oversight”, 11 June 2012 (Annex 111 to the Count-Memorial of Nicaragua (NCM) in the
Dispute Concerning Certain Activities Carried out by Nicaragua in the Bor(Costa Rica
v. Nicaragua); see also La Nación , Costa Rica, E. Oviedo, “Conavi built a dirt road along the
border without a single design plan,” 23 May 2012 (NM, Vol. II, Annex 31).

1 Road” into five sections, and to assign each of th e sections to different

2 3
contractors – again, without providing them with any plans or blueprints. Costa

Rica was in such a hurry that it did not bother to conduct the environmental

impact assessments required by international law or even by its own internal law.

1.3 Costa Rica describes the Road and some of its motivations for

constructing it as follows:

“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 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 . . . . This road . . . runs from Los Chiles to Delta
Costa Rica, and is approximately 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, i.e. the area where the right margin of the San

Juan River marks the boundary between Costa Rica and
Nicaragua. It is this part of the Border Road which is the
object of the present dispute.” 4

1.4 The statement that only the part of the “Border Road” that runs

next to the River “is the object of the present dispute” is not correct. The totality

of the road that runs next to the border is in dispute. But, by any measure, this is a

2Cases concerning Construction of a Road in Costa Rica along the San Juan River (Nicaragua v.
Costa Rica) and Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v.
Nicaragua), Provisional Measures Hearing, CR 2013/29, 6 November 2013, p. 16, para. 14
(Brenes).
3NM, p. 27, para. 2.25.
4CRCM, pp. 6-7, para. 1.11 (footnotes omitted).

2Road” into five sections, and to assign each of th e sections to different

2 3
contractors – again, without providing them with any plans or blueprints. Costa

Rica was in such a hurry that it did not bother to conduct the environmental

impact assessments required by international law or even by its own internal law.

1.3 Costa Rica describes the Road and some of its motivations for

constructing it as follows:

“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 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 . . . . This road . . . runs from Los Chiles to Delta
Costa Rica, and is approximately 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, i.e. the area where the right margin of the San

Juan River marks the boundary between Costa Rica and
Nicaragua. It is this part of the Border Road which is the
object of the present dispute.” 4

1.4 The statement that only the part of the “Border Road” that runs

next to the River “is the object of the present dispute” is not correct. The totality

of the road that runs next to the border is in dispute. But, by any measure, this is a

2Cases concerning Construction of a Road in Costa Rica along the San Juan River (Nicaragua v.
Costa Rica) and Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v.
Nicaragua), Provisional Measures Hearing, CR 2013/29, 6 November 2013, p. 16, para. 14
(Brenes).
3NM, p. 27, para. 2.25.
4CRCM, pp. 6-7, para. 1.11 (footnotes omitted). Rican environment, ecology, soil erosion and sedi ment production along nearly

three quarters of its length ranges between low and imperceptible.” 8

1.6 Costa Rica is mistaken. It is well known that constructing roads for

vehicular traffic on pre -existing “rustic roads” or “tracks” is not an

environmentally sound practice. A 1996 Report on the San Juan River Basin

published by the Organization of American States (OAS), explains:

“Many of the roads are built on paths, tracks, or animal
trails, which are usually unsuitable for vehicular traffic.
This makes the environmental impact even worse. A

significant amount of the sediment going into the rivers
comes from these roads, which are regularly washed by the
rain, thereby polluting the rivers. Such informal roadways
also lead to disorderly settlement of the basin.” 9

Thus the use of “pre-existing rural roads or tracks” for the construction of the

Road, which will have to accommodate heavy vehicle traffic, does not lessen the

impact on the environment. In fact, it “makes the environmental impact even

worse,” in part because “[a] significant amount of the sediment going into the

rivers comes from these roads, which are regularly washed by the rain, thereby

10
polluting the rivers.” Thus, by Costa Rica’s own account, some 64% of the

Road is constructed in a way that will exacerbate its environmental impact and

contribute substantially to the delivery of sediment into the San Juan.

8
Ibid., p. 7, para. 1.12 (footnote omitted).
9 PROCUENCA SAN JU AN, Formulation of a Strategic Action Program for the
Integrated Management of Water Resources and the Sustainable Development of
the San Juan River Basin and its Coastal Zone, document; Transboundary
Diagnostic Analysis (TDA) (Including Root Cause Anal ysis), available at
http://www.oas.org/sanjuan/english/documents/tda/information/overexploi…
10Ibid.

4Rican environment, ecology, soil erosion and sedi ment production along nearly

three quarters of its length ranges between low and imperceptible.” 8

1.6 Costa Rica is mistaken. It is well known that constructing roads for

vehicular traffic on pre -existing “rustic roads” or “tracks” is not an

environmentally sound practice. A 1996 Report on the San Juan River Basin

published by the Organization of American States (OAS), explains:

“Many of the roads are built on paths, tracks, or animal
trails, which are usually unsuitable for vehicular traffic.
This makes the environmental impact even worse. A

significant amount of the sediment going into the rivers
comes from these roads, which are regularly washed by the
rain, thereby polluting the rivers. Such informal roadways
also lead to disorderly settlement of the basin.” 9

Thus the use of “pre-existing rural roads or tracks” for the construction of the

Road, which will have to accommodate heavy vehicle traffic, does not lessen the

impact on the environment. In fact, it “makes the environmental impact even

worse,” in part because “[a] significant amount of the sediment going into the

rivers comes from these roads, which are regularly washed by the rain, thereby

10
polluting the rivers.” Thus, by Costa Rica’s own account, some 64% of the

Road is constructed in a way that will exacerbate its environmental impact and

contribute substantially to the delivery of sediment into the San Juan.

8
Ibid., p. 7, para. 1.12 (footnote omitted).
9 PROCUENCA SAN JU AN, Formulation of a Strategic Action Program for the
Integrated Management of Water Resources and the Sustainable Development of
the San Juan River Basin and its Coastal Zone, document; Transboundary
Diagnostic Analysis (TDA) (Including Root Cause Anal ysis), available at
http://www.oas.org/sanjuan/english/documents/tda/information/overexploi…
10Ibid. the governing law, including the 1858 Treaty of Limits, 14 the 1888 Cleveland

15 16
Award and 1897-1900 Alexander Awards, and the Court’s judgment in the

17
Navigational and Related Rights case. Nicaragua does not “obstruct” navigation

by anyone from Costa Rica, unless by “obstruct” Costa Rica refers to actions by

Nicaragua in compliance with the governing law. This is yet another example of

Costa Rica not being able to ac cept the fact that it does not have full navigation

rights on the San Juan River.

1.9 Paragraph (b) refers to the dispute that is sub judice in the Certain

Activities case. It is based on Costa Rica’s allegation that Nicaragua has

“occupied and claimed sovere ignty over part of Costa Rica’s territory in Isla

Portillos,” an allegation that Nicaragua emphatically rejects. In any event, Costa

Rica had brought this dispute to the Court on 18 November 2010, 18 before it

14Ibid.
15 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 (Cleveland Award), reprinted United Nations,
Report of International Arbitral Awa rds, Vol. XXVIII (2006), pp. 207 -211 Washington, D.C., 22

16rch 1888, NM, Vol. II, Annex 6(1).
First Award of the Umpire EP Alexander in the boundary question between Costa Rica and
Nicaragua, reprinted United Nations, Reports of International Arbitral A wards, Vol. XXVIII
(2007) pp.215 -221, San Juan del Norte, 30 September 1897; Second Award of the Umpire EP
Alexander in the boundary question between Costa Rica and Nicaragua, reprinted United Nations,
Reports of International Arbitral Awards, Vol. XXVIII (2007) pp.223-225, San Juan del Norte, 20
December 1897; Third Award of the Umpire EP Alexander in the boundary question between
Costa Rica and Nicaragua, reprinted United Nations, Reports of International Arbitral Awards,

Vol. XXVIII (2007) pp.227-230, San Juan del Norte, 22 March 1898; Fourth Award of the Umpire
EP Alexander in the boundary question between Costa Rica and Nicaragua, reprinted United
Nations, Reports of International Arbitral Awards, Vol. XXVIII (2007) pp.231-235, Greytown, 26
July 1899, NM, Vol. II, Annex 6 (2)(3)(4)(5).
17Dispute regarding Navigational and Related Rights (Costa Rica v. Nicaragua), Judgment, I.C.J.
Reports 2009, p. 213.
18Application Instituting Proceedings, filed in the Registry of the Court on 18 November 2010,

Certain Activities Carried Out By Nicaragua In The Border Area (Costa Rica V. Nicaragua),
available on the Court’s website, http://www.icj-cij.org/docket/files/150/16279.pdf.

6the governing law, including the 1858 Treaty of Limits, 14 the 1888 Cleveland

15 16
Award and 1897-1900 Alexander Awards, and the Court’s judgment in the

17
Navigational and Related Rights case. Nicaragua does not “obstruct” navigation

by anyone from Costa Rica, unless by “obstruct” Costa Rica refers to actions by

Nicaragua in compliance with the governing law. This is yet another example of

Costa Rica not being able to ac cept the fact that it does not have full navigation

rights on the San Juan River.

1.9 Paragraph (b) refers to the dispute that is sub judice in the Certain

Activities case. It is based on Costa Rica’s allegation that Nicaragua has

“occupied and claimed sovere ignty over part of Costa Rica’s territory in Isla

Portillos,” an allegation that Nicaragua emphatically rejects. In any event, Costa

Rica had brought this dispute to the Court on 18 November 2010, 18 before it

14Ibid.
15Award of the Arbitrator, the President of the United States, upon the validity of the Treaty of
Limits of 1858 between Nicaragua and Costa Rica (Cleveland Award), reprinted United Nations,
Report of International Arbitral Awa rds, Vol. XXVIII (2006), pp. 207 -211 Washington, D.C., 22

16rch 1888, NM, Vol. II, Annex 6(1).
First Award of the Umpire EP Alexander in the boundary question between Costa Rica and
Nicaragua, reprinted United Nations, Reports of International Arbitral A wards, Vol. XXVIII
(2007) pp.215 -221, San Juan del Norte, 30 September 1897; Second Award of the Umpire EP
Alexander in the boundary question between Costa Rica and Nicaragua, reprinted United Nations,
Reports of International Arbitral Awards, Vol. XXVIII (2007) pp.223-225, San Juan del Norte, 20
December 1897; Third Award of the Umpire EP Alexander in the boundary question between
Costa Rica and Nicaragua, reprinted United Nations, Reports of International Arbitral Awards,

Vol. XXVIII (2007) pp.227-230, San Juan del Norte, 22 March 1898; Fourth Award of the Umpire
EP Alexander in the boundary question between Costa Rica and Nicaragua, reprinted United
Nations, Reports of International Arbitral Awards, Vol. XXVIII (2007) pp.231-235, Greytown, 26
July 1899, NM, Vol. II, Annex 6 (2)(3)(4)(5).
17Dispute regarding Navigational and Related Rights (Costa Rica v. Nicaragua), Judgment, I.C.J.
Reports 2009, p. 213.
18Application Instituting Proceedings, filed in the Registry of the Court on 18 November 2010,

Certain Activities Carried Out By Nicaragua In The Border Area (Costa Rica V. Nicaragua),
available on the Court’s website, http://www.icj-cij.org/docket/files/150/16279.pdf. 23
Counter-Memorial in the Certain Activities case, filed on August 6, 2012. It was

hardly a “threat” and certainly cannot have justified construction of the Road,

with or without an Emergency Decree.

1.11 The issue is treated in two sent ences in Costa Rica’s Counter -

Memorial: “The Colorado River runs entirely within Costa Rican territory.

Nicaragua has no right of navigation on the Colorado River.” 24 (It received even

briefer treatment in Costa Rica’s Memorial in the Certain Activities case. 25) How

the proposition in the second sentence follows from the fact stated in the first is

not, and cannot be, explained. As shown in Nicaragua’s Counter-Memorial in the

Certain Activities case, Nicaragua’s right to navigate on the Colorado is based on

26
the 1858 Treaty of Limits itself.

1.12 The final “circumstance” purportedly justifying construction of the

Road in great haste and with neither prior planning nor notice to Nicaragua 27 is

that Nicaragua allegedly, “(d) in the context of all of the above [i.e ., (a) through

(c)], increased the presence of its soldiers along the San Juan River.” It perhaps

goes without saying that a State is sovereign over its own territory and is free to

23Dispute concerning Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica

v. Nicaragua), NCM, Chapter 4, section C, “Nicaragua’s Right to Navigate on the Colorado
Branch of the San Juan de Nicaragua River, p. 119. Costa Rica also cites a press account of an
announcement by Nicaragua’s President on 13 November 2010.
24CRCM, pp. 29-30, para. 2.15.
25 Certain Activities case, CRM, p. 80, para. 3.29: The Colorado is “a river belonging wholly to
Costa Rica and over which Nicaragua has no navigational rights.”
26See Certain Activities, NCM, pp. 120-121, paras. 4.67-4.69.
27 Costa Rica states that it “formally communicated with Nicaragua through off icial channels,

promptly and in good faith, concerning the road infrastructure works on Costa Rican territory…..”
CRCM, p. 10, para. 1.17. However, no citation to any such communication accompanies this
statement which is, in fact, false.

8 23
Counter-Memorial in the Certain Activities case, filed on August 6, 2012. It was

hardly a “threat” and certainly cannot have justified construction of the Road,

with or without an Emergency Decree.

1.11 The issue is treated in two sent ences in Costa Rica’s Counter -

Memorial: “The Colorado River runs entirely within Costa Rican territory.

Nicaragua has no right of navigation on the Colorado River.” 24 (It received even

briefer treatment in Costa Rica’s Memorial in the Certain Activities case. 25) How

the proposition in the second sentence follows from the fact stated in the first is

not, and cannot be, explained. As shown in Nicaragua’s Counter-Memorial in the

Certain Activities case, Nicaragua’s right to navigate on the Colorado is based on

26
the 1858 Treaty of Limits itself.

1.12 The final “circumstance” purportedly justifying construction of the

Road in great haste and with neither prior planning nor notice to Nicaragua 27 is

that Nicaragua allegedly, “(d) in the context of all of the above [i.e ., (a) through

(c)], increased the presence of its soldiers along the San Juan River.” It perhaps

goes without saying that a State is sovereign over its own territory and is free to

23Dispute concerning Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica

v. Nicaragua), NCM, Chapter 4, section C, “Nicaragua’s Right to Navigate on the Colorado
Branch of the San Juan de Nicaragua River, p. 119. Costa Rica also cites a press account of an
announcement by Nicaragua’s President on 13 November 2010.
24CRCM, pp. 29-30, para. 2.15.
25Certain Activities case, CRM, p. 80, para. 3.29: The Colorado is “a river belonging wholly to
Costa Rica and over which Nicaragua has no navigational rights.”
26See Certain Activities, NCM, pp. 120-121, paras. 4.67-4.69.
27 Costa Rica states that it “formally communicated with Nicaragua through off icial channels,

promptly and in good faith, concerning the road infrastructure works on Costa Rican territory…..”
CRCM, p. 10, para. 1.17. However, no citation to any such communication accompanies this
statement which is, in fact, false. 33
Juan de Nicaragua River, inevitable, as shown in Nicaragua’s Memorial. It will

be recalled that Costa Rica blundered ahead with its Road project before

necessary engineerin g studies and designs were prepared. Costa Rica’s own

national professional association of engineers and architects, CFIA, came to this

34
conclusion in a June , 2012 report. The CFIA found that Costa Rica undertook

the project “without a single plan to indi cate the path that was to be opened, or

what its characteristics should have been.” 35 We now know that the CFIA was

prophetic in concluding that constructing a road in this way will inevitably “cause

increased costs, environmental problems, and a rapid det erioration of the

project.” 36

1.15 The CFIA was not the only Costa Rican organization to find that

the manner in which the Road was constructed was substandard. The National

Laboratory of the University of Costa Rica ( “LANAMME” by its Spanish

acronym) concluded that “the project failed to follow basic engineering practices

during planning and implementation, such as: land survey for road layout; critical

point geotechnical assessment; drainage structure location, design, and

construction; defining suitable and u niform technical standards; [and proper]

33NM, Chapter 3, section B, pp. 47-87.
34Federated Association of Engineers and Architects of Costa Rica (CFIA), “Report on Inspection
of the Border Road, Northern Area Parallel to th e San Juan River,” 8 June 2012 (NM, Vol. II,

35nex 4, p. 257).
36Ibid., p. 25, para. 5.3.
Ibid.

10 33
Juan de Nicaragua River, inevitable, as shown in Nicaragua’s Memorial. It will

be recalled that Costa Rica blundered ahead with its Road project before

necessary engineerin g studies and designs were prepared. Costa Rica’s own

national professional association of engineers and architects, CFIA, came to this

34
conclusion in a June , 2012 report. The CFIA found that Costa Rica undertook

the project “without a single plan to indi cate the path that was to be opened, or

what its characteristics should have been.” 35 We now know that the CFIA was

prophetic in concluding that constructing a road in this way will inevitably “cause

increased costs, environmental problems, and a rapid det erioration of the

project.” 36

1.15 The CFIA was not the only Costa Rican organization to find that

the manner in which the Road was constructed was substandard. The National

Laboratory of the University of Costa Rica ( “LANAMME” by its Spanish

acronym) concluded that “the project failed to follow basic engineering practices

during planning and implementation, such as: land survey for road layout; critical

point geotechnical assessment; drainage structure location, design, and

construction; defining suitable and u niform technical standards; [and proper]

33NM, Chapter 3, section B, pp. 47-87.
34Federated Association of Engineers and Architects of Costa Rica (CFIA), “Report on Inspection
of the Border Road, Northern Area Parallel to the San Juan River,” 8 June 2012 (NM, Vol. II,

35nex 4, p. 257).
36Ibid., p. 25, para. 5.3.
Ibid. 1.18 One of the most alarming aspects of the project is C osta Rica’s

heedless sedimentation of the San Juan River through the unplanned and

uncontrolled – in a word, chaotic – manner in which the Road is being

constructed. This sediment, which as discussed below , is above and beyond the

massive volumes delivered into the San Juan River by Costa Rican tributaries due

to irresponsible land -use practices in that country, is washed into the river in

staggering quantities equivalent to over sixteen thousand dump-truck loads every

year 43 as a result of nothing more tha n normal rainfall. This result was entirely

foreseeable.

1.19 In this Reply, Nicaragua will show that none of the alleged

“Circumstances leading to the Construction of the Road” cited by Costa Rica 44

necessitated proceeding in such blind haste, in a way that ma de substantial harm

45
to Nicaragua virtually inevitable. Costa Rica has in fact demonstrated itself,

through its own conduct that it did not, and does not, regard completion of the

Road as a pressing matter. Work on the Road was slowed or suspended in

December 2011, Costa Rica having failed to allocate sufficient funds for its

46
construction. To date, some four years after construction began, the Road is

43
See 2014 Kondolf Report, Section 7 (NR, Vol. II, Annex 1). As explained i3 Chapter 2 below,
Dr. Kondolf now estimates that the Road is contributing as much as3130,000 m of sediment to the
San Juan River per year, which is enough to fill 16,250 standard 8-mump trucks. This estimate
does not account for erosion from the many kilometers of access roads that were also part of the
project and contribute additional sediment to the River. Ibid.
44CRCM, Chapter 2, p. 21, et seq.
45NM, Chapter 3(B), pp. 47-87.
46
In the Hearings on Provisional Measures held in November, 2013, Costa Rica stated that “funds
[for the construction of the Road] were depleted by December 2011 . . . .” Cases concerning

12 1.18 One of the most alarming aspects of the project is C osta Rica’s

heedless sedimentation of the San Juan River through the unplanned and

uncontrolled – in a word, chaotic – manner in which the Road is being

constructed. This sediment, which as discussed below , is above and beyond the

massive volumes delivered into the San Juan River by Costa Rican tributaries due

to irresponsible land -use practices in that country, is washed into the river in

staggering quantities equivalent to over sixteen thousand dump-truck loads every

year 43 as a result of nothing more tha n normal rainfall. This result was entirely

foreseeable.

1.19 In this Reply, Nicaragua will show that none of the alleged

“Circumstances leading to the Construction of the Road” cited by Costa Rica 44

necessitated proceeding in such blind haste, in a way that ma de substantial harm

45
to Nicaragua virtually inevitable. Costa Rica has in fact demonstrated itself,

through its own conduct that it did not, and does not, regard completion of the

Road as a pressing matter. Work on the Road was slowed or suspended in

December 2011, Costa Rica having failed to allocate sufficient funds for its

46
construction. To date, some four years after construction began, the Road is

43
See 2014 Kondolf Report, Section 7 (NR, Vol. II, Annex 1). As explained i3 Chapter 2 below,
Dr. Kondolf now estimates that the Road is contributing as much as3130,000 m of sediment to the
San Juan River per year, which is enough to fill 16,250 standard 8-mump trucks. This estimate
does not account for erosion from the many kilometers of access roads that were also part of the
project and contribute additional sediment to the River. Ibid.
44CRCM, Chapter 2, p. 21, et seq.
45NM, Chapter 3(B), pp. 47-87.
46
In the Hearings on Provisional Measures held in November, 2013, Costa Rica stated that “funds
[for the construction of the Road] were depleted by December 2011 . . . .” Cases concerning actually issued two months after construction of the Road had begun. Thus , the

work on the Road project was not in fact authorized under Costa Ri can law when

it began, even according to Costa Rica ’s own evidence. The Emergency Decree

was evidently an afterthought, a would-be legal fig leaf that was both too little and

too late. It will be for Costa Rica to explain whether it is standard practice under

its law to proceed with projects first and find legal justification later. But it is

certainly not standard practice, or even permissible, under international law to do

so.

1.22 The Emergency Decree cannot excuse Costa Rica from its

obligations under int ernational law. This follows from one of the most basic

principles of international law, as shown in Chapter 6, section C, of this Reply.

There being no general exception for “emergencies” under international law,

Costa Rica would have to establish that the wrongfulness of its conduct was

precluded by necessity, something Costa Rica admits not even having attempted

51 52
to do, as shown in Chapter 6, below. Costa Rica’s decision not to make such

an attempt was in a sense well -advised, since it would not have been possible for

(LANAMME), “Report on Reconnaissance Trip to Route 1856 – Juan Rafael Mora Porras Border
Trail,” May 2012 (hereinafter the “LANAMME Report”), p. 5: “Construction of the road . . . was
announced in December 2010 by authorities of the Government of Costa Rica to protnational
sovereignty and as a permanent solution allowing free traffic of both people and agricultural
products in Costa Rica’s north border region.” (NM, Vol. II, Annex 3, p. 209).
51CRCM, p. 113, para. 5.15 (“Costa Rica has not invoked Article 25 of the ILC’s Articles on State
Responsibility [“Necessity”] as Nicaragua correctly points out, and it is not incumbent upon it to
do so.”)
52NR, Chapter 6, section C.

14actually issued two months after construction of the Road had begun. Thus , the

work on the Road project was not in fact authorized under Costa Ri can law when

it began, even according to Costa Rica ’s own evidence. The Emergency Decree

was evidently an afterthought, a would-be legal fig leaf that was both too little and

too late. It will be for Costa Rica to explain whether it is standard practice under

its law to proceed with projects first and find legal justification later. But it is

certainly not standard practice, or even permissible, under international law to do

so.

1.22 The Emergency Decree cannot excuse Costa Rica from its

obligations under int ernational law. This follows from one of the most basic

principles of international law, as shown in Chapter 6, section C, of this Reply.

There being no general exception for “emergencies” under international law,

Costa Rica would have to establish that the wrongfulness of its conduct was

precluded by necessity, something Costa Rica admits not even having attempted

51 52
to do, as shown in Chapter 6, below. Costa Rica’s decision not to make such

an attempt was in a sense well -advised, since it would not have been possible for

(LANAMME), “Report on Reconnaissance Trip to Route 1856 – Juan Rafael Mora Porras Border
Trail,” May 2012 (hereinafter the “LANAMME Report”), p. 5: “Construction of the road . . . was
announced in December 2010 by authorities of the Government of Costa Rica to protnational
sovereignty and as a permanent solution allowing free traffic of both people and agricultural
products in Costa Rica’s north border region.” (NM, Vol. II, Annex 3, p. 209).
51CRCM, p. 113, para. 5.15 (“Costa Rica has not invoked Article 25 of the ILC’s Articles on State
Responsibility [“Necessity”] as Nicaragua correctly points out, and it is not incumbent upon it to
do so.”)
52NR, Chapter 6, section C. 54
“relatively insignificant.” But the term “relatively” is crucial here. What Costa

Rica argues is that sedimentation of the river from the Road project is

insignificant in comparison with what Costa Rica’s expert, Professor Colin

Thorne, calls “the high and variable sediment inputs from the San Carlos and

Sarapiqui basins [in Cos ta Rica], which supply the vast majority of sediment

carried by the River.” 55

1.25 Thus Costa Rica says that even if the quantities of sediment

delivered into the San Juan by the Road project are substantial, they pale into

“insignificance” in comparison with other sediment in the River, the “vast

majority” of which comes from Costa Rica itself. What Costa Rica fails to

mention is why such vast quantities of sediment originate within its territory. The

following figure depicting the amount of forested area in Costa Rica in 1940 and

again in 1987 tells the story succinctly:

54CRCM, p. 111, para. 5.12.
55Professor Colin Thorne, “Assessment of the Impact of the Construction of the Border Road in
Costa Rica on the San Juan River,” para. 9.10, CRCM, Appendix A (hereafter “Thorne Report”).

16 54
“relatively insignificant.” But the term “relatively” is crucial here. What Costa

Rica argues is that sedimentation of the river from the Road project is

insignificant in comparison with what Costa Rica’s expert, Professor Colin

Thorne, calls “the high and variable sediment inputs from the San Carlos and

Sarapiqui basins [in Cos ta Rica], which supply the vast majority of sediment

carried by the River.” 55

1.25 Thus Costa Rica says that even if the quantities of sediment

delivered into the San Juan by the Road project are substantial, they pale into

“insignificance” in comparison with other sediment in the River, the “vast

majority” of which comes from Costa Rica itself. What Costa Rica fails to

mention is why such vast quantities of sediment originate within its territory. The

following figure depicting the amount of forested area in Costa Rica in 1940 and

again in 1987 tells the story succinctly:

54CRCM, p. 111, para. 5.12.
55Professor Colin Thorne, “Assessment of the Impact of the Construction of the Border Road in
Costa Rica on the San Juan River,” para. 9.10, CRCM, Appendix A (hereafter “Thorne Report”). “In the 1970s and 1980s Costa Rica was mainly in the
negative environmental headlines for having one of the
highest deforestation rates worldwide; in the 1970s an
average deforestation of 50 000 ha yr−1 is reported . . . ,

and for the period of 1950 to 1984 a deforestation rate of
3.9% per year . . . . The deforestation rates averaged
consistently two to three times higher than the overall
regional average for Latin America . . . .” 56

1.27 As Professor Andrews explains in his report annexed to this Reply,

deforestation in the tropics often leads to sedimentation of rivers in the affected

57
basins. This has unquestionably been true of the San Juan. Professor Andrews

reviewed the available studies of forested tropical river basins, “includ[ing] basins

that, like the Río San Juan basin, contain areas of volcanic soil and steep slopes

58
and receive significant rainfall.” He concluded from this comparative study

that: “the sediment yields in the Rio San Juan Basin prior to appreciable forest

2
clearing and landscape disturbance were likely to fall between 20 to 50 tons/km

per year, which would be 1/20 thto 1/50 of Thorne’s estimated basin-wide value

2 59
of 1080 tons/km per year.” Professor Kondolf agrees that the sediment load of

the San Juan River is “much higher than would be expected from a forested

60
landscape in this region.” He adds: “The explanation is the uncontrolled

56
Christoph Kleinn, et al., Forest Area In Costa Rica: A Comparative Study of ropical Forest
Cover Estimates Over Time, Environmental Monitoring and Assessment 73: 17–40, 2002, at p. 19.
57Edmund D. Andrews, “An Evaluation of the Methods, Calculations, and Conclusions Provided
By Costa Rica Regarding the Yield and Transport of Sedim ent in the Rio San Juan Basin,” July
2014 (hereinafter the “Andrews Report”), Section IV(B) (NR, Vol. II, Annex 3).
58Ibid., Section IV(A).
59Ibid., Section IV(B).
602014 Kondolf Report, Section 10 (NR, Vol. II, Annex 1).

18 “In the 1970s and 1980s Costa Rica was mainly in the
negative environmental headlines for having one of the
highest deforestation rates worldwide; in the 1970s an
average deforestation of 50 000 ha yr−1 is reported . . . ,

and for the period of 1950 to 1984 a deforestation rate of
3.9% per year . . . . The deforestation rates averaged
consistently two to three times higher than the overall
regional average for Latin America . . . .” 56

1.27 As Professor Andrews explains in his report annexed to this Reply,

deforestation in the tropics often leads to sedimentation of rivers in the affected

57
basins. This has unquestionably been true of the San Juan. Professor Andrews

reviewed the available studies of forested tropical river basins, “includ[ing] basins

that, like the Río San Juan basin, contain areas of volcanic soil and steep slopes

58
and receive significant rainfall.” He concluded from this comparative study

that: “the sediment yields in the Rio San Juan Basin prior to appreciable forest

2
clearing and landscape disturbance were likely to fall between 20 to 50 tons/km

per year, which would be 1/20 thto 1/50 of Thorne’s estimated basin-wide value

2 59
of 1080 tons/km per year.” Professor Kondolf agrees that the sediment load of

the San Juan River is “much higher than would be expected from a forested

60
landscape in this region.” He adds: “The explanation is the uncontrolled

56
Christoph Kleinn, et al., Forest Area In Costa Rica: A Comparative Study of ropical Forest
Cover Estimates Over Time, Environmental Monitoring and Assessment 73: 17–40, 2002, at p. 19.
57Edmund D. Andrews, “An Evaluation of the Methods, Calculations, and Conclusions Provided
By Costa Rica Regarding the Yield and Transport of Sedim ent in the Rio San Juan Basin,” July
2014 (hereinafter the “Andrews Report”), Section IV(B) (NR, Vol. II, Annex 3).
58Ibid., Section IV(A).
59Ibid., Section IV(B).
602014 Kondolf Report, Section 10 (NR, Vol. II, Annex 1). percentage of the sediment the Road has contributed to the River. The rest,

together with Costa Rica’s other massi ve contributions of sediment, is causing

impediments to navigation in the Lower San Juan through the creation and

augmentation of sand bars, and the accumulation of sediment from Costa Rica

where there used to be only water.

B. SUMMARY OF THE REPLY

1.31 The balance of this Reply is organized as follows: Chapter 2

demonstrates that despite Costa Rica’s claims to the contrary , significant harm

was, and continues to be, caused to Nicaragua by Costa Rica’s Road project .

Chapter 3 shows there is also a significant ris k of further harm in the future.

Chapter 4 exposes Costa Rica’s erroneous conception of the legal regime of the

San Juan de Nicaragua river and the applicable law. Chapter 5 refutes Costa

Rica’s argument that its Road project does not breach the legal reg ime of the San

Juan de Nicaragua River. Next, Chapter 6 shows why Costa Rica’s claims that its

Road project does not breach its obligations under international environmental

law are without merit. Finally, Chapter 7 sets forth the remedies requested by

Nicaragua. This Reply concludes with Nicaragua’s Submissions.

20percentage of the sediment the Road has contributed to the River. The rest,

together with Costa Rica’s other massi ve contributions of sediment, is causing

impediments to navigation in the Lower San Juan through the creation and

augmentation of sand bars, and the accumulation of sediment from Costa Rica

where there used to be only water.

B. SUMMARY OF THE REPLY

1.31 The balance of this Reply is organized as follows: Chapter 2

demonstrates that despite Costa Rica’s claims to the contrary , significant harm

was, and continues to be, caused to Nicaragua by Costa Rica’s Road project .

Chapter 3 shows there is also a significant ris k of further harm in the future.

Chapter 4 exposes Costa Rica’s erroneous conception of the legal regime of the

San Juan de Nicaragua river and the applicable law. Chapter 5 refutes Costa

Rica’s argument that its Road project does not breach the legal reg ime of the San

Juan de Nicaragua River. Next, Chapter 6 shows why Costa Rica’s claims that its

Road project does not breach its obligations under international environmental

law are without merit. Finally, Chapter 7 sets forth the remedies requested by

Nicaragua. This Reply concludes with Nicaragua’s Submissions. Section C exposes the methodological flaws in Costa Rica’s analysis that render

its sediment calculations inherently unreliable.

A. THE ROAD’S CONTRIBUTION OF SEDIMENT TO THE

SAN JUAN RIVER.

1. Worsening Erosion

2.3 Costa Rica congratulates its experts -- many of whom are Costa

Rican Government employees -- for having “produced” what it calls

“comprehensive scientific and technical evidence” that “address[es] the question

whether the Road is contributing sediment to the River, and if so, how much

sediment.” 63 B ased on their work, Costa Rica concludes that insignificant

amounts of sediment are entering the River. But even a cursory visual inspection

of the Road demonstrates that Costa Rica’s experts are wrong. In fact, erosion

resulting from construction of the Road is causing massive amounts of sediment

to enter the River.

2.4 Nicaragua annexed to its Memo rial a r eport by Professor G.

Mathias Kondolf, an expert on fluvial geomorphology at the University of

California, Ber keley, and Mr. Danny Hagans and Dr. Bill Weaver, fluvial

geomorphologists with decades of experience evaluating the environmental

impacts of roads constructed near rivers. 64 Their report, which was submitted in

December 2012, showed that, as of that date, dozens of sites on the Costa Rican

bank of the River were ex periencing severe erosion or were at risk of doing so,

63CRCM, para. 3.7.
642012 Kondolf Report (NM, Vol. II, Annex 1).

22Section C exposes the methodological flaws in Costa Rica’s analysis that render

its sediment calculations inherently unreliable.

A. THE ROAD’S CONTRIBUTION OF SEDIMENT TO THE

SAN JUAN RIVER.

1. Worsening Erosion

2.3 Costa Rica congratulates its experts -- many of whom are Costa

Rican Government employees -- for having “produced” what it calls

“comprehensive scientific and technical evidence” that “address[es] the question

whether the Road is contributing sediment to the River, and if so, how much

sediment.” 63 B ased on their work, Costa Rica concludes that insignificant

amounts of sediment are entering the River. But even a cursory visual inspection

of the Road demonstrates that Costa Rica’s experts are wrong. In fact, erosion

resulting from construction of the Road is causing massive amounts of sediment

to enter the River.

2.4 Nicaragua annexed to its Memo rial a r eport by Professor G.

Mathias Kondolf, an expert on fluvial geomorphology at the University of

California, Ber keley, and Mr. Danny Hagans and Dr. Bill Weaver, fluvial

geomorphologists with decades of experience evaluating the environmental

impacts of roads constructed near rivers. 64 Their report, which was submitted in

December 2012, showed that, as of that date, dozens of sites on the Costa Rican

bank of the River were ex periencing severe erosion or were at risk of doing so,

63CRCM, para. 3.7.
642012 Kondolf Report (NM, Vol. II, Annex 1). Hagans and Dr. Weaver ob serve that “ [n]umerous locations along Route 1856

between Mojon II and the Rio San Carlos are in a disastrous state of disrepair and

68
exhibit severe instability since road construction began in 2011.” As they detail

in the Report included with this Reply as Annex 2: “Most all road reaches and

stream crossings we observed are exhibiting varying degrees of active, ongoing

erosion as a result of inadequate planning (location), design, construction, erosion

control, and maintenance practices.” 69 They conclude that “[t]he extent of

observed erosional impacts is extraordinary in scale, especially considering the

very average rainfall patterns that the road has experienced over the three year

period since construction began.” 70 In fact, the Road is in such a deteriorated state

that “[i]mmediate emergency actions are needed to curtail ongoing and future

erosion and sediment delivery to the Rio San Juan, and these emergency actions

should be of the highest priority to all parties involved.” 71

2.7 Dr. Kondolf reached the same conclusion. As he explains in his

Report, which is included with this Reply as Annex 1, ongoing observation of the

Road allowed him to “document changes over the period Oct 2012 – May 2014,”

and “to make precise measurements of the horizontal dimensions of features at the

eroding sites, allowing [him] to quantify with confidence the size of many

68Danny Hagans & Bill Weaver, “Evaluation of Erosion, Environmental Impacts and Road Repair

Efforts at Selected Sites along Juan Rafael Mora Route 1856 in Costa Rica, Adjacent to the Rio
San Juan, Nicaragua,” July 2014 (hereinafter the “Hagans & Weaver Report”), Section I (NR, Vol.
69, Annex 2).
Ibid.
70Ibid.
71Ibid.

24Hagans and Dr. Weaver ob serve that “ [n]umerous locations along Route 1856

between Mojon II and the Rio San Carlos are in a disastrous state of disrepair and

68
exhibit severe instability since road construction began in 2011.” As they detail

in the Report included with this Reply as Annex 2: “Most all road reaches and

stream crossings we observed are exhibiting varying degrees of active, ongoing

erosion as a result of inadequate planning (location), design, construction, erosion

control, and maintenance practices.” 69 They conclude that “[t]he extent of

observed erosional impacts is extraordinary in scale, especially considering the

very average rainfall patterns that the road has experienced over the three year

period since construction began.” 70 In fact, the Road is in such a deteriorated state

that “[i]mmediate emergency actions are needed to curtail ongoing and future

erosion and sediment delivery to the Rio San Juan, and these emergency actions

should be of the highest priority to all parties involved.” 71

2.7 Dr. Kondolf reached the same conclusion. As he explains in his

Report, which is included with this Reply as Annex 1, ongoing observation of the

Road allowed him to “document changes over the period Oct 2012 – May 2014,”

and “to make precise measurements of the horizontal dimensions of features at the

eroding sites, allowing [him] to quantify with confidence the size of many

68Danny Hagans & Bill Weaver, “Evaluation of Erosion, Environmental Impacts and Road Repair

Efforts at Selected Sites along Juan Rafael Mora Route 1856 in Costa Rica, Adjacent to the Rio
San Juan, Nicaragua,” July 2014 (hereinafter the “Hagans & Weaver Report”), Section I (NR, Vol.
69, Annex 2).
Ibid.
70Ibid.
71Ibid. 77
and mischaracterize it as “typical of a road under construction,” even they are

forced to concede that Costa Rica must undertake further work “to control the

78
runoff and reduce sediment yields along Route 1856.”

2. Poorly Constructed Stream Crossings

2.10 Some of the worst erosion is taking place where the Road crosses

steams that debouch e into the River. Costa Rica’s experts, Drs. Mende and

Astorga, report that a total of 103 stream crossings have been constructed. 79 In all

but one of these locations, Costa Rica has built crossings by depositing excavated

dirt (known as “fill”) into the stream channels so that the Road can pass over. In

many of these locations (48, according to Costa Rica’s experts), stream flows

have been re-channeled through the fill to the River via man-made tubes called

“culverts.” 80 At three other locations, “tree trunks rather than culverts have been

installed [in the fill] to allow water to pass beneath the Road.” 81 And, at a further

16 locations, the stream crossing has been cut off entirely, with fill placed in the

stream to block it from crossing the Road at all. 82 As Dr. Kondolf explained in his

2012 Report, all of these crossings are “inherently unstable features, because they

involve placement of massive volumes of fill within the stream channel and

valley, where it can easily be eroded and enter the river system.” 83

77Ibid.
78
79Ibid., p. 30.
80See ibid., p. 27.
81Ibid.
Ibid.
82Ibid.
832012 Kondolf, p. 13; see also Figure and explanation on p. 14 (NM, Vol. II, Annex 1).

26 77
and mischaracterize it as “typical of a road under construction,” even they are

forced to concede that Costa Rica must undertake further work “to control the

78
runoff and reduce sediment yields along Route 1856.”

2. Poorly Constructed Stream Crossings

2.10 Some of the worst erosion is taking place where the Road crosses

steams that debouch e into the River. Costa Rica’s experts, Drs. Mende and

Astorga, report that a total of 103 stream crossings have been constructed. 79 In all

but one of these locations, Costa Rica has built crossings by depositing excavated

dirt (known as “fill”) into the stream channels so that the Road can pass over. In

many of these locations (48, according to Costa Rica’s experts), stream flows

have been re-channeled through the fill to the River via man-made tubes called

“culverts.” 80 At three other locations, “tree trunks rather than culverts have been

installed [in the fill] to allow water to pass beneath the Road.” 81 And, at a further

16 locations, the stream crossing has been cut off entirely, with fill placed in the

stream to block it from crossing the Road at all. 82 As Dr. Kondolf explained in his

2012 Report, all of these crossings are “inherently unstable features, because they

involve placement of massive volumes of fill within the stream channel and

valley, where it can easily be eroded and enter the river system.” 83

77Ibid.
78
79Ibid., p. 30.
80See ibid., p. 27.
81Ibid.
Ibid.
82Ibid.
832012 Kondolf, p. 13; see also Figure and explanation on p. 14 (NM, Vol. II, Annex 1). into the San Juan River can be plainly seen when the two satellite image are

compared.

2.13 As Mr. Haga ns and Dr. Weaver observe, these examples of

“actively failing and eroding hill slope, cut bank, fill slope and stream crossing

areas ... illustrate the severe inadequacy and nearly total lack of erosion control

88
efforts at failing road locations.” In these places, which have significantly

higher erosion rates and volumes of erosion than claimed by Costa Rica:

“the lack of any design and construction standards along
the route has resulted in constructing extremely unstable
road reaches that will be subjec t to continuing and future

slope failures and erosional impacts to the Rio San Juan for
decades to come. In their present state of disrepair, these
sections of road are extremely unsafe for commercial

and/or public transportation, and will require substant ial
financial resources to either properly close ... or redesign
and reconstruct these specific road sections, as well as
many other similar locations we have observed along Route

1856 in order to be suitable for p89lic use, as well as
protect Nicaraguan resources.”

88Hagans & Weaver Report, Section II (NR, Vol. II, Annex 2).
89Ibid.

28into the San Juan River can be plainly seen when the two satellite image are

compared.

2.13 As Mr. Haga ns and Dr. Weaver observe, these examples of

“actively failing and eroding hill slope, cut bank, fill slope and stream crossing

areas ... illustrate the severe inadequacy and nearly total lack of erosion control

88
efforts at failing road locations.” In these places, which have significantly

higher erosion rates and volumes of erosion than claimed by Costa Rica:

“the lack of any design and construction standards along
the route has resulted in constructing extremely unstable
road reaches that will be subjec t to continuing and future

slope failures and erosional impacts to the Rio San Juan for
decades to come. In their present state of disrepair, these
sections of road are extremely unsafe for commercial

and/or public transportation, and will require substant ial
financial resources to either properly close ... or redesign
and reconstruct these specific road sections, as well as
many other similar locations we have observed along Route

1856 in order to be suitable for p89lic use, as well as
protect Nicaraguan resources.”

88Hagans & Weaver Report, Section II (NR, Vol. II, Annex 2).
89Ibid. 2.14 Site “C” in the satellite images above corresponds to Site 9.4 in the

Inventory of Severely Eroding Sites included as Appendix A to Dr. Kondolf’s

90
2014 Report. The progressive worsening of the site’s erosion can be seen in the

following three images: Figure 2.2 from October 2012; Figure 2.3 from

December 2013; and Figure 2.4 from May 2014.

Figure 2.2. Severely Eroding Site 9.4, 18 km downstream of Mojon II.
Oblique aerial view from October 2012.

90
2014 Kondolf Report, Appendix A (NR, Vol. II, Annex 1).

30 2.14 Site “C” in the satellite images above corresponds to Site 9.4 in the

Inventory of Severely Eroding Sites included as Appendix A to Dr. Kondolf’s

90
2014 Report. The progressive worsening of the site’s erosion can be seen in the

following three images: Figure 2.2 from October 2012; Figure 2.3 from

December 2013; and Figure 2.4 from May 2014.

Figure 2.2. Severely Eroding Site 9.4, 18 km downstream of Mojon II.
Oblique aerial view from October 2012.

90
2014 Kondolf Report, Appendix A (NR, Vol. II, Annex 1). 2.15 When Dr. Kondolf inspected the site in October 2012, the fill prism

blocking the s tream that previously flowed into the River had a volume of

approximately 21,900 m 3.91Although the fill prism was then still intact, the fill

face was visibly eroded by rills, gullies and sheet erosion. Consistent with these

findings, Mr. Hagans and Dr. Weaver describe the site as of 2012 as follows:

“The oblique October 2012 aerial photograph illustrates the
poorly constructed, unstable fill, and the absence of any
serious effort to apply appropriate, effective erosion control
measures at and near the cr ossing. The fill slope clearly

displays rapid deformation following initial construction
work and the road and adjacent cut and fill slopes lack any
attempt at stabilization or erosion control.” 92

2.16 This situation facilitated erosion of sediment into the Rive r. They

explain:

“Both road approaches to the crossing along Route 1856,

and the associated high cut banks, can be assured to be
delivering eroded sediment from the visible and
unprotected bare soil areas by surface erosion, rill erosion,
and gully erosio n processes. Most all these sediments are

transported to the stream crossing since it is the
topographically low point seen in the images. Finally, the
smaller road that has been constructed across the hill slopes
below Route 1856 also appear s to be a source of
uncontrolled surface erosion, rill and gully erosion that is

also being transported directly to the same natural stream
channel, and then into the Rio San Juan. As a result, this
tributary deposited a delta of eroded sediment in
Nicaragua’s Rio San Juan.” 93

912014 Kondolf Report, Section 3 (NR, Vol. II, Annex 1).
92Hagans & Weaver Report, Section II.B (NR, Vol. II, Annex 2).
93Ibid., Section II.B.

32 2.15 When Dr. Kondolf inspected the site in October 2012, the fill prism

blocking the s tream that previously flowed into the River had a volume of

approximately 21,900 m 3.91 Although the fill prism was then still intact, the fill

face was visibly eroded by rills, gullies and sheet erosion. Consistent with these

findings, Mr. Hagans and Dr. Weaver describe the site as of 2012 as follows:

“The oblique October 2012 aerial photograph illustrates the
poorly constructed, unstable fill, and the absence of any
serious effort to apply appropriate, effective erosion control
measures at and near the cr ossing. The fill slope clearly

displays rapid deformation following initial construction
work and the road and adjacent cut and fill slopes lack any
attempt at stabilization or erosion control.” 92

2.16 This situation facilitated erosion of sediment into the Rive r. They

explain:

“Both road approaches to the crossing along Route 1856,

and the associated high cut banks, can be assured to be
delivering eroded sediment from the visible and
unprotected bare soil areas by surface erosion, rill erosion,
and gully erosio n processes. Most all these sediments are

transported to the stream crossing since it is the
topographically low point seen in the images. Finally, the
smaller road that has been constructed across the hill slopes
below Route 1856 also appear s to be a source of
uncontrolled surface erosion, rill and gully erosion that is

also being transported directly to the same natural stream
channel, and then into the Rio San Juan. As a result, this
tributary deposited a delta of eroded sediment in
Nicaragua’s Rio San Juan.” 93

912014 Kondolf Report, Section 3 (NR, Vol. II, Annex 1).
92Hagans & Weaver Report, Section II.B (NR, Vol. II, Annex 2).
93Ibid., Section II.B. 97
of the stream crossing fill.” They observe that “[a] large area of ponded water (a

small lake) has formed at the inside edge of the road (Route 1856), clearly

suggesting the culvert was either significantly undersized to convey even average

98
rainfall events, or was poorly installed high in the fill, or both.” Further, “[t]he

downstream natural tributary channel is visibly impacted by recent deposits of

transported and stored sediment,” and “the delta of eroded sediment that formed

in the Rio San Juan has rapidly grown in size.” 99

2.20 Portions of the initial inadequate culvert were transported to the

100
River, and had to be removed by Nicaragua, as shown in Figure 2.5.

Figure 2.5. Removal of culvert fragments from San Juan River adjacent to Severely Eroding Site
9.4, 18.0 km downstream of Mojon II. Photograph from October 27, 2013.

97
98Hagans & Weaver Report, Section II,B (NR, Vol. II, Annex 2).
Ibid.
99Ibid.
1002014 Kondolf Report, Section 3 (NR, Vol. II, Annex 1).

34 97
of the stream crossing fill.” They observe that “[a] large area of ponded water (a

small lake) has formed at the inside edge of the road (Route 1856), clearly

suggesting the culvert was either significantly undersized to convey even average

98
rainfall events, or was poorly installed high in the fill, or both.” Further, “[t]he

downstream natural tributary channel is visibly impacted by recent deposits of

transported and stored sediment,” and “the delta of eroded sediment that formed

in the Rio San Juan has rapidly grown in size.” 99

2.20 Portions of the initial inadequate culvert were transported to the

100
River, and had to be removed by Nicaragua, as shown in Figure 2.5.

Figure 2.5. Removal of culvert fragments from San Juan River adjacent to Severely Eroding Site
9.4, 18.0 km downstream of Mojon II. Photograph from October 27, 2013.

97
98Hagans & Weaver Report, Section II,B (NR, Vol. II, Annex 2).
Ibid.
99Ibid.
1002014 Kondolf Report, Section 3 (NR, Vol. II, Annex 1). in the December 2013 image has been partially filled to permit limited vehicle

passage on the road.” 105 However, “[a] large body of ponded water is still visible

upstream of the road, sugges ting the culvert now in place (whether the remnants

of the original culvert or a replacement culvert) is plugged and deeply buried by

sediments from the collapsing, rapidly eroding, and failing stream crossing

fills.”06 They further note the absence of any “Costa Rican efforts” to

“effectively stabilize[] the failing, un -compacted stream crossing fills,” to

“properly install adequate stream crossing drainage structures (culverts or

bridges), or to address uncontrolled runoff and erosion from all the visible bare

soil areas.”107

2.24 Mr. Hagans and Dr. Weaver conclude their assessment of the state

of the site as of May 2014 by warning:

“The site is a construction disaster that has not been treated
or stabilized, and it clearly threatens to fail catastrophically

if a significant storm causes the ponded tributary to overtop
the fill again, thereby eroding a larger portion of the entire
stream crossing fill and delivering up to 21,900 m 3 of
sediment (equivalent to 2,740 8 -m 3 dump truck loads)

directly into the Rio San Juan. The delta in the R io San
Juan appears significantly larger in the 2014 photo than in
the 2012 photo … growth that will continue over the next

rainy season , since no concerted efforts have been
undertaken to properly redesign and reconstruct the
crossing, and thereby to eliminate the active erosional
processes occurring at the site.” 108

105Ibid.
106Ibid.
107Ibid.
108Ibid.

36in the December 2013 image has been partially filled to permit limited vehicle

passage on the road.” 105 However, “[a] large body of ponded water is still visible

upstream of the road, sugges ting the culvert now in place (whether the remnants

of the original culvert or a replacement culvert) is plugged and deeply buried by

sediments from the collapsing, rapidly eroding, and failing stream crossing

fills.”06 They further note the absence of any “Costa Rican efforts” to

“effectively stabilize[] the failing, un -compacted stream crossing fills,” to

“properly install adequate stream crossing drainage structures (culverts or

bridges), or to address uncontrolled runoff and erosion from all the visible bare

soil areas.”107

2.24 Mr. Hagans and Dr. Weaver conclude their assessment of the state

of the site as of May 2014 by warning:

“The site is a construction disaster that has not been treated
or stabilized, and it clearly threatens to fail catastrophically

if a significant storm causes the ponded tributary to overtop
the fill again, thereby eroding a larger portion of the entire
stream crossing fill and delivering up to 21,900 m 3 of
sediment (equivalent to 2,740 8 -m 3 dump truck loads)

directly into the Rio San Juan. The delta in the R io San
Juan appears significantly larger in the 2014 photo than in
the 2012 photo … growth that will continue over the next

rainy season , since no concerted efforts have been
undertaken to properly redesign and reconstruct the
crossing, and thereby to eliminate the active erosional
processes occurring at the site.” 108

105Ibid.
106Ibid.
107Ibid.
108Ibid. 110
slopes stabilized, as would be required by international standards.” Once again,

no culvert is visible, indicating that it too was significantly undersized (assuming

one had been installed at all). 111

2.27 By the time of the December 2013 satellite image, “ large-scale

112
failure of the fill is evident,” as can be seen in the close -up reproduced at

Figure 2.7, below.

Figure 2.7. Severely Eroding Site 9.5, 18.1 km downstream of Mojon II.
High-resolution satellite image of December 2013.

110
1112014 Kondolf Report, Section 3 (NR, Vol. II, Annex 1).
112Ibid.
Ibid.

38 110
slopes stabilized, as would be required by international standards.” Once again,

no culvert is visible, indicating that it too was significantly undersized (assuming

one had been installed at all). 111

2.27 By the time of the December 2013 satellite image, “ large-scale

112
failure of the fill is evident,” as can be seen in the close -up reproduced at

Figure 2.7, below.

Figure 2.7. Severely Eroding Site 9.5, 18.1 km downstream of Mojon II.
High-resolution satellite image of December 2013.

110
1112014 Kondolf Report, Section 3 (NR, Vol. II, Annex 1).
112Ibid.
Ibid. Figure 2.8. Severely Eroding Site 9.5, 18.1 km downstream of Mojon II.
Oblique aerial view from May 2014.

2.30 As can be seen in the May 2014 photograph reproduced at Figure

2.8 above, the failed crossing had by that time been reconstructed, with new fill

118
having been placed in the void left by the prior failure. However, this did not

solve the problem. Erosion had begun anew and the stream crossing failed

119
again.

2.31 As Mr. Hagans and Dr. Weaver explain, the May 2014 photograph

shows “two large landslides” that are located “on the hill slopes just upstream of

the road crossing ,” and t hese “may have caused the stream crossing failure by

plugging the culvert, or they may have been triggered by saturation of the toe of

the slopes when the new stream crossing culvert plugged and a small lake formed

118
1192014 Kondolf Report, Section 3 (NR, Vol. II, Annex 1).
Ibid.; Hagans & Weaver Report, Section II.C (NR, Vol. II, Annex 2).

40 Figure 2.8. Severely Eroding Site 9.5, 18.1 km downstream of Mojon II.
Oblique aerial view from May 2014.

2.30 As can be seen in the May 2014 photograph reproduced at Figure

2.8 above, the failed crossing had by that time been reconstructed, with new fill

118
having been placed in the void left by the prior failure. However, this did not

solve the problem. Erosion had begun anew and the stream crossing failed

119
again.

2.31 As Mr. Hagans and Dr. Weaver explain, the May 2014 photograph

shows “two large landslides” that are located “on the hill slopes just upstream of

the road crossing ,” and t hese “may have caused the stream crossing failure by

plugging the culvert, or they may have been triggered by saturation of the toe of

the slopes when the new stream crossing culvert plugged and a small lake formed

118
1192014 Kondolf Report, Section 3 (NR, Vol. II, Annex 1).
Ibid.; Hagans & Weaver Report, Section II.C (NR, Vol. II, Annex 2). Figure 2.9. Severely Eroding Site 9.6, 18.2 km downstream of Mojon II.
Oblique aerial view from October 2012.

2.34 Once again, a stream crossing has been blocked with fill to allow

the Road to cross over. Mr. Hagans and Dr. Weaver explain that this image

shows that the site is already “undergoing serious deformation a nd erosion of the

126
downstream fill slop e very soon after construction.” The amount of fill

blocking the stream is much larger than in the preceding two examples, totaling

approximately 44,000 m in volume. 127 In addition, the culvert, which is barely

126
Hagans & Weaver Report, Section II.D (NR, Vol. II, Annex 2).
127Ibid.

42 Figure 2.9. Severely Eroding Site 9.6, 18.2 km downstream of Mojon II.
Oblique aerial view from October 2012.

2.34 Once again, a stream crossing has been blocked with fill to allow

the Road to cross over. Mr. Hagans and Dr. Weaver explain that this image

shows that the site is already “undergoing serious deformation a nd erosion of the

126
downstream fill slop e very soon after construction.” The amount of fill

blocking the stream is much larger than in the preceding two examples, totaling

approximately 44,000 m in volume. 127 In addition, the culvert, which is barely

126
Hagans & Weaver Report, Section II.D (NR, Vol. II, Annex 2).
127Ibid. Figure 2.10. Severely Eroding Site 9.6, 18.2 km downstream of Mojon II.
High-resolution satellite image of December 2013.

2.37 Dr. Kondolf reports that “the[se] gullies measure 80 m across (in

the direction parallel to the river bank), and 50 m horizontally from the headcuts

133
down to the foot of the fill slope.” He calculates that “the volume represented

by these three gullies – the volume of sediment already eroded from the stream

crossing fill prism – totals about 6,600 m , or about 15% of the original total fill

volume. This is a truly massive quantity of sediment, the equivalent of about 825

133
2014 Kondolf Report, Section 3 (NR, Vol. II, Annex 1).

44 Figure 2.10. Severely Eroding Site 9.6, 18.2 km downstream of Mojon II.
High-resolution satellite image of December 2013.

2.37 Dr. Kondolf reports that “the[se] gullies measure 80 m across (in

the direction parallel to the river bank), and 50 m horizontally from the headcuts

133
down to the foot of the fill slope.” He calculates that “the volume represented

by these three gullies – the volume of sediment already eroded from the stream

crossing fill prism – totals about 6,600 m , or about 15% of the original total fill

volume. This is a truly massive quantity of sediment, the equivalent of about 825

133
2014 Kondolf Report, Section 3 (NR, Vol. II, Annex 1). Figure 2.11. Severely Eroding Site 9.6, 18.2 km downstream of Mojon II.
Oblique aerial view from May 2014.

2.39 Steep slopes are not the only locations where defective stream

crossings have caused ever-worsening erosion into the River. It is also occurring

140
in flat areas where, Costa Rica insists, “there is nothing to say.” Consider, for

instance, the following stream crossing (Figure 2.12), which is located on level

ground 2 km downstream from the three sites discussed above.

140See CRCM, paras. 3.17, 3.19.

46 Figure 2.11. Severely Eroding Site 9.6, 18.2 km downstream of Mojon II.
Oblique aerial view from May 2014.

2.39 Steep slopes are not the only locations where defective stream

crossings have caused ever-worsening erosion into the River. It is also occurring

140
in flat areas where, Costa Rica insists, “there is nothing to say.” Consider, for

instance, the following stream crossing (Figure 2.12), which is located on level

ground 2 km downstream from the three sites discussed above.

140See CRCM, paras. 3.17, 3.19. had been used to build the crossing had entered the San Juan River. 141 This

failure alone produced a sediment pulse of approximately 480 m 3 – over 800 tons

– of fill material , which has created a sizeable delta of sediment in the River

142
(depicted in Figure 2.13 below).

Figure 2.13. Broken culvert pipes and fill material extending into the San Juan River at location
of stream crossing failure on flat land. Photograph from March 31, 2014.

2.41 Since that failure, the crossing has been re -filled with fill material,

only this time without the benefit any culvert at all, as can be seen in Figure 2.14

below. 143 Consequently, water from the stream is flowing directly over the

1412014 Kondolf Report, Section 5 (NR, Vol. II, Annex 1).
142Ibid.
143Ibid.

48had been used to build the crossing had entered the San Juan River. 141 This

failure alone produced a sediment pulse of approximately 480 m 3 – over 800 tons

– of fill material , which has created a sizeable delta of sediment in the River

142
(depicted in Figure 2.13 below).

Figure 2.13. Broken culvert pipes and fill material extending into the San Juan River at location
of stream crossing failure on flat land. Photograph from March 31, 2014.

2.41 Since that failure, the crossing has been re -filled with fill material,

only this time without the benefit any culvert at all, as can be seen in Figure 2.14

below. 143 Consequently, water from the stream is flowing directly over the

1412014 Kondolf Report, Section 5 (NR, Vol. II, Annex 1).
142Ibid.
143Ibid. 3. Slopes

2.42 Large-scale sediment transfers to the River are also taking place

along steep hillsides where shoddy construction has all but guaranteed this result.

2.43 Mr. Hagans and Dr. Weaver observe there “are many locations

along Route 1856 where recentl y constructed cut slopes and fill slopes are

experiencing uncontrolled and inordinately high rates of erosion following

construction.” 146 In these places, “large bare soil areas are eroding and failing by

147
all three erosional processes: landsliding, gullying and surface erosion.” They

note that “ [w]hile some efforts have been undertaken to stabilize a few of the

locations, at many it appears as if the road has been abandoned and no efforts

have been made to control or curtail the ongoing erosion and slope f ailures, or to

reduce potential impacts to the Rio San Juan , over the 20 -month period of our

photographic record.” 148

2.44 The phenomenon is illustrated well at two such sites located 200 m

from one another in a stretch of River located approximately 2 km upstream of the

first severely eroding stream crossing discussed above . In both cases, worsening

erosion and the consequent deposit of sediment into the River is clear from a

comparison of images captured between October 2012 and May 2014. As Mr.

Hagans and Dr. Weaver explain, these sites are “ examples of poorly designed,

146Hagans & Weaver Report, Section III (NR, Vol. II, Annex 2).
147Ibid.
148Ibid.

50 3. Slopes

2.42 Large-scale sediment transfers to the River are also taking place

along steep hillsides where shoddy construction has all but guaranteed this result.

2.43 Mr. Hagans and Dr. Weaver observe there “are many locations

along Route 1856 where recentl y constructed cut slopes and fill slopes are

experiencing uncontrolled and inordinately high rates of erosion following

construction.” 146 In these places, “large bare soil areas are eroding and failing by

147
all three erosional processes: landsliding, gullying and surface erosion.” They

note that “ [w]hile some efforts have been undertaken to stabilize a few of the

locations, at many it appears as if the road has been abandoned and no efforts

have been made to control or curtail the ongoing erosion and slope f ailures, or to

reduce potential impacts to the Rio San Juan , over the 20 -month period of our

photographic record.” 148

2.44 The phenomenon is illustrated well at two such sites located 200 m

from one another in a stretch of River located approximately 2 km upstream of the

first severely eroding stream crossing discussed above . In both cases, worsening

erosion and the consequent deposit of sediment into the River is clear from a

comparison of images captured between October 2012 and May 2014. As Mr.

Hagans and Dr. Weaver explain, these sites are “ examples of poorly designed,

146Hagans & Weaver Report, Section III (NR, Vol. II, Annex 2).
147Ibid.
148Ibid. Figure 2.15. Severely Eroding Site 8.1, 16.1 km downstream of Mojon II.

Oblique aerial view from October 2012.

Figure 2.16. Severely Eroding Site 8.1, 16.1 km downstream of Mojon II.
High-resolution satellite image of December 2013.

52Figure 2.15. Severely Eroding Site 8.1, 16.1 km downstream of Mojon II.

Oblique aerial view from October 2012.

2.46
Figure 2.16. Severely Eroding Site 8.1, 16.1 km downstream of Mojon II.
High-resolution satellite image of December 2013.
October 2012. Figure 2.16 is a satellite image of the same site from December

2013. Figure 2.17 is another helicopter-based photograph of the same site taken

in May 2014. Comparison of the three images shows the effects of Costa Rica’s

failure to take erosion-control measures, causing sediment to erode into the River.

As Mr. Hagans and Dr. Weaver explain: “The sequence of three images captured

in 2012, 2013 and 2014 indicate initial construction activities were completed

along the road reach by October 2012, and no visible or substantive work on the

failing road has been done since 2012.”

during the 20 month t

152Hagans & Weaver Report, Section III.B (NR, Vol. II, Annex 2). enlarging gullies and landslides present on the un -compacted, sidecast fill slopes,

and evidence of widespread surface erosion on the visible bare soil areas through

153
time.”

2.47 In particular, the October 20 12 photograph reveals that, by that

time, the site was characterized by a “smooth textured excavation surface” and

that “[p]oor or non-existent fill compaction during construction could have easily

led an experienced geologist or engineer in October 2012 t o predict the resulting

154
instabilities and extent of erosion now present on the fill slopes at this site.”

2.48 Subsequent images from 2013 and 2014 demonstrate that Costa

Rica ceased construction work without attempting to control the inevitable

erosion. Mr. Hagans and Dr. Weaver observe that “the reach of road was just

abandoned (walked away from) following the 2012 construction work, with no

visible efforts to address and control surface erosion from the large expanse of

exposed bare soil through seeding and/or mulching the surfaces to protect the soil

155
from raindrop impact and sheet wash erosional processes.” T he result was

“widespread and obvious gullies of varying dimensions,” which Mr. Hagans and

Dr. Weaver observe , “are undermining and further contribu ting to the

formation/incidence of fill slope failures observed and present on the 2014

photograph.” 156

153
Ibid.
154Ibid.
155Ibid.
156Ibid.

54enlarging gullies and landslides present on the un -compacted, sidecast fill slopes,

and evidence of widespread surface erosion on the visible bare soil areas through

153
time.”

2.47 In particular, the October 20 12 photograph reveals that, by that

time, the site was characterized by a “smooth textured excavation surface” and

that “[p]oor or non-existent fill compaction during construction could have easily

led an experienced geologist or engineer in October 2012 t o predict the resulting

154
instabilities and extent of erosion now present on the fill slopes at this site.”

2.48 Subsequent images from 2013 and 2014 demonstrate that Costa

Rica ceased construction work without attempting to control the inevitable

erosion. Mr. Hagans and Dr. Weaver observe that “the reach of road was just

abandoned (walked away from) following the 2012 construction work, with no

visible efforts to address and control surface erosion from the large expanse of

exposed bare soil through seeding and/or mulching the surfaces to protect the soil

155
from raindrop impact and sheet wash erosional processes.” T he result was

“widespread and obvious gullies of varying dimensions,” which Mr. Hagans and

Dr. Weaver observe , “are undermining and further contribu ting to the

formation/incidence of fill slope failures observed and present on the 2014

photograph.” 156

153
Ibid.
154Ibid.
155Ibid.
156Ibid. Figure 2.18. Severely Eroding Site 8.2, 16.2 km downstream of Mojon II.
Oblique aerial view from October 2012.

Figure 2.19. Severely Eroding Site 8.2, 16.2 km downstream of Mojon II.
High-resolution satellite image of December 2013.

56Figure 2.18. Severely Eroding Site 8.2, 16.2 km downstream of Mojon II.
Oblique aerial view from October 2012.

Figure 2.19. Severely Eroding Site 8.2, 16.2 km downstream of Mojon II.
High-resolution satellite image of December 2013.
2.50

2012, there was already a “cut slope landslide” that may be seen “in the center of

the photo.”

scarp system along the outer edge of the road”; this indicates “pending fill slope

failures within the un -compacted, loose sidecast fill materials that had been

bulldozed onto the steep hill slope during road building.”

2.51

worsened by that time. Mr. Hagans and Dr. Weaver observe that “the scarp

system continue[d] to be more pronounced and integrated along the outside edge

of the road, as the unstable fill slopes continue[d] to deform” and that the “largest

160
161Hagans & Weaver Report, Section III.C (NR, Vol. II, Annex 2).
Ibid. gullies at Site 8.2 are coincidently located along the lateral scarp margins that

162
define the most unstable and actively failing fill slopes at the site.”

2.52 These problems are even more evident i n the May 2014

photograph, which also shows the development of “two more recent and larger cut

slope failures” located at “either end of the cut bank.” 163 Mr. Hagans and Dr.

Weaver explain:

“These features clearly suggest there was little or no pre -

construction geotechnical analysis of the terrain and
subsurface geology that would have indicated the unstable
nature of th e earth materials. This common -place and
standard geotechnical and geologic analysis would have

predicted the lack of soil and bedrock comp etency and
strength, and subsequently would have been used to
develop proper engineering designs for this and other sites

along the road which are now164hibiting massive surface
erosion and road failure.”

2.53 In sum, with respect to the eroding hilly slopes l ocated at Sites 8.1

and 8.2, Mr. Hagans and Dr. Weaver conclude:

“Over the 20 month period of our analysis of oblique aerial
photographs and high-resolution satellite images, there is a

clear lack of any significant or visible efforts to control,
repair or prevent the very visible, ongoing and future
landslide, gully and surface erosion that is apparent in the
two cut and fill slope examples. The incompletely

constructed road reach at Site 8.1 and 8.2 reveals a
complete disregard for following even the most basic, well
accepted road engineering and road maintenance principles
normally applied during road construction. Even more

egregious is the total disregard for site specific and
cumulative environmental impacts that continue to be

162Ibid.
163Ibid.
164Ibid.

58gullies at Site 8.2 are coincidently located along the lateral scarp margins that

162
define the most unstable and actively failing fill slopes at the site.”

2.52 These problems are even more evident i n the May 2014

photograph, which also shows the development of “two more recent and larger cut

slope failures” located at “either end of the cut bank.” 163 Mr. Hagans and Dr.

Weaver explain:

“These features clearly suggest there was little or no pre -

construction geotechnical analysis of the terrain and
subsurface geology that would have indicated the unstable
nature of th e earth materials. This common -place and
standard geotechnical and geologic analysis would have

predicted the lack of soil and bedrock comp etency and
strength, and subsequently would have been used to
develop proper engineering designs for this and other sites

along the road which are now164hibiting massive surface
erosion and road failure.”

2.53 In sum, with respect to the eroding hilly slopes l ocated at Sites 8.1

and 8.2, Mr. Hagans and Dr. Weaver conclude:

“Over the 20 month period of our analysis of oblique aerial
photographs and high-resolution satellite images, there is a

clear lack of any significant or visible efforts to control,
repair or prevent the very visible, ongoing and future
landslide, gully and surface erosion that is apparent in the
two cut and fill slope examples. The incompletely

constructed road reach at Site 8.1 and 8.2 reveals a
complete disregard for following even the most basic, well
accepted road engineering and road maintenance principles
normally applied during road construction. Even more

egregious is the total disregard for site specific and
cumulative environmental impacts that continue to be

162Ibid.
163Ibid.
164Ibid. B. THE ACCUMULATION OF SEDIMENT IN THE RIVER

1. Deltas

2.55 Costa Rica denies that the significant sediment transfers into the

River caused by these and other failures have had any appreciable impact. 167 This

is plainly wrong. The most obvious impact is the huge accumulations of

sediment, known as “deltas,” that have developed in the River itself (which, it

must always be recalled, is entirely within Nicaragua’s sovereign territory).

2.56 The deltas caused by erosion from the sites just reviewed are a few

examples. They are, by any measure, substantial in size. By 30 March 2014,

when it was measured in the field, the eastern most of the two shown in Figure

2.11 extended fully 15 meters into the River, and measured 21 meters across and 2

meters above the River’s surface. 168 Close- up images may be found at Figure

169
2.21. The western delta is of similar dimensions.

167
168.g., CRCM, para. 3.76.
2014 Kondolf Report, Section 11, Appendix F (NR, Vol. II, Annex 1).
169Ibid. In light of size of this and the other deltas described above, Professor Thorne’s claim that
the Road -related deltas have “smal l dimensions” and are of “morphological insignificance” is
inexplicable. Dec. 2013 Thorne Report, para. 9.1 (CRCM, Vol I, Appendix A).

60 B. THE ACCUMULATION OF SEDIMENT IN THE RIVER

1. Deltas

2.55 Costa Rica denies that the significant sediment transfers into the

River caused by these and other failures have had any appreciable impact. 167 This

is plainly wrong. The most obvious impact is the huge accumulations of

sediment, known as “deltas,” that have developed in the River itself (which, it

must always be recalled, is entirely within Nicaragua’s sovereign territory).

2.56 The deltas caused by erosion from the sites just reviewed are a few

examples. They are, by any measure, substantial in size. By 30 March 2014,

when it was measured in the field, the eastern most of the two shown in Figure

2.11 extended fully 15 meters into the River, and measured 21 meters across and 2

meters above the River’s surface. 168 Close- up images may be found at Figure

169
2.21. The western delta is of similar dimensions.

167
168E.g., CRCM, para. 3.76.
2014 Kondolf Report, Section 11, Appendix F (NR, Vol. II, Annex 1).
169Ibid. In light of size of this and the other deltas described above, Professor Thorne’s claim that
the Road -related deltas have “smal l dimensions” and are of “morphological insignificance” is
inexplicable. Dec. 2013 Thorne Report, para. 9.1 (CRCM, Vol I, Appendix A). Figure 2.22. Delta deposit below Severely Eroding Site 9.4.
Photograph from March 30, 2014.

Figure 2.23. Delta deposit below Severely Eroding Site 9.4.
Photograph from March 30, 2014.

62Figure 2.22. Delta deposit below Severely Eroding Site 9.4.
Photograph from March 30, 2014. 2.58 Similarly, as shown in Figure 2.24, a March 2014 inspection of the

failed stream crossing on level terrain discussed at paragraphs 2.39-2.41 above,

also reveals a large sediment delta reaching into the Ri ver that consists of

approximately 40-80 tons of sediment (representing only a small percentage of

what the full pulse had been), as well as fragments of the failed culvert.

Figure 2.24. Delta deposit from fill material of failed crossing 20.3 km downstream of Mojon 2
extending into the San Juan River. Photograph from March 31, 2014.

Figure 2.23. Delta deposit below Severely Eroding Site 9.4.
Photograph from March 30, 2014.

2.59 There are other examples as well, including

Figures 2.25-2.27, below, which relate s to Dr. Kondolf’s Severely Eroding Site

9.7 (not one of the sites discussed in detail above).

171See Ibid., Section 5. Figure 2.25. Delta deposit from Severely Eroding Site 9.7.
Aerial photograph from May 2, 2014.

Figure 2.26. Delta deposit from Severely Eroding Site 9.7.
Photograph from March 30, 2014.

64Figure 2.25. Delta deposit from Severely Eroding Site 9.7.
Aerial photograph from May 2, 2014.

Figure 2.26. Delta deposit from Severely Eroding Site 9.7.
Photograph from March 30, 2014.
2.

2.60 Costa Rica argues that there are no significant impacts to the Lower

San Juan River

average increase in the rate of aggradation of the bed would be less than 0.02 mm

[per year] – less than the diameter of a single grain of sand.”

explains, “[w]hile perhaps a visually compelling image, this argument is a

significant distortion and is fallacious on two important counts.”

172
173CRCM, para. 3.76(c).
2014 Kondolf Report, Section 11 (NR, Vol. II, Annex 1). 2.61 Costa Rica’s argument (which is itself based on an unreasonably

low estimate of how much road -derived sediment is making its way to the San

174
Juan River ) betrays a fundamental misunderstanding of the d ynamics of

sediment distribution. As the Counter -Memorial explains, the 0.02 mm figure is

based on two assumptions:

 That “only the sand fraction of the additional sediment would
actually be likely to be deposited on the bed” 175 and

 That it will be distributed over the entire Lower San Juan,
176
which “has a bed area of 2.7 million m2.”

Both of these assumptions are incorrect and do not reflect the realities of sediment

177
deposition in deltas.

2.62 As Dr. Andrews explains, Costa Rica’s assumption that 90 -95% of

the Road’s contribution of sediment will be washed out to the Caribbean Sea 178 is

at odds with well -established principles concerning how sediment behaves in

deltaic regions.

174
See Section C of this Chapter, below. Costa Rica also incorrectly assumes that only 10% of the
Road’s contribution of sediment will end up in the Lower San Juan. Andrews Report, Section
V(F) (NR, Vol. II, Annex 3).
175CRCM, para. 3.32.
176Ibid.
177Dr. Andrews observes that it is not only the underlying assumptions of Costa Rica’s assertion

that are erroneous, but the simple calculation itselAndrews Report, Section V(I ) (NR, Vol. II,
Annex 3). The -1unter-Memorial’s assertion that “[a]dditional aggradation is therefore likely to
be 0.02 mm y ” is based on Professor Thorne’s calculation that if all the sediment from the Road
that enters the Lower San Juan (3,650 m3per year according to his estimate) were deposited across
a bed area of 2,700,000 m 2, “the average increase in the rate of aggradation of the bed would be
less than 0.2 mm y -.” CRCM, para 3.32; Thorne para 8.59. However, as Dr. Andrews observes,
“3650 m 3 of sediment spread over 2.7 mill ion m would be 1.35 mm thick, not less than 0.2 mm as

178ted; (3650/2,700,000 = 0.00135).” Andrews Report, Section V(I) (NR, Vol. II, Annex 3).
CRCM, para 3.32.

66 2.61 Costa Rica’s argument (which is itself based on an unreasonably

low estimate of how much road -derived sediment is making its way to the San

174
Juan River ) betrays a fundamental misunderstanding of the d ynamics of

sediment distribution. As the Counter -Memorial explains, the 0.02 mm figure is

based on two assumptions:

 That “only the sand fraction of the additional sediment would
actually be likely to be deposited on the bed” 175 and

 That it will be distributed over the entire Lower San Juan,
176
which “has a bed area of 2.7 million m2.”

Both of these assumptions are incorrect and do not reflect the realities of sediment

177
deposition in deltas.

2.62 As Dr. Andrews explains, Costa Rica’s assumption that 90 -95% of

the Road’s contribution of sediment will be washed out to the Caribbean Sea 178is

at odds with well -established principles concerning how sediment behaves in

deltaic regions.

174
See Section C of this Chapter, below. Costa Rica also incorrectly assumes that only 10% of the
Road’s contribution of sediment will end up in the Lower San Juan. Andrews Report, Section
V(F) (NR, Vol. II, Annex 3).
175CRCM, para. 3.32.
176Ibid.
177Dr. Andrews observes that it is not only the underlying assumptions of Costa Rica’s assertion

that are erroneous, but the simple calculation itseAndrews Report, Section V(I ) (NR, Vol. II,
Annex 3). The-1ounter-Memorial’s assertion that “[a]dditional aggradation is therefore likely to
be 0.02 mm y ” is based on Professor Thorne’s calculation that if all the sediment from the Road
that enters the Lower San Juan (3,650 m3per year according to his estimate) were deposited across
a bed area of 2,700,000 m , “the average increase in the rate of aggradation of the bed would be
less than 0.2 mm y-1.” CRCM, para 3.32; Thorne para 8.59. However, as Dr. Andrews observes,
“3650 m 3 of sediment spread over 2.7 mill ion m would be 1.35 mm thick, not less than 0.2 mm as

178ted; (3650/2,700,000 = 0.00135).” Andrews Report, Section V(I) (NR, Vol. II, Annex 3).
CRCM, para 3.32. islands and/or the river bank,” which can result in islands increasing in size and

the enlargement of the bank, even “causing the two features to join.” 183 The

places where sediment is most likely to accumulate are those where the river’s

flow is slow, “such as along the river bank and where velocities are slowed by

184
islands or other features,” including existing sand bars. This can also cause the

clogging of s mall distributary channels, which will force the flow of water to

185
move to a new location.

2.65 Dr. Andrews concurs, explaining that a focus on “average thickness

of deposition understates the magnitude of the potential problems, because the

accumulating sediment won’t be distributed evenly across the delta channels.” 186

Rather, “accumulating sediment” will

“tend to form bars, which are evident along the
delta channels, creating reach -wise instabilities and
obstructions to navigation. River bars will grow
over time and merge with the river banks; a process

known as ‘accretion.’ Vegetation will gradually
become established on the river bars, which will
induce more sediment deposition and the channel
will narrow. As the channel fills with sediment, the

capacity of the channel will be reduced over time
and eventually the flow will find a new course to
the ocean. Thus, an increased supply of sediment to

the head of the delta will tend to accelerate the rate
of filling and abandonment of one channel and the
diversion of flow to a new channel.” 187

183
Ibid.
184Ibid.
185Ibid.
186Andrews Report, Section V(I) (NR, Vol. II, Annex 3).
187Ibid.

68islands and/or the river bank,” which can result in islands increasing in size and

the enlargement of the bank, even “causing the two features to join.” 183 The

places where sediment is most likely to accumulate are those where the river’s

flow is slow, “such as along the river bank and where velocities are slowed by

184
islands or other features,” including existing sand bars. This can also cause the

clogging of s mall distributary channels, which will force the flow of water to

185
move to a new location.

2.65 Dr. Andrews concurs, explaining that a focus on “average thickness

of deposition understates the magnitude of the potential problems, because the

accumulating sediment won’t be distributed evenly across the delta channels.” 186

Rather, “accumulating sediment” will

“tend to form bars, which are evident along the
delta channels, creating reach -wise instabilities and
obstructions to navigation. River bars will grow
over time and merge with the river banks; a process

known as ‘accretion.’ Vegetation will gradually
become established on the river bars, which will
induce more sediment deposition and the channel
will narrow. As the channel fills with sediment, the

capacity of the channel will be reduced over time
and eventually the flow will find a new course to
the ocean. Thus, an increased supply of sediment to

the head of the delta will tend to accelerate the rate
of filling and abandonment of one channel and the
diversion of flow to a new channel.” 187

183
Ibid.
184Ibid.
185Ibid.
186Andrews Report, Section V(I) (NR, Vol. II, Annex 3).
187Ibid. the River nearer to the Caribbean. In those reaches, a process called

“flocculation” occurs, in which fine sediment particles such as silt and clay will

clump together, and sink to the bottom of the channel. Dr. Andrews estimates that

the “vast majority” of the finer portions of road -derived sediment will accumulate

190
in the Delta, including in the Lower San Juan and its distributary channels.

2.68 Where exactly this accumulation takes places will depend on such

factors as tide and storm surges, whi ch can push seawater farther into the Lower

San Juan and related areas, and whether the River’s flow is high or low, because

high flows have the capacity to push salty water back out to the sea. As Dr.

Andrews explains, “[a] substantial portion of the sed iment will be deposited,

191
eroded, transported, and then re- deposited.” Costa Rica’s claims regarding

accumulation in the Lower San Juan ignores this process and what is likely to be

the true destination of the great majority of the road-derived sediment that reaches

the Delta. Between accumulation of coarser particles in the upper portion of the

channel, and accumulation of the finer suspended particles in the lower reaches

through flocculation, almost all of the sediment supplied by the Road to the

Lower San Juan will remain there.

2.69 Costa Rica also wrongly assumes that only the sediment from the

Road itself is relevant. In reality, the threat of aggradation and accretion in the

Lower San Juan stems not only from Road -derived sediment, but also from what

190
191Ibid.
Ibid.

70the River nearer to the Caribbean. In those reaches, a process called

“flocculation” occurs, in which fine sediment particles such as silt and clay will

clump together, and sink to the bottom of the channel. Dr. Andrews estimates that

the “vast majority” of the finer portions of road -derived sediment will accumulate

190
in the Delta, including in the Lower San Juan and its distributary channels.

2.68 Where exactly this accumulation takes places will depend on such

factors as tide and storm surges, whi ch can push seawater farther into the Lower

San Juan and related areas, and whether the River’s flow is high or low, because

high flows have the capacity to push salty water back out to the sea. As Dr.

Andrews explains, “[a] substantial portion of the sed iment will be deposited,

191
eroded, transported, and then re- deposited.” Costa Rica’s claims regarding

accumulation in the Lower San Juan ignores this process and what is likely to be

the true destination of the great majority of the road-derived sediment that reaches

the Delta. Between accumulation of coarser particles in the upper portion of the

channel, and accumulation of the finer suspended particles in the lower reaches

through flocculation, almost all of the sediment supplied by the Road to the

Lower San Juan will remain there.

2.69 Costa Rica also wrongly assumes that only the sediment from the

Road itself is relevant. In reality, the threat of aggradation and accretion in the

Lower San Juan stems not only from Road -derived sediment, but also from what

190
191Ibid.
Ibid. when long-term average flows and sediment transport rates are taken into account,

the true load of coarse sediment delivered to the Lower San Juan on a n annual

basis is 100,000 to 150,000 m 3 per year. 200 Either way, the fundamental point is

the same: the Lower San Juan does not have the capacity to transport a large

portion of the coarse sediment delivered to it (most of which comes from Costa

Rica, as Co sta Rica concedes). Anything the River cannot carry will be

deposited; and because the river cannot carry this excess sediment far, it is highly

likely that all of it will accumulate in the upper 3 km of the Lower San Juan.

2.71 If the excess coarse sediment delivered to the Lower San Juan were

to be spread evenly over the first 3 kilometers where it will actually deposit, levels

of accumulation would be somewhere between 10 and 30 centimeters per year, far

greater than “a single grain of sand.” Once again, however, sediment will actually

be worse in certain places where the flow is slower, as on sand bars, islands, and

along the banks.

2.72 In this context, any new input from the Road will be deposited, and

exacerbate existing problems largely attributable to poor land-use practices in

Costa Rica. As sediment accumulates in the channel, it decreases the River’s

ability to transport sediment, which, in a positive feedback loop, accelerates the

201
process of accumulation.

200Andrews Report, Section V(I) (NR, Vol. II, Annex 3).
201Ibid.

72when long-term average flows and sediment transport rates are taken into account,

the true load of coarse sediment delivered to the Lower San Juan on a n annual

basis is 100,000 to 150,000 m 3 per year. 200 Either way, the fundamental point is

the same: the Lower San Juan does not have the capacity to transport a large

portion of the coarse sediment delivered to it (most of which comes from Costa

Rica, as Co sta Rica concedes). Anything the River cannot carry will be

deposited; and because the river cannot carry this excess sediment far, it is highly

likely that all of it will accumulate in the upper 3 km of the Lower San Juan.

2.71 If the excess coarse sediment delivered to the Lower San Juan were

to be spread evenly over the first 3 kilometers where it will actually deposit, levels

of accumulation would be somewhere between 10 and 30 centimeters per year, far

greater than “a single grain of sand.” Once again, however, sediment will actually

be worse in certain places where the flow is slower, as on sand bars, islands, and

along the banks.

2.72 In this context, any new input from the Road will be deposited, and

exacerbate existing problems largely attributable to poor land-use practices in

Costa Rica. As sediment accumulates in the channel, it decreases the River’s

ability to transport sediment, which, in a positive feedback loop, accelerates the

201
process of accumulation.

200Andrews Report, Section V(I) (NR, Vol. II, Annex 3).
201Ibid. suggest that it does not pollute . It is for this reason that sediment, sand and dirt

206
are frequently defined as pollutants in environmental laws, are prohibited or

207
restricted from being discharged into bodies of water, and when discharged into

water, meet the definition of pollution set out in still more environmental laws 208

209
and international agreements.

2.76 The widespread understanding that sediment is a pollutant reflects

the scientific consensus that it can harm the natural environment, including

especially water quality and aquatic organisms. The United States Environmental

Protection Agency’s Framework for Developing Suspended and Bedded

Sediments (SABS) Water Quality Criteria describe some of the many effects that

sediments have on aquatic life, including:

 reducing the productivity of algae on which other organisms

rely as a source of food;

 inducing adverse behavioral, physiological, and toxicological

responses in invertebrates, thus reducing population diversity

and growth;

206
E.g., E.g., 33 U.S.C. 1362(6) (Clean Water Act); 314 CMR 3.02 (Massachusetts); Va. Code
Ann. § 62.1-44.15:24; CVIR 12-007-000, Sec. 184-2(87)(i)(B) (U.S. Virgin Islands).
207E.g., Ontario Regulation 242/08 §23.4(9) ; New Brunswick Regulation 2001 -83 §6(a); Nova
Scotia NS Reg 113/2006 §10(1); Newfoundland and Labrador Regulation 39/07 §15.3.
20E.g., EU Water Framework Directive 2000/60/EC, art. 2(33) (“’Pollution’ means the direct or
indirect introduction, as a result of human activity, of substances . . . into the air, water or land

which may be harmful to . . . the quality of aquatic ecosystems . . . or which impair or interfere
with amenities and other legitimate uses of the environment.”); RManagement Act 1991
(New Zealand), 1991 No. 69 §2(1) (“contaminant includes any substance . . . [that] when
discharged into water, changes or is likely to change the physical, chemical, or biological
condition of the water. . . .”).
209E.g., UN Watercourses Convention, art. 21(1) (defining pollution of an international
watercourse as “any detrimental alteration in the composition or quality of the waters of an

international watercourse which results directly or indirectly from human conduct.”); Helsinki
Rules on the Uses of the Waters of International Rivers, art. IX (adopting a similar definition).

74suggest that it does not pollute . It is for this reason that sediment, sand and dirt

206
are frequently defined as pollutants in environmental laws, are prohibited or

207
restricted from being discharged into bodies of water, and when discharged into

water, meet the definition of pollution set out in still more environmental laws 208

209
and international agreements.

2.76 The widespread understanding that sediment is a pollutant reflects

the scientific consensus that it can harm the natural environment, including

especially water quality and aquatic organisms. The United States Environmental

Protection Agency’s Framework for Developing Suspended and Bedded

Sediments (SABS) Water Quality Criteria describe some of the many effects that

sediments have on aquatic life, including:

 reducing the productivity of algae on which other organisms

rely as a source of food;

 inducing adverse behavioral, physiological, and toxicological

responses in invertebrates, thus reducing population diversity

and growth;

206
E.g., E.g., 33 U.S.C. 1362(6) (Clean Water Act); 314 CMR 3.02 (Massachusetts); Va. Code
Ann. § 62.1-44.15:24; CVIR 12-007-000, Sec. 184-2(87)(i)(B) (U.S. Virgin Islands).
207E.g., Ontario Regulation 242/08 §23.4(9) ; New Brunswick Regulation 2001 -83 §6(a); Nova
Scotia NS Reg 113/2006 §10(1); Newfoundland and Labrador Regulation 39/07 §15.3.
208E.g., EU Water Framework Directive 2000/60/EC, art. 2(33) (“’Pollution’ means the direct or
indirect introduction, as a result of human activity, of substances . . . into the air, water or land

which may be harmful to . . . the quality of aquatic ecosystems . . . or which impair or interfere
with amenities and other legitimate uses of the environment.”); ReManagement Act 1991
(New Zealand), 1991 No. 69 §2(1) (“contaminant includes any substance . . . [that] when
discharged into water, changes or is likely to change the physical, chemical, or biological
condition of the water. . . .”).
209 E.g., UN Watercourses Convention, art. 21(1) (defining pollution of an international
watercourse as “any detrimental alteration in the composition or quality of the waters of an

international watercourse which results directly or indirectly from human conduct.”); Helsinki
Rules on the Uses of the Waters of International Rivers, art. IX (adopting a similar definition). and survivorship, and causes higher concentrations of lysozyme in blood, an

indication of stress. Dr. Kondolf discusses these examples, as well as documented

vulnerabilities in th e Poecilid and migratory Mugiliidae families, which are also

common in the River, in his Report. 213

2.79 Equally unsupportable is Costa Rica’s claim that “the contribution

of sediment to a river such as the San Juan is a natural process” that is “commonly

regarded as beneficial.” 214 While it is true that sediment may in limited amounts

be naturally transferred to a river, this is distinctly not what is occurring in regard

to the San Juan River. In Chapter 1, Nicaragua indicated that Costa Rica’s poor

land use pract ices, including especially its deforestation and agriculture, have

caused very large quantities of sediment to erode into the River. Even before

Costa Rica’s recent road construction project, the San Juan River was already

215
burdened by an excessive sedimen t load attributable to Costa Rica. The River

now must contend with the additional sediment eroding from another (Costa

Rican) man-made source along its southern bank.

2.80 This is undeniably not a “natural process,” much less one that is

216
beneficial. Not o nly are t he steep slopes, unstable fills, and failing stream

crossings discussed above contributing sediment to the River , but there are

locations where Costa Rica has dug channels leading from the Road to the River

213
2142014 Kondolf Report, Section 8 (NR, Vol. II, Annex 1).
215CRCM, para. 3.4.
This has been repeatedly claimed by Nicaragua as shown in its Counter Memori al in the
Dispute regarding Navigational and Related Rights (Costa Rica v. Nicaragua), 2009, p. 251 (3).
216CRCM, para. 4.9.

76and survivorship, and causes higher concentrations of lysozyme in blood, an

indication of stress. Dr. Kondolf discusses these examples, as well as documented

vulnerabilities in th e Poecilid and migratory Mugiliidae families, which are also

common in the River, in his Report. 213

2.79 Equally unsupportable is Costa Rica’s claim that “the contribution

of sediment to a river such as the San Juan is a natural process” that is “commonly

regarded as beneficial.” 214 While it is true that sediment may in limited amounts

be naturally transferred to a river, this is distinctly not what is occurring in regard

to the San Juan River. In Chapter 1, Nicaragua indicated that Costa Rica’s poor

land use pract ices, including especially its deforestation and agriculture, have

caused very large quantities of sediment to erode into the River. Even before

Costa Rica’s recent road construction project, the San Juan River was already

215
burdened by an excessive sedimen t load attributable to Costa Rica. The River

now must contend with the additional sediment eroding from another (Costa

Rican) man-made source along its southern bank.

2.80 This is undeniably not a “natural process,” much less one that is

216
beneficial. Not o nly are t he steep slopes, unstable fills, and failing stream

crossings discussed above contributing sediment to the River , but there are

locations where Costa Rica has dug channels leading from the Road to the River

213
2142014 Kondolf Report, Section 8 (NR, Vol. II, Annex 1).
215CRCM, para. 3.4.
This has been repeatedly claimed by Nicaragua as shown in its Counter Memori al in the
Dispute regarding Navigational and Related Rights (Costa Rica v. Nicaragua), 2009, p. 251 (3).
216CRCM, para. 4.9. 2.81 Other channels have been created by the lack of drainage for large

areas of exposed sediment close to the River. As Dr. Kondolf explains, poor

drainage on unnaturally exposed areas has led to increased runoff and sediment

transport from bare slopes, leading to the cr eation of channels that carry sediment

from disturbed areas to the River. 217 Figures 2.30 below, which includes two

images of the same quarry site located 25.3 km downstream of Mojon II, provides

an example of this phenomenon. As can be seen, uncontrolled drainage (already

visible in October 2012) from the exposed site had led (by May 2014 or earlier) to

218
the incision of a channel that transports eroded sediments into the River.

217
2014 Kondolf Report, Section 4 (NR, Vol. II, Annex 1).
218Ibid.

78 2.81 Other channels have been created by the lack of drainage for large

areas of exposed sediment close to the River. As Dr. Kondolf explains, poor

drainage on unnaturally exposed areas has led to increased runoff and sediment

transport from bare slopes, leading to the cr eation of channels that carry sediment

from disturbed areas to the River. 217 Figures 2.30 below, which includes two

images of the same quarry site located 25.3 km downstream of Mojon II, provides

an example of this phenomenon. As can be seen, uncontrolled drainage (already

visible in October 2012) from the exposed site had led (by May 2014 or earlier) to

218
the incision of a channel that transports eroded sediments into the River.

217
2014 Kondolf Report, Section 4 (NR, Vol. II, Annex 1).
218Ibid. 2.82 In paragraphs 2.55-2.59, above, Nicaragua described some of the

large sediment deltas that have formed in the River from sediment eroding from

Road-related constructi on. These are not the only ones ; there are further

219
examples. The creation of deltas of such size in a watercourse is, as the

environmental engineers from Golder Associates describe in their Expert Report,

“totally unacceptable” from an environmental impact perspective, and constitutes

220
“environmental negligence.” According to Dr. Kondolf:

“The fact that sediment from Rte 1856 has been permitted
to enter the Rio San Juan in sufficient quantities to create

large, visible deltas reflects the lack of planni ng for the
project, the lack of even basic environmental safeguards
and sound construction practices, and the lack of effective

erosion control and slope stabilization. This d221 not
constitute acceptable practice in any way.”

2.83 There is well-documented evidence that the road-derived sediment

is already harming the ecological health of the River, including in proximity to

these deltas . Sampling from the River demonstrates statistically significant

differences between algal and macroinvertebrate communities living on and near

the deltas caused by the Road, on the one hand, and naturally occurring deltas on

the Nicaraguan bank that have not received road -related sediment deposits, on the

other.

219
See 2014 Kondolf Report, Section 11 (NR, Vol. II, Annex 1). Thes e delta bear little
220emblance to the natural deltas on the Nicaraguan bank of the River. Ibid.
Golder Associates, Inc., “The Requirements of Impact Assessment for Large -Scale Road
Construction Project in Costa Rica Along the San Juan River, Nicaragua, ” July 2014 (hereinafter
the “Golder Report”), Section 6 (NR, Vol. II, Annex 6).
2212014 Kondolf Report, Section 11 (NR, Vol. II, Annex 1).

80 2.82 In paragraphs 2.55-2.59, above, Nicaragua described some of the

large sediment deltas that have formed in the River from sediment eroding from

Road-related constructi on. These are not the only ones ; there are further

219
examples. The creation of deltas of such size in a watercourse is, as the

environmental engineers from Golder Associates describe in their Expert Report,

“totally unacceptable” from an environmental impact perspective, and constitutes

220
“environmental negligence.” According to Dr. Kondolf:

“The fact that sediment from Rte 1856 has been permitted
to enter the Rio San Juan in sufficient quantities to create

large, visible deltas reflects the lack of planni ng for the
project, the lack of even basic environmental safeguards
and sound construction practices, and the lack of effective

erosion control and slope stabilization. This d221 not
constitute acceptable practice in any way.”

2.83 There is well-documented evidence that the road-derived sediment

is already harming the ecological health of the River, including in proximity to

these deltas . Sampling from the River demonstrates statistically significant

differences between algal and macroinvertebrate communities living on and near

the deltas caused by the Road, on the one hand, and naturally occurring deltas on

the Nicaraguan bank that have not received road -related sediment deposits, on the

other.

219
See 2014 Kondolf Report, Section 11 (NR, Vol. II, Annex 1). Thes e delta bear little
220emblance to the natural deltas on the Nicaraguan bank of the River. Ibid.
Golder Associates, Inc., “The Requirements of Impact Assessment for Large -Scale Road
Construction Project in Costa Rica Along the San Juan River, Nicaragua, ” July 2014 (hereinafter
the “Golder Report”), Section 6 (NR, Vol. II, Annex 6).
2212014 Kondolf Report, Section 11 (NR, Vol. II, Annex 1). information regarding its impairment.” 225 For these and other reasons, these

226
species are “used worldwide in stream and river bio-monitoring programs.”

2.87 Dr. Rios’s sampling of these aquatic species involved collecting

samples from 16 deltas in the San Juan River – 8 along the north bank, and 8

along the south bank. She did so on three occasions: March 2014, April 2014, and

May 2014. This monitoring programme is an expansion of the earlier study

described in Dr. Kondolf’s Third Report 227 and discussed in November 2013 at

the hearings on Nicaragua’s Request for the Indication of Provisional

228
Measures. At that time, Costa Rica’s expert, Professor Thorne, accepted that it

229
would be “fair to compare” periphyton and macroinvertebrate samples from the

two sides of the River, as long as all samples were collected on deltas. 230 That is

what was done previously, 231 and that is what has been done again, this time at

232
more sites and on more occasions.

2.88 The results of the sampling are consistent with those that Nicaragua

previously presented to the Court: the aquatic life forms are healthier, more

225Ibid., Section 1(b).
226
227Ibid.
Dr. G. Mathias Kondolf “Continued Impacts of Erosion from Rte 1856, Costa Rica to the Río
San Juan, Nicaragua” 30 October 2013, p.13.
228Ibid.
229Periphyton are “algae and other organisms growing on the surfaces of gravel and rock.” 2014
Kondolf Report, Section 11; see also Section 8 (NR, Vol. II, Annex 1).
230CRCM, Vol. II, Annex 9, para. 82.
231
2322014 Kondolf Report, Section 8 (NR, Vol. II, Annex 1).
Rios Report, Section 2 (NR, Vol. II, Annex 4).

82information regarding its impairment.” 225 For these and other reasons, these

226
species are “used worldwide in stream and river bio-monitoring programs.”

2.87 Dr. Rios’s sampling of these aquatic species involved collecting

samples from 16 deltas in the San Juan River – 8 along the north bank, and 8

along the south bank. She did so on three occasions: March 2014, April 2014, and

May 2014. This monitoring programme is an expansion of the earlier study

described in Dr. Kondolf’s Third Report 227 and discussed in November 2013 at

the hearings on Nicaragua’s Request for the Indication of Provisional

228
Measures. At that time, Costa Rica’s expert, Professor Thorne, accepted that it

229
would be “fair to compare” periphyton and macroinvertebrate samples from the

two sides of the River, as long as all samples were collected on deltas. 230 That is

what was done previously, 231 and that is what has been done again, this time at

232
more sites and on more occasions.

2.88 The results of the sampling are consistent with those that Nicaragua

previously presented to the Court: the aquatic life forms are healthier, more

225Ibid., Section 1(b).
226
227Ibid.
Dr. G. Mathias Kondolf “Continued Impacts of Erosion from Rte 1856, Costa Rica to the Río
San Juan, Nicaragua” 30 October 2013, p.13.
228Ibid.
229Periphyton are “algae and other organisms growing on the surfaces of gravel and rock.” 2014
Kondolf Report, Section 11; see also Section 8 (NR, Vol. II, Annex 1).
230CRCM, Vol. II, Annex 9, para. 82.
231
2322014 Kondolf Report, Section 8 (NR, Vol. II, Annex 1).
Rios Report, Section 2 (NR, Vol. II, Annex 4). 2.90 The River’s macroinvertebrate communities in areas imp acted by

the Road exhibit similar levels of degradation, both in terms of species richness,

which is significantly lower than in comparable, non -impacted areas (Figure

2.32) and abundance, which is significantly lower as well (Figure 2.33).

Figure 2.32. Differences in benthic macroinvertebrate richness at deltas on the north bank and the
south bank of the San Juan River.

84 2.90 The River’s macroinvertebrate communities in areas imp acted by

the Road exhibit similar levels of degradation, both in terms of species richness,

which is significantly lower than in comparable, non -impacted areas (Figure

2.32) and abundance, which is significantly lower as well (Figure 2.33).

Figure 2.32. Differences in benthic macroinvertebrate richness at deltas on the north bank and the
south bank of the San Juan River. 2.92 In short, sampling of the aquatic organisms that are used for

evaluating the water quality and ecological health of a watercourse, using the

methodology endorsed by Costa Rica, proves that sediment from the Road is

causing significant harm to aquatic organisms in the River.

4. Visual Impacts and Tourism

2.93 The EDA acknowledges that “the San Juan River department ” is

one of Nicaragua’s “ priority destinations “ for its developing nature tourism

237
industry, and that “[t]he tourism potential of the region is sufficient to justify

238
attracting international visitors.”

2.94 The area’s tourism potential, however, has been significantly

impaired by the Road. As the Golder Report explains, “The visual impacts

associated with the road construction have created a scar on the natural landscape

that will have impact on national and foreign visitors along the river when

239
viewing the Costa Rica landscape.” Given that tourism in the area “is mostly

associated with the natural beauty of this remote and non -highly commercialized

240
region,” the only reasonable conclusion is that Costa Ric a’s project

detrimentally impacts tourism in Nicaragua.

2.95 Costa Rica ’s Counter -Memorial cavalierly dismissed in a single

paragraph Nicaragua’s concerns regarding the Road’s impact on tourism. It

237
238EDA, pp. 159-160 (CRCM, Vol. II, Annex 10).
Ibid., p. 159.
239Golder Report, Section 7 (NR, Vol. II, Annex 6).
240Ibid.

86 2.92 In short, sampling of the aquatic organisms that are used for

evaluating the water quality and ecological health of a watercourse, using the

methodology endorsed by Costa Rica, proves that sediment from the Road is

causing significant harm to aquatic organisms in the River.

4. Visual Impacts and Tourism

2.93 The EDA acknowledges that “the San Juan River department ” is

one of Nicaragua’s “ priority destinations “ for its developing nature tourism

237
industry, and that “[t]he tourism potential of the region is sufficient to justify

238
attracting international visitors.”

2.94 The area’s tourism potential, however, has been significantly

impaired by the Road. As the Golder Report explains, “The visual impacts

associated with the road construction have created a scar on the natural landscape

that will have impact on national and foreign visitors along the river when

239
viewing the Costa Rica landscape.” Given that tourism in the area “is mostly

associated with the natural beauty of this remote and non -highly commercialized

240
region,” the only reasonable conclusion is that Costa Ric a’s project

detrimentally impacts tourism in Nicaragua.

2.95 Costa Rica ’s Counter -Memorial cavalierly dismissed in a single

paragraph Nicaragua’s concerns regarding the Road’s impact on tourism. It

237
238EDA, pp. 159-160 (CRCM, Vol. II, Annex 10).
Ibid., p. 159.
239Golder Report, Section 7 (NR, Vol. II, Annex 6).
240Ibid. 247
16,574 in 2012.” The EDA is thus constrained to qualify its claim that , “[t]o

date, there are no significant changes in the flow of visitors,” by observing that

“[i]n some instances, th e contrary is what is taking place, with important

decreases in tourism being reported.” 248 In other words, tourism in Nicaragua has

suffered.

C. COSTA RICA’S FLAWED ANALYSIS OF

SEDIMENTATION

2.97 In its Memorial, Nicaragua showed, based on the technical analysis

presented by Dr. Kondolf, that the steep, eroding sites located in the upper 41 km

3
of the Road are alone contributing an estimated 87,000 – 109,000 m of sediment

to the River annually. 249

2.98 Costa Rica denies th ese numbers , although it concedes that a

substantial quantity of sediment does, in fact, reach the River . According to Costa

Rica, the annual average sediment contribution to the River from the Road is

36,500 m 3.250 Even this amount is the equivalent of approximately 4,560 standard

247EDA Tourism Appendix, p. 9 (CRCM, Vol. II, Annex 10, p. 687).
248EDA Tourism Appendix, p. 18.(CRCM, Vol. II, p. 696).
249As explained in paragraph 2.4, above, Dr. Kondolf has updated his estimate to include the
remainder of the River-adjacent Road, as well as the many km of access roads that were impacted

through th3 project. He now estimates that Costa Rica’s road works are contributing as much as
150,000 m of sediment to the River per year. 2014 Kondolf Report, Section 7 (NR, Vol. II,
Annex 1).
250CRCM, paras. 3.25, 3.76(b). Nothing in Costa Rica’s Counter -Memorial or expert reports
undermine Dr. Kondolf’s erosion estimate. In that regard, the Counter-Memorial contends that Dr.
Kondolf estimates “that cut and fill slopes along the Road are erodin– i.e., the land surface is
lowering – at an average of 1 m per year” and that this erosion rate “is occurring on 40% to 50% of
the slopes.” CRCM, para. 3.15. Based on this understanding of Dr. Kondolf’s analysis, Costa

Rica concludes that the estimated erosi on rate “probably too high by a factor of ten” for the 108 -
km length of the Road. CRCM. para. 3.22, citing Thorne, para. 8.34. However, Dr. Kondolf did
not suggest that the average lowering of 1 m per year applied throughout the entire course of the

88 247
16,574 in 2012.” The EDA is thus constrained to qualify its claim that , “[t]o

date, there are no significant changes in the flow of visitors,” by observing that

“[i]n some instances, th e contrary is what is taking place, with important

decreases in tourism being reported.” 248 In other words, tourism in Nicaragua has

suffered.

C. COSTA RICA’S FLAWED ANALYSIS OF

SEDIMENTATION

2.97 In its Memorial, Nicaragua showed, based on the technical analysis

presented by Dr. Kondolf, that the steep, eroding sites located in the upper 41 km

3
of the Road are alone contributing an estimated 87,000 – 109,000 m of sediment

to the River annually. 249

2.98 Costa Rica denies th ese numbers , although it concedes that a

substantial quantity of sediment does, in fact, reach the River . According to Costa

Rica, the annual average sediment contribution to the River from the Road is

36,500 m 3.250 Even this amount is the equivalent of approximately 4,560 standard

247EDA Tourism Appendix, p. 9 (CRCM, Vol. II, Annex 10, p. 687).
248EDA Tourism Appendix, p. 18.(CRCM, Vol. II, p. 696).
249As explained in paragraph 2.4, above, Dr. Kondolf has updated his estimate to include the
remainder of the River-adjacent Road, as well as the many km of access roads that were impacted

through th3 project. He now estimates that Costa Rica’s road works are contributing as much as
150,000 m of sediment to the River per year. 2014 Kondolf Report, Section 7 (NR, Vol. II,
Annex 1).
250CRCM, paras. 3.25, 3.76(b). Nothing in Costa Rica’s Counter -Memorial or expert reports
undermine Dr. Kondolf’s erosion estimate. In that regard, the Counter-Memorial contends that Dr.
Kondolf estimates “that cut and fill slopes along the Road are erodin– i.e., the land surface is
lowering – at an average of 1 m per year” and that this erosion rate “is occurring on 40% to 50% of
the slopes.” CRCM, para. 3.15. Based on this understanding of Dr. Kondolf’s analysis, Costa

Rica concludes that the estimated erosi on rate “probably too high by a factor of ten” for the 108 -
km length of the Road. CRCM. para. 3.22, citing Thorne, para. 8.34. However, Dr. Kondolf did
not suggest that the average lowering of 1 m per year applied throughout the entire course of the 41.6 km of the Road, where much of the worst erosion is occurring. 253 It is

mistaken: the 26 km stretch excluded from Cos ta Rica’s study contains numerous

254
sites with much more serious erosion than those studied in the 15 km upriver.

2.101 The UCR Report’s treatment of landslide and gully erosion is a

good example. It considers landslide erosion at two locations (Figures 2.34 and

2.35) and gully erosion at three locations (Figures 2.36, 2.37 and 2.38).

Figure 2.34. Photograph of UCR Site 1: Landslide on cut slope.

253CRCM, para. 3.20.
2542014 Kondolf Report, Section 7 and Inventory of Severely Eroding Sites , Appendix A (NR,

Vol. II, Annex 1).

9041.6 km of the Road, where much of the worst erosion is occurring. 253 It is

mistaken: the 26 km stretch excluded from Cos ta Rica’s study contains numerous

254
sites with much more serious erosion than those studied in the 15 km upriver.

2.101 The UCR Report’s treatment of landslide and gully erosion is a

good example. It considers landslide erosion at two locations (Figures 2.34 and

2.35) and gully erosion at three locations (Figures 2.36, 2.37 and 2.38).

Figure 2.34. Photograph of UCR Site 1: Landslide on cut slope.

253CRCM, para. 3.20.
2542014 Kondolf Report, Section 7 and Inventory of Severely Eroding Sites , Appendix A (NR,

Vol. II, Annex 1). Figure 2.37. Aerial image of UCR Site 8: Gully on road fill.

Figure 2.38. Aerial image of UCR Site 9: Gully on road fill.

92Figure 2.37. Aerial image of UCR Site 8: Gully on road fill. 2.102 As these images make clear, although the erosion at the se sites is

significant, it is taking place on a m

elsewhere, including at the sites described above in Section A of this Chapter, all

of which were ignored by the authors of the UCR Report.

2.103 This raises the following questions: How can Costa Rica claim that

the UCR Report’s sites are “representative of the erosion which is likely to occur”

in that stretch?

presents erosion rates “from nine of the most active sites”?

UCR Report conclude, “The se

examples of erosion by land sliding, sheet erosion, rilling and gullying that exist

along Route 1856”?

Figure 2.38. Aerial image of UCR Site 9: Gully on road fill.
2.104 As Dr. Kondolf explains, there is no scientific justification for

applying the erosion rates measured at small erosional features to larger ones.

However, that is exactly what the UCR Report does. Rather than gathering actual

measurements at an adequate number of genuinely representative sites to develop

scientifically defensible erosion rates, the UCR Report extrapolates from what Dr.

255CRCM, para. 3.20.
256CRCM, para. 3.20.
257UCR Report, p. 2 (CRCM, Vol. II, Annex 1). The UCR Report is also incorrect when it claims
that the erosion rates are “highly conservative” because most other slopes and fills have bee n the

subject of meaningful mitigation measures “and are experiencing much less erosion than the sites
258ected for study.” Ibid., pp. 1-2.
2014 Kondolf Report, Section 7 (NR, Vol. II, Annex 1). Kondolf calls an “absurdly small sample” of unrepresentative erosional

259
features. The result is unreasonably low rates.

2.105 The UCR Report contains other flaws that also resulted in an

artificially low estimate of erosion rates. For instance, its authors estimated the

size of e rosion features (e.g., discrete gullies) and then calculated erosion rates

based on those estimates. However, the erosion rates were then divided over the

area of the entire exposed “slope” in which th e particular erosion feature

occurred. 260 This artificially reduced the rate because the size of the exposed

slope on which the eroding feature occurred was unrelated to the eroding feature

261
itself.

2.106 In some instances, the authors of the UCR Report compounded this

error by using exaggerated area figures, which drove the reported erosion rate

262
down even further. The UCR Report presents the resulting very small numbers

as “average” erosion rates for the particular erosional features. As Dr. Kondolf

explains, this flawed approach both reduces the true erosion rates for each feature

and ignores other erosion taking place on the remainder of the bare, exposed

slope. In reality, “the total erosion from [each] site would be the erosion

measured in [each erosion fe ature, e.g., a gully] (without dividing it over the

259
260Ibid.
261Ibid.,.see also Dec. 2013 Thorne Report, paras. 8.27, 8.28, 8.30 (CRCM, Vol. I, Appendix A).
2014 Kondolf Report, Section 7 (NR, Vol. II, Annex 1).
262Ibid.

94Kondolf calls an “absurdly small sample” of unrepresentative erosional

259
features. The result is unreasonably low rates.

2.105 The UCR Report contains other flaws that also resulted in an

artificially low estimate of erosion rates. For instance, its authors estimated the

size of e rosion features (e.g., discrete gullies) and then calculated erosion rates

based on those estimates. However, the erosion rates were then divided over the

area of the entire exposed “slope” in which th e particular erosion feature

occurred. 260 This artificially reduced the rate because the size of the exposed

slope on which the eroding feature occurred was unrelated to the eroding feature

261
itself.

2.106 In some instances, the authors of the UCR Report compounded this

error by using exaggerated area figures, which drove the reported erosion rate

262
down even further. The UCR Report presents the resulting very small numbers

as “average” erosion rates for the particular erosional features. As Dr. Kondolf

explains, this flawed approach both reduces the true erosion rates for each feature

and ignores other erosion taking place on the remainder of the bare, exposed

slope. In reality, “the total erosion from [each] site would be the erosion

measured in [each erosion fe ature, e.g., a gully] (without dividing it over the

259
260Ibid.
261Ibid.,.see also Dec. 2013 Thorne Report, paras. 8.27, 8.28, 8.30 (CRCM, Vol. I, Appendix A).
2014 Kondolf Report, Section 7 (NR, Vol. II, Annex 1).
262Ibid. 270
states that it relied in stead on a still a different study, an “Inventory of Slopes

and Water Courses,” prepared by two Costa Rican scientists, Dr. Mende and Dr.

Astorga (henceforth the “Mende and Astorga Inventory”). 271

2.109 Drs. Mende and Astorga claim to have applied the UCR Report’ s

“data on erosion depths and rates of land surface lowering due to sheet, rill,

landslide and gully erosion,” in “estimat[ing] the sediment yields from all the cut

and fill slopes that exist along the border road between Mojon II and Delta Costa

272
Rica.” Upon careful examination, however, the erosion rates they actually used

are, in many cases, not the UCR Report’s rates. A s shown by Dr. Kondolf, they

mixed-and-matched rates, applied unexplained and apparently arbitrary rate

increases (one of which they c all a “margin of safety”), and/or arbitrarily

substituted other rates. They did not present “a coherent scientific justification for

their seemingly random selection of rates to use in different contexts.” 273

2.110 The Mende and Astorga Inventory claims to be “a complete

inventory of all cut slopes, fill slopes, and wa tercourse intersections (crossings)

270Ibid.
271Although the Mende and Astorga Inventory is dated October 2013 and was apparently relied

upon in the preparation of the ICE Report that was submitted on 4 November 2013 in connection
with the hearings on Nicaragua’s request for the indication of provisional measures, the Mende
and Astorga Inventory was not submitted at that time.
272Mende & Astorga Inventory, p. 1 (CRCM, Vol. II, Annex 6).
2732014 Kondolf Report, Section 7 (NR, Vol. II, Annex 1). A careful reading of the Thorne report
reveals that he does not agree with the Astorga and Mende Inventory’s des cription of its own
method: “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…which are based on areas recorded in their 2013 inventory
of slopes and application of the erosiondepths reported in the 2013 UCR Report” (emphasis in
original). Dec. 2013 Thorne Report, pp. 78-79 (CRCM, Vol. I, Appendix A).

96 270
states that it relied in stead on a still a different study, an “Inventory of Slopes

and Water Courses,” prepared by two Costa Rican scientists, Dr. Mende and Dr.

Astorga (henceforth the “Mende and Astorga Inventory”). 271

2.109 Drs. Mende and Astorga claim to have applied the UCR Report’ s

“data on erosion depths and rates of land surface lowering due to sheet, rill,

landslide and gully erosion,” in “estimat[ing] the sediment yields from all the cut

and fill slopes that exist along the border road between Mojon II and Delta Costa

272
Rica.” Upon careful examination, however, the erosion rates they actually used

are, in many cases, not the UCR Report’s rates. A s shown by Dr. Kondolf, they

mixed-and-matched rates, applied unexplained and apparently arbitrary rate

increases (one of which they c all a “margin of safety”), and/or arbitrarily

substituted other rates. They did not present “a coherent scientific justification for

their seemingly random selection of rates to use in different contexts.” 273

2.110 The Mende and Astorga Inventory claims to be “a complete

inventory of all cut slopes, fill slopes, and wa tercourse intersections (crossings)

270Ibid.
271Although the Mende and Astorga Inventory is dated October 2013 and was apparently relied

upon in the preparation of the ICE Report that was submitted on 4 November 2013 in connection
with the hearings on Nicaragua’s request for the indication of provisional measures, the Mende
and Astorga Inventory was not submitted at that time.
272Mende & Astorga Inventory, p. 1 (CRCM, Vol. II, Annex 6).
2732014 Kondolf Report, Section 7 (NR, Vol. II, Annex 1). A careful reading of the Thorne report
reveals that he does not agree with the Astorga and Mende Inventory’s des cription of its own
method: “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…which are based on areas recorded in their 2013 inventory
of slopes and application of the erosiondepths reported in the 2013 UCR Report” (emphasis in
original). Dec. 2013 Thorne Report, pp. 78-79 (CRCM, Vol. I, Appendix A). have horizontal components. The resulting underestimation of “slope” area s is

significant because Drs. Mende and Astorga multiplied these areas by the erosion

rates discussed above to calculate the sediment y ields for each location. Their

inaccurately low areas thus resulted in inaccurately low estimates for each site.

Because those estimates are summed and incorporated directly into ICE’s

calculation of total erosion from the Road, the errors in the Mende a nd Astorga

278
Inventory impact the accuracy of Costa Rica’s total erosion estimate.

2.112 The Court need not take Nicaragua’s word for it. Drs. Mende and

Astorga have submitted an additional report, found at Annex 5 to the Counter -

Memorial, which disproves their own claim in Annex 6 that the total slope erosion

estimates contained in the latter report represent the “‘worst case ‘scenario.” 279

2.113 For instance, the first stream crossing discussed in Section A of this

Chapter is Dr. Kondolf’s Severely Eroding Site 9.4 (discussed at paragraphs 2.14-

2.24, above). The same site is identified as slope T -68 in the Mende and Astorga

Inventory, which estimates a total of 456 m 3 of erosion per year. 280 Using Costa

Rica’s conversion factor of 1.67, this equals approximately 762 t ons per year.

However, in Annex 5, Drs. Mende and Astorga conclude that the “Maximum

Sediment Production” for the same site is 2,250 tons (or approximately 1,347 m 3)

278See ICE Report, p. 30 (“cut and fill erosion is based o n the findings of Mende and Astorga”)

and Table 12 (in3orporating directly the Mende & Astorga Inventory’s estimate for erosion from
slopes: 36,580 m per year) (CRCM, Vol. 3I, Annex 4); compare with the sum in Appendix A of
279 Mende & Astorga Inventory (36,587 m per year) (CRCM, Vol. II, Annex 4, p. 408).
Mende & Astorga Inventory, p. 31 (CRCM, Vol. II, Annex 6).
280CRCM, Vol. II, p. 407 (lines T-68a + T-68b).

98have horizontal components. The resulting underestimation of “slope” area s is

significant because Drs. Mende and Astorga multiplied these areas by the erosion

rates discussed above to calculate the sediment y ields for each location. Their

inaccurately low areas thus resulted in inaccurately low estimates for each site.

Because those estimates are summed and incorporated directly into ICE’s

calculation of total erosion from the Road, the errors in the Mende a nd Astorga

278
Inventory impact the accuracy of Costa Rica’s total erosion estimate.

2.112 The Court need not take Nicaragua’s word for it. Drs. Mende and

Astorga have submitted an additional report, found at Annex 5 to the Counter -

Memorial, which disproves their own claim in Annex 6 that the total slope erosion

estimates contained in the latter report represent the “‘worst case ‘scenario.” 279

2.113 For instance, the first stream crossing discussed in Section A of this

Chapter is Dr. Kondolf’s Severely Eroding Site 9.4 (discussed at paragraphs 2.14-

2.24, above). The same site is identified as slope T -68 in the Mende and Astorga

Inventory, which estimates a total of 456 m 3 of erosion per year. 280 Using Costa

Rica’s conversion factor of 1.67, this equals approximately 762 t ons per year.

However, in Annex 5, Drs. Mende and Astorga conclude that the “Maximum

Sediment Production” for the same site is 2,250 tons (or approximately 1,347 m 3)

278See ICE Report, p. 30 (“cut and fill erosion is based o n the findings of Mende and Astorga”)

and Table 12 (in3orporating directly the Mende & Astorga Inventory’s estimate for erosion from
slopes: 36,580 m per year) (CRCM, Vol. 3I, Annex 4); compare with the sum in Appendix A of
279 Mende & Astorga Inventory (36,587 m per year) (CRCM, Vol. II, Annex 4, p. 408).
Mende & Astorga Inventory, p. 31 (CRCM, Vol. II, Annex 6).
280CRCM, Vol. II, p. 407 (lines T-68a + T-68b). 285
Road to populated areas. According to publishe d reports, these access roads

cover as much as 440 kilometers. 286The extent of the new construction or repairs

287
-- involving stretches of “significant works” -- is visible in Figure 2.39, which

appeared as Sketch Map 4 in Costa Rica’s Counter-Memorial.

Figure 2.39. Costa Rica’s Sketch Map 4 from the Counter-Memorial: “Transport Network in the
Area After Construction of Route 1856,” with access roads indicated in red.

2.117 Costa Rica’s eros ion estimate does not consider the sediment

contribution of any of these roads. This creates a misleading impression of the

amount of Road -related sediment that enters the San Juan River. Since these

access roads are located in catchments that drain into t he River, sediment from

285
CRCM paras. 2.25, 2.30.
286NM, Vol. II Annex 31 (Statement attributed to CONAVI in Costa Rican news)
287NM, Vol. II, Annex 34 (CONAVI Press Release)

100 285
Road to populated areas. According to publishe d reports, these access roads

cover as much as 440 kilometers. 286The extent of the new construction or repairs

287
-- involving stretches of “significant works” -- is visible in Figure 2.39, which

appeared as Sketch Map 4 in Costa Rica’s Counter-Memorial.

Figure 2.39. Costa Rica’s Sketch Map 4 from the Counter-Memorial: “Transport Network in the
Area After Construction of Route 1856,” with access roads indicated in red.

2.117 Costa Rica’s eros ion estimate does not consider the sediment

contribution of any of these roads. This creates a misleading impression of the

amount of Road -related sediment that enters the San Juan River. Since these

access roads are located in catchments that drain into t he River, sediment from

285
CRCM paras. 2.25, 2.30.
286NM, Vol. II Annex 31 (Statement attributed to CONAVI in Costa Rican news)
287NM, Vol. II, Annex 34 (CONAVI Press Release) and Astorga I nventory). It thus ignores sediment contributed by f ailing stream

crossings like the ones discussed in Section A of this Chapter. For example, the

failed stream crossing located in the flat stretch of Road 20.3 km downstream

from Mojon II, which contributed over 800 tons of fill material into the River and

created a large delta (depicted in Figures 2.13, 2.14 and 2.24 above) is excluded

from Costa Rica’s estimate.

3. Costa Rica’s Flawed Sediment Load Estimate

2.120 Equally unreliable are Costa Rica’s claims regarding the total

sediment load of the River, which it u ses to suggest that the contribution from the

Road is relatively minor. In that regard, the Counter -Memorial makes the

remarkable assertion that “[t]he sediment load carried by the San Juan in the

period since construction of the Road is actually lower than it was before the Road

292
was constructed.” This claim, which is base d on a comparision of limited data

collected in the 1970s with equally limited data from the post-construction period,

is deeply flawed. The “detailed study” that purportedly forms the basis for Costa

Rica’s remarkable contention is the ICE Report. However, as Dr. Andrews

explains, this contains “numerous examples of insufficient and poor quality

hydrologic information, incorrect and improper analysis, and unsupported or

293
wrong conclusions.”

29CRCM, paras. 3.14 & 3.76(a) (emphasis in original).
29Andrews Report, Section V(B) (NR, Vol. II, Annex 3).

102and Astorga I nventory). It thus ignores sediment contributed by f ailing stream

crossings like the ones discussed in Section A of this Chapter. For example, the

failed stream crossing located in the flat stretch of Road 20.3 km downstream

from Mojon II, which contributed over 800 tons of fill material into the River and

created a large delta (depicted in Figures 2.13, 2.14 and 2.24 above) is excluded

from Costa Rica’s estimate.

3. Costa Rica’s Flawed Sediment Load Estimate

2.120 Equally unreliable are Costa Rica’s claims regarding the total

sediment load of the River, which it u ses to suggest that the contribution from the

Road is relatively minor. In that regard, the Counter -Memorial makes the

remarkable assertion that “[t]he sediment load carried by the San Juan in the

period since construction of the Road is actually lower than it was before the Road

292
was constructed.” This claim, which is base d on a comparision of limited data

collected in the 1970s with equally limited data from the post-construction period,

is deeply flawed. The “detailed study” that purportedly forms the basis for Costa

Rica’s remarkable contention is the ICE Report. However, as Dr. Andrews

explains, this contains “numerous examples of insufficient and poor quality

hydrologic information, incorrect and improper analysis, and unsupported or

293
wrong conclusions.”

292CRCM, paras. 3.14 & 3.76(a) (emphasis in original).
293Andrews Report, Section V(B) (NR, Vol. II, Annex 3). 2.124 Such temporally limited flow records and so few suspended

sediment samples, he concludes, are “insufficient and cannot be relied upon to

make informed decisions.” 296

2.125 Second, the da ta relied upon by Costa Rica cannot support its

conclusions because river flows and suspended sediment loads vary considerably

from year to year. Consequently, in comparing data from two short periods, one

cannot determine whether differences indicate a change over time, or are the result

of abnormal river flows and/or sediment loads during one or both periods. This is

an especially relevant consideration where, as here, one sampled period may have

297
been unusually rainy, while the other may have been unusually dry. In that

connection, Dr. Andrews observes that “hydrologic conditions in the Rio San Juan

basin were quite different” in the 40 years that separated the operation of the “ La

298
Trinidad and the Delta Colorado gages .” The ICE Report and Professor

Thorne, however, fail to account for this variability, an omission that is surprising

296
297Ibid.
Ibid., Section V(E).
298Ibid., Section V(D). In fact, the much more robust and useful data provided in the ICE Report
for other gages – those not on the San Juan River or its Colorado distribut– demonstrate that
the period in the 1970s when the La Trinidad gage was operate d was wetter than average,
involving higher than average river flows(103%) and substantially higher sediment concentrations
than the long-term mean (163%). The opposite is true with regard to the Delta Colorado station,

which was operated at a time with below-average river flows (85%) and suspended sediment loads
far below average (46%). Ibid., Section V(E). Accordingly, these datasets “should not be
compared directly or serve as the basis for conclusions.”Ibid., Section V(D). As Dr. Andrews
explains, their “apparent similarity” is “solely an artifact of the hydrologic conditions during the
brief periods, nearly 40 years apart, when these gages were operated.” Ibid., Section V(E).

104 2.124 Such temporally limited flow records and so few suspended

sediment samples, he concludes, are “insufficient and cannot be relied upon to

make informed decisions.” 296

2.125 Second, the da ta relied upon by Costa Rica cannot support its

conclusions because river flows and suspended sediment loads vary considerably

from year to year. Consequently, in comparing data from two short periods, one

cannot determine whether differences indicate a change over time, or are the result

of abnormal river flows and/or sediment loads during one or both periods. This is

an especially relevant consideration where, as here, one sampled period may have

297
been unusually rainy, while the other may have been unusually dry. In that

connection, Dr. Andrews observes that “hydrologic conditions in the Rio San Juan

basin were quite different” in the 40 years that separated the operation of the “ La

298
Trinidad and the Delta Colorado gages .” The ICE Report and Professor

Thorne, however, fail to account for this variability, an omission that is surprising

296
297Ibid.
Ibid., Section V(E).
298Ibid., Section V(D). In fact, the much more robust and useful data provided in the ICE Report
for other gages – those not on the San Juan River or its Colorado distribut– demonstrate that
the period in the 1970s when the La Trinidad gage was operate d was wetter than average,
involving higher than average river flows(103%) and substantially higher sediment concentrations
than the long-term mean (163%). The opposite is true with regard to the Delta Colorado station,

which was operated at a time with below-average river flows (85%) and suspended sediment loads
far below average (46%). Ibid., Section V(E). Accordingly, these datasets “should not be
compared directly or serve as the basis for conclusions.”Ibid., Section V(D). As Dr. Andrews
explains, their “apparent similarity” is “solely an artifact of the hydrologic conditions during the
brief periods, nearly 40 years apart, when these gages were operated.” Ibid., Section V(E). 303
moment varies appreciably from bank to bank and from river bed to surface.”

The appropriate methodology to account for this physical reality has be en

304
established for decades an d is used worldwide. It requires “collecting

discharge-weighted samples of the flow at many verticals across the river

305
channel,” which are combined to form one suspended sediment sample. Thus,

according to Dr. Andrews, “one and one -half to two hours w ill be required to

collect a representative sample of suspended sediment at a channel as wide as

306
exists near the Delta Colorado gage.”

2.128 The data presented in the ICE Report , however, demonstrate that,

on at least three occasions, ICE’s samples cannot have b een properly collected.

On each of those dates, two suspended sediment samples are reported as having

been collected less than ten minutes apart. Dr. Andrews explains: “It is physically

impossible to collect a representative sample of suspended sediment from a river

cross-section that is several hundred meters wide in just a few minutes. The

307
samples collected on these dates are invalid and cannot be relied upon.”

2.129 Further, there is no basis for assuming that any of the other

suspended sediment samples collected by ICE at the Delta station were properly

collected, as no information has been provided regarding the methods or

equipment used to carry out the sampling. Dr. Andrews observes:

303
304Ibid., Section V(B).
Ibid.
305Ibid.
306Ibid., Section V(K).
307Ibid.

106 303
moment varies appreciably from bank to bank and from river bed to surface.”

The appropriate methodology to account for this physical reality has be en

304
established for decades an d is used worldwide. It requires “collecting

discharge-weighted samples of the flow at many verticals across the river

305
channel,” which are combined to form one suspended sediment sample. Thus,

according to Dr. Andrews, “one and one -half to two hours w ill be required to

collect a representative sample of suspended sediment at a channel as wide as

306
exists near the Delta Colorado gage.”

2.128 The data presented in the ICE Report , however, demonstrate that,

on at least three occasions, ICE’s samples cannot have b een properly collected.

On each of those dates, two suspended sediment samples are reported as having

been collected less than ten minutes apart. Dr. Andrews explains: “It is physically

impossible to collect a representative sample of suspended sediment from a river

cross-section that is several hundred meters wide in just a few minutes. The

307
samples collected on these dates are invalid and cannot be relied upon.”

2.129 Further, there is no basis for assuming that any of the other

suspended sediment samples collected by ICE at the Delta station were properly

collected, as no information has been provided regarding the methods or

equipment used to carry out the sampling. Dr. Andrews observes:

303
304Ibid., Section V(B).
Ibid.
305Ibid.
306Ibid., Section V(K).
307Ibid. rolls along the river bed. 311 As Dr. Andrews explains, bedload “accumulate[s] on

the river bed when the flow slackens” and is primarily responsible (together with

the coarsest suspended sediment) for “the growth of sandbars and the restriction

312
of navigation in the delta channels.”

2.132 The ICE Report claims to have calculated the bedload in the

Colorado River using a complicated equation, coming up with a value of

2,488,000 tons per year. However, this figure is unreasonably high given the

313
normal behavior of sediment in rivers. As Dr. Andrews explains, ICE’s

calculations are substantially exaggerated because they assume an excessively

314
steep river slope, a figure that is approximately 60% too high for the San Juan.

Slope is an important variable in river processes, because the steeper the slope, the

greater the energy available to erode and transport sediment. When this error is

corrected, bedload is closer to 330,000 tons per year, less than one -seventh of

315
Costa Rica’s estimate. This exaggeration of bedload means that Costa Rica’s

total sediment load calculations, which incorporate its erroneous bedload

figures,316 are likewise exaggerated.

2.133 An additional point about slope values is important to appreciate.

Professor Thorne presents what he says are river slopes in Table 1 of h is report.

311
312Ibid., Section V(G).
Ibid.
313Ibid., Section V(H).
314Ibid.
315Ibid.
316
CRCM. para. 3.27.

108rolls along the river bed. 311 As Dr. Andrews explains, bedload “accumulate[s] on

the river bed when the flow slackens” and is primarily responsible (together with

the coarsest suspended sediment) for “the growth of sandbars and the restriction

312
of navigation in the delta channels.”

2.132 The ICE Report claims to have calculated the bedload in the

Colorado River using a complicated equation, coming up with a value of

2,488,000 tons per year. However, this figure is unreasonably high given the

313
normal behavior of sediment in rivers. As Dr. Andrews explains, ICE’s

calculations are substantially exaggerated because they assume an excessively

314
steep river slope, a figure that is approximately 60% too high for the San Juan.

Slope is an important variable in river processes, because the steeper the slope, the

greater the energy available to erode and transport sediment. When this error is

corrected, bedload is closer to 330,000 tons per year, less than one -seventh of

315
Costa Rica’s estimate. This exaggeration of bedload means that Costa Rica’s

total sediment load calculations, which incorporate its erroneous bedload

figures,316 are likewise exaggerated.

2.133 An additional point about slope values is important to appreciate.

Professor Thorne presents what he says are river slopes in Table 1 of h is report.

311
312Ibid., Section V(G).
Ibid.
313Ibid., Section V(H).
314Ibid.
315Ibid.
316
CRCM. para. 3.27. 2.135 The “length” and “fall in elevation” values presented by Professor

Thorne should lead to slope calculations between 0.000123 (0.0123%) and

0.000173 (0.0173%). Professor Thorne’s slope values , however, are exaggerated

by a factor of 55-58. This leads Professor Thorne to the mistaken conclusion that

the slopes are as high as one percent in two reaches, and just below one percent

(0.7-0.9%) in the other three reaches. As Dr. Kondolf observes, “Experienced

geomorphologists would recognize 1 percent as an extremely high slope for a

large river.”319

2.136 The implications of Professor Thorne’s slope err or are significant.

The use of an exaggerated slope when calculating bedload produces not only an

exaggerated bedload figure, but also an exaggerated total load figure. This is

what has happened here: exaggera ted slope values led to an exaggerated bedload

figures in Costa Rica’s reports and, consequently, exaggerated total load

estimates. This, in turn, led Costa Rica to underestimate the relative portion of

sediment in the River that is attributable to the Road. 320

319
320Ibid.
It is surprising that Professor Thorne incorporates so much the ICE Report’s fladata and
unjustified conclusions into his own reportBut what is even more surprising is that Professor
Thorne claims to have played a key role in the preparation of this deeply flawed document, as well
as that of the equally flawed documents describedabove which form the basis for Costa Rica’s
unreasonably low estimate of how much sediment from the Road is making its way into the San
Juan River. Professor Thorne says that he “requested, formulated and supervised” the preparation
of these “scientific and technical studies,” “participated in technical meetings” with the authors of
those reports “during which [they] discussed approaches and methodologies to be employed in

performing the work, reviewed progress and discussed the results,” and “reviewed the preliminary
findings of the team, requesting additional analyses where appropriateHe characterizes all of
Costa Rica’s “scientific and technical” reports as being “the outcomes of this supervised research
process.” Thorne, para. 3.3.Their many errors and inaccuracies are, accordingly, attributable not
only to the government employees who authored them, but to him as well.

110 2.135 The “length” and “fall in elevation” values presented by Professor

Thorne should lead to slope calculations between 0.000123 (0.0123%) and

0.000173 (0.0173%). Professor Thorne’s slope values , however, are exaggerated

by a factor of 55-58. This leads Professor Thorne to the mistaken conclusion that

the slopes are as high as one percent in two reaches, and just below one percent

(0.7-0.9%) in the other three reaches. As Dr. Kondolf observes, “Experienced

geomorphologists would recognize 1 percent as an extremely high slope for a

large river.”319

2.136 The implications of Professor Thorne’s slope err or are significant.

The use of an exaggerated slope when calculating bedload produces not only an

exaggerated bedload figure, but also an exaggerated total load figure. This is

what has happened here: exaggera ted slope values led to an exaggerated bedload

figures in Costa Rica’s reports and, consequently, exaggerated total load

estimates. This, in turn, led Costa Rica to underestimate the relative portion of

sediment in the River that is attributable to the Road. 320

319
320Ibid.
It is surprising that Professor Thorne incorporates so much the ICE Report’s fladata and
unjustified conclusions into his own reportBut what is even more surprising is that Professor
Thorne claims to have played a key role in the preparation of this deeply flawed document, as well
as that of the equally flawed documents describedabove which form the basis for Costa Rica’s
unreasonably low estimate of how much sediment from the Road is making its way into the San
Juan River. Professor Thorne says that he “requested, formulated and supervised” the preparation
of these “scientific and technical studies,” “participated in technical meetings” with the authors of
those reports “during which [they] discussed approaches and methodologies to be employed in

performing the work, reviewed progress and discussed the results,” and “reviewed the preliminary
findings of the team, requesting additional analyses where appropriateHe characterizes all of
Costa Rica’s “scientific and technical” reports as being “the outcomes of this supervised research
process.” Thorne, para. 3.3.Their many errors and inaccuracies are, accordingly, attributable not
only to the government employees who authored them, but to him as well.112 CHAPTER 3

THE RISK OF HARM TO NICARAGUA

3.1 In the previous Chapter, Nicaragua showed the real and substantial

transboundary harm already caused to it by Costa Rica’s hasty and negligent

construction of Route 1856. In this Chapter, Nicaragua responds to Costa Rica’s

claim that the Road does not pose a significant risk of further transboundary harm.

Section A describes the risks to which Nicaragua has been exposed by Costa

Rica’s failure to comply with the relevant standard s for the design, construction

and maintenance of roads, including the Central American standards Costa Rica

itself helped develop. Section B refutes the contention that Costa Rica has

undertaken adequate mitigation measures. Finally, in Sections C , D an d E,

Nicaragua addresses additional risks posed by the Road, including from spills of

toxic substances transported on the Road (C), from further development along the

Costa Rican bank of the River (D), and from natural disasters, including

hurricanes, tropical storms and earthquakes (E).

A. THE RISKS POSED BY COSTA RICA’S CONTINUING
FAILURE TO COMPLY WITH ROAD CONSTRUCTION

STANDARDS

3.2 Costa Rica acknowledges that many sections of the Road are

currently in a “rudimentary condition,”321 the Counter-Memorial’s euphemistic

description of the Road’s failing slopes and stream crossings. The significant

harms these deficiencies have caused to Nicaragua, and the serious risks they

321
CRCM, para. 2.26.

113 continue to pose are the direct result of Costa Rica’s near total failure to abide by

international, regional, and Costa Rican standards for how roads should be

designed, constructed, and maintained. As Mr. Hagans and Dr. Weaver explain,

Costa Rica has violated “the most basic, well accepted road engineering and road

322
maintenance principles nor mally applied during road construction.” In their

view:

“Costa Rica’s poor (or absent) design and construction
standards, and the apparent lack of construction engineering

oversight during road building, are completely contrary to
modern road constructio n standards found in any design
manual in the last 30 years.” 323

3.3 Among the standards violated by Costa Rica are those agreed to by

the Ministries of Transportation of the Governments of Nicaragua, Costa Rica,

Guatemala, Honduras and El Salvador, which are set out in manuals developed by

the Secretariat for the Economic Integration of Central America. 324 These

manuals establish the regional standards for highway design, construction and

maintenance, as well as environmental norms for the prevention, mitigation, and

correction of road-related impacts. Costa Rica’s continuing violation of them puts

Nicaragua at risk.

322
323Hagans and Weaver Report, Section III.D (NR, Vol. II, Annex 2).
324Ibid., Section II.E.
These include the following four manuals: Central American Manual of Environmental Norms
for the Design, Construction and Maintenance of Roads (Nov. 2002); Central American Manual of
Specifications for the Construction of Regional Roads and Bridges (2nd. Edition, Mar. 204);
Central American Manual on the Maintenance of Roads (2010 Edition); Central American Manual
of Norms for the Geometric Design of Roads (3rd. Edition 2011). See Affidavit of Ana Isabel
Izaguirre Amador, 18 July 2014 (NR, Vol. II, Annex 14).

114continue to pose are the direct result of Costa Rica’s near total failure to abide by

international, regional, and Costa Rican standards for how roads should be

designed, constructed, and maintained. As Mr. Hagans and Dr. Weaver explain,

Costa Rica has violated “the most basic, well accepted road engineering and road

322
maintenance principles nor mally applied during road construction.” In their

view:

“Costa Rica’s poor (or absent) design and construction
standards, and the apparent lack of construction engineering

oversight during road building, are completely contrary to
modern road constructio n standards found in any design
manual in the last 30 years.” 323

3.3 Among the standards violated by Costa Rica are those agreed to by

the Ministries of Transportation of the Governments of Nicaragua, Costa Rica,

Guatemala, Honduras and El Salvador, which are set out in manuals developed by

the Secretariat for the Economic Integration of Central America. 324 These

manuals establish the regional standards for highway design, construction and

maintenance, as well as environmental norms for the prevention, mitigation, and

correction of road-related impacts. Costa Rica’s continuing violation of them puts

Nicaragua at risk.

322
323Hagans and Weaver Report, Section III.D (NR, Vol. II, Annex 2).
324Ibid., Section II.E.
These include the following four manuals: Central American Manual of Environmental Norms
for the Design, Construction and Maintenance of Roads (Nov. 2002); Central American Manual of
Specifications for the Construction of Regional Roads and Bridges (2nd. Edition, Mar. 204);
Central American Manual on the Maintenance of Roads (2010 Edition); Central American Manual
of Norms for the Geometric Design of Roads (3rd. Edition 2011). See Affidavit of Ana Isabel
Izaguirre Amador, 18 July 2014 (NR, Vol. II, Annex 14). National Laboratory of the University of C osta Rica (“LANAMME”) concluded

327
that the Road “was done without any basic geometric design,” and it “failed to

follow basic engineering practices during planning and implementation.” Costa

Rica’s design omissions included, among other things that Costa R ica failed to

perform: “land survey for road layout; critical point geotechnical assessment;

drainage structure location, design, and construction; defining suitable and

uniform technical standards; inspection deficiency.” 328 Other Costa Rican reports

echoed these conclusions. 329

3.7 Dr. Kondolf likewise highlights Costa Rica’s failure to design the

Road, observing that “[i]t is apparent that bulldozer operators would simply ‘wing

it,’ in many places attempting to put the road up steep slopes that in a normal road

building project, with standard engineering and environmental safeguards, would

330
never have been selected for a road in the first place.” This often occurred very

331
near the San Juan River, despite Costa Rican regulations dictating minimum

buffer zones. 332

327LANAMME Report, pp. 50-51 (NM, Vol. II, Annex 3).
328Ibid., p. 50.
329 CFIA Report, p. 25: “The project has no plans or prel iminary studies…. The route was
constructed without a single plan to indicate the path that was to be opened, or what its

characteristics should have been. This situation causes increased costs, environmental problems,
and a rapid deterioration of the pro ject.” CONAVI, acknowledging that the project was not
“subjected to the procedures for development of infrastructure projects that take into account, for
example, stages of conceptualization, feasibility, design and management of the work.” (NM, Vol.
II, Annex 4.)
3302014 Kondolf Report, Section 4 (NR, Vol. II, Annex 1).
3312012 Kondolf Report, p. 23 (explaining that nearly half of the Road is within 100 meters of the

332er bank, with 30% within 50 meters) (NM, Vol. I, Annex 1).
See ibid., p. 8.

116National Laboratory of the University of C osta Rica (“LANAMME”) concluded

327
that the Road “was done without any basic geometric design,” and it “failed to

follow basic engineering practices during planning and implementation.” Costa

Rica’s design omissions included, among other things that Costa R ica failed to

perform: “land survey for road layout; critical point geotechnical assessment;

drainage structure location, design, and construction; defining suitable and

uniform technical standards; inspection deficiency.” 328 Other Costa Rican reports

echoed these conclusions. 329

3.7 Dr. Kondolf likewise highlights Costa Rica’s failure to design the

Road, observing that “[i]t is apparent that bulldozer operators would simply ‘wing

it,’ in many places attempting to put the road up steep slopes that in a normal road

building project, with standard engineering and environmental safeguards, would

330
never have been selected for a road in the first place.” This often occurred very

331
near the San Juan River, despite Costa Rican regulations dictating minimum

buffer zones. 332

327LANAMME Report, pp. 50-51 (NM, Vol. II, Annex 3).
328Ibid., p. 50.
329CFIA Report, p. 25: “The project has no plans or prel iminary studies…. The route was
constructed without a single plan to indicate the path that was to be opened, or what its

characteristics should have been. This situation causes increased costs, environmental problems,
and a rapid deterioration of the pro ject.” CONAVI, acknowledging that the project was not
“subjected to the procedures for development of infrastructure projects that take into account, for
example, stages of conceptualization, feasibility, design and management of the work.” (NM, Vol.
II, Annex 4.)
3302014 Kondolf Report, Section 4 (NR, Vol. II, Annex 1).
3312012 Kondolf Report, p. 23 (explaining that nearly half of the Road is within 100 meters of the

332er bank, with 30% within 50 meters) (NM, Vol. I, Annex 1).
See ibid., p. 8. because roads “disturb pre -existing natural drainage patterns, increasing storm

runoff from a given rainfall, and more importantly, concentrating surface runoff

such that it is capable of eroding gullies and transporting sediment and

335
contaminants to surrounding river systems.”

3.9 The relevant standards preclude, among other things, “side

casting.” This is where a “bulldozer blade simply push[es] material (removed

336
from the cutbank) ‘over the edge’ so that it tumbles down the bank.”

Sidecasting rends a project prone to erosion and landsliding, especially if the

underlying slope was not prop erly cleared or if debris is allowed to persist in the

sidecast fill. 337 For that reason, LANAMME and Costa Rica’s professional

association of engineers and architects (or “CFIA,” by its Spanish acronym) have

the maximum density.”; Article 204.10, p. 200 -13 “Construction of fillslope. Add in the fillslope
only adequate material excavated from the track”; and Article 704.03, p. 700 -33: “Use granular
material and fine soil free of excess of moisture, mud, roots, seeds, and other deleterious materials.

335 particles of rock and hard soil lumps larger than 75mm must be removed”.
2012 Kondolf Report, p. 4 (NM, Vol. II, Annex 1). See Central American Manual of Norms
for the Geometric Design of Roads (3rd. Edition 2011) (NR, Vol. II, Annex 13) , Section 8.1.4, p.
305: “Water is one of the elements that causes major problems on the roads and paths because it
decreases the resistance of soils, creating failures in fillslopes, cuts and bearsurfaces. This is
why it is necessary to build efficient drainage to drain the water away from the project in the

shortest amount of time.” See also Central American Manual of Specifications for the
Construction of Regional Roads and Bridges (2nd. Edition 2004) (NR, Vol. II, Annex 11), Section
602, p. 600 -5: Culverts and drainage; Article 602.03, p. 600 -5: “General Requirements for
Construction. Use the same materials and coatings on all the sections of continuous pipe
extensions and special sections.” See also Central American Manual on the Maintenance of Roads
(2010 Edition) (NR, Vol. II, Annex 12) , Section 802.01, p 192: “Cleaning of Culverts and other

drainage structures. This activity consists of the collection, extraction and removal of all material s
which have been deposited in the section of the sewers, boxes and input and output channels,
regardless of their respective dimension, including the cleaning and removal of all material found
in other elements that make up the soil. It is necessary to ke ep in mind that these tasks are
designed to achieve the fast channeling of the water through these systems.”
3362012 Kondolf Report, p. 11 (NM, Vol. II, Annex 1).

337
Ibid.

118because roads “disturb pre -existing natural drainage patterns, increasing storm

runoff from a given rainfall, and more importantly, concentrating surface runoff

such that it is capable of eroding gullies and transporting sediment and

335
contaminants to surrounding river systems.”

3.9 The relevant standards preclude, among other things, “side

casting.” This is where a “bulldozer blade simply push[es] material (removed

336
from the cutbank) ‘over the edge’ so that it tumbles down the bank.”

Sidecasting rends a project prone to erosion and landsliding, especially if the

underlying slope was not prop erly cleared or if debris is allowed to persist in the

sidecast fill. 337 For that reason, LANAMME and Costa Rica’s professional

association of engineers and architects (or “CFIA,” by its Spanish acronym) have

the maximum density.”; Article 204.10, p. 200 -13 “Construction of fillslope. Add in the fillslope
only adequate material excavated from the track”; and Article 704.03, p. 700 -33: “Use granular
material and fine soil free of excess of moisture, mud, roots, seeds, and other deleterious materials.

335 particles of rock and hard soil lumps larger than 75mm must be removed”.
2012 Kondolf Report, p. 4 (NM, Vol. II, Annex 1). See Central American Manual of Norms
for the Geometric Design of Roads (3rd. Edition 2011) (NR, Vol. II, Annex 13) , Section 8.1.4, p.
305: “Water is one of the elements that causes major problems on the roads and paths because it
decreases the resistance of soils, creating failures in fillslopes, cuts and beasurfaces. This is
why it is necessary to build efficient drainage to drain the water away from the project in the

shortest amount of time.” See also Central American Manual of Specifications for the
Construction of Regional Roads and Bridges (2nd. Edition 2004) (NR, Vol. II, Annex 11), Section
602, p. 600 -5: Culverts and drainage; Article 602.03, p. 600 -5: “General Requirements for
Construction. Use the same materials and coatings on all the sections of continuous pipe
extensions and special sections.” See also Central American Manual on the Maintenance of Roads
(2010 Edition) (NR, Vol. II, Annex 12) , Section 802.01, p 192: “Cleaning of Culverts and other

drainage structures. This activity consists of the collection, extraction and removal of all material s
which have been deposited in the section of the sewers, boxes and input and output channels,
regardless of their respective dimension, including the cleaning and removal of all material found
in other elements that make up the soil. It is necessary to ke ep in mind that these tasks are
designed to achieve the fast channeling of the water through these systems.”
3362012 Kondolf Report, p. 11 (NM, Vol. II, Annex 1).

337
Ibid. explains,“[t]hese are inherently unstable features, because they involve placement

of massive volumes of fill within the stream channel and valley, where it can

easily be eroded and enter the river system, and depend on the culvert to

successfully pass all flood flows through a constr icting pipe.” 343 Proper

construction of such crossings requires, among other things, a strong culvert that

is large enough to allow high flows. This must be placed “on the original

streambed, aligned with the natural stream channel above and below the cros sing

site,” and put in a location where it will not erode the fill, which itself must be

“compacted to engineering standards so that it can bear the weight of the

344
anticipated traffic.”

3.12 LANAMME criticized Costa Rica’s defective stream crossings,

and urged that they be “replaced as soon as possible with culverts properly

designed according to ... each stream flow rate to prevent eventual road

embankment damage during the rainy season.” 345 CFIA came to the same

conclusion, recommending replacement of Costa Ri ca’s existing stream crossings

because the “wooden logs, trailer containers and drainages that are being used as

343
344Ibid.
Ibid. See Central American Manual of Specifications for the Construction of Regional Roads
and Bridges (2nd. Edition, 2004) (NR, Vol. II, Annex 11), Article 602.04, p. 600-6: “Placement of
concrete pipe and precast reinforced concrete boxes for culverts. Start by placing on the site of the
lower outlet and place the bell or groove upstream. Fill all joint s of sections completely. Place the
circular elliptical reinforcing steel tubing, with the minor axis of the reinforcement, vertical. Build
boards according to one of the following methods.”
345LANAMME Report, p. 40 (NM, Vol. II, Annex 3).

120explains,“[t]hese are inherently unstable features, because they involve placement

of massive volumes of fill within the stream channel and valley, where it can

easily be eroded and enter the river system, and depend on the culvert to

successfully pass all flood flows through a constr icting pipe.” 343 Proper

construction of such crossings requires, among other things, a strong culvert that

is large enough to allow high flows. This must be placed “on the original

streambed, aligned with the natural stream channel above and below the cros sing

site,” and put in a location where it will not erode the fill, which itself must be

“compacted to engineering standards so that it can bear the weight of the

344
anticipated traffic.”

3.12 LANAMME criticized Costa Rica’s defective stream crossings,

and urged that they be “replaced as soon as possible with culverts properly

designed according to ... each stream flow rate to prevent eventual road

embankment damage during the rainy season.” 345 CFIA came to the same

conclusion, recommending replacement of Costa Ri ca’s existing stream crossings

because the “wooden logs, trailer containers and drainages that are being used as

343
344Ibid.
Ibid. See Central American Manual of Specifications for the Construction of Regional Roads
and Bridges (2nd. Edition, 2004) (NR, Vol. II, Annex 11), Article 602.04, p. 600-6: “Placement of
concrete pipe and precast reinforced concrete boxes for culverts. Start by placing on the site of the
lower outlet and place the bell or groove upstream. Fill all joint s of sections completely. Place the
circular elliptical reinforcing steel tubing, with the minor axis of the reinforcement, vertical. Build
boards according to one of the following methods.”
345LANAMME Report, p. 40 (NM, Vol. II, Annex 3). emphasizes the substandard nature of these works and the risk they create for

Nicaragua:

“It is not ‘typical’ to have multiple stream cross ings fail
within the first few years after construction. It is not

‘typical’ to have multiple fill slopes fail within a year or
two of construction, nor to have massive gullies develop on
fill slopes and stream -crossing fills. In the US, such

violations result in severe penalties for the perpetrators, and
we would hardly consider these destructive actions
‘typical’. They represent a level of incompetence and
blatant disregard for environment and safety that has

already impacted the Rio San Juan, and poses even more
significant threats from future contamination by chemical
spills … and massive failures triggered by future intense
350
rains or earthquakes.”

3.15 Dr. Kondolf pointed out these problems in his 2012 Report, 351 and

predicted that “[s]tream crossing failur es will occur when storm flows cause

culverts to plug or culvert capacity to be exceeded, and the fill is eroded or the

stream is diverted onto adjacent, unprotected hillslopes leading to the Río San

Juan,” causing “road and hillslope gullies that will res ult in additional volumes of

gully erosion and sediment delivery to the receiving tributaries and to the Río San

352
Juan.” This is exactly what has happened, as described in Section A of this

Chapter, above . It is bound to happen again (and again), unless a nd until

necessary remediation is performed by Costa Rica at all vulnerable sites.

350
Ibid. (emphasis added).
3512012 Kondolf Report, pp. 30-34 (NM, Vol. II, Annex 1).
352Ibid., p. 30.

122emphasizes the substandard nature of these works and the risk they create for

Nicaragua:

“It is not ‘typical’ to have multiple stream cross ings fail
within the first few years after construction. It is not

‘typical’ to have multiple fill slopes fail within a year or
two of construction, nor to have massive gullies develop on
fill slopes and stream -crossing fills. In the US, such

violations result in severe penalties for the perpetrators, and
we would hardly consider these destructive actions
‘typical’. They represent a level of incompetence and
blatant disregard for environment and safety that has

already impacted the Rio San Juan, and poses even more
significant threats from future contamination by chemical
spills … and massive failures triggered by future intense
350
rains or earthquakes.”

3.15 Dr. Kondolf pointed out these problems in his 2012 Report, 351 and

predicted that “[s]tream crossing failur es will occur when storm flows cause

culverts to plug or culvert capacity to be exceeded, and the fill is eroded or the

stream is diverted onto adjacent, unprotected hillslopes leading to the Río San

Juan,” causing “road and hillslope gullies that will res ult in additional volumes of

gully erosion and sediment delivery to the receiving tributaries and to the Río San

352
Juan.” This is exactly what has happened, as described in Section A of this

Chapter, above . It is bound to happen again (and again), unless a nd until

necessary remediation is performed by Costa Rica at all vulnerable sites.

350
Ibid. (emphasis added).
3512012 Kondolf Report, pp. 30-34 (NM, Vol. II, Annex 1).
352Ibid., p. 30. however, belie its promises, and make plain that Nicaragua remains at serious risk

because effective remediation is still not taking place.

3.17 The Counter-Memorial asserts that “Costa Rica has taken a series

of measures designed to lessen the environmental impact of the Border Road,” but

denies any remediation is needed to mitigate risks to Nicaragua because, it

contends, the project’s impacts are felt exclusively in Costa Rica. This claim,

however, is amply refuted by the facts presented in the previous Chapter showing

the harm to Nicaragua that has already occurred. It is also disproven by the

“Environmental Management Plan” 357 that Costa Rica produce d in April 2012

(henceforth the “2012 EMP” 358).

359
3.18 Although Nicaragua addressed the 2012 EMP in its Memorial,

Costa Rica’s Counter-Memorial conspicuously avoids any mention of it. Included

in the 2012 EMP is a table of color -coded “Priority” remediation works 360 which

Rica’s argument about a purported “em ergency” is refuted in Chapter 6 . For now, it suffices to
note that, by implementing these “temporary” solutions – in violation of standard practices – and
by leaving them in place for an extended period of time, Costa Rica has failed to meet even its
own putat ive objectives since collapsed slopes and stream crossings impede safe access and
interrupt the “continuous thoroughfare” Costa Rica claims to have needed to construct on an
emergency basis.
357 As the Golder Report explains, proper Environmental Management Plans (EMPs) are an

offshoot of an EIA process, and they are “the framework to ensure that all issues identified during
the [EIA] process are addressed through appropriate mitigation and monitoring .” Golder Report,
Section 5 (NR, Vol. II, Annex 6). Costa Rica’s EMP was not the product of an EIA, as no EIA
was ever conducted.
358 Costa Rican Ministry of Environment, Energy and Telecommunications, National

Conservation Area System, Ministry of Public Works and Transportation, National Road Council,
and Nation al Risk Prevention and Emergency Response Commission, “Environmental
Management Plan: Juan Rafael Mora Porras Road,” April 2012 (hereinafter the “2012 EMP”)
(NM, Vol. II, Annex 2).
359E.g., NM, paras. 3.12, 3.15, 3.23, 3.29, 3.39, 3.44, 3.52, 3.59, 5.28.
3602012 EMP, Annex 2 (NM, Vol. II, Annex 2, pp. 191-194).

124however, belie its promises, and make plain that Nicaragua remains at serious risk

because effective remediation is still not taking place.

3.17 The Counter-Memorial asserts that “Costa Rica has taken a series

of measures designed to lessen the environmental impact of the Border Road,” but

denies any remediation is needed to mitigate risks to Nicaragua because, it

contends, the project’s impacts are felt exclusively in Costa Rica. This claim,

however, is amply refuted by the facts presented in the previous Chapter showing

the harm to Nicaragua that has already occurred. It is also disproven by the

“Environmental Management Plan” 357 that Costa Rica produce d in April 2012

(henceforth the “2012 EMP” 358).

359
3.18 Although Nicaragua addressed the 2012 EMP in its Memorial,

Costa Rica’s Counter-Memorial conspicuously avoids any mention of it. Included

in the 2012 EMP is a table of color -coded “Priority” remediation works 360which

Rica’s argument about a purported “em ergency” is refuted in Chapter 6 . For now, it suffices to
note that, by implementing these “temporary” solutions – in violation of standard practices – and
by leaving them in place for an extended period of time, Costa Rica has failed to meet even its
own putat ive objectives since collapsed slopes and stream crossings impede safe access and
interrupt the “continuous thoroughfare” Costa Rica claims to have needed to construct on an
emergency basis.
357 As the Golder Report explains, proper Environmental Management Plans (EMPs) are an

offshoot of an EIA process, and they are “the framework to ensure that all issues identified during
the [EIA] process are addressed through appropriate mitigation and monitoring .” Golder Report,
Section 5 (NR, Vol. II, Annex 6). Costa Rica’s EMP was not the product of an EIA, as no EIA
was ever conducted.
358 Costa Rican Ministry of Environment, Energy and Telecommunications, National

Conservation Area System, Ministry of Public Works and Transportation, National Road Council,
and Nation al Risk Prevention and Emergency Response Commission, “Environmental
Management Plan: Juan Rafael Mora Porras Road,” April 2012 (hereinafter the “2012 EMP”)
(NM, Vol. II, Annex 2).
359E.g., NM, paras. 3.12, 3.15, 3.23, 3.29, 3.39, 3.44, 3.52, 3.59, 5.28.
3602012 EMP, Annex 2 (NM, Vol. II, Annex 2, pp. 191-194). Rica’s failure to implement that measure made it necessary for the Novem ber

365
2013 EDA to recommend the improvement of drainage structures, emphasizing

that drainage systems are needed “as soon as possible, especially on unstable

slopes to avoid sedimentation of aquatic media.” 366 As Dr. Kondolf observes, this

367
remains undone.

3.20 The 2012 EMP also recognized the need for arranging for the

proper disposal of debris, 368 and “soil conservation works,” 369 including covering

exposed soils, 370to limit the transfer of such materials to nearby bodies of water, a

measure plainly relevant to the S an Juan River. Relevant too are the EMP’s

recommendations that “hydrological studies should be made for all water

crossings” to ensure that stream crossings are properly designed 371; that related

works “should not alter or change a waterbody[’s] natural chan nel, to the extent

372
possible ; and that a “channel maintenance plan” to clean accumulated

373
sediments from stream crossings should be enacted. These recommendations

were ignored as well, prompting the 2013 EDA to subsequently observe that

plugged river crossings have the potential to cause environmental damage when

streams,” and that care needs to be taken “to make sure no oil or fuel leaks reach bodies of water.”
Ibid.
365EDA, p. 146; see also p. 162 (CRCM. Vol. II, Annex 10).
366
367Ibid., pp. 148, 149.
3682014 Kondolf Report, Section 6 (NR, Vol. II, Annex 1).
2012 EMP, pp. 20, 22 -24 (NM, Vol II, Annex 2); see also 2012 EMP, Annex 3 ( NM, Vol. II,
Annex 2, pp. 195, 198).
3692012 EMP, p. 22 (NM, Vol. II, Annex 2).
370Ibid., p. 23.
371Ibid., p. 19; see also 2012 EMP, Annex 3 (NM, Vol. II, Annex 2, p. 199).
372
3732012 EMP, p. 20 (NM, Vol. II, Annex 2).
Ibid.

126Rica’s failure to implement that measure made it necessary for the Novem ber

365
2013 EDA to recommend the improvement of drainage structures, emphasizing

that drainage systems are needed “as soon as possible, especially on unstable

slopes to avoid sedimentation of aquatic media.” 366 As Dr. Kondolf observes, this

367
remains undone.

3.20 The 2012 EMP also recognized the need for arranging for the

proper disposal of debris, 368 and “soil conservation works,” 369 including covering

exposed soils, 370to limit the transfer of such materials to nearby bodies of water, a

measure plainly relevant to the S an Juan River. Relevant too are the EMP’s

recommendations that “hydrological studies should be made for all water

crossings” to ensure that stream crossings are properly designed 371; that related

works “should not alter or change a waterbody[’s] natural chan nel, to the extent

372
possible ; and that a “channel maintenance plan” to clean accumulated

373
sediments from stream crossings should be enacted. These recommendations

were ignored as well, prompting the 2013 EDA to subsequently observe that

plugged river crossings have the potential to cause environmental damage when

streams,” and that care needs to be taken “to make sure no oil or fuel leaks reach bodies of water.”
Ibid.
365EDA, p. 146; see also p. 162 (CRCM. Vol. II, Annex 10).
366
367Ibid., pp. 148, 149.
3682014 Kondolf Report, Section 6 (NR, Vol. II, Annex 1).
2012 EMP, pp. 20, 22 -24 (NM, Vol II, Annex 2); see also 2012 EMP, Annex 3 ( NM, Vol. II,
Annex 2, pp. 195, 198).
3692012 EMP, p. 22 (NM, Vol. II, Annex 2).
370Ibid., p. 23.
371Ibid., p. 19; see also 2012 EMP, Annex 3 (NM, Vol. II, Annex 2, p. 199).
372
3732012 EMP, p. 20 (NM, Vol. II, Annex 2).
Ibid. seedling-planting), confirms this. It states, “Work was carried out in the Tiricias

379
sector, and the project spanned the approximate distance of 15 km.” Thus, the

remediation measures described in the Counter Memorial have not been taken

with respect to any of the remaining 165 km of the Road.

3.23 Limiting its remedial work to the upper 15 km stretch is

particularly problematic because the worst eroding sites are located elsewhere,

along the steep, highly erodible terrain where gashes from failed and incomplete

sections of the Road have been left to erode into the River, as described in

380
Chapter 2. Costa Rica’s reme dial work has thus ignored the part of the

highway in the most urgent need of attention.

3.24 Moreover, the remedial measures in the 15 km stretch where Costa

Rica has taken action are insufficient to prevent erosion into the River. Dr.

Kondolf observed sites where Costa Rica has done nothing more than drape

381
geotextiles over exposed slopes. Even when installed properly, this cannot

prevent the erosion of steep slopes. 382As LANAMME has noted, while sheeting

may reduce wind and rain erosion, it “will not dec rease the amount of

379
Consejo Nacional de Vialidad (CONAVI), “Program for the Consolidation and Co ntinued
Improvement of Route No 1856,” 25 October 2013, p. 3 ( CRCM, Vol. II, Annex 8). An associated
map then clarifies this location.
380See also 2014 Kondolf Report, Sections 3 & 6 (NR, Vol. II, Annex 1); Hagans & Weaver
Report (NR, Vol. II, Annex 2).
381
3822014 Kondolf Report, Section 6 (NR, Vol. II, Annex 1).
Golder Report, Sections 6 & 7 (NR, Vol. II, Annex 6).

128seedling-planting), confirms this. It states, “Work was carried out in the Tiricias

379
sector, and the project spanned the approximate distance of 15 km.” Thus, the

remediation measures described in the Counter Memorial have not been taken

with respect to any of the remaining 165 km of the Road.

3.23 Limiting its remedial work to the upper 15 km stretch is

particularly problematic because the worst eroding sites are located elsewhere,

along the steep, highly erodible terrain where gashes from failed and incomplete

sections of the Road have been left to erode into the River, as described in

380
Chapter 2. Costa Rica’s reme dial work has thus ignored the part of the

highway in the most urgent need of attention.

3.24 Moreover, the remedial measures in the 15 km stretch where Costa

Rica has taken action are insufficient to prevent erosion into the River. Dr.

Kondolf observed sites where Costa Rica has done nothing more than drape

381
geotextiles over exposed slopes. Even when installed properly, this cannot

prevent the erosion of steep slopes. 382As LANAMME has noted, while sheeting

may reduce wind and rain erosion, it “will not dec rease the amount of

379
Consejo Nacional de Vialidad (CONAVI), “Program for the Consolidation and Co ntinued
Improvement of Route No 1856,” 25 October 2013, p. 3 ( CRCM, Vol. II, Annex 8). An associated
map then clarifies this location.
380See also 2014 Kondolf Report, Sections 3 & 6 (NR, Vol. II, Annex 1); Hagans & Weaver
Report (NR, Vol. II, Annex 2).
381
3822014 Kondolf Report, Section 6 (NR, Vol. II, Annex 1).
Golder Report, Sections 6 & 7 (NR, Vol. II, Annex 6). 3.25 Other “remediation” measures implemented by Costa Rica, Dr.

Kondolf explains, are equally “superficial,” and “do nothing to prevent massive

failures of cut slopes” or “un -engineered fillslopes an d stream crossing fill

385
prisms,” which are the problems that place Nicaragua at the greatest risk. These

include Costa Rica’s attempts to cover bare -earth roads with rock; line ditches

adjacent to the road surface; install drains along the inside and outsi de portion of

certain road segments; and cover some steep fill slopes with erosion control

fabrics.386 These measures do not reduce the most serious risks to Nicaragua

because they cannot prevent the surface from cascading to the bottom of the hill in

a landslide, 387 which has already happened in numerous locations, as detailed in

388
Section A Chapter 2, above.

3.26 In many places, Costa Rica’s post -construction work has been

limited to reconstructing failed parts of the Road in the same flawed manner that

caused the failure in the first place. For instance, as described in paragraphs 2.30-

2.32, above, after the stream crossing failed at Site 9.5 in Dr. Kondolf’s Inventory

of Severely Eroding Sites, Costa Rica refilled it with soil and improperly installed

a culvert, which caused the failure to reoccur by May 2014 , washing tons of

385
386Ibid.
Ibid.
387Ibid.
388Ibid., Section 2; Hagans & Weaver Report (NR, Vol. II, Annex 2).

130 3.25 Other “remediation” measures implemented by Costa Rica, Dr.

Kondolf explains, are equally “superficial,” and “do nothing to prevent massive

failures of cut slopes” or “un -engineered fillslopes an d stream crossing fill

385
prisms,” which are the problems that place Nicaragua at the greatest risk. These

include Costa Rica’s attempts to cover bare -earth roads with rock; line ditches

adjacent to the road surface; install drains along the inside and outsi de portion of

certain road segments; and cover some steep fill slopes with erosion control

fabrics.386 These measures do not reduce the most serious risks to Nicaragua

because they cannot prevent the surface from cascading to the bottom of the hill in

a landslide, 387 which has already happened in numerous locations, as detailed in

388
Section A Chapter 2, above.

3.26 In many places, Costa Rica’s post -construction work has been

limited to reconstructing failed parts of the Road in the same flawed manner that

caused the failure in the first place. For instance, as described in paragraphs 2.30-

2.32, above, after the stream crossing failed at Site 9.5 in Dr. Kondolf’s Inventory

of Severely Eroding Sites, Costa Rica refilled it with soil and improperly installed

a culvert, which caused the failure to reoccur by May 2014 , washing tons of

385
386Ibid.
Ibid.
387Ibid.
388Ibid., Section 2; Hagans & Weaver Report (NR, Vol. II, Annex 2). Figure 3.3. May 2013 photograph of road runoff directed from drainage structure into fill.

Figure 3.4. May 2014 photograph of erosion resulting from direct drainage from road onto fill.

132Figure 3.3. May 2013 photograph of road runoff directed from drainage structure into fill.

Figure 3.4. May 2014 photograph of erosion resulting from direct drainage from road onto fill. 3.30 Thus, Professor Thorne recognizes that as of December 2013,

Costa Rica had still not undertaken the “necessary work” in regard to “design,

planning and construction” that would “permanently solve erosion problems,” and

that this needs to be done “as soon as possible.” In so stating, Professor Thorne

echoed the 2012 EDA, which likewise recognized the need to “stabilize slopes as

soon as possible, especially those considered unstable, to avoid sedimentation of

aquatic environments.” 396 Regretably, Costa Rica does not share this sense of

urgency.

3.31 In some places, the deficiencies in the Road are so fundamental that

the only way the risks to Nicaragua can be adequately mitigated is by relocating

the Road further away from the River. Even Costa Rica’s EDA recognizes that at

least one section of the Road – the portion containing the Severely Eroding Sites

discussed above – is so problematic that relocation to the south, that is, farther

from the River, should be evaluated. It recommends that Costa Rica:

“evaluate the technical possibility of modifying the route

designated for Route 1856 at the point called Infiernillo
[sic] to include the use of local roads built on less sloping
terrain, tracing the road some km. to the south, where there

are open areas and settlement397ith more favorable
topographical conditions.”

396EDA, para 7.2.19 (emphasis added) (CRCM, Vol. II, Annex 10).
397Ibid., pp. 147, 162; see also Map 1 of 6 (CRCM, Vol . II, Annex 10, p. 524 ) showing the

location of “Infiernillo” [sic] immediately adjacent to “Crucitas,” which is the name for the stretch
containing Severely Eroding Sites 9.4, 9.5, and 9.6. Severely Eroding Sites 8.1 and 8.2 are located
between Crucitas and the Rio “Infiernillo”. Similarly, Costa Rica’s EMP determined that concerns
over “project integrity” necessitate d reviewing whether there is adequate distance between the
Road and the River in the stretch between the Medio Queso River and Boca San Carlos. 2012
EMP, p. 10 (NM, Vol. II, Annex 2).

134 3.30 Thus, Professor Thorne recognizes that as of December 2013,

Costa Rica had still not undertaken the “necessary work” in regard to “design,

planning and construction” that would “permanently solve erosion problems,” and

that this needs to be done “as soon as possible.” In so stating, Professor Thorne

echoed the 2012 EDA, which likewise recognized the need to “stabilize slopes as

soon as possible, especially those considered unstable, to avoid sedimentation of

aquatic environments.” 396 Regretably, Costa Rica does not share this sense of

urgency.

3.31 In some places, the deficiencies in the Road are so fundamental that

the only way the risks to Nicaragua can be adequately mitigated is by relocating

the Road further away from the River. Even Costa Rica’s EDA recognizes that at

least one section of the Road – the portion containing the Severely Eroding Sites

discussed above – is so problematic that relocation to the south, that is, farther

from the River, should be evaluated. It recommends that Costa Rica:

“evaluate the technical possibility of modifying the route

designated for Route 1856 at the point called Infiernillo
[sic] to include the use of local roads built on less sloping
terrain, tracing the road some km. to the south, where there

are open areas and settlement397ith more favorable
topographical conditions.”

396EDA, para 7.2.19 (emphasis added) (CRCM, Vol. II, Annex 10).
397Ibid., pp. 147, 162; see also Map 1 of 6 (CRCM, Vol . II, Annex 10, p. 524 ) showing the

location of “Infiernillo” [sic] immediately adjacent to “Crucitas,” which is the name for the stretch
containing Severely Eroding Sites 9.4, 9.5, and 9.6. Severely Eroding Sites 8.1 and 8.2 are located
between Crucitas and the Rio “Infiernillo”. Similarly, Costa Rica’s EMP determined that concerns
over “project integrity” necessitate d reviewing whether there is adequate distance between the
Road and the River in the stretch between the Medio Queso River and Boca San Car los. 2012
EMP, p. 10 (NM, Vol. II, Annex 2). 403 404
contaminated by fuel from an overturned truck. There are many more. Even

well-engineered roads are not immune, as evidenced by a spill that occurred in

New Zealand in 2011 that left wildlife near the Awakino River coated in oil. 405

Even the security of rails is not a guarantee against toxic spills into a river:

hundreds of thousands of fish and virtually all plant life along a 45 mile stretch of

the Sacramento River in California were killed in 1991 when a train derailed,

spilling pesticide into the river.406

403“Ombudsman Investigates Mining Company Spillage into River”, Los Andes, 26 August 2009

404, Vol. II, Annex 26).
See, e.g., “Oil Spill Contaminates Lake”, Perú21, 9 May 2012 (NR, Vol. II, Annex 27) (truck
overturned, spilling petroleum into Lake Huachucocha in Perú); Drinking Water in Chinese
Province Returning to Normal After Spill, N.Y. TIMES (June 7, 2011), available at
http://www.nytimes.com/2011/06/08/world/asia/08spill.html (20 tons of carbolic acid spilled from

truck and were washed downhill into the Xin’an River near Hangzhou, China after a collision);
“Oil Truck Overturned near the Cruces River”,l Mercurio Online, 3 January 2009 (NR, Vol. II,
Annex 28) (truck overturned on a small wooden bridge without guardrails, spilling about 100 liters
of fuel directly into tributary to the Cruces River near Valdivia, Chi“Truck Spilled 9,000
Gallons of Fuel into Rivers”, Enlace Nacional, 4 February2008 (NR, Vol. II, Annex 29) (the

Chiguilla and Huaracané Rivers in Perú were contaminated when truck overturned, spilling 9,000
gallons of fuel); China: Truck Spills 30 Tons of Sulfuric Acid,N.Y. T IMES (Feb. 14, 2008),
available at http://www.nytimes.com/2008/02/14/world/asia/14briefs-acid.html (many fish killed
when truck overturned, spilling 30 tons of sulfuric acid into a drainage ditch feeding the Xinsi

River in Yunnan, China); Toxic Spill Fouls Water Supply for 2 Towns in China, W ASHINGTON
POST (Nov. 2, 2006), available at http://www.washingtonpost.com/wp -
dyn/content/article/2006/11/01/AR2006110103048. html (33 tons of toxic creosote spilled into a
river feeding the Yangjiapo Reservoir in China as a result of truck crash).
405Birds Affected by Awakino Oil Spill, O TAGO DAILY TIMES (June 24, 2011), available at

http://www.odt.co.nz/166288/birds-affected-awakino-oil-spill; see also Crews Try to Contain
Diesel Spill, S POKESMAN REVIEW .COM (Jan. 8, 2002), available at
http://www.spokesmanreview.com/news-story.asp?date=010802&ID=s1081581 (most of a truck’s
cargo of 10,000 ga llons of diesel fuel spilled into the Clearwater River in Idaho after the truck

406rturned along a highway).
See, e.g., Keith Schneider, California Spill Exposes Gaps in Rail Safety RulesIMESY(July
27, 1991), available at http://www.nytimes.com/1991/07/27/us/california-spill-exposes-gaps-in-
rail-safety-rules.html. Train derailments that result in toxic spills are far from rareSee,well.
e.g., Oil Tanker Train Derails in Lynchburg, Va., Triggering Fire and Spill , L.A.(Apr. 30,

2014), available at http://www.latimes.com/nation/nationnow/la-na-nn-lynchburg-virginia-tra…-
derailment-20140430-story.html (derailment sent several train cars into the James River in
Virginia, spilling the oil they carriedCrude Oil Tank Cars Ablaze after Train Derails in
Alabama, R EUTERS (Nov. 8, 2013), available at http://www.reuters.com/article/2013/11/09/us-

136 403 404
contaminated by fuel from an overturned truck. There are many more. Even

well-engineered roads are not immune, as evidenced by a spill that occurred in

New Zealand in 2011 that left wildlife near the Awakino River coated in oil. 405

Even the security of rails is not a guarantee against toxic spills into a river:

hundreds of thousands of fish and virtually all plant life along a 45 mile stretch of

the Sacramento River in California were killed in 1991 when a train derailed,

spilling pesticide into the river.406

403“Ombudsman Investigates Mining Company Spillage into River”, Los Andes, 26 August 2009

404, Vol. II, Annex 26).
See, e.g., “Oil Spill Contaminates Lake”, Perú21, 9 May 2012 (NR, Vol. II, Annex 27) (truck
overturned, spilling petroleum into Lake Huachucocha in Perú); Drinking Water in Chinese
Province Returning to Normal After Spill, N.Y. T IMES (June 7, 2011), available at
http://www.nytimes.com/2011/06/08/world/asia/08spill.html (20 tons of carbolic acid spilled from

truck and were washed downhill into the Xin’an River near Hangzhou, China after a collision);
“Oil Truck Overturned near the Cruces River”,l Mercurio Online, 3 January 2009 (NR, Vol. II,
Annex 28) (truck overturned on a small wooden bridge without guardrails, spilling about 100 liters
of fuel directly into tributary to the Cruces River near Valdivia, Chil“Truck Spilled 9,000
Gallons of Fuel into Rivers”, Enlace Nacional, 4 February2008 (NR, Vol. II, Annex 29) (the

Chiguilla and Huaracané Rivers in Perú were contaminated when truck overturned, spilling 9,000
gallons of fuel); China: Truck Spills 30 Tons of Sulfuric Acid,N.Y. T IMES (Feb. 14, 2008),
available at http://www.nytimes.com/2008/02/14/world/asia/14briefs-acid.html (many fish killed
when truck overturned, spilling 30 tons of sulfuric acid into a drainage ditch feeding the Xinsi

River in Yunnan, China); Toxic Spill Fouls Water Supply for 2 Towns in China, W ASHINGTON
POST (Nov. 2, 2006), available at http://www.washingtonpost.com/wp -
dyn/content/article/2006/11/01/AR2006110103048. html (33 tons of toxic creosote spilled into a
river feeding the Yangjiapo Reservoir in China as a result of truck crash).
405Birds Affected by Awakino Oil Spill, O TAGO D AILY TIMES (June 24, 2011), available at

http://www.odt.co.nz/166288/birds-affected-awakino-oil-spill; see also Crews Try to Contain
Diesel Spill, SPOKESMAN REVIEW .COM (Jan. 8, 2002), available at
http://www.spokesmanreview.com/news-story.asp?date=010802&ID=s1081581 (most of a truck’s
cargo of 10,000 ga llons of diesel fuel spilled into the Clearwater River in Idaho after the truck

406rturned along a highway).
See, e.g., Keith Schneider, California Spill Exposes Gaps in Rail Safety RulesIMESY(July
27, 1991), available at http://www.nytimes.com/1991/07/27/us/california-spill-exposes-gaps-in-
rail-safety-rules.html. Train derailments that result in toxic spills are far from rareSee,well.
e.g., Oil Tanker Train Derails in Lynchburg, Va., Triggering Fire and Spill , L.A.(Apr. 30,

2014), available at http://www.latimes.com/nation/nationnow/la-na-nn-lynchburg-virginia-tra…-
derailment-20140430-story.html (derailment sent several train cars into the James River in
Virginia, spilling the oil they carriedCrude Oil Tank Cars Ablaze after Train Derails in
Alabama, R EUTERS (Nov. 8, 2013), available at http://www.reuters.com/article/2013/11/09/us- 410
with guardrails. The Road’s stream crossings, many of which are built from

logs and other rudimentary materials, are already “in imminent danger of

411
collapsing,” making the risk all the more pronounced. Reports on the Road by

CFIA, LANAMME and Dr. Kondolf have all repeatedly criticised the project for

its improperly constructed stream crossings, each a potential cause of a toxic

412
spill.

3.39 Although the poor condition of the Road is problematic on its own,

the risk it poses is accentuated by the fact that Costa Rica sited it much closer to

413
the River than is acceptable under internationally -accepted standards and its

414
own buffer requirements. Seventeen percent of the Road -- that is, nearly 18 km

415
of it -- is within fifty meters (and genera lly uphill) of the River, and in some

places it is much closer. As a result, any hazardous materials spilled from the

410
See, e.g., “Truck Overturns - Severe Environmental Damage”, La Angostura Digital, 23 July
2009), (NR, Vol. II, Annex 30) (truck carrying 10,000 liters of fuel crashed through a guardrail
and fell 50 meters into Nahuel Huapi Lake in Argentina).
411
4122014 Kondolf Report, Section 5 (quoting CFIA Report) (NR, Vol. II, Annex 1).
See CFIA Report, p. 9 (reporting the existence of “a bridge comprised of two trailers [sic]
containers and wooden logs” with the containers “already bulging and in imminent danger of
collapsing”) (NM, Vol II, Annex 4); LANAMME Report, pp. 10, 49 (describing a bridge “in poor

operating condition” and culverts “under risk of collapsing,” respectively) (NM, Vol. II, Annex 3);
2012 Kondolf Report, para. 4.6 (“ of approximately 60 recently constructed stream crossings, we
observed that essential ly all road -stream crossings exhibited some form of serious design and/or
construction deficiency”) (NM, Vol. II, Annex 1); 2014 Kondolf Report Sections 3 & 5 (NR, Vol.

413 Annex 1).
Golder Report, Section 6 (NR, Vol. II, Annex 6).
414The CFIA Report found that “there are doubts regarding the recesses of the road along the Río
San Juan in some stretches where it is only a few meters from the bank” and that recesses (the gaps

between the Road and River) in some areas should be “evaluated for compliancethe law.”
CFIA Report, pp. 18, 26; see also pp. 9, 10, 13, 16, 27 (NM, Vol. II, Annex 4).
4152012 Kondolf Report, p. 22 (NM, Vol. II, Annex 1).

138 410
with guardrails. The Road’s stream crossings, many of which are built from

logs and other rudimentary materials, are already “in imminent danger of

411
collapsing,” making the risk all the more pronounced. Reports on the Road by

CFIA, LANAMME and Dr. Kondolf have all repeatedly criticised the project for

its improperly constructed stream crossings, each a potential cause of a toxic

412
spill.

3.39 Although the poor condition of the Road is problematic on its own,

the risk it poses is accentuated by the fact that Costa Rica sited it much closer to

413
the River than is acceptable under internationally -accepted standards and its

414
own buffer requirements. Seventeen percent of the Road -- that is, nearly 18 km

415
of it -- is within fifty meters (and genera lly uphill) of the River, and in some

places it is much closer. As a result, any hazardous materials spilled from the

410
See, e.g., “Truck Overturns - Severe Environmental Damage”, La Angostura Digital, 23 July
2009), (NR, Vol. II, Annex 30) (truck carrying 10,000 liters of fuel crashed through a guardrail
and fell 50 meters into Nahuel Huapi Lake in Argentina).
411
4122014 Kondolf Report, Section 5 (quoting CFIA Report) (NR, Vol. II, Annex 1).
See CFIA Report, p. 9 (reporting the existence of “a bridge comprised of two trailers [sic]
containers and wooden logs” with the containers “already bulging and in imminent danger of
collapsing”) (NM, Vol II, Annex 4); LANAMME Report, pp. 10, 49 (describing a bridge “in poor

operating condition” and culverts “under risk of collapsing,” respectively) (NM, Vol. II, Annex 3);
2012 Kondolf Report, para. 4.6 (“ of approximately 60 recently constructed stream crossings, we
observed that essential ly all road -stream crossings exhibited some form of serious design and/or
construction deficiency”) (NM, Vol. II, Annex 1); 2014 Kondolf Report Sections 3 & 5 (NR, Vol.

413 Annex 1).
Golder Report, Section 6 (NR, Vol. II, Annex 6).
414The CFIA Report found that “there are doubts regarding the recesses of the road along the Río
San Juan in some stretches where it is only a few meters from the bank” and that recesses (the gaps

between the Road and River) in some areas should be “evaluated for compliancethe law.”
CFIA Report, pp. 18, 26; see also pp. 9, 10, 13, 16, 27 (NM, Vol. II, Annex 4).
4152012 Kondolf Report, p. 22 (NM, Vol. II, Annex 1). creatures of vital habitat.21 Hazardous substances can inhibit aquatic life -forms’

ability to reproduce, damaging populations over the long term. 422

3.42 All of this reinforces the conclusion that the Road’s condition is

such that any attempt to transport hazardous materials along it would create a

significant risk of a toxic spill, with potentially devastating effects on Nicaragua’s

River.

D. THE RISK POSED BY COSTA RICAN DEVELOPMENT

3.43 The risk of harm to Nicaragua is heightened by the fact that the

Road provides a platform for further development of the River’s southern bank.

Costa Rica’s 2013 EDA recognizes this when it observes that “[t]he construction

of Route 1856 could attract settlers to the region,” 423 and “could create

424
development opportunities for local communities.” Increased development,

however, inevitably entails adverse impacts to the surrounding environment,

including the River.

3.44 There is already evidence that such development is occurring. On

their most recent visit to the San Juan River in May 2014, Nicaragua’s experts

observed that power lines have been installed along 14 km of Road (between

421UNITED STATES ENVIRONMENTAL P ROTECTION AGENCY , UNDERSTANDING O ILSPILLS ANDO IL
SPILL R ESPONSE 7, 21 (1999), available at http://www.epa.gov/osweroe1/content/learning/
pdfbook.htm.
422
EUROPEAN ENVIRONMENT A GENCY, H AZARDOUS SUBSTANCES IN E UROPE’S FRESH AND
M ARINE W ATERS: AN OVERVIEW , EEA Technical Report No. 8/2011, at 31 –32 (2011), available
at http://www.eea.europa.eu/publications/hazardous-substances-in-europes-f….
423EDA, p. 65 (CRCM, Vol. II, Annex 10, p. 565).
424EDA Tourism Annex, “Impact Assessment of the Implementation of the Route 1856 Project on
the Development of Tourism Activities in the San Juan Riv er,” p. 20 (CRCM, Vol. II, Annex 10,

p. 698).

140creatures of vital habitat.21Hazardous substances can inhibit aquatic life -forms’

ability to reproduce, damaging populations over the long term. 422

3.42 All of this reinforces the conclusion that the Road’s condition is

such that any attempt to transport hazardous materials along it would create a

significant risk of a toxic spill, with potentially devastating effects on Nicaragua’s

River.

D. THE RISK POSED BY COSTA RICAN DEVELOPMENT

3.43 The risk of harm to Nicaragua is heightened by the fact that the

Road provides a platform for further development of the River’s southern bank.

Costa Rica’s 2013 EDA recognizes this when it observes that “[t]he construction

of Route 1856 could attract settlers to the region,” 423 and “could create

424
development opportunities for local communities.” Increased development,

however, inevitably entails adverse impacts to the surrounding environment,

including the River.

3.44 There is already evidence that such development is occurring. On

their most recent visit to the San Juan River in May 2014, Nicaragua’s experts

observed that power lines have been installed along 14 km of Road (between

421UNITED STATES ENVIRONMENTAL PROTECTION A GENCY , NDERSTANDING O ILSPILLS ANDOIL
SPILL R ESPONSE 7, 21 (1999), available at http://www.epa.gov/osweroe1/content/learning/
pdfbook.htm.
422
E UROPEAN ENVIRONMENT AGENCY , HAZARDOUS SUBSTANCES IN EUROPE ’S FRESH AND
M ARINE W ATERS: ANO VERVIEW , EEA Technical Report No. 8/2011, at 31 –32 (2011), available
at http://www.eea.europa.eu/publications/hazardous-substances-in-europes-f….
423EDA, p. 65 (CRCM, Vol. II, Annex 10, p. 565).
424EDA Tourism Annex, “Impact Assessment of the Implementation of the Route 1856 Project on
the Development of Tourism Activities in the San Juan Riv er,” p. 20 (CRCM, Vol. II, Annex 10,

p. 698). 429
havoc on the San Juan River and its zone of influence. Costa Rica’s responses

range from cavalier dismissal of this concern to statements that present a

remarkably skewed view of the geography and meteorology of the region. Its

dismissal of the risks posed by hurri canes and tropical storms would surely have

seemed out of place in 2000, when Costa Rica joined other Central American

countries that, taking account of the damage caused by Hurricane Mitch two years

earlier, and taking notice that natural disasters do not abide by political

boundaries, began working to standarize and modernize technical standards for

roads to reduce the region’s vulnerability to natural disasters , an effort which led

430
to the formulation of the regional standards discussed above.

3.48 Costa Ric a does not deny that erosion from the Road, and its

corresponding impact on Nicaraguan territory, would rise to even more dramatic

levels when the inevitable happens again and a major storm strikes the River.

Instead, it offers false assurances that such a n event is unlikely. To that end, the

Counter-Memorial incorrectly states that “[t]he region in which the Road is

located has never been directly hit by a hurricane.” 431 This assertion is based on

Professor Thorne’s narrower statement that “the Río San Juan . . . [being] struck

by a hurricane or tropical storm . . .would actually be unprecedented and it is

therefore highly unlikely.” The only basis Professor Thorne offers for his

429
NM, paras. 3.80, 4.19.
430See generally, Resolution 03-99 (XXI COMITRAN), Guatemala, 18 Nov. 1999 (NR, Vol. II,
Annex 9).
431CRCM, para. 3.34.

142 429
havoc on the San Juan River and its zone of influence. Costa Rica’s responses

range from cavalier dismissal of this concern to statements that present a

remarkably skewed view of the geography and meteorology of the region. Its

dismissal of the risks posed by hurri canes and tropical storms would surely have

seemed out of place in 2000, when Costa Rica joined other Central American

countries that, taking account of the damage caused by Hurricane Mitch two years

earlier, and taking notice that natural disasters do not abide by political

boundaries, began working to standarize and modernize technical standards for

roads to reduce the region’s vulnerability to natural disasters , an effort which led

430
to the formulation of the regional standards discussed above.

3.48 Costa Ric a does not deny that erosion from the Road, and its

corresponding impact on Nicaraguan territory, would rise to even more dramatic

levels when the inevitable happens again and a major storm strikes the River.

Instead, it offers false assurances that such a n event is unlikely. To that end, the

Counter-Memorial incorrectly states that “[t]he region in which the Road is

located has never been directly hit by a hurricane.” 431 This assertion is based on

Professor Thorne’s narrower statement that “the Río San Juan . . . [being] struck

by a hurricane or tropical storm . . .would actually be unprecedented and it is

therefore highly unlikely.” The only basis Professor Thorne offers for his

429
NM, paras. 3.80, 4.19.
430See generally, Resolution 03-99 (XXI COMITRAN), Guatemala, 18 Nov. 1999 (NR, Vol. II,
Annex 9).
431CRCM, para. 3.34. 436
per day over the four day period. By any measure, this is a significant amount

of rainfall over a short span of time. Another of the hurricanes whose rainfall

Costa Rica dismisses as “unexceptional” --- Hurricane Mitch in 1998 -- killed

seven people by flooding and forced thousands from their homes in northea st

437
Costa Rica.

3.51 Costa Rica argues that this intense rainfall is somehow insignificant

because it is “within the natural range of rainfall in the area, which is

438
abundant.” Costa Rica’s Annex 68 states that “[t]he average annual rain

accumulation can reach 6,000mm” in “the north area of [Costa Rica.]” 439

Regardless of whether annual rainfall can reach 6,000mm somewhere in “the

north area” of the country, Costa Rica’s own EDA reports that “[i]n the project

area the average annual rainfall varies between 2300 m illimeters and 4400

440
millimeters.” In this context, the effects felt in Costa Rica during hurricanes

have been more exceptional than Costa Rica and Professor Thorne allow.

3.52 Professor Thorne also argues that the rainfall associated with a

hurricane is unlik ely to cause “widespread destruction because the basin of the

Rio San Juan receives abundant rainfall in most years and the hydrology,

436Letter from the General Director of the Costa Rican National Meteorological Institute to H.E.

437ar Ugalde Álvarez, 7 Nov. 2013 (CRCM, Vol. III, Annex 68).
4382014 Kondolf Report, Section 12 (NR, Vol. II, Annex 1).
439CRCM, para. 3.35.
Letter from the General Director of the Costa Rican National Meteorological Institute to H.E.
440ar Ugalde Álvarez, 7 Nov. 2013, p. 2 (CRCM, Vol. III, Annex 68).
EDA, p. 36. Elsewhere the EDA states that the study ar ea receives “annual rainfall that varies
between 2300 and 2800 mm.” Ibid., p. 42. The EDA also finds that, to the climate of the region,
hurricanes are "influential . . . particularly those that come close to, or even penetrate, the Central
American Isthmus." Ibid., at p. 35 (CRCM, Vol. II, Annex 10).

144 436
per day over the four day period. By any measure, this is a significant amount

of rainfall over a short span of time. Another of the hurricanes whose rainfall

Costa Rica dismisses as “unexceptional” --- Hurricane Mitch in 1998 -- killed

seven people by flooding and forced thousands from their homes in northea st

437
Costa Rica.

3.51 Costa Rica argues that this intense rainfall is somehow insignificant

because it is “within the natural range of rainfall in the area, which is

438
abundant.” Costa Rica’s Annex 68 states that “[t]he average annual rain

accumulation can reach 6,000mm” in “the north area of [Costa Rica.]” 439

Regardless of whether annual rainfall can reach 6,000mm somewhere in “the

north area” of the country, Costa Rica’s own EDA reports that “[i]n the project

area the average annual rainfall varies between 2300 m illimeters and 4400

440
millimeters.” In this context, the effects felt in Costa Rica during hurricanes

have been more exceptional than Costa Rica and Professor Thorne allow.

3.52 Professor Thorne also argues that the rainfall associated with a

hurricane is unlik ely to cause “widespread destruction because the basin of the

Rio San Juan receives abundant rainfall in most years and the hydrology,

436Letter from the General Director of the Costa Rican National Meteorological Institute to H.E.

437ar Ugalde Álvarez, 7 Nov. 2013 (CRCM, Vol. III, Annex 68).
4382014 Kondolf Report, Section 12 (NR, Vol. II, Annex 1).
439CRCM, para. 3.35.
Letter from the General Director of the Costa Rican National Meteorological Institute to H.E.
440ar Ugalde Álvarez, 7 Nov. 2013, p. 2 (CRCM, Vol. III, Annex 68).
EDA, p. 36. Elsewhere the EDA states that the study ar ea receives “annual rainfall that varies
between 2300 and 2800 mm.” Ibid., p. 42. The EDA also finds that, to the climate of the region,
hurricanes are "influential . . . particularly those that come close to, or even penetrate, the Central
American Isthmus." Ibid., at p. 35 (CRCM, Vol. II, Annex 10). far higher frequency and severity of landslides than areas
not affected by the road construction, other factors being
the same. If the massive fill piles along Rte 1856 (such as
those documented at Severely Eroding Sites 9.4, 9.5, 9.6,

and elsewhere) are not removed and the cutslope stabilized,
there is a substant ial risk of sudden, massive transfers of
sediment into the Río San Juan during intense rains.” 443

3.54 A hurricane is not the only potential source of the intense rains that

would produce these effects. Other tropical storms are capable of supplying

enough precipitation to trigger landslides, and contrary to Costa Rica’s assertions,

are not unprecedented in the region. 444

3.55 Heavy rains cause erosion, including from major, sudden failures

of the Road’s slopes or stream crossings. Costa Rica ’s experts acknowledge that

445
recent years have been drier than average. A return of heavier rain will only

increase the sediment already being washed into the River in significant

quantities.

3.56 Severe erosion from the Road can also be expected in the event of

an earthquake. As Dr. Kondolf explains,

“Clearing and earth moving for road construction causes
previously stable slopes to be destabilized, by removing
vegetation cover, breaking up soil structure, and increasing
slope steepness. Moreover, once the vegetation dies, deep

roots begin to decay (which typically occurs over a couple
of years), which further destabilizes the slope through the
loss of root strength. Weakened slopes are subject to much
greater frequency of landsliding than native slopes[, and an]

4432014 Kondolf Report, Section 12 (NR, Vol. II, Annex 1).
444Ibid.
445Dec. 2013 Thorne Report, para 8.12 (“the post -Road period has been drier than usual”)
(CRCM, Vol. I, Appendix A)..

146 far higher frequency and severity of landslides than areas
not affected by the road construction, other factors being
the same. If the massive fill piles along Rte 1856 (such as
those documented at Severely Eroding Sites 9.4, 9.5, 9.6,

and elsewhere) are not removed and the cutslope stabilized,
there is a substant ial risk of sudden, massive transfers of
sediment into the Río San Juan during intense rains.” 443

3.54 A hurricane is not the only potential source of the intense rains that

would produce these effects. Other tropical storms are capable of supplying

enough precipitation to trigger landslides, and contrary to Costa Rica’s assertions,

are not unprecedented in the region. 444

3.55 Heavy rains cause erosion, including from major, sudden failures

of the Road’s slopes or stream crossings. Costa Rica ’s experts acknowledge that

445
recent years have been drier than average. A return of heavier rain will only

increase the sediment already being washed into the River in significant

quantities.

3.56 Severe erosion from the Road can also be expected in the event of

an earthquake. As Dr. Kondolf explains,

“Clearing and earth moving for road construction causes
previously stable slopes to be destabilized, by removing
vegetation cover, breaking up soil structure, and increasing
slope steepness. Moreover, once the vegetation dies, deep

roots begin to decay (which typically occurs over a couple
of years), which further destabilizes the slope through the
loss of root strength. Weakened slopes are subject to much
greater frequency of landsliding than native slopes[, and an]

4432014 Kondolf Report, Section 12 (NR, Vol. II, Annex 1).
444Ibid.
445Dec. 2013 Thorne Report, para 8.12 (“the post -Road period has been drier than usual”)
(CRCM, Vol. I, Appendix A).. processes and inc451se the sedimentation rate towards the
San Juan River.”

3.58 Put si mply, Costa Rica must be required to bring its Road into

compliance with the standards necessary to ensure that it does not pose a threat to

the San Juan River and its area of influence, both under ordinary conditions and in

the event of a natural disaster such as a hurricane, tropical storm, or earthquake.

These standards are reflected in the Central American standards, the very

formulation of which is an expression of the need to prepare roads such as Costa

Rica’s for natural disasters. 452 The condition of Costa Rica’s Road remains far

short of those standards.

F. CONCLUSION

3.59 In sum, Costa Rica’s failure to construct the Road in conformity

with the relevant design, construction and maintenance standards has placed

Nicaragua at grave risk of continued harm, and n othing Costa Rica has done has

mitigated this risk. The possibility of toxic spills, further development of the

Costa Rican bank of the River, and the likelihood of natural disasters, all

accentuate the risk to Nicaragua.

45EDA, p. 33 (CRCM, Vol. II, Annex 10).
45RESOLUTION 03-99 (XXI COMITRAN), Guatemala, 18 Nov. 1999 (NR, Vo l. II, Annex 9);
see also Central American Manual of Specifications for the Construction of Regional Roads and
Bridges (2nd. Edition, Mar. 2004), p. iii (NR, Vol. II, Annex 11); Central American Manual on the
Maintenance of Roads (2010 Edition), p. 7 (NR, Vol. II, Annex 12).

148 processes and incr451e the sedimentation rate towards the
San Juan River.”

3.58 Put si mply, Costa Rica must be required to bring its Road into

compliance with the standards necessary to ensure that it does not pose a threat to

the San Juan River and its area of influence, both under ordinary conditions and in

the event of a natural disaster such as a hurricane, tropical storm, or earthquake.

These standards are reflected in the Central American standards, the very

formulation of which is an expression of the need to prepare roads such as Costa

Rica’s for natural disasters. 452 The condition of Costa Rica’s Road remains far

short of those standards.

F. CONCLUSION

3.59 In sum, Costa Rica’s failure to construct the Road in conformity

with the relevant design, construction and maintenance standards has placed

Nicaragua at grave risk of continued harm, and n othing Costa Rica has done has

mitigated this risk. The possibility of toxic spills, further development of the

Costa Rican bank of the River, and the likelihood of natural disasters, all

accentuate the risk to Nicaragua.

451EDA, p. 33 (CRCM, Vol. II, Annex 10).
452RESOLUTION 03-99 (XXI COMITRAN), Guatemala, 18 Nov. 1999 (NR, Vo l. II, Annex 9);
see also Central American Manual of Specifications for the Construction of Regional Roads and
Bridges (2nd. Edition, Mar. 2004), p. iii (NR, Vol. II, Annex 11); Central American Manual on the
Maintenance of Roads (2010 Edition), p. 7 (NR, Vol. II, Annex 12). in question do not harm its neighbours’ territory – in the present case, the waters

of the San Juan River over which Nicaragua has “exclusively the dominion and

sovereignty” (“exclusivamente el dominio y sumo imperio ”) from its origin at the

Lake to its mouth in the Caribbean, in accordance with the 1858 Treaty of Limits

which remains the main applicable instrument in the present case. This dominion

and sovereignty is only limited b y the recognition, in favour of Costa Rica, of a

“perpetual right of free navigation […] for the purposes of commerce.”

4.4 As Nicaragua recalled in its Memorial, in the 2009 Judgment the

Court considered that: “[t]he 1858 Treaty of Limits completely defines t he rules

applicable to the section of the San Juan River that is in dispute in respect of

457
navigation.” But this is only an exception, a treaty limitation, to the, for the rest

unlimited, Nicaraguan sovereignty over the waters of the River. And it goes

without saying that when it uses the River as a garbage dump, or builds

infrastructure works in a way that impedes or endangers free navigation on the

River, Costa Rica undermines Nicaragua’s territorial sovereignty.

4.5 Costa Rica accepts that “[o]bviously the 1 858 Treaty of Limits is

fundamental to the relations between the Parties in the matter of the River.” 458

Such an admission is hardly reconcilable with the other view expressed by Costa

Rica according to which: “Costa Rica’s position is that the 1858 Treaty o f Limits

457I.C.J., Judgement, 13 July 2009,Dispute regarding Navigational and Related Rights (Costa
Rica v. Nicaragua), I.C.J. Reports 2009, p. 233, para. 36, quoted in NM, paras. 4.12, 4.28 or 5.5.
458CRCM, para. 4.2.

150in question do not harm its neighbours’ territory – in the present case, the waters

of the San Juan River over which Nicaragua has “exclusively the dominion and

sovereignty” (“exclusivamente el dominio y sumo imperio ”) from its origin at the

Lake to its mouth in the Caribbean, in accordance with the 1858 Treaty of Limits

which remains the main applicable instrument in the present case. This dominion

and sovereignty is only limited b y the recognition, in favour of Costa Rica, of a

“perpetual right of free navigation […] for the purposes of commerce.”

4.4 As Nicaragua recalled in its Memorial, in the 2009 Judgment the

Court considered that: “[t]he 1858 Treaty of Limits completely defines t he rules

applicable to the section of the San Juan River that is in dispute in respect of

457
navigation.” But this is only an exception, a treaty limitation, to the, for the rest

unlimited, Nicaraguan sovereignty over the waters of the River. And it goes

without saying that when it uses the River as a garbage dump, or builds

infrastructure works in a way that impedes or endangers free navigation on the

River, Costa Rica undermines Nicaragua’s territorial sovereignty.

4.5 Costa Rica accepts that “[o]bviously the 1 858 Treaty of Limits is

fundamental to the relations between the Parties in the matter of the River.” 458

Such an admission is hardly reconcilable with the other view expressed by Costa

Rica according to which: “Costa Rica’s position is that the 1858 Treaty o f Limits

457I.C.J., Judgement, 13 July 2009,Dispute regarding Navigational and Related Rights (Costa
Rica v. Nicaragua), I.C.J. Reports 2009, p. 233, para. 36, quoted in NM, paras. 4.12, 4.28 or 5.5.
458CRCM, para. 4.2. remain applicable as long as they are not contradicted by the 1858 Treaty of

Limits. In this respect, Nic aragua draws attention once more to the authorities

463
referred to in Chapter 4 of its Memorial in the Road case, beginning with the

Award in the Island of Palmas case, in which the arbitrator considered that

territorial sovereignty:

“has a corollary duty: the obligation to protect within the
territory the rights of other States, in particular their right to
integrity and inviolability in peace and in war, together with
the rights which each State may claim for its nationals in
464
foreign territory.”

4.8 This Court itself confirmed the principle in the Corfu Channel case

when it referred in its 1949 Judgment to the obligation of every State “not to

allow knowingly its territory to be used for acts contrary to the rights of other

465
States.”

4.9 In the context of transbou ndary pollution, which is involved in the

present case, the arbitral tribunal in the well -known 1941 Trail Smelter

Arbitration applied this principle in the following terms:

“[U]nder the principles of international law, . . . no State

has the right to use or permit the use of its territory in such
a manner as to cause injury by fumes in or to the territory
of another or the properties or persons therein, when the

463
Dispute concerning Construction of a Road in Costa Rica along the San Juan River (Nicaragua
464Costa Rica), NM, Chapter 4, especially paras. 4.33-4.36.
Arbitral Award, 4 April 1928, Island of Palmas (Netherlands v. United States of America),
UNRIAA, vol. II, P. 839.
465I.C.J., Judgment, 9 April 1949, Corfu Channel (United Kingdom of Great Britain and Northern
Ireland v. Albania), I.C.J. Reports 1949, p. 22.

152remain applicable as long as they are not contradicted by the 1858 Treaty of

Limits. In this respect, Nic aragua draws attention once more to the authorities

463
referred to in Chapter 4 of its Memorial in the Road case, beginning with the

Award in the Island of Palmas case, in which the arbitrator considered that

territorial sovereignty:

“has a corollary duty: the obligation to protect within the
territory the rights of other States, in particular their right to
integrity and inviolability in peace and in war, together with
the rights which each State may claim for its nationals in
464
foreign territory.”

4.8 This Court itself confirmed the principle in the Corfu Channel case

when it referred in its 1949 Judgment to the obligation of every State “not to

allow knowingly its territory to be used for acts contrary to the rights of other

465
States.”

4.9 In the context of transbou ndary pollution, which is involved in the

present case, the arbitral tribunal in the well -known 1941 Trail Smelter

Arbitration applied this principle in the following terms:

“[U]nder the principles of international law, . . . no State

has the right to use or permit the use of its territory in such
a manner as to cause injury by fumes in or to the territory
of another or the properties or persons therein, when the

463
Dispute concerning Construction of a Road in Costa Rica along the San Juan River (Nicaragua
464Costa Rica), NM, Chapter 4, especially paras. 4.33-4.36.
Arbitral Award, 4 April 1928, Island of Palmas (Netherlands v. United States of America),
UNRIAA, vol. II, P. 839.
465I.C.J., Judgment, 9 April 1949, Corfu Channel (United Kingdom of Great Britain and Northern
Ireland v. Albania), I.C.J. Reports 1949, p. 22. sites, many of which are located entirely within the jurisdiction of a State, is

illustrated by resolutions adopted by the CoP concerning Ukraine’s Bystroe

navigation canal. The Bystroe canal is a project located in Ukraine’s portion of

the Danube Delta, in a Ramsar protected area. This project, although wholly

within Ukrainian territory, has caused the Ramsar CoP to adopt resolutions calling

for Ukraine to:

“a) suspend further works pending a full environmental
impact assessment being conducted and its findings acted
upon;

b) make available full documentation including the findings
of the environmental impact assessment for Phase II of the
project to all stakeholders, including the government of
Romania as a potentially affected State;

c) ensure that compensatory provision is made for any

damage to the ecological character of desig nated Ramsar
sites and other wetlands caused by the works which have
already been carried out;

d) establish, in cooperation with relevant international

organizations and the government of Romania, a
programme of international monitoring of the ecological
character of the Ramsar sites and Danube Delta Biosphere
Reserve, in line with the Convention's guidance on wetland
monitoring (Annex to Resolution VI.1; Ramsar Wise Use

Handbook 8); and

e) in line with Article 5 of the Convention, apply
international norms in the provision of information,
consultation and involvement in decision-making processes
469
of all stakeholders concerning Phase II of the project; ”

and to

469
Ramsar CoP Resolution IX.15, para. 27(iv) (Kampala, 2005), available at
http://www.ramsar.org/cda/en/ramsar-documents-resol-resolution-ix-15-th…-
107%5E23476_4000_0__.

154sites, many of which are located entirely within the jurisdiction of a State, is

illustrated by resolutions adopted by the CoP concerning Ukraine’s Bystroe

navigation canal. The Bystroe canal is a project located in Ukraine’s portion of

the Danube Delta, in a Ramsar protected area. This project, although wholly

within Ukrainian territory, has caused the Ramsar CoP to adopt resolutions calling

for Ukraine to:

“a) suspend further works pending a full environmental
impact assessment being conducted and its findings acted
upon;

b) make available full documentation including the findings
of the environmental impact assessment for Phase II of the
project to all stakeholders, including the government of
Romania as a potentially affected State;

c) ensure that compensatory provision is made for any

damage to the ecological character of desig nated Ramsar
sites and other wetlands caused by the works which have
already been carried out;

d) establish, in cooperation with relevant international

organizations and the government of Romania, a
programme of international monitoring of the ecological
character of the Ramsar sites and Danube Delta Biosphere
Reserve, in line with the Convention's guidance on wetland
monitoring (Annex to Resolution VI.1; Ramsar Wise Use

Handbook 8); and

e) in line with Article 5 of the Convention, apply
international norms in the provision of information,
consultation and involvement in decision-making processes
469
of all stakeholders concerning Phase II of the project; ”

and to

469
Ramsar CoP Resolution IX.15, para. 27(iv) (Kampala, 2005), available at
http://www.ramsar.org/cda/en/ramsar-documents-resol-resolution-ix-15-th…-
107%5E23476_4000_0__. “uncontestable, being prior to that of the inhabitants of Color ado by hundreds of

472
years…” Harmon stated, in response to a request by the State Department for a

legal opinion: “The fundamental principle of international law is the absolute

473
sovereignty of every nation, as against all others, within its own territory.” He

concluded:

“The case presented is a novel one. Whether the
circumstances make it possible or proper to take any action
from considerations of comity is a question which does not

pertain to the Department [of Justice]; but that question
should be decide d as one of policy only, because, in my
opinion, the rules, principles, and precedents of
international law impose no liability or obligation upon the
474
United States.”

In other words, in Attorney General Harmon’s opinion, the United States could do

whatever it wished with the river within its own territory regardless of the

consequences for Mexico. “[I]nternational law [would] impose no liability or

obligation upon the United States” for any harm caused to the downstream State.

The doctrine has been widely criticized and is today universally repudiated,

including by the United States, and was not followed in the dispute that gave rise

to it. That dispute was resolved by the conclusion in 1906 of the Convention

between the United States of America and Mexico concerning the Equitable

Distribution of the Waters of the Rio Grande for Irrigation Purposes. 475The treaty

provides for the United States to construct a storage dam in New Mexico from

47As quoted in 21 Op. Att’y Gen. p. 277 (1895).
47Ibid., p. 281.
47Ibid., p. 283.
47Washington, 21 May 1906, United States Treaty Series, No. 455.

156“uncontestable, being prior to that of the inhabitants of Color ado by hundreds of

472
years…” Harmon stated, in response to a request by the State Department for a

legal opinion: “The fundamental principle of international law is the absolute

473
sovereignty of every nation, as against all others, within its own territory.” He

concluded:

“The case presented is a novel one. Whether the
circumstances make it possible or proper to take any action
from considerations of comity is a question which does not

pertain to the Department [of Justice]; but that question
should be decide d as one of policy only, because, in my
opinion, the rules, principles, and precedents of
international law impose no liability or obligation upon the
474
United States.”

In other words, in Attorney General Harmon’s opinion, the United States could do

whatever it wished with the river within its own territory regardless of the

consequences for Mexico. “[I]nternational law [would] impose no liability or

obligation upon the United States” for any harm caused to the downstream State.

The doctrine has been widely criticized and is today universally repudiated,

including by the United States, and was not followed in the dispute that gave rise

to it. That dispute was resolved by the conclusion in 1906 of the Convention

between the United States of America and Mexico concerning the Equitable

Distribution of the Waters of the Rio Grande for Irrigation Purposes. 475 The treaty

provides for the United States to construct a storage dam in New Mexico from

472As quoted in 21 Op. Att’y Gen. p. 277 (1895).
473Ibid., p. 281.
474Ibid., p. 283.
475Washington, 21 May 1906, United States Treaty Series, No. 455. obligation of notification; and an obligation not to cause significant transboundary

harm.” 478But clearly the recognition of these three principles by both Parties does

not prevent them from having strong differences as to their application in the

instant case. The breaches by Costa Rica of these remaining general rules, which

have not been supplanted by the Treaty, are dealt with in Chapter 6 of this Reply.

478
CRCM, para. 5.6.

158obligation of notification; and an obligation not to cause significant transboundary

harm.” 478But clearly the recognition of these three principles by both Parties does

not prevent them from having strong differences as to their application in the

instant case. The breaches by Costa Rica of these remaining general rules, which

have not been supplanted by the Treaty, are dealt with in Chapter 6 of this Reply.

478
CRCM, para. 5.6. assimilated to an ‘invasion’ or violation of sovereignty or
territorial integrity. Costa Rica has not exercised any State
activity in the territory of Nicaragua by undertaking works

on its road infrastructure entirely on its own territory. Nor
has it proceeded to dump material into the San Juan
River.” 480

481
5.4 This is untrue . As Nicaragua explained in its Memorial and

reaffirmed in Chapter 2 of the present Reply, Costa Ri ca’s road construction has

caused and continues to cause significant harm to the San Juan River – that is, to

Nicaragua’s territory. By virtue of Article VI of the 1858 Treaty of Limits ,

Nicaragua has exclusively the dominion and sovereign jurisdiction over the River.

5.5 Far from decreasing since the Memorial was submitted, the harm

has, in fact, increased. By no means is this a natural phenomenon. As clearly

established in the experts reports annexed to this Reply, the harm results directly

from the poor construction of the road and its defects . In his Report, Professor

Kondolf concludes that “[e]rosion has visibly worsened since I first observed Rte

1856 in October 2012” and that “[t]he progression of erosion and delivery of large

quantities of sediment to the Rio San Juan is obvious in sequences of aerial

(helicopter) photographs and cloud-free satellite imagery that has become

available.” 482 Similarly, Mr . Hagans and Dr . Weaver, two eminently qualified

geomorphologists report that:

“A review of paired obl ique aerial photographs taken from

helicopters in October 2012 and May 2014 illustrates the

480CRCM, para. 4.9.
481NM, Chapter 3, pp. 45-121.
4822014 Kondolf Report, Section 3 (NR, Vol. II, Annex 1).

160 assimilated to an ‘invasion’ or violation of sovereignty or
territorial integrity. Costa Rica has not exercised any State
activity in the territory of Nicaragua by undertaking works

on its road infrastructure entirely on its own territory. Nor
has it proceeded to dump material into the San Juan
River.” 480

481
5.4 This is untrue . As Nicaragua explained in its Memorial and

reaffirmed in Chapter 2 of the present Reply, Costa Ri ca’s road construction has

caused and continues to cause significant harm to the San Juan River – that is, to

Nicaragua’s territory. By virtue of Article VI of the 1858 Treaty of Limits ,

Nicaragua has exclusively the dominion and sovereign jurisdiction over the River.

5.5 Far from decreasing since the Memorial was submitted, the harm

has, in fact, increased. By no means is this a natural phenomenon. As clearly

established in the experts reports annexed to this Reply, the harm results directly

from the poor construction of the road and its defects . In his Report, Professor

Kondolf concludes that “[e]rosion has visibly worsened since I first observed Rte

1856 in October 2012” and that “[t]he progression of erosion and delivery of large

quantities of sediment to the Rio San Juan is obvious in sequences of aerial

(helicopter) photographs and cloud-free satellite imagery that has become

available.” 482 Similarly, Mr . Hagans and Dr . Weaver, two eminently qualified

geomorphologists report that:

“A review of paired obl ique aerial photographs taken from

helicopters in October 2012 and May 2014 illustrates the

480CRCM, para. 4.9.
481NM, Chapter 3, pp. 45-121.
4822014 Kondolf Report, Section 3 (NR, Vol. II, Annex 1). 490
1856 range from 61,000 (Thorne) to 240,000 (Kondolf) tons per year.”

Therefore, the “ construction of Route 1856 has contributed a very substantial

amount of sediment to the Río San Juan compared to the circumstances prior to

491
deforestation.”

5.8 This causal relationship between the road and the sedimentation of

the River is accepted in barely veiled terms by Costa Rica’s own experts. Thus,

Professor Thorne acknowledges that Costa Rica’s so-called mitigation measures

“are part of ongoing efforts intended to reduce erosion risks stemming from the

way the Road was constructed in 2011” but that “they are not intended to provide

a permanent solution to erosion issues. ” 492The simple fact that “ work has been

493
carried out to protect the Road and to mitigate the effects of the Road” is a clear

recognition of its initial misconception and defects.

5.9 Costa Rica attempts to minimize the adverse impact of its conduct

494
on the San Juan River. Nicaragua disagrees and has established that the harm

caused to the River by the road is far from negligible. But even accepting the

absence of “long-term effect on the river by aggradations of the river channel …

caused by additional sediment from the construction on the road” accepted prima

490Ibid.
491Ibid.
492C. Thorne, Assessment of the Impact of the Construction of the Border Road in Costa Rica on
the San Juan River, November 2013, p. 118, para. 11.18 (CRCM, Vol. I, Appendix A, p. 264; see

also p. 242). See also C. Thorne, Report on the Risk of Irreversible Harm to the Río San Juan
relating to the Construction of the Border Road in Costa Rica, 4 November 2013 p. 41, para. 90
(CRCM, vol. II, Annex 9, p. 495).
493CRCM, para. 3.45. See also para. 2.38.
494See CRCM, Chapter 3, pp. 47-86.

162 490
1856 range from 61,000 (Thorne) to 240,000 (Kondolf) tons per year.”

Therefore, the “ construction of Route 1856 has contributed a very substantial

amount of sediment to the Río San Juan compared to the circumstances prior to

491
deforestation.”

5.8 This causal relationship between the road and the sedimentation of

the River is accepted in barely veiled terms by Costa Rica’s own experts. Thus,

Professor Thorne acknowledges that Costa Rica’s so-called mitigation measures

“are part of ongoing efforts intended to reduce erosion risks stemming from the

way the Road was constructed in 2011” but that “they are not intended to provide

a permanent solution to erosion issues. ” 492 The simple fact that “ work has been

493
carried out to protect the Road and to mitigate the effects of the Road” is a clear

recognition of its initial misconception and defects.

5.9 Costa Rica attempts to minimize the adverse impact of its conduct

494
on the San Juan River. Nicaragua disagrees and has established that the harm

caused to the River by the road is far from negligible. But even accepting the

absence of “long-term effect on the river by aggradations of the river channel …

caused by additional sediment from the construction on the road” accepted prima

490Ibid.
491Ibid.
492C. Thorne, Assessment of the Impact of the Construction of the Border Road in Costa Rica on
the San Juan River, November 2013, p. 118, para. 11.18 (CRCM, Vol. I, Appendix A, p. 264; see

also p. 242). See also C. Thorne, Report on the Risk of Irreversible Harm to the Río San Juan
relating to the Construction of the Border Road in Costa Rica, 4 November 2013 p. 41, para. 90
(CRCM, vol. II, Annex 9, p. 495).
493CRCM, para. 3.45. See also para. 2.38.
494See CRCM, Chapter 3, pp. 47-86. conduct of an international obligation of the State. The
question is whether those two necessary conditions are also
sufficient. It is sometimes said that international

responsibility is not engaged by conduct of a State in
disregard of its obligations unless some further element
exists, in particular, ‘damage’ to another State. But whether
such elements are required depends on the content of the

primary o498gation, and there is no general rule in this
respect.”

5.12 Clearly the principle established in Article VI of the 1858 Treaty is

self-sufficient and does not incorporate any requirement of damage to be

breached. As so clearly expressed by Arbitrator Max Huber in the Island of

Palmas arbitration:

“Sovereignty in the relations between States signifies
independence. Independence in regard to a portion of the
globe is the right to exercise therein, to the exclusion of any

other State, the functions of a Stat e. […I]t may be stated
that territorial sovereignty belongs always to one, or in
exceptional circumstances to several States, to the
exclusion of all others.” 499

As a consequence, a State “may not exercise its power in any form in the territory

of another State.” 500

5.13 Finally, Costa Rica seems to argue that its responsibility is

excluded because the harm caused to the River – that is to Nicaragua’s territory –

was not intentional. 501 Costa Rica is mistaken about this too.

498
Commentary on the Articles on responsibility of States for internationally wrongful acts,
Yearbook of the International Law Commission , 2001, vol. II, Part Two, p. 36, para. (9) of the
499mentary of Article 2.
Arbitral Award, 4 April 1928, Island of Palmas , UNRIAA, vol. II, p. 838;see also I.C.J.,
Judgment, 9 April 1949, Corfu Channel (United Kingdom of great Britain and Northern Ireland v.
Albania), I.C.J. Reports 1949 , p. 22: “[b]eween independent States, respect for territorial
sovereignty is an essential foundation of international relations.”
500P.C.I.J., Judgment, 7 September 1927, The Case of the S.S. “Lotus”, Series A, No. 10, p. 18.

164 conduct of an international obligation of the State. The
question is whether those two necessary conditions are also
sufficient. It is sometimes said that international

responsibility is not engaged by conduct of a State in
disregard of its obligations unless some further element
exists, in particular, ‘damage’ to another State. But whether
such elements are required depends on the content of the

primary o498gation, and there is no general rule in this
respect.”

5.12 Clearly the principle established in Article VI of the 1858 Treaty is

self-sufficient and does not incorporate any requirement of damage to be

breached. As so clearly expressed by Arbitrator Max Huber in the Island of

Palmas arbitration:

“Sovereignty in the relations between States signifies
independence. Independence in regard to a portion of the
globe is the right to exercise therein, to the exclusion of any

other State, the functions of a Stat e. […I]t may be stated
that territorial sovereignty belongs always to one, or in
exceptional circumstances to several States, to the
exclusion of all others.” 499

As a consequence, a State “may not exercise its power in any form in the territory

of another State.” 500

5.13 Finally, Costa Rica seems to argue that its responsibility is

excluded because the harm caused to the River – that is to Nicaragua’s territory –

was not intentional. 501 Costa Rica is mistaken about this too.

498
Commentary on the Articles on responsibility of States for internationally wrongful acts,
Yearbook of the International Law Commission , 2001, vol. II, Part Two, p. 36, para. (9) of the
499mentary of Article 2.
Arbitral Award, 4 April 1928, Island of Palmas , UNRIAA, vol. II, p. 838;see also I.C.J.,
Judgment, 9 April 1949, Corfu Channel (United Kingdom of great Britain and Northern Ireland v.
Albania), I.C.J. Reports 1949 , p. 22: “[b]eween independent States, respect for territorial
sovereignty is an essential foundation of international relations.”
500P.C.I.J., Judgment, 7 September 1927, The Case of the S.S. “Lotus”, Series A, No. 10, p. 18. erosion at Dr. Kondolf’s Severely Eroding Site 4.1 , speaks for itself, as do all the

others presented throughout this Reply.

Figure 5.1. Severely Eroding Site 4.1, located 8.2-8.7 km downstream of Mojon II.

5.16 Moreover, even if the harm caused to the San Juan was not

intentional (quod non), Costa Rica’s international responsibility would still be

engaged. As explained by the ILC, fault does not constitute “a necessary element

of the internationally wrongful act of a State”:

“This is certainly not the case if by ‘fault’ one unde rstands
the existence, for example, of an intention to harm. In the
absence of any specific requirement of a mental element in

terms of the primary obligation, it is only the a505of a State
that matters, independently of any intention.”

505Commentary of Article 2 of the ILC Articles on Responsibility of States for Internationally
Wrongful Acts, Yearbook of the International Law Commis sion, 2001, vol. II, Part Two, p. 36,
para. 10.

166erosion at Dr. Kondolf’s Severely Eroding Site 4.1 , speaks for itself, as do all the

others presented throughout this Reply.

Figure 5.1. Severely Eroding Site 4.1, located 8.2-8.7 km downstream of Mojon II.

5.16 Moreover, even if the harm caused to the San Juan was not

intentional (quod non), Costa Rica’s international responsibility would still be

engaged. As explained by the ILC, fault does not constitute “a necessary element

of the internationally wrongful act of a State”:

“This is certainly not the case if by ‘fault’ one unde rstands
the existence, for example, of an intention to harm. In the
absence of any specific requirement of a mental element in

terms of the primary obligation, it is only the ac505f a State
that matters, independently of any intention.”

505Commentary of Article 2 of the ILC Articles on Responsibility of States for Internationally
Wrongful Acts, Yearbook of the International Law Commis sion, 2001, vol. II, Part Two, p. 36,
para. 10. Figure 5.2. Delta deposit below Severely Eroding Site 9.4. Photograph from March 30, 2014.

Figure 5.3. Delta deposit below Severely Eroding Site 9.4. Photograph from March 30, 2014.

168Figure 5.2. Delta deposit below Severely Eroding Site 9.4. Photograph from March 30, 2014. Figure 5.4. Delta deposit from fill material of failed crossing 20.3 km downstream of Mojon 2
extending into the San Juan River. Photograph from March 31, 2014.

Figure 5.3. Delta deposit below Severely Eroding Site 9.4. Photograph from March 30, 2014. 5.20 As Mr. Hagans & Dr. Weaver explain in their 2014 Report, these

deltas will continue to enlarge in the absence of truly effective remediation

509
measures.

5.21 The territorial integrity of States is one of the most fun damental

principles of contemporary international law. As the Court put it, in line with

Article 2 (4) of the United Nations Charter: 510

“Between independent States, respect for territorial
sovereignty is an essential foundation of international
relations.”511

B. BREACH OF NICARAGUA’S RIGHT OF NAVIGATION
AND OF OTHER GENERAL RIGHTS

5.22 Costa Rica is exclusively concerned with preserving its own

limited right of navigation over the San Juan de Nicaragua River, which it

describes as “one of the essential bases of the fundamental instrument between the

two countries” and as “[t]he condition for Costa Rica’s acceptance of Nicaraguan

512
sovereignty over the entire waters of the San Juan River .” In focusing on its

own limited right, Costa Rica overlooks Nicaragua’s unlimited right to navigation

on the River over which it has “ exclusively the dominion and sovereign

jurisdiction.”513 This oversight includes Nicaragua’s sovereign right to other uses

509
Hagans & Weaver Report, Section II (NR, Vol. II, Annex 2).
510See also Resolution 2625 (XXV), 24 October 1970, “Declaration on Principles of Internatio nal
Law concerning Friendly Relations and Co-operation among States in accordance with the Charter
of the United Nations”.
51I.C.J., Judgment, 4 April 1949, Corfu Channel case, Reports 1949, p. 35.
51CRCM, para. 4.19. See also para. 4.4.
511858 Treaty of Limits, Article VI.

170 5.20 As Mr. Hagans & Dr. Weaver explain in their 2014 Report, these

deltas will continue to enlarge in the absence of truly effective remediation

509
measures.

5.21 The territorial integrity of States is one of the most fun damental

principles of contemporary international law. As the Court put it, in line with

Article 2 (4) of the United Nations Charter: 510

“Between independent States, respect for territorial
sovereignty is an essential foundation of international
relations.”511

B. BREACH OF NICARAGUA’S RIGHT OF NAVIGATION
AND OF OTHER GENERAL RIGHTS

5.22 Costa Rica is exclusively concerned with preserving its own

limited right of navigation over the San Juan de Nicaragua River, which it

describes as “one of the essential bases of the fundamental instrument between the

two countries” and as “[t]he condition for Costa Rica’s acceptance of Nicaraguan

512
sovereignty over the entire waters of the San Juan River .” In focusing on its

own limited right, Costa Rica overlooks Nicaragua’s unlimited right to navigation

on the River over which it has “ exclusively the dominion and sovereign

jurisdiction.”513 This oversight includes Nicaragua’s sovereign right to other uses

509
Hagans & Weaver Report, Section II (NR, Vol. II, Annex 2).
510See also Resolution 2625 (XXV), 24 October 1970, “Declaration on Principles of Internatio nal
Law concerning Friendly Relations and Co-operation among States in accordance with the Charter
of the United Nations”.
511I.C.J., Judgment, 4 April 1949, Corfu Channel case, Reports 1949, p. 35.
512CRCM, para. 4.19. See also para. 4.4.
5131858 Treaty of Limits, Article VI. south bank. ” 516 For instance, at Severely Eroding Sites 9.4 to 9.6, significant

517
deltas of sediments are clearly visible. These and other Road-derived deltas on

the River have a clear negative impact on navigation, as it is no longer possible to

navigate the River in the locations the deltas have come to occupy. The fragments

of culverts that have been transferred to the River through the washing out of

Costa Rica’s improperly constructed stream crossings have also created obstacles

to safe navigation, and Nicaragua has incurred the cost of removing this debris. 518

5.25 While Nicaragua has, by virtue of the 1858 Treaty, an obligation to

respect Costa Rica’s limited right of navigation on the River, it goes without

saying that this obligation is even more pressing in respect of Costa Rica. To be

clear, Nicaragua is not suggesting that the 1858 Treaty of Limits prevent s Costa

Rica from carrying out road projects on its own territory. But it must do so in a

way that does not result in the trespass of Nicaragua’s territory (including the

River) or the impairment of the navigation or other uses of the River.

C. BREACHES OF THE OBLIGATION OF NOTIFICATION

5.26 In paragraphs 4.13 to 4.17 of its Counter -Memorial, Costa Rica

tries to demonstrate that it “is not obliged under the Treaty of Limits to ‘notify’

Nicaragua”. This argument can be dispatched briefly.

512014 Kondolf Report, Section 11 (NR, Vol. II, Annex 1).
51See supra Figures 2.2-2.5, 2.9-2.11.
51See figures 2.5, 2.13.

172south bank. ” 516 For instance, at Severely Eroding Sites 9.4 to 9.6, significant

517
deltas of sediments are clearly visible. These and other Road-derived deltas on

the River have a clear negative impact on navigation, as it is no longer possible to

navigate the River in the locations the deltas have come to occupy. The fragments

of culverts that have been transferred to the River through the washing out of

Costa Rica’s improperly constructed stream crossings have also created obstacles

to safe navigation, and Nicaragua has incurred the cost of removing this debris. 518

5.25 While Nicaragua has, by virtue of the 1858 Treaty, an obligation to

respect Costa Rica’s limited right of navigation on the River, it goes without

saying that this obligation is even more pressing in respect of Costa Rica. To be

clear, Nicaragua is not suggesting that the 1858 Treaty of Limits prevent s Costa

Rica from carrying out road projects on its own territory. But it must do so in a

way that does not result in the trespass of Nicaragua’s territory (including the

River) or the impairment of the navigation or other uses of the River.

C. BREACHES OF THE OBLIGATION OF NOTIFICATION

5.26 In paragraphs 4.13 to 4.17 of its Counter -Memorial, Costa Rica

tries to demonstrate that it “is not obliged under the Treaty of Limits to ‘notify’

Nicaragua”. This argument can be dispatched briefly.

5162014 Kondolf Report, Section 11 (NR, Vol. II, Annex 1).
517See supra Figures 2.2-2.5, 2.9-2.11.
518See figures 2.5, 2.13. particular, in order to facilitate and expedite traffic on the

Pan American Highway and on the San Juan River within
the terms of the Treaty of 15 April 1858 and its
interpretation given by arbitration on 22 March 1888, and
also in order to facilitate thos e transport services which

may be provided to the territory of one Party by enterprises
which are nationals of the other.’

It is difficult to see how the obligation, set out under the terms of the 1956

Agreement, to collaborate to facilitate traffic on th e San Juan and to
facilitate transport services being provided in the territory of one country
by the nationals of the other could be met without Nicaragua notifying
Costa Rica of relevant regulations which it adopts.

95. The second factor indicating that Nicaragua is obliged to notify the
adoption of the regulations lies in its very subject -matter: navigation on a

river in which two States have rights, the one as sovereign, the other to
freedom of navigation. Such a requirement arises from the practical
necessities of navigation on such a waterway. If the various purposes of
navigation are to be achieved, it must be subject to some discipline, a

discipline whi522depends on proper notification of the relevant
regulations.”

5.29 Not only do these factors apply mutatis mutandis to the present

case, they apply a fortiori, because:

- we are not in the presence of “regulations” only, but of actual concrete

acts;

- these acts are not only detrimental to the navigation on the River, but on

the very sovereignty of Nicaragua over its waters, guaranteed by Article VI of the

1858 Treaty.

5.30 In this respect, Nicaragua observes that Costa Rica does not even

try to argue that it notified Nicaragua about the road project. The reason is

522I.C.J., Judgement, 13 July 2009,Dispute regarding Navigational and Related Rights (Costa
Rica v. Nicaragua), I.C.J. Reports 2009, pp. 251-252, paras. 94-95.

174 particular, in order to facilitate and expedite traffic on the

Pan American Highway and on the San Juan River within
the terms of the Treaty of 15 April 1858 and its
interpretation given by arbitration on 22 March 1888, and
also in order to facilitate thos e transport services which

may be provided to the territory of one Party by enterprises
which are nationals of the other.’

It is difficult to see how the obligation, set out under the terms of the 1956

Agreement, to collaborate to facilitate traffic on th e San Juan and to
facilitate transport services being provided in the territory of one country
by the nationals of the other could be met without Nicaragua notifying
Costa Rica of relevant regulations which it adopts.

95. The second factor indicating that Nicaragua is obliged to notify the
adoption of the regulations lies in its very subject -matter: navigation on a

river in which two States have rights, the one as sovereign, the other to
freedom of navigation. Such a requirement arises from the practical
necessities of navigation on such a waterway. If the various purposes of
navigation are to be achieved, it must be subject to some discipline, a

discipline whi522depends on proper notification of the relevant
regulations.”

5.29 Not only do these factors apply mutatis mutandis to the present

case, they apply a fortiori, because:

- we are not in the presence of “regulations” only, but of actual concrete

acts;

- these acts are not only detrimental to the navigation on the River, but on

the very sovereignty of Nicaragua over its waters, guaranteed by Article VI of the

1858 Treaty.

5.30 In this respect, Nicaragua observes that Costa Rica does not even

try to argue that it notified Nicaragua about the road project. The reason is

522I.C.J., Judgement, 13 July 2009,Dispute regarding Navigational and Related Rights (Costa
Rica v. Nicaragua), I.C.J. Reports 2009, pp. 251-252, paras. 94-95. be resumed until ‘the end of 2014 or the beginning of the year 2015.’” 526 Once

again, Costa Rica refused to provide any information to Nicaragua, stating that

“Costa Rica never said that it would suspend the works. ”527

5.32 Any such works must be notified to Nicaragua. Such notification is

the only means by which Nicaragua (and neutral experts who might be appointed

by the Court) could be sure that the “remediation works” envisaged by Costa Rica

actually work, unlike those it has already undertaken.

5.33 Finally, even if the obligation to notify does not stem from the

528
1858 Treaty, it would, as shown in the next Chapter , nevertheless result from

general international law. In either case , it plainly has not been respected by

Costa Rica.

5.34 As shown in the pr esent Chapter, Costa Rica has breached and

continues to breach several of its obligations to Nicaragua derived from the 1858

Treaty of Limits. By executing ill-considered road works with no prior planning,

the result of which has been the delivery of significant amounts of sediment and

other materials to the River, Costa Rica has:

(i) violated the territorial integrity and sovereignty of Nicaragua, as

established by the 1858 Treaty of Limits;

526Note from the Minister of Foreign Affairs of Nicaragua to the Minister of Foreign Affairs of
Costa Rica, Ref: MRE/DM/645//12/13, 17 December 2013 – italics in the original text. . (NR, Vol.
II, Annex 7)
527Note from the Minister of Foreign Affairs of Costa Rica, to the Minister of Foreign A ffairs of
Nicaragua, Ref.: DM-AM-704-13, 19 December 2013.(NR, Vol. II, Annex 8)
52See Chapter 6, Section D.

176be resumed until ‘the end of 2014 or the beginning of the year 2015.’” 526 Once

again, Costa Rica refused to provide any information to Nicaragua, stating that

“Costa Rica never said that it would suspend the works. ”527

5.32 Any such works must be notified to Nicaragua. Such notification is

the only means by which Nicaragua (and neutral experts who might be appointed

by the Court) could be sure that the “remediation works” envisaged by Costa Rica

actually work, unlike those it has already undertaken.

5.33 Finally, even if the obligation to notify does not stem from the

528
1858 Treaty, it would, as shown in the next Chapter , nevertheless result from

general international law. In either case , it plainly has not been respected by

Costa Rica.

5.34 As shown in the pr esent Chapter, Costa Rica has breached and

continues to breach several of its obligations to Nicaragua derived from the 1858

Treaty of Limits. By executing ill-considered road works with no prior planning,

the result of which has been the delivery of significant amounts of sediment and

other materials to the River, Costa Rica has:

(i) violated the territorial integrity and sovereignty of Nicaragua, as

established by the 1858 Treaty of Limits;

526Note from the Minister of Foreign Affairs of Nicaragua to the Minister of Foreign Affairs of
Costa Rica, Ref: MRE/DM/645//12/13, 17 December 2013 – italics in the original text. . (NR, Vol.
II, Annex 7)
527Note from the Minister of Foreign Affairs of Costa Rica, to the Minister of Foreign A ffairs of
Nicaragua, Ref.: DM-AM-704-13, 19 December 2013.(NR, Vol. II, Annex 8)
528See Chapter 6, Section D.178 CHAPTER 6

COSTA RICA’S BREACHES OF ITS ENVIRONMENTAL

OBLIGATIONS

A. INTRODUCTION

6.1 In Chapter 5 of its Counter -Memorial, “Alleged Breaches of

Obligations in respect of the Environment,” Costa Rica denies that the reckless

and unplanned manner in which it launched into construction of Route 1856 and

the resulting sediment and debris delivered from t he Road project into

Nicaragua’s sovereign territory, the San Juan de Nicaragua River, breached any of

its obligations under International Environmental Law. Costa Rica’s case comes

down to this: it breached no international environmental obligations bec ause (a)

everything it did was in its own territory and therefore “need not be explained or

529
justified at the international level, and still less to a neighbouring State;” it

acted in response to an ostensible emergency created by Nicaragua; and (c) th e

amount of soil, sediment and other debris that the Road project has caused to be

transported to the San Juan River is small in comparison to the already heavy

sediment load carried by the river and therefore gives rise to no legal obligations

vis-à-vis Nicaragua.

6.2 The present chapter will respond to these arguments. It will show

that they have no merit, and reflect a misunderstanding and mischaracterization of

Costa Rica’s obligations under International Environmental Law.

529
CRCM p. 107, para. 5.3.

179 530
6.3 Section B of the present Chapte r will again demonstrate that

Costa Rica’s invocation of an “emergency” under its national law does not excuse

its violations of international law. Section C will show that Costa Rica breached

the obligation to prepare, in advance, an environmental impac t assessment

concerning its Road project. Section D will demonstrate that Costa Rica breached

the obligation to notify Nicaragua prior to commencing construction on the Road

project. Section E will show that Costa Rica breached the obligation not to caus e

significant transboundary harm. Section F will respond to Costa Rica’s

contention that the manner in which the Road was constructed breaches no treaties

to which both States are parties. Conclusions will be set forth in Section G.

B. COSTA RICA’S INVOCATION OF AN “EMERGENCY”
UNDER ITS NATIONAL LAW DOES NOT EXCUSE ITS

VIOLATIONS OF INTERNATIONAL LAW.

6.4 Costa Rica contends that the national emergency it declared

exempts it from all otherwise -applicable obligations, not only under its own law

but also under int ernational law. Nicaragua has shown in its Memorial that this

531
contention lacks merit. In its Counter-Memorial, Costa Rica rehearses the same

arguments it had made earlier in support of its position that the Emergency Decree

532
issued by its President on 21 February 2011 exempts it from its international

obligations in respect of the Road project. This section will respond to the

530Nicaragua had addressed the emergency decree and its ineffectiveness to exempt Costa Rica
from its international obligations in its Memorial, NM, Chapter 2, pp. 19 -30, paras. 2.15-2.26; and
Chapter 5, paras. 5.14-5.27.
531Ibid.
532NM, Annex 11.

180 530
6.3 Section B of the present Chapte r will again demonstrate that

Costa Rica’s invocation of an “emergency” under its national law does not excuse

its violations of international law. Section C will show that Costa Rica breached

the obligation to prepare, in advance, an environmental impac t assessment

concerning its Road project. Section D will demonstrate that Costa Rica breached

the obligation to notify Nicaragua prior to commencing construction on the Road

project. Section E will show that Costa Rica breached the obligation not to caus e

significant transboundary harm. Section F will respond to Costa Rica’s

contention that the manner in which the Road was constructed breaches no treaties

to which both States are parties. Conclusions will be set forth in Section G.

B. COSTA RICA’S INVOCATION OF AN “EMERGENCY”
UNDER ITS NATIONAL LAW DOES NOT EXCUSE ITS

VIOLATIONS OF INTERNATIONAL LAW.

6.4 Costa Rica contends that the national emergency it declared

exempts it from all otherwise -applicable obligations, not only under its own law

but also under int ernational law. Nicaragua has shown in its Memorial that this

531
contention lacks merit. In its Counter-Memorial, Costa Rica rehearses the same

arguments it had made earlier in support of its position that the Emergency Decree

532
issued by its President on 21 February 2011 exempts it from its international

obligations in respect of the Road project. This section will respond to the

530Nicaragua had addressed the emergency decree and its ineffectiveness to exempt Costa Rica
from its international obligations in its Memorial, NM, Chapter 2, pp. 19 -30, paras. 2.15-2.26; and
Chapter 5, paras. 5.14-5.27.
531Ibid.
532NM, Annex 11. 535
preclude the wrongfulness of its conduct. According to the ILC, “necessity will

only rarely be available to excuse non -performance of an obligation and . . . it is

536
subject to strict limitations to safeguard against possible abuse.”

6.7 There being no circumstance precluding wrongfulness recognized

by international law for an “emergency” per se, necessity would be the

circumstance that is closest to what Costa Rica is claiming as a ground for

exempting itself from its international obligations – i.e., for precluding the

wrongfulness of its breaches. 537

6.8 Costa Rica responds that

“it would be appropriate as a matter of current international

law (as articulated by the Court) to have recourse to
domestic law. It follows that Nicaragua’s reference to
customary international law rules concerning states of
538
necessity is likewise inapposite. Costa Rica has not
invoked Article 25 of the ILC’s Articl es on State
Responsibility as Nicaragua correctly points out, and it is

not incumbent upon it to do so. As with other States, Costa
Rica’s domestic legislation does not require the conduct of
an environmental impact assessment in an emergency
situation, wh ile international law comprises a renvoi to
539
domestic law.”

6.9 As shown in the following section, the “ renvoi to domestic law”

referred to by the Court in Pulp Mills has to do with the content of an

535 Articles on Responsibility of States for internationally wrongful acts, Yearbook of the
International Law Commission 2001, Vol. II, Part Two, p. 26, Article 25, p. 80.
536
537Ibid.
538NM, p. 164, para. 5.27.
Interestingly, Costa Rica has pointed out that a “state of emergency” is defined under its law as:
“[A] [s]tatement made by the Executive Branch, by executive decree, based on a state of necessity
and urgency . . . .” CRCM, p. 37, para. 2.28 (emphasis added). (Footnote added).
539CRCM, p. 113, para. 5.15 (footnotes omitted).

182 535
preclude the wrongfulness of its conduct. According to the ILC, “necessity will

only rarely be available to excuse non -performance of an obligation and . . . it is

536
subject to strict limitations to safeguard against possible abuse.”

6.7 There being no circumstance precluding wrongfulness recognized

by international law for an “emergency” per se, necessity would be the

circumstance that is closest to what Costa Rica is claiming as a ground for

exempting itself from its international obligations – i.e., for precluding the

wrongfulness of its breaches. 537

6.8 Costa Rica responds that

“it would be appropriate as a matter of current international

law (as articulated by the Court) to have recourse to
domestic law. It follows that Nicaragua’s reference to
customary international law rules concerning states of
538
necessity is likewise inapposite. Costa Rica has not
invoked Article 25 of the ILC’s Articl es on State
Responsibility as Nicaragua correctly points out, and it is

not incumbent upon it to do so. As with other States, Costa
Rica’s domestic legislation does not require the conduct of
an environmental impact assessment in an emergency
situation, wh ile international law comprises a renvoi to
539
domestic law.”

6.9 As shown in the following section, the “ renvoi to domestic law”

referred to by the Court in Pulp Mills has to do with the content of an

535 Articles on Responsibility of States for internationally wrongful acts, Yearbook of the
International Law Commission 2001, Vol. II, Part Two, p. 26, Article 25, p. 80.
536
537Ibid.
538NM, p. 164, para. 5.27.
Interestingly, Costa Rica has pointed out that a “state of emergency” is defined under its law as:
“[A] [s]tatement made by the Executive Branch, by executive decree, based on a state of necessity
and urgency . . . .” CRCM, p. 37, para. 2.28 (emphasis added). (Footnote added).
539CRCM, p. 113, para. 5.15 (footnotes omitted). 6.11 Costa Rica plainly could not satisfy even the requirement of

imminence. A timeline will help to place Costa Rica’s emergency declaration in

context:

 On or about 18 October 2010, according to Costa Ric a,544

Nicaraguan workers began cleaning a caño leading from the San

Juan River to Harbor Head Lagoon.

 On 18 November 2010 Costa Rica brought the Certain Activities

case before the Court through an Applic ation filed on that date,

alleging that the caño being cleaned was in Costa Rican territory, -

something Nicaragua denies- and certain works of dredging on the

San Juan River.

 Also on 18 November 2010, having filed its Application, Costa

Rica submitted a Re quest for the indication of provisional

measures.

 According to Costa Rica (no notice having been given to

Nicaragua), construction of the Road commenced in December
545
2010.

 In January 2011, in the hearings on provisional measures sought by

Costa Rica in th e Certain Activities case, Nicaragua informed the

544
Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v. Nicaragua),
Application, p. 4, para. 4.
545Cases concerning Construction of a Road in Costa Rica along the San Juan River (icaragua
v. Costa Rica) and Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v.
Nicaragua), Provisional Measures Hearing, CR 2013/29, 6 November 2013, p. 14, para. 9
(Brenes). See also LANAMME Report, p. 5 : “Construction of the road . . . was announced in

December 2010 by authorities of the Government of Costa Rica to protect national sovereignty
and as a permanent solution allowing free traffic of both people and agricultural products in Costa
Rica’s north border region.” (NM, Vol. II, Annex 3, p. 209).

184 6.11 Costa Rica plainly could not satisfy even the requirement of

imminence. A timeline will help to place Costa Rica’s emergency declaration in

context:

 On or about 18 October 2010, according to Costa Ric a,544

Nicaraguan workers began cleaning a caño leading from the San

Juan River to Harbor Head Lagoon.

 On 18 November 2010 Costa Rica brought the Certain Activities

case before the Court through an Applic ation filed on that date,

alleging that the caño being cleaned was in Costa Rican territory, -

something Nicaragua denies- and certain works of dredging on the

San Juan River.

 Also on 18 November 2010, having filed its Application, Costa

Rica submitted a Re quest for the indication of provisional

measures.

 According to Costa Rica (no notice having been given to

Nicaragua), construction of the Road commenced in December
545
2010.

 In January 2011, in the hearings on provisional measures sought by

Costa Rica in th e Certain Activities case, Nicaragua informed the

544
Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v. Nicaragua),
Application, p. 4, para. 4.
545Cases concerning Construction of a Road in Costa Rica along the San Juan River (icaragua
v. Costa Rica) and Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v.
Nicaragua), Provisional Measures Hearing, CR 2013/29, 6 November 2013, p. 14, para. 9
(Brenes). See also LANAMME Report, p. 5 : “Construction of the road . . . was announced in

December 2010 by authorities of the Government of Costa Rica to protect national sovereignty
and as a permanent solution allowing free traffic of both people and agricultural products in Costa
Rica’s north border region.” (NM, Vol. II, Annex 3, p. 209).  It is reported that Giselle Alfaro, Supervisory Engineer at

CONAVI, does not exclude the possibility that the Road “may be

completed during the [current] Solis -Rivera administration,” 553

which will end in 2018.

6.12 This timeline exposes several important points. First, it will be

immediately evident that the “Emergency Decree,” by which Costa Rica claims to

have authorized construction of the Road without complying with any of its

internal or international obligations relating to the project, was actually issued two

months after construction of the Road had begun. Moreover, the Decree was not

implemented until some nine months after construction had commenced. Thus ,

the work on the Road project was not in fact authorized under Costa Rican law

when it began, according to the evidence provided by Costa Rica. Even if this is

normal procedure under Costa Rican law, which is prima facie doubtful, it is

certainly not normal, or even permissible, under international law.

6.13 Second, the timeline also shows clearly that even if Costa Rica

perceived that there was a grave and imminent pe ril – which Nicaragua has

demonstrated it could not, in fact, reasonably have done 554 – the action it took

bore no relation to the perceived peril that allegedly gave rise to the emergency.

A State facing an imminent threat would respond with measures that could be put

in place immediately, or at least quickly. The Road project is clearly not such a

553Rebeca Madrigal, Works on the Trail Paralyzed while Waiting for Designs and Modular
Bridges, crhoy.com, July 10, 2014. (NR, Vol. II, Annex 21).
554See, e.g., NM, p. 21, para. 2.17, recalling that in the hearings on provisional measures in
January, 2011, the Agent of Nicaragua informed the Court that: “no Nicaraguan military or other
governmental personnel have been present in the disputed area since December 2010.”

186  It is reported that Giselle Alfaro, Supervisory Engineer at

CONAVI, does not exclude the possibility that the Road “may be

completed during the [current] Solis -Rivera administration,” 553

which will end in 2018.

6.12 This timeline exposes several important points. First, it will be

immediately evident that the “Emergency Decree,” by which Costa Rica claims to

have authorized construction of the Road without complying with any of its

internal or international obligations relating to the project, was actually issued two

months after construction of the Road had begun. Moreover, the Decree was not

implemented until some nine months after construction had commenced. Thus ,

the work on the Road project was not in fact authorized under Costa Rican law

when it began, according to the evidence provided by Costa Rica. Even if this is

normal procedure under Costa Rican law, which is prima facie doubtful, it is

certainly not normal, or even permissible, under international law.

6.13 Second, the timeline also shows clearly that even if Costa Rica

perceived that there was a grave and imminent pe ril – which Nicaragua has

demonstrated it could not, in fact, reasonably have done 554– the action it took

bore no relation to the perceived peril that allegedly gave rise to the emergency.

A State facing an imminent threat would respond with measures that could be put

in place immediately, or at least quickly. The Road project is clearly not such a

553Rebeca Madrigal, Works on the Trail Paralyzed while Waiting for Designs and Modular
Bridges, crhoy.com, July 10, 2014. (NR, Vol. II, Annex 21).
554See, e.g., NM, p. 21, para. 2.17, recalling that in the hearings on provisional measures in
January, 2011, the Agent of Nicaragua informed the Court that: “no Nicaraguan military or other
governmental personnel have been present in the disputed area since December 2010.” 6.16 Moreover, it would have been impossible for the Road to reach

what is referred to as the “disputed territory” in the Certain Activities case 557

because the Colorado River branches off from the San Juan at the Road’s

terminus and would have to be spanned by a long bridge to allow traffic to reach

the other side. Even if such a bridge were constructed – and there is no indication

that one is planned – Costa Rica would still have to construct a road from the left

bank of the Colorado River to the area in dispute, something that would be very

difficult in the wetlands in the area. Thus , the Road bears no relationship

whatsoever to the cause of Costa Rica’s dispute with Nicaragua.

6.17 Costa Rica’s Emergency Decree and the Road project it made

possible under Costa Rican law not only bear no relation, in time or space, to the

actions taken by Nicaragua that allegedly precipitated them; they also fly in the

face of fundamental principles of international law, as noted in Nicaragua’s

Memorial. 558 For present purposes, Nicaragua will recall only the foundational

principle of international law that a State may not invoke its internal l aw as

justification for its failure to perform obligations under international law. This

principle is reflected in both Article 27 of the Vienna Convention on the Law of

559
Treaties, “Internal law and observance of treaties,” and Article 32 of the

Articles on Responsibility of States for Internationally Wrongful Acts,

557
See the Court’s Order of 8 March 2011, Certain Activities Carried Out By Nicaragua in the
Border Area (Costa Rica V. Nicaragua), Provisional Measures, Order of 8 March 2011, I.C.J.
Reports 2011 (I), p. 19, para. 55, identifying the disputed territory.
558NM, pp. 156-165, paras. 5.14-5.27.
559Vienna Convention on the Law of Treaties, 23 May 1969, 1155 U.N.T.S. 331, Article 27.

188 6.16 Moreover, it would have been impossible for the Road to reach

what is referred to as the “disputed territory” in the Certain Activities case 557

because the Colorado River branches off from the San Juan at the Road’s

terminus and would have to be spanned by a long bridge to allow traffic to reach

the other side. Even if such a bridge were constructed – and there is no indication

that one is planned – Costa Rica would still have to construct a road from the left

bank of the Colorado River to the area in dispute, something that would be very

difficult in the wetlands in the area. Thus , the Road bears no relationship

whatsoever to the cause of Costa Rica’s dispute with Nicaragua.

6.17 Costa Rica’s Emergency Decree and the Road project it made

possible under Costa Rican law not only bear no relation, in time or space, to the

actions taken by Nicaragua that allegedly precipitated them; they also fly in the

face of fundamental principles of international law, as noted in Nicaragua’s

Memorial. 558 For present purposes, Nicaragua will recall only the foundational

principle of international law that a State may not invoke its internal l aw as

justification for its failure to perform obligations under international law. This

principle is reflected in both Article 27 of the Vienna Convention on the Law of

559
Treaties, “Internal law and observance of treaties,” and Article 32 of the

Articles on Responsibility of States for Internationally Wrongful Acts,

557
See the Court’s Order of 8 March 2011, Certain Activities Carried Out By Nicaragua in the
Border Area (Costa Rica V. Nicaragua), Provisional Measures, Order of 8 March 2011, I.C.J.
Reports 2011 (I), p. 19, para. 55, identifying the disputed territory.
558NM, pp. 156-165, paras. 5.14-5.27.
559Vienna Convention on the Law of Treaties, 23 May 1969, 1155 U.N.T.S. 331, Article 27. “It is our opinion that no emergency, except cases where

human life is in danger (which is not the case) justifies
nowadays, an environmental risk such as the one posed by
this project as a consequence of not having conducted
necessary studies to prevent processes that at this point, are
563
very difficult and costly to correct.”

6.20 In sum, Costa Rica’s own actions demonstrate that it did not

believe that there was an “emergency” that required initiating work on the Road

project in a hasty, unplanned manner that was not in accordance with international

law. The Emergency Decree was adopted on 21 February 2011; over three years

later, in the summer of 2014, the Road remains far from being complete and some

sections are impassable and require major remediation. In terms of geography,

the Road is far removed from the area in dispute and thus bears no physical

relation to that area. Furthermore, fundamental principles of international la w

prohibit Costa Rica from invoking its internal law – the Emergency Decree – as

justification for failure to comply with its obligations under international law.

And Costa Rica has not even attempted to justify its wrongful acts by invoking a

circumstance precluding wrongfulness.

6.21 Nicaragua now turns to what Costa Rica characterizes as “three

central obligations: an obligation to conduct an environmental impact assessment

where there is a risk that works may have a significant impact in a transboundary

context; an equivalent obligation of notification; and an obligation not to cause

563Alberto Cabezas, Border Trail Case, published 4 June 201, Revista Amauta ( NR, Vol. II,
Annex 22).

190 “It is our opinion that no emergency, except cases where

human life is in danger (which is not the case) justifies
nowadays, an environmental risk such as the one posed by
this project as a consequence of not having conducted
necessary studies to prevent processes that at this point, are
563
very difficult and costly to correct.”

6.20 In sum, Costa Rica’s own actions demonstrate that it did not

believe that there was an “emergency” that required initiating work on the Road

project in a hasty, unplanned manner that was not in accordance with international

law. The Emergency Decree was adopted on 21 February 2011; over three years

later, in the summer of 2014, the Road remains far from being complete and some

sections are impassable and require major remediation. In terms of geography,

the Road is far removed from the area in dispute and thus bears no physical

relation to that area. Furthermore, fundamental principles of international la w

prohibit Costa Rica from invoking its internal law – the Emergency Decree – as

justification for failure to comply with its obligations under international law.

And Costa Rica has not even attempted to justify its wrongful acts by invoking a

circumstance precluding wrongfulness.

6.21 Nicaragua now turns to what Costa Rica characterizes as “three

central obligations: an obligation to conduct an environmental impact assessment

where there is a risk that works may have a significant impact in a transboundary

context; an equivalent obligation of notification; and an obligation not to cause

563Alberto Cabezas, Border Trail Case, published 4 June 201, Revista Amauta ( NR, Vol. II,
Annex 22). 6.23 Nearly twenty years earlier, in 1992, the United Nations

Conference on Environment and Development, or Earth Summit, recognized in

Principle 17 of the Rio Declaration that:

“Environmental impact assessment, as a national
instrument, shall be undertaken for proposed activities that
are likely to have a significant adverse impact on the

environment and are s568ect to a decision of a competent
national authority.”

6.24 Costa Rica does not deny that it failed to follow the directives of

either the Court in Pulp Mills or the Earth Summit in the Rio Declaration. It does

not deny that it failed to prepare an environmental impact assessment ( “EIA”)

concerning possible impacts of the Road project within its own territory, as

counseled by the Rio D eclaration and required by its own national law; 569 and it

also does not deny that it failed to prepare an EIA concerning possible impacts of

the Road project on Nicaragua, as required by general international law. This

notwithstanding Costa Rica’s insistenc e in the Certain Activities case on “[t]he

necessity of a proper environmental impact assessment in order to prevent or

minimize transboundary harm,” which it called “a well-recognized requirement of

general international law . . . .”570 Given Costa Rica’s prima facie breaches of its

obligations to conduct an EIA under both national and international law, how does

568Rio Declaration on Environment and Development, adopted by the United Nations Conference
on Environment and Development, Rio de Janeiro, June 14, 1992, 31 I.L.M. 874 (1992), Principle
17.
569Golder Report, Section 4 (NR, Vol. II, Annex 6).
570Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v. Nicarag,a)
CRM, p. 209, para. 5.23.

192 6.23 Nearly twenty years earlier, in 1992, the United Nations

Conference on Environment and Development, or Earth Summit, recognized in

Principle 17 of the Rio Declaration that:

“Environmental impact assessment, as a national
instrument, shall be undertaken for proposed activities that
are likely to have a significant adverse impact on the

environment and are s568ect to a decision of a competent
national authority.”

6.24 Costa Rica does not deny that it failed to follow the directives of

either the Court in Pulp Mills or the Earth Summit in the Rio Declaration. It does

not deny that it failed to prepare an environmental impact assessment ( “EIA”)

concerning possible impacts of the Road project within its own territory, as

counseled by the Rio D eclaration and required by its own national law; 569 and it

also does not deny that it failed to prepare an EIA concerning possible impacts of

the Road project on Nicaragua, as required by general international law. This

notwithstanding Costa Rica’s insistenc e in the Certain Activities case on “[t]he

necessity of a proper environmental impact assessment in order to prevent or

minimize transboundary harm,” which it called “a well-recognized requirement of

general international law . . . .”570 Given Costa Rica’s prima facie breaches of its

obligations to conduct an EIA under both national and international law, how does

568Rio Declaration on Environment and Development, adopted by the United Nations Conference
on Environment and Development, Rio de Janeiro, June 14, 1992, 31 I.L.M. 874 (1992), Principle
17.
569Golder Report, Section 4 (NR, Vol. II, Annex 6).
570Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v. Nicaragu,)
CRM, p. 209, para. 5.23. on biological diversity” before an EIA must be conducted. It r epeats its argument

that “the Road was and is being constructed exclusively within Costa Rican

573 574
territory” and, relying on post hoc studies, contends that the quantities of

sediment discharged into the river by the Road project “in no sense risk having a

575
significant adverse impact on the San Juan River . . . .” However, as

demonstrated in Chapter 2, the expert studies annexed to the present Reply show

that the sediment delivered into the river from the Road are, in fact, having a

significant adverse impact on the San Juan.

6.28 But of course the obligation to conduct an EIA is to conduct the

study prior to initiation of work on a project, not to wait until work is well

underway to assess its effects. As shown in this Chapter, Costa Rica had ample

reason to believe that the Road project would have significant adverse effects on

biological diversity and the aquatic ecosystem of the San Juan, given the

sensitivity and protected status of those receiving environments. 576 Thus , the

threshold requirement in respect o f the obligation under the CBD to conduct an

EIA for the Road project was met.

573Ibid., p. 111, para. 5.12.
574
See, e.g., Professor Colin Thorne, Report on the Risk of Irreversible Harm to the Río San Juan
relating to the Construction of the Border Road in Costa Rica, 4 November 2013, CRCM, Volume
II, Annex 9, p. 453; and 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,
CRCM, Volume II, Annex 4, p. 133.
575Ibid.
576See paras. 6.47 -6.51 below , and Sheate Report, Section 5 (NR, Vol. II, Annex 5); Golder
Report, Section 4 (NR, Vol. II, Annex 6).

194on biological diversity” before an EIA must be conducted. It r epeats its argument

that “the Road was and is being constructed exclusively within Costa Rican

573 574
territory” and, relying on post hoc studies, contends that the quantities of

sediment discharged into the river by the Road project “in no sense risk having a

575
significant adverse impact on the San Juan River . . . .” However, as

demonstrated in Chapter 2, the expert studies annexed to the present Reply show

that the sediment delivered into the river from the Road are, in fact, having a

significant adverse impact on the San Juan.

6.28 But of course the obligation to conduct an EIA is to conduct the

study prior to initiation of work on a project, not to wait until work is well

underway to assess its effects. As shown in this Chapter, Costa Rica had ample

reason to believe that the Road project would have significant adverse effects on

biological diversity and the aquatic ecosystem of the San Juan, given the

sensitivity and protected status of those receiving environments. 576 Thus , the

threshold requirement in respect o f the obligation under the CBD to conduct an

EIA for the Road project was met.

573Ibid., p. 111, para. 5.12.
574
See, e.g., Professor Colin Thorne, Report on the Risk of Irreversible Harm to the Río San Juan
relating to the Construction of the Border Road in Costa Rica, 4 November 2013, CRCM, Volume
II, Annex 9, p. 453; and 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,
CRCM, Volume II, Annex 4, p. 133.
575Ibid.
576See paras. 6.47 -6.51 below , and Sheate Report, Section 5 (NR, Vol. II, Annex 5); Golder
Report, Section 4 (NR, Vol. II, Annex 6). 6.32 Costa Rica’s case thus rests on its conclusion that the Road has not

had “a significant adverse impact on the San Juan River,” and is not “liable to

affect the régime of the River or the quality of its waters.” But Nicaragua has

shown, in Chapter 2 above, that expert studies conclude that significant harm has,

in fact been caused by the Road project to the river, its régime – in particular, its

581
ecosystem – and the quality of its waters. This finding also refutes Costa

Rica’s argument that its Road project has not caused Nicaragua significant harm,

as shown in section F, below.

6.33 Costa Rica’s third argument is that although “[t]he Pulp Mills case

does not address directly the issue of conduct of an environmental impact

assessment in the context of an emergency[,] . . . as follows from the general

principles as reflected in Pulp Mills, this issue must be approached by reference to

582
the domestic law of the State concerned.” Costa Rica then reproduces the

following passage from the Pulp Mills judgment:

“[I]t 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 p roject, 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

581NR, Chapter 2; 2014 Kondolf Report, Section 8 (NR, Vol. II, Annex 1); Rios Report (NR, Vo l.
II, Annex 4).
582CRCM, p. 112, para. 5.13.

196 6.32 Costa Rica’s case thus rests on its conclusion that the Road has not

had “a significant adverse impact on the San Juan River,” and is not “liable to

affect the régime of the River or the quality of its waters.” But Nicaragua has

shown, in Chapter 2 above, that expert studies conclude that significant harm has,

in fact been caused by the Road project to the river, its régime – in particular, its

581
ecosystem – and the quality of its waters. This finding also refutes Costa

Rica’s argument that its Road project has not caused Nicaragua significant harm,

as shown in section F, below.

6.33 Costa Rica’s third argument is that although “[t]he Pulp Mills case

does not address directly the issue of conduct of an environmental impact

assessment in the context of an emergency[,] . . . as follows from the general

principles as reflected in Pulp Mills, this issue must be approached by reference to

582
the domestic law of the State concerned.” Costa Rica then reproduces the

following passage from the Pulp Mills judgment:

“[I]t 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 p roject, 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

581NR, Chapter 2; 2014 Kondolf Report, Section 8 (NR, Vol. II, Annex 1); Rios Report (NR, Vo l.
II, Annex 4).
582CRCM, p. 112, para. 5.13. 586
domestic law.” The passage quoted has nothing to do with the obligation to

“carry out” an assessment, only with its content.

6.36 The second way in which the passage assists Nicaragua’s case is

that the Court makes clear the requirement that “an environmental impact

587
assessment must be conducted prior to the implementation of a project.” Costa

Rica seeks to substitute its post hoc Environmental Diagnostic Assessment

(“EDA”) 588for a prior EIA, contending that if there is an obligation to conduct an

EIA “on the very particular facts of this case, that obligation ha s been satisfied by

completion of the Environmental Diagnostic Assessment.” 589

6.37 It is difficult to see how what amounts to a post-hoc damage

assessment can substitute for an ex ante analysis of the harm the project might

cause. Assessment ex ante and monitoring ex post are two separate processes,

with different rationales, as the Court recognized in the last sentence of the

passage quoted by Costa Rica. There the Court said that not only must an EIA be

conducted prior to the implementation of a project: “M oreover, once operations

have started and, where necessary, throughout the life of the project, continuous

590
monitoring of its effects on the environment shall be undertaken.” Finally, the

586
587Ibid.
Pulp Mills on the River Uruguay (Argentina v. Uruguay), Judgment, I.C.J. Reports 2010 , p. 14,
58883, para. 205 (emphasis added).
CRCM, Annex 10.
589CRCM, p. 114, para. 516.
590Pulp Mills on the River Uruguay (Argentina v. Uruguay), Judgment, I.C.J. Reports 2 010, p. 14,
pp. 83 -84, para. 205.

198 586
domestic law.” The passage quoted has nothing to do with the obligation to

“carry out” an assessment, only with its content.

6.36 The second way in which the passage assists Nicaragua’s case is

that the Court makes clear the requirement that “an environmental impact

587
assessment must be conducted prior to the implementation of a project.” Costa

Rica seeks to substitute its post hoc Environmental Diagnostic Assessment

(“EDA”) 588for a prior EIA, contending that if there is an obligation to conduct an

EIA “on the very particular facts of this case, that obligation ha s been satisfied by

completion of the Environmental Diagnostic Assessment.” 589

6.37 It is difficult to see how what amounts to a post-hoc damage

assessment can substitute for an ex ante analysis of the harm the project might

cause. Assessment ex ante and monitoring ex post are two separate processes,

with different rationales, as the Court recognized in the last sentence of the

passage quoted by Costa Rica. There the Court said that not only must an EIA be

conducted prior to the implementation of a project: “M oreover, once operations

have started and, where necessary, throughout the life of the project, continuous

590
monitoring of its effects on the environment shall be undertaken.” Finally, the

586
587Ibid.
Pulp Mills on the River Uruguay (Argentina v. Uruguay), Judgment, I.C.J. Reports 2010 , p. 14,
58883, para. 205 (emphasis added).
CRCM, Annex 10.
589CRCM, p. 114, para. 516.
590Pulp Mills on the River Uruguay (Argentina v. Uruguay), Judgment, I.C.J. Reports 2 010, p. 14,
pp. 83 -84, para. 205. Road contradicts entirely its “emergency” pretext. Even assuming there was a

need to improve delivery of governmental services to the local population, what

made it so urgent in 2011 that, all of a sudden, it had to be satisfied on an

“emergency” basis without proper planning or assessment of environmental

impact? Certainly Costa Rica had not thought there was an emergency previously,

before it inexplicably an d without any warning or other hint of forethought

contracted with thirty-five separate construction companies to build five different

594
sections of the Road, without any blueprints or other plans. The lack of plans

virtually guaranteed the Road, if it cou ld be built in the first place, would fail

sufficiently to satisfy the achievement of Costa Rica’s purported objectives. It

was guaranteed to be a self -destructing venture. There would be no route to

“allow Costa Rican police direct and expeditious acces s to the border area, in
595
order to provide the local population with essential services,” there would still

exist “no safe and efficient route of evacuation, and no means by which to provide

the local population with essential services in the areas of secu rity, health, and

education.” 596 And this is indeed what has occurred.

6.41 In short, the manner in which the Road was ordered constructed by

the Costa Rican Government begs the question whether that Government

genuinely believed there was an emergency. It wa s entirely foreseeable that an

unplanned, unengineered road that was constructed in an area with abundant

594NM, p. 123, para. 4.1 and sources there cited.
595CRCM, p. 21, para. 2.2.
596CRCM, p. 23, para. 2.4.

200Road contradicts entirely its “emergency” pretext. Even assuming there was a

need to improve delivery of governmental services to the local population, what

made it so urgent in 2011 that, all of a sudden, it had to be satisfied on an

“emergency” basis without proper planning or assessment of environmental

impact? Certainly Costa Rica had not thought there was an emergency previously,

before it inexplicably an d without any warning or other hint of forethought

contracted with thirty-five separate construction companies to build five different

594
sections of the Road, without any blueprints or other plans. The lack of plans

virtually guaranteed the Road, if it cou ld be built in the first place, would fail

sufficiently to satisfy the achievement of Costa Rica’s purported objectives. It

was guaranteed to be a self -destructing venture. There would be no route to

“allow Costa Rican police direct and expeditious acces s to the border area, in
595
order to provide the local population with essential services,” there would still

exist “no safe and efficient route of evacuation, and no means by which to provide

the local population with essential services in the areas of secu rity, health, and

education.” 596 And this is indeed what has occurred.

6.41 In short, the manner in which the Road was ordered constructed by

the Costa Rican Government begs the question whether that Government

genuinely believed there was an emergency. It wa s entirely foreseeable that an

unplanned, unengineered road that was constructed in an area with abundant

594NM, p. 123, para. 4.1 and sources there cited.
595CRCM, p. 21, para. 2.2.
596CRCM, p. 23, para. 2.4. Rica in this case, Costa Rica would have to show that it had not “contributed to

the situation of necessity,” 599 which it certainly could not do.

6.45 While Costa Rica, characteristically, blames Nicaragua for Costa

Rica’s own failure to provide the necessary infrastructure to permit the local

600
population to transit the border area, that argument is fallacious, both factually

and legally. Costa Rica contends that the Road is necessary because of

Nicaragua’s alleged “obstruction . . . of the exercise of Costa Rica’s right to

navigate the San Juan River . . . .” 601 Nicaragua emphatically denies that it has

“obstruct[ed] . . . the exercise of Costa Rica’s right to navigate the San Juan

River” – a right which th e Court has defined narrowly and which Nicaragua

scrupulously observes.

6.46 In the relevant portions of its dispositif in the Navigational and

Related Rights case, the Court held that “Costa Rica has the right of free

navigation on the San Juan River for purposes of commerce,” that “the inhabitants

of the Costa Rican bank of the San Juan River have the right to navigate on the

river between the riparian communities for the purposes of the essential needs of

everyday life which require expeditious transportatio n,” and that “Costa Rica has

the right of navigation on the San Juan River with official vessels used solely, in

specific situations, to provide essential services for the inhabitants of the riparian

599Article 25 of the Articles on the Responsibility of States for Internationally Wrongful Acts
provides in paragraph 2(b) that “necessity may not be invoked by a State as a ground for
precluding wrongfulness if: . . . (b) the state has contributed to the situation of necessity.” Articles
on the Responsibility of States for Internationally Wrongful Acts, op cit. supra, Article 25(2)(b).
600See, e.g., CRCM, p. 23, para. 2.4.
601Ibid.

202Rica in this case, Costa Rica would have to show that it had not “contributed to

the situation of necessity,” 599 which it certainly could not do.

6.45 While Costa Rica, characteristically, blames Nicaragua for Costa

Rica’s own failure to provide the necessary infrastructure to permit the local

600
population to transit the border area, that argument is fallacious, both factually

and legally. Costa Rica contends that the Road is necessary because of

Nicaragua’s alleged “obstruction . . . of the exercise of Costa Rica’s right to

navigate the San Juan River . . . .” 601 Nicaragua emphatically denies that it has

“obstruct[ed] . . . the exercise of Costa Rica’s right to navigate the San Juan

River” – a right which th e Court has defined narrowly and which Nicaragua

scrupulously observes.

6.46 In the relevant portions of its dispositif in the Navigational and

Related Rights case, the Court held that “Costa Rica has the right of free

navigation on the San Juan River for purposes of commerce,” that “the inhabitants

of the Costa Rican bank of the San Juan River have the right to navigate on the

river between the riparian communities for the purposes of the essential needs of

everyday life which require expeditious transportatio n,” and that “Costa Rica has

the right of navigation on the San Juan River with official vessels used solely, in

specific situations, to provide essential services for the inhabitants of the riparian

599Article 25 of the Articles on the Responsibility of States for Internationally Wrongful Acts
provides in paragraph 2(b) that “necessity may not be invoked by a State as a ground for
precluding wrongfulness if: . . . (b) the state has contributed to the situation of necessity.” Articles
on the Responsibility of States for Internationally Wrongful Acts, op cit. supra, Article 25(2)(b).
600See, e.g., CRCM, p. 23, para. 2.4.
601Ibid. importance of conducting such an analysis in these situations. 606 Specifically,

Costa Rica knew or should have known that the Road project would be

constructed through or in the immediate vicinity of the following protected areas:

 Nationally protected areas

o Nicaraguan protected areas

 Indio Maíz Reserve (1990)
o Costa Rican protected areas

 Refugio de Vida Silvestre Corredor Fronterizo (1994)

 Internationally protected areas

o Ramsar Wetlands Convention

 Refugio de Vida Silvestre Rio San Juan (Nicaragua,
2001)
 Humedal Caribe Noreste (Costa Rica, 1996)

 Humedal Maquenque (Costa Rica, 2010)
 Cano Negro (Costa Rica, 1991)

o UNESCO MAB Biosphere Reserve

 San Juan River – Nicaragua Biosphere Reserve (2003,
incorporating Indio Maíz607serve and Refugio de Vida
Silvestre Rio San Juan).

6.49 In addition, much of the Road – i.e., the entire stretch between the

Infiernito River and the Delta – was to pass through what Costa Rica’s EDA

classifies as “the life zone category of Very Humid Tropical Forest . . . .” 608 The

EDA says of this zone:

“It is a well known fact that the areas located within the
Very Humid Tropical Forest life zone are very restrictive
environments for the establishment of many different

606CRCM, Volume II, Annex 10, folio pp. 18-19, 42, 47, 59, 60, 65-66, 67, and 106.
607This table is adapted from the Sheate Report (NR, Vol. II, Annex 5).
608CRCM, Volume II, Annex 10, p. 44.

204importance of conducting such an analysis in these situations. 606 Specifically,

Costa Rica knew or should have known that the Road project would be

constructed through or in the immediate vicinity of the following protected areas:

 Nationally protected areas

o Nicaraguan protected areas

 Indio Maíz Reserve (1990)
o Costa Rican protected areas

 Refugio de Vida Silvestre Corredor Fronterizo (1994)

 Internationally protected areas

o Ramsar Wetlands Convention

 Refugio de Vida Silvestre Rio San Juan (Nicaragua,
2001)
 Humedal Caribe Noreste (Costa Rica, 1996)

 Humedal Maquenque (Costa Rica, 2010)
 Cano Negro (Costa Rica, 1991)

o UNESCO MAB Biosphere Reserve

 San Juan River – Nicaragua Biosphere Reserve (2003,
incorporating Indio Maíz 607erve and Refugio de Vida
Silvestre Rio San Juan).

6.49 In addition, much of the Road – i.e., the entire stretch between the

Infiernito River and the Delta – was to pass through what Costa Rica’s EDA

classifies as “the life zone category of Very Humid Tropical Forest . . . .” 608 The

EDA says of this zone:

“It is a well known fact that the areas located within the
Very Humid Tropical Forest life zone are very restrictive
environments for the establishment of many different

606CRCM, Volume II, Annex 10, folio pp. 18-19, 42, 47, 59, 60, 65-66, 67, and 106.
607This table is adapted from the Sheate Report (NR, Vol. II, Annex 5).
608CRCM, Volume II, Annex 10, p. 44. 6.52 Moreover, Costa Rica has been on notice since the mid -1990s that

this kind of project carries with it a high risk of environmental harm. A 1996

OAS study concluded:

“The construction of roads without proper drainage

measures or in territories subject to penetration a nd
settlement are high-stress factors for ecosystems, especially
those which are highly fragile as a result of their weather
612
conditions and the nature of their soil and water.”

The study also found that:

“there is a heavy environmental impact caused [by] the
mechanical process of road construction, especially on
aquatic ecosystems and more specifically on rivers.” 613

6.53 In the specific context of the obligation to conduct an EIA, the

findings are of pivotal importance because they show that Costa Rica had long

been on notice that the kind of project involved in this case would almost certainly

have significant environmental impacts, not only in Costa Rica but in Nicaraguan

territory, as well.

6.54 The foregoing establishes that Costa Rica breached its obligation

to conduct a transboundary EIA prior to undertaking its Road Project. If and to

the extent that Costa Rica’s declaration of an emergency constituted an internal

and an international justification, quod non, it should have prepared a preliminary

EIA at the v ery least. The fact that more than three years have passed since the

612
PROCUENCA SA N JUAN, Formulation of a Strategic Action Program for the Integrated
Management of Water Resources and the Sustainable Development of the San Juan River Basin
and its Coastal Zone, document; Transboundary Diagnostic Analysis (TDA) (Including Root
Cause Ana lysis, available at
http://www.oas.org/sanjuan/english/documents/tda/information/overexploi….
613Ibid., p. IV-45.

206 6.52 Moreover, Costa Rica has been on notice since the mid -1990s that

this kind of project carries with it a high risk of environmental harm. A 1996

OAS study concluded:

“The construction of roads without proper drainage
measures or in territories subject to penetration a nd

settlement are high-stress factors for ecosystems, especially
those which are highly fragile as a result of their weather
conditions and the nature of their soil and water.” 612

The study also found that:

“there is a heavy environmental impact caused [by] the
mechanical process of road construction, especially on
613
aquatic ecosystems and more specifically on rivers.”

6.53 In the specific context of the obligation to conduct an EIA, the

findings are of pivotal importance because they show that Costa Rica had long

been on notice that the kind of project involved in this case would almost certainly

have significant environmental impacts, not only in Costa Rica but in Nicaraguan

territory, as well.

6.54 The foregoing establishes that Costa Rica breached its obligation

to conduct a transboundary EIA prior to undertaking its Road Project. If and to

the extent that Costa Rica’s declaration of an emergency constituted an internal

and an international justification, quod non, it should have prepared a preliminary

EIA at the v ery least. The fact that more than three years have passed since the

612PROCUENCA SA N JUAN, Formulation of a Strategic Action Program for the Integrated
Management of Water Resources and the Sustainable Development of the San Juan River Basin
and its Coastal Zone, document; Transboundary Diagnostic Analysis (TDA) (Including Root
Cause Ana lysis), available at
http://www.oas.org/sanjuan/english/documents/tda/information/overexploi….
613Ibid., p. IV-45. to Nicaragua that has already occurred 617(including restitution, compensation and

618
satisfaction ) as shown in Chapter 7 below, Cost a Rica must conduct a

transboundary EIA before recommencing work on the Road project and

communicate it to the Court and to Nicaragua.

6.56 Moreover, because of the particular risk of grave and irreparable

harm posed by the transport of hazardous materials in t he vicinity of rivers and

other bodies of water, Costa Rica is under an obligation not to transport such

materials on its Border Road, as shown in section F below. Any plans Costa Rica

may have to transport such materials, including chemicals, fertilizers, and fuel and

other petroleum products, despite the high risk of doing so, must be subjected to a

full and particularly rigorous environmental impact assessment, including with

regard to transboundary impacts, with full notification to Nicaragua and

opportunity for Nicaragua to express its views. Prior to this assessment and the

execution of its recommendations, no transit with dangerous substances can be

allowed.

D. COSTA RICA BREACHED THE OBLIGATION TO
NOTIFY NICARAGUA PRIOR TO COMMENCING

CONSTRUCTION ON THE ROAD PROJECT

6.57 Costa Rica has acknowledged “[t]hat States are under a procedural

obligation to notify and consult in respect of those activities which carry a risk of

617Articles on Responsibility of States for Internationally Wrongfulop. cit. supra , Article
31.
61Ibid., Article 34.

208to Nicaragua that has already occurred 617 (including restitution, compensation and

618
satisfaction ) as shown in Chapter 7 below, Cost a Rica must conduct a

transboundary EIA before recommencing work on the Road project and

communicate it to the Court and to Nicaragua.

6.56 Moreover, because of the particular risk of grave and irreparable

harm posed by the transport of hazardous materials in t he vicinity of rivers and

other bodies of water, Costa Rica is under an obligation not to transport such

materials on its Border Road, as shown in section F below. Any plans Costa Rica

may have to transport such materials, including chemicals, fertilizers, and fuel and

other petroleum products, despite the high risk of doing so, must be subjected to a

full and particularly rigorous environmental impact assessment, including with

regard to transboundary impacts, with full notification to Nicaragua and

opportunity for Nicaragua to express its views. Prior to this assessment and the

execution of its recommendations, no transit with dangerous substances can be

allowed.

D. COSTA RICA BREACHED THE OBLIGATION TO
NOTIFY NICARAGUA PRIOR TO COMMENCING

CONSTRUCTION ON THE ROAD PROJECT

6.57 Costa Rica has acknowledged “[t]hat States are under a procedural

obligation to notify and consult in respect of those activities which carry a risk of

617Articles on Responsibility of States for Internationally Wrongfulop. cit. supra , Article
31.
618Ibid., Article 34. studies that the project has, in fact, caused significant harm to the River and its

ecosystems, and continues to do so. 622

6.59 As to Costa Rica’s first argument, that it is exempt from the

notification requirement because of the emergency it had declared, the

ineffectiveness of the Emergency Decree to exempt Costa Rica from its

obligations under international law has been demonstrated in section C above and

623
in Nicaragua’s Memorial. Costa Rica contends, however, that its failure even

to notify Nicaragua of its intention to construct its Road is excused by the

principle reflected in Article 19 of the 1997 Convention on the Law of the Non -

Navigational Uses of International Watercourses. 624 Costa Rica selectively quotes

625
paragraph 1 of that article. The entire article reads as follows:

Article 19
Urgent implementation of planned measures

1. In the event that the implementation of planned measures is of

the utmost urgency in order to protect public health, public
safety or other equally important interests, the State planning
the measures may, subject to articles 5 and 7, immediately
proceed to implementation, notwithstanding the provisions of

article 14 and paragraph 3 of article 17.

2. In such a case, a formal declaration of the urgency of the

measures shall be communicated without delay to the other
watercourse States referred to in article 12 together with the
relevant data and information.

622See 2014 Kondolf Report (NR, Vol. II, Annex 1); Rios Report (NR, Vol. II, Annex 4). See also
Chapter 2, above.
623NM, Chapter 5, pp. 152-165, paras. 5.6-5.29
624New York, 21 May 1997, U.N. Doc. A/RES/51/868, Annex, 36 I.L.M. 700 (1997) (hereinafter
UN Watercourses Convention).
625CRCM, p. 117, para. 5.22.

210studies that the project has, in fact, caused significant harm to the River and its

ecosystems, and continues to do so. 622

6.59 As to Costa Rica’s first argument, that it is exempt from the

notification requirement because of the emergency it had declared, the

ineffectiveness of the Emergency Decree to exempt Costa Rica from its

obligations under international law has been demonstrated in section C above and

623
in Nicaragua’s Memorial. Costa Rica contends, however, that its failure even

to notify Nicaragua of its intention to construct its Road is excused by the

principle reflected in Article 19 of the 1997 Convention on the Law of the Non -

Navigational Uses of International Watercourses. 624 Costa Rica selectively quotes

625
paragraph 1 of that article. The entire article reads as follows:

Article 19
Urgent implementation of planned measures

1. In the event that the implementation of planned measures is of

the utmost urgency in order to protect public health, public
safety or other equally important interests, the State planning
the measures may, subject to articles 5 and 7, immediately
proceed to implementation, notwithstanding the provisions of

article 14 and paragraph 3 of article 17.

2. In such a case, a formal declaration of the urgency of the

measures shall be communicated without delay to the other
watercourse States referred to in article 12 together with the
relevant data and information.

622See 2014 Kondolf Report (NR, Vol. II, Annex 1); Rios Report (NR, Vol. II, Annex 4). See also
Chapter 2, above.
623NM, Chapter 5, pp. 152-165, paras. 5.6-5.29
624New York, 21 May 1997, U.N. Doc. A/RES/51/868, Annex, 36 I.L.M. 700 (1997) (hereinafter
UN Watercourses Convention).
625CRCM, p. 117, para. 5.22. 6.63 Leaving aside for the moment the question of whether the

circumstances in which Costa Rica commenced construction of the Road were of

the “highly exceptional” kind referred to in the ILC’s commentar y, Costa Rica

failed entirely to comply with the conditions laid down in the article, which is

based on State practice. Those conditions are:

 First, that urgent implementation of planned measures is “subject to

articles 5 and 7” (Article 19(1)). These pr ovisions reflect

obligations that are firmly embedded in customary international

law: Article 5, the obligation of equitable and reasonable

utilization; and Article 7, the obligation of prevention of significant

harm. While Costa Rica quoted Article 19(1) in its Counter-

Memorial, it failed to note this condition for invoking the

exception to the obligation to provide prior notification of planned

measures. Costa Rica breached the rule embodied in Article 5 by

proceeding to construct its Road in a manner th at was not

“consistent with adequate protection of the watercourse.” And it

breached Article 7 by not “tak[ing] all appropriate measures to

prevent the causing of significant harm” to Nicaragua. Costa Rica

had ample reason to believe that the project wou ld have a

significant adverse effect upon Nicaragua, yet failed to exercise

212 6.63 Leaving aside for the moment the question of whether the

circumstances in which Costa Rica commenced construction of the Road were of

the “highly exceptional” kind referred to in the ILC’s commentar y, Costa Rica

failed entirely to comply with the conditions laid down in the article, which is

based on State practice. Those conditions are:

 First, that urgent implementation of planned measures is “subject to

articles 5 and 7” (Article 19(1)). These pr ovisions reflect

obligations that are firmly embedded in customary international

law: Article 5, the obligation of equitable and reasonable

utilization; and Article 7, the obligation of prevention of significant

harm. While Costa Rica quoted Article 19(1) in its Counter-

Memorial, it failed to note this condition for invoking the

exception to the obligation to provide prior notification of planned

measures. Costa Rica breached the rule embodied in Article 5 by

proceeding to construct its Road in a manner th at was not

“consistent with adequate protection of the watercourse.” And it

breached Article 7 by not “tak[ing] all appropriate measures to

prevent the causing of significant harm” to Nicaragua. Costa Rica

had ample reason to believe that the project wou ld have a

significant adverse effect upon Nicaragua, yet failed to exercise situation,” and are to be “conducted on the basis that each State

must in good faith pay reasonable regard to the rights and

632
legitimate interests of the other State .” Yet , Costa Rica

repeatedly rebuffed all of Nicaragua’s requests for information

about the Road project, including requests for an environmental

impact assessment, and otherwise refused to consult with

Nicaragua about Nicaragua’s concerns relating to t he project.

Costa Rica states that it “formally communicated with Nicaragua

through official channels, promptly and in good faith, concerning

633
the road infrastructure works on Costa Rican territory . . . .”

However, no citation to any such communication accompanies this

statement which is, in fact, untrue.

6.64 These conditions are aimed precisely at “guard[ing] against

possibilities of abuse of the exception [Article 19] establishes.” 634 Put another

way, a State may not simply issue a unilateral, self -judging declaration of

emergency and thereby exempt itself from all of its relevant international

obligations. Such a state of affairs would make a mockery of the principle

expressed in both Article 27 of the Vienna Convention on the Law of Treaties,

632
The quotations are from paragraphs 1 and 2 of Article 17 of the Convention, which paragraph 3
of Article 19 refers to with regard to the manner in which consultation s and negotiations are to be
held.
633CRCM, p. 10, para. 1.17.
634Yearbook of the International Law Commission, 1994, vol. II, Part Two, p. 118.

214 situation,” and are to be “conducted on the basis that each State

must in good faith pay reasonable regard to the rights and

632
legitimate interests of the other State .” Yet , Costa Rica

repeatedly rebuffed all of Nicaragua’s requests for information

about the Road project, including requests for an environmental

impact assessment, and otherwise refused to consult with

Nicaragua about Nicaragua’s concerns relating to t he project.

Costa Rica states that it “formally communicated with Nicaragua

through official channels, promptly and in good faith, concerning

633
the road infrastructure works on Costa Rican territory . . . .”

However, no citation to any such communication accompanies this

statement which is, in fact, untrue.

6.64 These conditions are aimed precisely at “guard[ing] against

possibilities of abuse of the exception [Article 19] establishes.” 634 Put another

way, a State may not simply issue a unilateral, self -judging declaration of

emergency and thereby exempt itself from all of its relevant international

obligations. Such a state of affairs would make a mockery of the principle

expressed in both Article 27 of the Vienna Convention on the Law of Treaties,

632
The quotations are from paragraphs 1 and 2 of Article 17 of the Convention, which paragraph 3
of Article 19 refers to with regard to the manner in which consultation s and negotiations are to be
held.
633CRCM, p. 10, para. 1.17.
634Yearbook of the International Law Commission, 1994, vol. II, Part Two, p. 118. reach what is referred to as the “disputed territory” in the Certain Activities case639

because as noted earlier a long bridge would have to be built to span the Colorado

branch of the San Juan, which is the terminus of “Route 1856,” and a road would

have to be constructed through wetlands fro m the left bank of the Colorado River

to the area in dispute. Thus , the Road bears no relationship whatsoever to Costa

Rica’s dispute with Nicaragua in the Certain Activities case.

6.66 Therefore, while Costa Rica is of course free to assert that the

circumstances giving rise to the dispute in the Certain Activities case were “highly

exceptional,” the construction of the Road bore, and bears, no relationship to

those circumstances. Costa Rica’s failure and, in fact, refusal, to observe its

international obligations of prior notification and consultation, and environmental

impact assessment, in relation to the Road cannot, therefore, be wiped out by a

declaration of an emergency relating to something else entirely.

6.67 On the question of whether the Road, regardle ss of its relation to

the territorial dispute, was a project of “utmost urgency,” the facts speak for

themselves. As noted earlier, it is now well over three years since the Emergency

Decree was issued by Costa Rica’s President on 21 February 2011. The R oad is

still far from being complete, with significant sections remaining entirely

impassable. Clearly, there would have been ample time to notify and consult with

639
See the Court’s Order of 8 March 2011Certain Activities Carried Out By Nicaragua in the
Border Area (Costa Rica V. Nicaragua), Provisional Measures, Order of 8 March 2011, I.C.J.
Reports 2011 (I), p. 19, para. 55, identifying the disputed territory.

216reach what is referred to as the “disputed territory” in the Certain Activities case639

because as noted earlier a long bridge would have to be built to span the Colorado

branch of the San Juan, which is the terminus of “Route 1856,” and a road would

have to be constructed through wetlands fro m the left bank of the Colorado River

to the area in dispute. Thus , the Road bears no relationship whatsoever to Costa

Rica’s dispute with Nicaragua in the Certain Activities case.

6.66 Therefore, while Costa Rica is of course free to assert that the

circumstances giving rise to the dispute in the Certain Activities case were “highly

exceptional,” the construction of the Road bore, and bears, no relationship to

those circumstances. Costa Rica’s failure and, in fact, refusal, to observe its

international obligations of prior notification and consultation, and environmental

impact assessment, in relation to the Road cannot, therefore, be wiped out by a

declaration of an emergency relating to something else entirely.

6.67 On the question of whether the Road, regardle ss of its relation to

the territorial dispute, was a project of “utmost urgency,” the facts speak for

themselves. As noted earlier, it is now well over three years since the Emergency

Decree was issued by Costa Rica’s President on 21 February 2011. The R oad is

still far from being complete, with significant sections remaining entirely

impassable. Clearly, there would have been ample time to notify and consult with

639
See the Court’s Order of 8 March 2011Certain Activities Carried Out By Nicaragua in the
Border Area (Costa Rica V. Nicaragua), Provisional Measures, Order of 8 March 2011, I.C.J.
Reports 2011 (I), p. 19, para. 55, identifying the disputed territory. E. COSTA RICA BREACHED THE OBLIGATION NOT TO
CAUSE SIGNIFICANT TRANSBOUNDARY HARM

6.69 The obligation not to cause transboundary harm is venerable, as

640
shown in section B, above. From the 1941 Trail Smelter arbitral award and the

Court’s 1949 judgment in Corfu Channel 641to the Court’s 1996 Advisory Opinion

642
on the Legality of the Threat or Use of Nuclear Weapons, the 2010 judgment in

643
Pulp Mills and the 2013 awards in the Indus Waters Kishenganga

Arbitration, 644 the obligation not to cause transboundary harm has long been

recognized by this Court and by internati onal arbitral tribunals. In the words of

the 1996 Advisory Opinion: “The existence of the general obligation of States to

ensure that activities within their jurisdiction and control respect the environment

of other States or of areas beyond national cont rol is now part of the corpus of

645
international law relating to the environment.”

6.70 Costa Rica does not challenge the existence of this obligation. In

fact, in its Order of 13 December 2013 in the Road case, the Court observed that

“Costa Rica acknowledged during the course of the oral proceedings that it has a

duty not to cause any significant transboundary harm as a result of the

640 Arbitral Award, 11 March 1941, Trail Smelte r Arbitration (United States of America v.

641ada), UNRIAA, vol. III, p. 1965.
I.C.J., Judgment, 9 April 1949, Corfu Channel (United Kingdom of Great Britain and Northern
Ireland v. Albania), I.C.J. Reports 1949, p. 22.
642Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion , I.C.J. Reports 1996, p.
226.
643Pulp Mills on the River Uruguay (Argentina v. Uruguay) , I.C.J. Reports 2010 , p. 14, p. 83,
para. 204.
644Partial Award, 18 February 2013, Indus Waters Kishenganga Arbitration (Pakistan v. I ndia),

645ilable at http://www.pca-cpa.org/showpage.asp?pag_id=1392.
Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, I.C.J. Reports 1996 (,)
pp. 241-242, para. 29.

218 E. COSTA RICA BREACHED THE OBLIGATION NOT TO
CAUSE SIGNIFICANT TRANSBOUNDARY HARM

6.69 The obligation not to cause transboundary harm is venerable, as

640
shown in section B, above. From the 1941 Trail Smelter arbitral award and the

Court’s 1949 judgment in Corfu Channel 641 to the Court’s 1996 Advisory Opinion

642
on the Legality of the Threat or Use of Nuclear Weapons, the 2010 judgment in

643
Pulp Mills and the 2013 awards in the Indus Waters Kishenganga

Arbitration, 644 the obligation not to cause transboundary harm has long been

recognized by this Court and by internati onal arbitral tribunals. In the words of

the 1996 Advisory Opinion: “The existence of the general obligation of States to

ensure that activities within their jurisdiction and control respect the environment

of other States or of areas beyond national cont rol is now part of the corpus of

645
international law relating to the environment.”

6.70 Costa Rica does not challenge the existence of this obligation. In

fact, in its Order of 13 December 2013 in the Road case, the Court observed that

“Costa Rica acknowledged during the course of the oral proceedings that it has a

duty not to cause any significant transboundary harm as a result of the

640 Arbitral Award, 11 March 1941, Trail Smelte r Arbitration (United States of America v.

641ada), UNRIAA, vol. III, p. 1965.
I.C.J., Judgment, 9 April 1949, Corfu Channel (United Kingdom of Great Britain and Northern
Ireland v. Albania), I.C.J. Reports 1949, p. 22.
642Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion , I.C.J. Reports 1996, p.
226.
643Pulp Mills on the River Uruguay (Argentina v. Uruguay) , I.C.J. Reports 2010 , p. 14, p. 83,
para. 204.
644Partial Award, 18 February 2013, Indus Waters Kishenganga Arbitration (Pakistan v. I ndia),

645ilable at http://www.pca-cpa.org/showpage.asp?pag_id=1392.
Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, I.C.J. Reports 1996 (,)
pp. 241-242, para. 29. 6.72 The meaning of “pollution” in the context of fresh water is

addressed in the 1997 Watercourses Convention, which defines “pollution of an

international watercourse” as follows:

“any detrimental alteration in the composition or quality of
the waters of an international watercourse which results
651
directly or indirectly from human conduct.”

6.73 Similar definitions, requiring some form of human involvement,

are contained in a number of other instruments, such as the 1979 Convention on

Long-range Transboundary Air Pollution 652 and the 1966 Helsinki Rules on the

653
Uses of the Waters of International Rivers.

6.74 The sediment contributed to the San Juan both by the Road project

and by Costa Rica’s poor land use practices results or is likely to result in a

“detrimental alteration in the composition or quality of the waters” 654 of the San

Juan, producing “such deleterious effects as harm to living resources and [aquatic]

life, hazards to human health, hindrance to [riverine] activities, including fishing

and other legitimate uses of the [river, such as navigation], impairment of quali ty

655
for use of [river] water and reduction of amenities; . . . .” The sedimentation of

the river results indirectly because it is allowed to run off into the waters of the

San Juan due to conditions created by Costa Rica. It also results directly from th e

651
652U.N. Watercourses Convention, op. cit. supra, Article 21(1).
Convention on Long -range Transboundary Air Pollution, Geneva, 13 November 1979, 1302
U.N.T.S. 217, Article 1(a).
653Helsinki Rules on the Uses of the Waters of International Rivers, Helsinki, 1966, Article IX,
International Law Association, Report of the Fifty -second Conference, Helsinki, 1966 (London,
1967).
654U.N. Watercourses Convention, op. cit. supra, Article 21(1).
655UNCLOS, Article 1(4). See 2014 Kondolf Report, Section 8 (NR, Vol. II, Annex 1).

220 6.72 The meaning of “pollution” in the context of fresh water is

addressed in the 1997 Watercourses Convention, which defines “pollution of an

international watercourse” as follows:

“any detrimental alteration in the composition or quality of
the waters of an international watercourse which results
651
directly or indirectly from human conduct.”

6.73 Similar definitions, requiring some form of human involvement,

are contained in a number of other instruments, such as the 1979 Convention on

Long-range Transboundary Air Pollution 652 and the 1966 Helsinki Rules on the

653
Uses of the Waters of International Rivers.

6.74 The sediment contributed to the San Juan both by the Road project

and by Costa Rica’s poor land use practices results or is likely to result in a

“detrimental alteration in the composition or quality of the waters” 654 of the San

Juan, producing “such deleterious effects as harm to living resources and [aquatic]

life, hazards to human health, hindrance to [riverine] activities, including fishing

and other legitimate uses of the [river, such as navigation], impairment of quali ty

655
for use of [river] water and reduction of amenities; . . . .” The sedimentation of

the river results indirectly because it is allowed to run off into the waters of the

San Juan due to conditions created by Costa Rica. It also results directly from th e

651
652U.N. Watercourses Convention, op. cit. supra, Article 21(1).
Convention on Long -range Transboundary Air Pollution, Geneva, 13 November 1979, 1302
U.N.T.S. 217, Article 1(a).
653Helsinki Rules on the Uses of the Waters of International Rivers, Helsinki, 1966, Article IX,
International Law Association, Report of the Fifty -second Conference, Helsinki, 1966 (London,
1967).
654U.N. Watercourses Convention, op. cit. supra, Article 21(1).
655UNCLOS, Article 1(4). See 2014 Kondolf Report, Section 8 (NR, Vol. II, Annex 1). and variable sediment inputs from the San Carlos and Sarapiqui basins, which

supply the vast majority of sediment carried by the River.” 658

6.77 These chemicals are also an element of the transboundary harm that

Costa Rica is inflicting on Nicaragua – harm that would occur to a far lesser

extent if Costa Rica would at least moderate its use of pesticides to bring it within

the world average.

6.78 In the surprisingly brief section of its Counter-Memorial devoted to

659
“Alleged significant transboundary harm,” Costa Rica states that Nicaragua’s

“allegation of significant transboundary harm . . . was made without the detailed

consideration of impact on the Rio San Juan’s existing sediment load that

constitutes the obvious prerequisi te to any serious case on harm.” 660 In other

words, in Costa Rica’s view the determination of whether harm is “significant”

can only be made by comparing the quantity of sediment and other debris

delivered into the San Juan as a result of the Road project w ith the quantity that

was carried by the river before any construction began. Thus, for Costa Rica, it is

the relative quantity of sediment delivered by the Road project into the river that

counts, not the absolute quantity.

6.79 This is not the international standard, however. For example, the

“Principles of conduct in the field of the environment for the guidance of States in

658
Professor Colin Thorne, “Assessment of the Impact of the Construction of the Border Road in
Costa Rica on the San Juan River,” para. 9.10, CRCM, Appendix A.
659CRCM, pp. 118-119, paras. 5.25-5.26.
660Ibid., p. 118, para. 5.25.

222and variable sediment inputs from the San Carlos and Sarapiqui basins, which

supply the vast majority of sediment carried by the River.” 658

6.77 These chemicals are also an element of the transboundary harm that

Costa Rica is inflicting on Nicaragua – harm that would occur to a far lesser

extent if Costa Rica would at least moderate its use of pesticides to bring it within

the world average.

6.78 In the surprisingly brief section of its Counter-Memorial devoted to

659
“Alleged significant transboundary harm,” Costa Rica states that Nicaragua’s

“allegation of significant transboundary harm . . . was made without the detailed

consideration of impact on the Rio San Juan’s existing sediment load that

constitutes the obvious prerequisi te to any serious case on harm.” 660 In other

words, in Costa Rica’s view the determination of whether harm is “significant”

can only be made by comparing the quantity of sediment and other debris

delivered into the San Juan as a result of the Road project w ith the quantity that

was carried by the river before any construction began. Thus, for Costa Rica, it is

the relative quantity of sediment delivered by the Road project into the river that

counts, not the absolute quantity.

6.79 This is not the international standard, however. For example, the

“Principles of conduct in the field of the environment for the guidance of States in

658
Professor Colin Thorne, “Assessment of the Impact of the Construction of the Border Road in
Costa Rica on the San Juan River,” para. 9.10, CRCM, Appendix A.
659CRCM, pp. 118-119, paras. 5.25-5.26.
660Ibid., p. 118, para. 5.25. 6.81 Turning now to Costa Rica’s test contention that the harm to

Nicaragua from the Road project is not significant , there are two answers . First,

even considering only the absolute quantity of sediment, there has in fact been

significant transboundary harm to Nicaragua in the form of increased levels of

sedimentation of the Sa n Juan. And second, even if, quod non, as Costa Rica

argues, the test for “significance” is a relative one, comparing the sediment

contributed by the Road project with the total sediment load carried by the river,

the proportion contributed by the Road project is still significant.

6.82 As to the first point, expert studies show that the quantity of

sediment contributed by the Road project to the river is, in fact, significant. Dr.

Andrews notes that: “[e]stimates of the sediment contributed by Route 1856 to the

665
Rio San Juan range from 61,000 (Thorne) to 240,000 tons per year (Kondolf).”

By any measure, these are significant quantities. They are certainly

“appreciable,” as are their effects.

6.83 This fact is particularly striking when the small pile of sedimen t

complained of by Costa Rica in the Certain Activities case is contrasted with the

thousands of tons of sediment the Road project is causing to be delivered into

Nicaragua’s sovereign territory, the San Juan River. As Nicaragua stated in its

Counter-Memorial in the Certain Activities case:

“Leaving aside the fact that all dredged sediments have

been deposited on Nicaraguan territory, the amount
deposited in the disputed area is trivial and can hardly be

665Andrews Report, Section IV (NR, Vol. II, Annex 3).

224 6.81 Turning now to Costa Rica’s test contention that the harm to

Nicaragua from the Road project is not significant , there are two answers . First,

even considering only the absolute quantity of sediment, there has in fact been

significant transboundary harm to Nicaragua in the form of increased levels of

sedimentation of the Sa n Juan. And second, even if, quod non, as Costa Rica

argues, the test for “significance” is a relative one, comparing the sediment

contributed by the Road project with the total sediment load carried by the river,

the proportion contributed by the Road project is still significant.

6.82 As to the first point, expert studies show that the quantity of

sediment contributed by the Road project to the river is, in fact, significant. Dr.

Andrews notes that: “[e]stimates of the sediment contributed by Route 1856 to the

665
Rio San Juan range from 61,000 (Thorne) to 240,000 tons per year (Kondolf).”

By any measure, these are significant quantities. They are certainly

“appreciable,” as are their effects.

6.83 This fact is particularly striking when the small pile of sedimen t

complained of by Costa Rica in the Certain Activities case is contrasted with the

thousands of tons of sediment the Road project is causing to be delivered into

Nicaragua’s sovereign territory, the San Juan River. As Nicaragua stated in its

Counter-Memorial in the Certain Activities case:

“Leaving aside the fact that all dredged sediments have

been deposited on Nicaraguan territory, the amount
deposited in the disputed area is trivial and can hardly be

665Andrews Report, Section IV (NR, Vol. II, Annex 3). the quantity and variability of the baseline sediment load – i.e., the sediment load

670
of the River as it was before the Road was constructed . . . .”

6.85 The problem with this argument for Costa Rica is that most of the

San Juan’s sediment load comes from Costa Rica. More significantly, most of the

other sediment from Costa Rica resu lts from poor land use practices, which add

considerably to what would be the River’s natural load. A maxim referred to by

Costa Rica, although not apposite in the context in which it was cited, 671 applies

by analogy here: ex turpi causa non oritur actio. But rather than the applicant

seeking to rely on an illegality, here it is the respondent. Put another way, a State

should be precluded from benefiting from its own wrong, or from its unclean

hands. Here, Costa Rica should be precluded from asserting tha t the quantity of

sediment added to the river by the Road project is insignificant in comparison to

the vast quantities contributed, and harm to Nicaragua done, as a result of Costa

Rica’s own pre-existing substandard land use practices.

6.86 Professor Thorne’s report – which is heavily relied upon by Costa

Rica – states that the San Juan’s sediment regime is “dominated by high and

variable sediment inputs from the San Carlos and Sarapiqui basins, which supply

the vast majority of sediment carried by the River.” 672 Referring to the Thorne

Report, Dr. Andrews observes that Professor Thorne:

670Ibid., p. 49, para. 3.6.
671CRCM, p. 114, para. 5.18.
672Professor Colin Thorne, “Assessment of the I mpact of the Construction of the Border Road in
Costa Rica on the San Juan River,” para. 9.10, CRCM, Appendix A.

226the quantity and variability of the baseline sediment load – i.e., the sediment load

670
of the River as it was before the Road was constructed . . . .”

6.85 The problem with this argument for Costa Rica is that most of the

San Juan’s sediment load comes from Costa Rica. More significantly, most of the

other sediment from Costa Rica resu lts from poor land use practices, which add

considerably to what would be the River’s natural load. A maxim referred to by

Costa Rica, although not apposite in the context in which it was cited, 671applies

by analogy here: ex turpi causa non oritur actio. But rather than the applicant

seeking to rely on an illegality, here it is the respondent. Put another way, a State

should be precluded from benefiting from its own wrong, or from its unclean

hands. Here, Costa Rica should be precluded from asserting tha t the quantity of

sediment added to the river by the Road project is insignificant in comparison to

the vast quantities contributed, and harm to Nicaragua done, as a result of Costa

Rica’s own pre-existing substandard land use practices.

6.86 Professor Thorne’s report – which is heavily relied upon by Costa

Rica – states that the San Juan’s sediment regime is “dominated by high and

variable sediment inputs from the San Carlos and Sarapiqui basins, which supply

the vast majority of sediment carried by the River.” 672 Referring to the Thorne

Report, Dr. Andrews observes that Professor Thorne:

670Ibid., p. 49, para. 3.6.
671CRCM, p. 114, para. 5.18.
672Professor Colin Thorne, “Assessment of the I mpact of the Construction of the Border Road in
Costa Rica on the San Juan River,” para. 9.10, CRCM, Appendix A. the Rio San Juan. Furthermore, bo676river gage records are
short - only about two years.”

6.88 After reviewing published literature on sediment loads of rivers in

undisturbed tropical basins comparable to that of the San Juan, Dr. Andrews finds

that “sediment yields in the Rio San Juan Basin prior to appreciable forest

clearing and landscape disturbance were likely to fall between 20 to 50 tons/km 2

th th
per year, which would be 1/20 to 1/50 of Thorne’s estimated basin-wide value

[of current sediment yields] of 1080 tons/km per year.” 677He therefore concludes

that “the present sediment load of the Rio San Juan is unnaturally elevated due

primarily to deforestation and associated land disturbance in the Costa Rican parts

of the basin.” 678

6.89 In Chapter 1, Nicaragua noted the alarming amount of deforestation

that occurred in Costa Rica in the fifty years between 1940 and 1990 (Figure 1.1).

Costa Rica’s Environmental Diagnostic Assessment (EDA) refers to a 1992 study:

“estimat[ing] that only 5% of the original forest in the

region remained intact; forest extractive activities during
the last decade have significantly reduced this percentage.
The present use of the land in th is area consists of a variety

of non sustainable uses of the forests, alternating with
cattle-raising and pineapple production, palm tree and root
crops in small scale.” 679

6.90 The expert evidence reviewed in the foregoing paragraphs shows

that Costa Rica, throu gh its acts and omissions, is responsible for the large -scale

676
Ibid., Section IV(A).
677Ibid.
678Ibid., Section IV(C).
679EDA, p. 46 (CRCM, Vol. II, Annex 10).

228 the Rio San Juan. Furthermore, bo676river gage records are
short - only about two years.”

6.88 After reviewing published literature on sediment loads of rivers in

undisturbed tropical basins comparable to that of the San Juan, Dr. Andrews finds

that “sediment yields in the Rio San Juan Basin prior to appreciable forest

clearing and landscape disturbance were likely to fall between 20 to 50 tons/km 2

th th
per year, which would be 1/20 to 1/50 of Thorne’s estimated basin-wide value

[of current sediment yields] of 1080 tons/km per year.” 677He therefore concludes

that “the present sediment load of the Rio San Juan is unnaturally elevated due

primarily to deforestation and associated land disturbance in the Costa Rican parts

of the basin.” 678

6.89 In Chapter 1, Nicaragua noted the alarming amount of deforestation

that occurred in Costa Rica in the fifty years between 1940 and 1990 (Figure 1.1).

Costa Rica’s Environmental Diagnostic Assessment (EDA) refers to a 1992 study:

“estimat[ing] that only 5% of the original forest in the

region remained intact; forest extractive activities during
the last decade have significantly reduced this percentage.
The present use of the land in th is area consists of a variety

of non sustainable uses of the forests, alternating with
cattle-raising and pineapple production, palm tree and root
crops in small scale.” 679

6.90 The expert evidence reviewed in the foregoing paragraphs shows

that Costa Rica, throu gh its acts and omissions, is responsible for the large -scale

676
Ibid., Section IV(A).
677Ibid.
678Ibid., Section IV(C).
679EDA, p. 46 (CRCM, Vol. II, Annex 10). on the resulting sediment load of the San Juan, which is some 20 to 50 times

683
greater than would be expected under natural conditions, to make the quantity

of sediment delivered into the San Juan by the Road appear to be minor, in

comparison. To permit such a comparison would be to allow Costa Ri ca to

benefit from its internationally wrongful conduct over many years. An analog of

the maxim ex turpi causa non oritur actio applies here: one may not avail oneself

of a defense that is unlawful. Costa Rica’s unclean hands should bar it from using

a “relativity” test even if such a test were appropriate (quod non).

6.93 Moreover, if a “relativity” test were appropriate (i.e., a test that

compares the quantity of sediment for which the Road project is responsible to the

river’s sediment load), the proper co mparison would be between what would be

expected to be the river’s natural sediment load and the sediment from the Road

project. Dr. Andrews has made such a comparison:

“Compared to the expected natural basin -wide sediment
yield the quantity of sediment associated with the
construction of Route 1856 is quite substantial. . . . Based

on [Professor Thorne and Dr. Kondolf’s erosion estimates ,]
the quantity of sediment eroded from the Road corridor
would have increased the total sediment load of the Rio San
Juan to the head of the delta by 15 to 140 percent over the
expected natural condition.” 684

6.94 Dr. Andrews’ conclusions thus provide an unequivocal answer: the

contribution of the Road project to the river’s expected natural sediment load is

683
684ndrews Report, Section IV(A) (NR, Vol. II, Annex 3).
Ibid., Section IV(D).

230on the resulting sediment load of the San Juan, which is some 20 to 50 times

683
greater than would be expected under natural conditions, to make the quantity

of sediment delivered into the San Juan by the Road appear to be minor, in

comparison. To permit such a comparison would be to allow Costa Ri ca to

benefit from its internationally wrongful conduct over many years. An analog of

the maxim ex turpi causa non oritur actio applies here: one may not avail oneself

of a defense that is unlawful. Costa Rica’s unclean hands should bar it from using

a “relativity” test even if such a test were appropriate (quod non).

6.93 Moreover, if a “relativity” test were appropriate (i.e., a test that

compares the quantity of sediment for which the Road project is responsible to the

river’s sediment load), the proper co mparison would be between what would be

expected to be the river’s natural sediment load and the sediment from the Road

project. Dr. Andrews has made such a comparison:

“Compared to the expected natural basin -wide sediment
yield the quantity of sediment associated with the
construction of Route 1856 is quite substantial. . . . Based

on [Professor Thorne and Dr. Kondolf’s erosion estimates ,]
the quantity of sediment eroded from the Road corridor
would have increased the total sediment load of the Rio San
Juan to the head of the delta by 15 to 140 percent over the
expected natural condition.” 684

6.94 Dr. Andrews’ conclusions thus provide an unequivocal answer: the

contribution of the Road project to the river’s expected natural sediment load is

683
684Andrews Report, Section IV(A) (NR, Vol. II, Annex 3).
Ibid., Section IV(D). 6.96 This is real and significant harm, caused by Costa Rica’s

substandard and irresponsible land use practices. It is harm for which Costa Rica

is responsible.

6.97 The following conclusions may be drawn from the foreg oing:

First, the obligation not to cause significant transboundary harm is well -

established and is accepted by Costa Rica. Second, the Road project is

responsible for the addition of significant quantities of sediment to the San Juan

River, whether measu red by the absolute or the relative quantity of sediment

delivered to the river. Third, these additional quantities of sediment have caused

Nicaragua significant harm, for which Costa Rica is responsible. And fourth,

Costa Rica is also responsible to Nic aragua for the harmful effects of the

substantial increases in sediment yields from Costa Rican tributaries due to poor

land use practices. 687

6.98 There is one further implication of the obligation not to cause

transboundary harm that should be noted here. The obligation is one of

prevention, as reflected in Article 7(1) of the U.N. Watercourses Convention:

“Watercourse States shall, in utilizing an international

watercourse in their territories, take all appropriate

687Costa Rica’s responsibility for all the damages it has caused to Nicaragua due to irresponsible
deforestation, enormous use of chemicals and general poo r land use practices is not fully before
the Court in the present case and Nicaragua reserves its rights on this issue in general. The purpose
of the evidence filed on this point is to make clear that Costa Rica cannot justify as “minor” the
damage caused by the road in comparison to the damage caused by Costa Rica’s other
environmental malfeasances.

232 6.96 This is real and significant harm, caused by Costa Rica’s

substandard and irresponsible land use practices. It is harm for which Costa Rica

is responsible.

6.97 The following conclusions may be drawn from the foreg oing:

First, the obligation not to cause significant transboundary harm is well -

established and is accepted by Costa Rica. Second, the Road project is

responsible for the addition of significant quantities of sediment to the San Juan

River, whether measu red by the absolute or the relative quantity of sediment

delivered to the river. Third, these additional quantities of sediment have caused

Nicaragua significant harm, for which Costa Rica is responsible. And fourth,

Costa Rica is also responsible to Nic aragua for the harmful effects of the

substantial increases in sediment yields from Costa Rican tributaries due to poor

land use practices. 687

6.98 There is one further implication of the obligation not to cause

transboundary harm that should be noted here. The obligation is one of

prevention, as reflected in Article 7(1) of the U.N. Watercourses Convention:

“Watercourse States shall, in utilizing an international

watercourse in their territories, take all appropriate

687Costa Rica’s responsibility for all the damages it has caused to Nicaragua due to irresponsible
deforestation, enormous use of chemicals and general poo r land use practices is not fully before
the Court in the present case and Nicaragua reserves its rights on this issue in general. The purpose
of the evidence filed on this point is to make clear that Costa Rica cannot justify as “minor” the
damage caused by the road in comparison to the damage caused by Costa Rica’s other
environmental malfeasances. derailed in Virginia, “spilling oil into the James River and forcing hundreds to

evacuate.” 693

6.101 Incidents like the one just mentioned would seem to be even more

likely to occur when trucks are carrying fuel or other hazardous substances along

the Border Road, in view of its substandard nature and the strong possibility of

694
landslides.

6.102 As indicated in the Gabčíkovo-Nagymaros and Pulp Mills cases,

vigilance and prevention are required to protect the environment. The Court in

Pulp Mills explained:

“This vigilance and prevention is all the more important in
the preservation of the ecological balance, since th e
negative impact of human activities on the waters of the

river may affect other components of the ecosystem of the
watercourse such as its flora, fauna, and soil.” 695

6.103 For these reasons, and because of the particular risk of grave and

irreparable harm posed by such materials, Nicaragua believes that it is imperative

that Costa Rica be precluded from transporting hazardous substances on its

Border Road, at least until such time as it can be proven that improvements to the

693
Selam Gebrekidan , “CSX oil train derails in Virginia, leaks into ri,” April 30, 2014,
available at http://www.reuters.com/article/2014/05/01/us-railways-accident-virginia-
idUSBREA3T0YW20140501. “This is the sixth fiery derailment to occur in North America since
a runaway train in Lac -Megantic, Quebec, derailed and exploded, killing 47 people last July.
Another CSX train carrying crude oil derailed in Philadelphia in January, nearly toppling over a
bridge.” Ibid.
69See 2014 Kondolf Report, Section 5 (NR, Vol. II, Annex 1).
695Pulp Mills on the River Uruguay (Argentina v. Uruguay) , judgment of 20 April 2010, p. 77,
para. 188.

234derailed in Virginia, “spilling oil into the James River and forcing hundreds to

evacuate.” 693

6.101 Incidents like the one just mentioned would seem to be even more

likely to occur when trucks are carrying fuel or other hazardous substances along

the Border Road, in view of its substandard nature and the strong possibility of

694
landslides.

6.102 As indicated in the Gabčíkovo-Nagymaros and Pulp Mills cases,

vigilance and prevention are required to protect the environment. The Court in

Pulp Mills explained:

“This vigilance and prevention is all the more important in
the preservation of the ecological balance, since th e
negative impact of human activities on the waters of the

river may affect other components of the ecosystem of the
watercourse such as its flora, fauna, and soil.” 695

6.103 For these reasons, and because of the particular risk of grave and

irreparable harm posed by such materials, Nicaragua believes that it is imperative

that Costa Rica be precluded from transporting hazardous substances on its

Border Road, at least until such time as it can be proven that improvements to the

693
Selam Gebrekidan , “CSX oil train derails in Virginia, leaks into ri,” April 30, 2014,
available at http://www.reuters.com/article/2014/05/01/us-railways-accident-virginia-
idUSBREA3T0YW20140501. “This is the sixth fiery derailment to occur in North America since
a runaway train in Lac -Megantic, Quebec, derailed and exploded, killing 47 people last July.
Another CSX train carrying crude oil derailed in Philadelphia in January, nearly toppling over a
bridge.” Ibid.
694See 2014 Kondolf Report, Section 5 (NR, Vol. II, Annex 1).
695Pulp Mills on the River Uruguay (Argentina v. Uruguay) , judgment of 20 April 2010, p. 77,
para. 188. breach of Article 8, which is concerned with the promotion of protection of

ecosystems, sustainable development and the rehabilitation of degraded

698
ecosystems.” The former contention has been refuted by expert reports

annexed to this Reply, 699 as noted above and shown more fully in Chapter 2.

6.107 The latter statement is a mere assertion, having been made without

reference to any supporting evidence.

700
6.108 Costa Rica also denies having breached Article 14 of the CBD,

which as Nicaragua pointed out in its Memorial “addresses the anticipatory

measures that Costa Rica failed entirely to take: environmental impact

assessment, planning to avoid adverse impacts on biological diversity, and

notification, exchange of information and consultation regardi ng planned

701
measures that may adversely affect biological diversity of other states.”

6.109 With respect to environmental impact assessment, Costa Rica relies

on its arguments already refuted above, which are again based on the contention

that there was no reaso n for Costa Rica to anticipate that its project would entail

the possibility of significant harm, and that in any event, Costa Rica’s Emergency

Decree allows it to ignore all otherwise applicable domestic and international

obligations. These arguments hav e been shown above to be without merit. If

Costa Rica had considered its own EIA regulation it would have been provided

698Ibid.
699E.g., 2014 Kondolf Report (NR, Vol. II, Annex 1).
700CRCM, pp. 120-121, paras. 5.30-5.31.
701NM, p. 195-196, para. 5.71.

236breach of Article 8, which is concerned with the promotion of protection of

ecosystems, sustainable development and the rehabilitation of degraded

698
ecosystems.” The former contention has been refuted by expert reports

annexed to this Reply, 699as noted above and shown more fully in Chapter 2.

6.107 The latter statement is a mere assertion, having been made without

reference to any supporting evidence.

700
6.108 Costa Rica also denies having breached Article 14 of the CBD,

which as Nicaragua pointed out in its Memorial “addresses the anticipatory

measures that Costa Rica failed entirely to take: environmental impact

assessment, planning to avoid adverse impacts on biological diversity, and

notification, exchange of information and consultation regardi ng planned

701
measures that may adversely affect biological diversity of other states.”

6.109 With respect to environmental impact assessment, Costa Rica relies

on its arguments already refuted above, which are again based on the contention

that there was no reaso n for Costa Rica to anticipate that its project would entail

the possibility of significant harm, and that in any event, Costa Rica’s Emergency

Decree allows it to ignore all otherwise applicable domestic and international

obligations. These arguments hav e been shown above to be without merit. If

Costa Rica had considered its own EIA regulation it would have been provided

698Ibid.
699E.g., 2014 Kondolf Report (NR, Vol. II, Annex 1).
700CRCM, pp. 120-121, paras. 5.30-5.31.
701NM, p. 195-196, para. 5.71. Activities are wrong. But even assuming they are correct, Nicaragua’s activities in

the area in dispute have nothing to do with reciprocity with respect to

“notification, exchange of information and consultation on activities under [a

party’s] jurisdiction or control which are likely to significantly affect adversely

705
the biological diversity of other States . . . .” Nicaragua has shown in its

Counter-Memorial in the Certain Activities case that it breached no obligations of

notification or consultation with regard to its activities in the area in dispute. 706

Nicaragua’s dredging was undisputedly conducted within its sovereign territory,

the San Juan de Nicaragua River, and could not possibly have any appreciable

707
effect, on biological diversity or otherwise, in Costa Rica; and Nicaragua’s

cleaning of the caño was conducted in what Nicaragua believed, and continues to

believe, is also part of its sovereign territory and would thus not affect Costa Rica;

Nicaragua has shown that in any event these activities did not, in fact, cause harm

to Costa Rica. 708 Therefore, reciprocity cannot possibly be found to be lacking.

2. Ramsar Convention

6.112 Costa Rica betrays a fundamental misunderstanding of its

obligations under the Ramsar Convention. Thus Costa Rica states:

“The construction of the Road in no way touches upon

protected Nicaraguan wetlands falling within the Ramsar
Convention, while it leads to no risk of significant harm to
the Río San Juan, let alone prot ected wetlands in

705
706CBD, op. cit. supra, Article 14(1)(c).
Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v. Nicaragua) ,
NCM, Volume I, Chapter 5(C).
707Ibid., Section E(1) and (2)(b).
708Ibid., Section E(2)(a).

238Activities are wrong. But even assuming they are correct, Nicaragua’s activities in

the area in dispute have nothing to do with reciprocity with respect to

“notification, exchange of information and consultation on activities under [a

party’s] jurisdiction or control which are likely to significantly affect adversely

705
the biological diversity of other States . . . .” Nicaragua has shown in its

Counter-Memorial in the Certain Activities case that it breached no obligations of

notification or consultation with regard to its activities in the area in dispute. 706

Nicaragua’s dredging was undisputedly conducted within its sovereign territory,

the San Juan de Nicaragua River, and could not possibly have any appreciable

707
effect, on biological diversity or otherwise, in Costa Rica; and Nicaragua’s

cleaning of the caño was conducted in what Nicaragua believed, and continues to

believe, is also part of its sovereign territory and would thus not affect Costa Rica;

Nicaragua has shown that in any event these activities did not, in fact, cause harm

to Costa Rica. 708 Therefore, reciprocity cannot possibly be found to be lacking.

2. Ramsar Convention

6.112 Costa Rica betrays a fundamental misunderstanding of its

obligations under the Ramsar Convention. Thus Costa Rica states:

“The construction of the Road in no way touches upon

protected Nicaraguan wetlands falling within the Ramsar
Convention, while it leads to no risk of significant harm to
the Río San Juan, let alone prot ected wetlands in

705
706CBD, op. cit. supra, Article 14(1)(c).
Certain Activities carried out by Nicaragua in the Border Area (Costa Rica v. Nicaragua) ,
NCM, Volume I, Chapter 5(C).
707Ibid., Section E(1) and (2)(b).
708Ibid., Section E(2)(a). 6.114 With regard to Article 5, Costa Rica fails entirely to explain why it

does not believe it has breached this provision. Article 5 requires the parties to:

“consult with each other about implementing obligations

arising from th e Convention especially in the case of a
wetland extending over the territories of more than one
Contracting Party or where a water system is shared by
712
Contracting Parties.”

As explained in Nicaragua’s Memorial, both situations mentioned in this

provision are applicable in the present case: wetlands extend over the territories of

Costa Rica and Nicaragua, and a “water system,” the San Juan River system,

including the tributaries originating in Costa Rica and the distributaries flowing

through that State, is shared by the two States. There is no requirement in this

article that a party’s activities cause or risk causing significant harm to another

party.

6.115 Costa Rica states that “Nicaragua’s reliance on this Convention in

713
the present case is misconceived.” On the basis of the foregoing it is clear that

it is Costa Rica that misconceives its obligations under the Ramsar Convention.

3. Central American Convention for the Protection of the

Environment and Other Regional Instruments

6.116 Costa deals summarily and dismis sively with Nicaragua’s

contentions that the manner in which the Road is being constructed breaches

Costa Rica’s obligations under four regional agreements: the Central American

712
713Ramsar Convention, op. cit. supra, Article 5.
CRCM, p. 122, para. 5.32.

240 6.114 With regard to Article 5, Costa Rica fails entirely to explain why it

does not believe it has breached this provision. Article 5 requires the parties to:

“consult with each other about implementing obligations

arising from th e Convention especially in the case of a
wetland extending over the territories of more than one
Contracting Party or where a water system is shared by
712
Contracting Parties.”

As explained in Nicaragua’s Memorial, both situations mentioned in this

provision are applicable in the present case: wetlands extend over the territories of

Costa Rica and Nicaragua, and a “water system,” the San Juan River system,

including the tributaries originating in Costa Rica and the distributaries flowing

through that State, is shared by the two States. There is no requirement in this

article that a party’s activities cause or risk causing significant harm to another

party.

6.115 Costa Rica states that “Nicaragua’s reliance on this Convention in

713
the present case is misconceived.” On the basis of the foregoing it is clear that

it is Costa Rica that misconceives its obligations under the Ramsar Convention.

3. Central American Convention for the Protection of the

Environment and Other Regional Instruments

6.116 Costa deals summarily and dismis sively with Nicaragua’s

contentions that the manner in which the Road is being constructed breaches

Costa Rica’s obligations under four regional agreements: the Central American

712
713Ramsar Convention, op. cit. supra, Article 5.
CRCM, p. 122, para. 5.32. 6.118 First, the CACJ carefully exa mined the question of jurisdiction in

720
its judgment. The following jurisdictional findings of the Court are illustrative:

“[T]he Tegucigalpa Protocol is a treaty that obliges the
State of Costa Rica, inasmuch as it establishes the

compulsory jurisdiction and authority of the Central
American Court of Justice, which constitutes an
international obligation for Costa Rica that is fully
enforceable by all SICA [Central American Integration
System] State Parties . . . and in the case at hand,

environmentalist organizations . . . . The jurisdiction and
competence established in Articles 12 and 35, second
paragraph, of the Tegucigalpa Protocol are not optional or
elective nor require further acts after the ratification and
deposit of the Tegucigalpa Protocol by t he States Parties to

become a perfect international obligation, which is fully
enforceable by all the State Members of the SICA, its
bodies, institutions and individuals. . . . The State of Costa
Rica has performed acts that recognize the jurisdiction an d

authority of the Central American Court of Justice, which
prevent this State from claiming any legal basis for not
recognizing them. . . . The Central American Court of
Justice has reiterated in its jurisprudence its Compulsory
Jurisdiction . . . . The State of Costa Rica was served notice
721
. . . .”

6.119 The principle of compétence de la compétence is a cornerstone of

national and international adjudication and arbitration: unless a tribunal has

authority to determine whether it has jurisdiction, a party co uld simply ignore

with impunity proceedings legitimately brought against it. Here, the CACJ

observed that Article 30 of its Statute provides that:

“the Court has the power to determine its jurisdiction in
each particular case, interpreting treaties or co nventions

720
721NM, Volume II, Annex 13, pp. 376-380.
Ibid.

242 6.118 First, the CACJ carefully exa mined the question of jurisdiction in

720
its judgment. The following jurisdictional findings of the Court are illustrative:

“[T]he Tegucigalpa Protocol is a treaty that obliges the
State of Costa Rica, inasmuch as it establishes the

compulsory jurisdiction and authority of the Central
American Court of Justice, which constitutes an
international obligation for Costa Rica that is fully
enforceable by all SICA [Central American Integration
System] State Parties . . . and in the case at hand,

environmentalist organizations . . . . The jurisdiction and
competence established in Articles 12 and 35, second
paragraph, of the Tegucigalpa Protocol are not optional or
elective nor require further acts after the ratification and
deposit of the Tegucigalpa Protocol by t he States Parties to

become a perfect international obligation, which is fully
enforceable by all the State Members of the SICA, its
bodies, institutions and individuals. . . . The State of Costa
Rica has performed acts that recognize the jurisdiction an d

authority of the Central American Court of Justice, which
prevent this State from claiming any legal basis for not
recognizing them. . . . The Central American Court of
Justice has reiterated in its jurisprudence its Compulsory
Jurisdiction . . . . The State of Costa Rica was served notice
721
. . . .”

6.119 The principle of compétence de la compétence is a cornerstone of

national and international adjudication and arbitration: unless a tribunal has

authority to determine whether it has jurisdiction, a party co uld simply ignore

with impunity proceedings legitimately brought against it. Here, the CACJ

observed that Article 30 of its Statute provides that:

“the Court has the power to determine its jurisdiction in
each particular case, interpreting treaties or co nventions

720
721NM, Volume II, Annex 13, pp. 376-380.
Ibid. 725
the ‘Judgment’ was based on no scientific evidence of harm whatever.” The

Court found that it had jurisdiction over Costa Rica as it was authorized to do by

its Statute and general principles of law, and it made its decision on the basis of

plentiful evidence, much of it of a scientific and technical nature. Its Judgment is

binding on Costa Rica.

6.125 If Costa Rica believed the Court lacked jurisdiction it should have

appeared to contest it. And, not having appeared even to contest jurisdiction,

Costa Rica cannot be heard to claim that the Court did not base its judgment on

any “scientific evidence of harm whatever.” Again, had Costa Rica believed that

the science was in its favor, it should have presented its case to the Court (it

should have done so even if the scientific evidence was not clearly in its favor).

This it decided not to do.

6.126 It is perhaps fitting to conclude the discussion of this point with

another observation of the CACJ:

“It is inadmissible that these Central American purposes to
unite conservation efforts among neighboring countries,

such as the case of the Trifinio Plan, Gulf of Fonseca and
others contemplated in the Central American Agreement on
Biodiversity signed by the countries of the region,

including SI A PAZ between Nicaragua and Costa Rica in
1992, have been contradicted, undervalued and, worst of
all, igno red and violated by a country like Costa Rica,
which prides itself and sells itself internationally as ‘a

model of eco 726environmental management within its
borders’ . . . .”

725CRCM, p. 87, para. 3.67.
726NM, Volume II, Annex 13, p. 372.

244 725
the ‘Judgment’ was based on no scientific evidence of harm whatever.” The

Court found that it had jurisdiction over Costa Rica as it was authorized to do by

its Statute and general principles of law, and it made its decision on the basis of

plentiful evidence, much of it of a scientific and technical nature. Its Judgment is

binding on Costa Rica.

6.125 If Costa Rica believed the Court lacked jurisdiction it should have

appeared to contest it. And, not having appeared even to contest jurisdiction,

Costa Rica cannot be heard to claim that the Court did not base its judgment on

any “scientific evidence of harm whatever.” Again, had Costa Rica believed that

the science was in its favor, it should have presented its case to the Court (it

should have done so even if the scientific evidence was not clearly in its favor).

This it decided not to do.

6.126 It is perhaps fitting to conclude the discussion of this point with

another observation of the CACJ:

“It is inadmissible that these Central American purposes to
unite conservation efforts among neighboring countries,

such as the case of the Trifinio Plan, Gulf of Fonseca and
others contemplated in the Central American Agreement on
Biodiversity signed by the countries of the region,

including SI A PAZ between Nicaragua and Costa Rica in
1992, have been contradicted, undervalued and, worst of
all, igno red and violated by a country like Costa Rica,
which prides itself and sells itself internationally as ‘a

model of eco 726environmental management within its
borders’ . . . .”

725CRCM, p. 87, para. 3.67.
726NM, Volume II, Annex 13, p. 372. and protect the region’s natural heritage, which is characterized by its high level

of biological and ecological diversity; . . .” 732

733
6.129 Costa Rica similarly denigrates the Tegucigalpa Protocol,

resorting t o blanket denial (“Such assertions are frivolous” 734), rather than

engagement in argument, or showing how the Road project is consistent with the

Protocol’s objectives and principles.

6.130 The 1992 Convention for the Conservation of Biodiversity and the

Protection of Wilderness Areas in Central America comes in for similar treatment

at the hands of Costa Rica. “To the extent that the provisions relied on by

Nicaragua impose obligations on Costa Rica,” its argument begins, “Nicaragua’s

case under this Convention fails for equivalent reasons to those identified above in

relation to the Convention on Biological Diversity and the Ramsar

735
Convention.” That is the sum total of Costa Rica’s response. It does not take

up the various specific provisions to which Nicaragu a refers. 736 Th ese include

Article 33, which Costa Rica quoted in its Memorial in the Certain Activities case,

then stated:

“The object and purpose of the Convention is to oblige the
Central American parties to the Convention not only to

physically preserve valuable natural resources, but also to
notify and consult with neighboring States whose
environment may be affected by potentially harmful

732
733CACPE, op. cit. supra, Article II(a).
CRCM, pp. 123-124, paras. 5.36-5.37.
734Ibid., p. 124, para. 5.37.
735Ibid., para. 5.38.
736NM, pp. 210-212, paras. 5.95-5.98.

246and protect the region’s natural heritage, which is characterized by its high level

of biological and ecological diversity; . . .” 732

733
6.129 Costa Rica similarly denigrates the Tegucigalpa Protocol,

resorting t o blanket denial (“Such assertions are frivolous” 734), rather than

engagement in argument, or showing how the Road project is consistent with the

Protocol’s objectives and principles.

6.130 The 1992 Convention for the Conservation of Biodiversity and the

Protection of Wilderness Areas in Central America comes in for similar treatment

at the hands of Costa Rica. “To the extent that the provisions relied on by

Nicaragua impose obligations on Costa Rica,” its argument begins, “Nicaragua’s

case under this Convention fails for equivalent reasons to those identified above in

relation to the Convention on Biological Diversity and the Ramsar

735
Convention.” That is the sum total of Costa Rica’s response. It does not take

up the various specific provisions to which Nicaragu a refers. 736 Th ese include

Article 33, which Costa Rica quoted in its Memorial in the Certain Activities case,

then stated:

“The object and purpose of the Convention is to oblige the
Central American parties to the Convention not only to

physically preserve valuable natural resources, but also to
notify and consult with neighboring States whose
environment may be affected by potentially harmful

732
733CACPE, op. cit. supra, Article II(a).
CRCM, pp. 123-124, paras. 5.36-5.37.
734Ibid., p. 124, para. 5.37.
735Ibid., para. 5.38.
736NM, pp. 210-212, paras. 5.95-5.98. and precautionary approach to pollution problems.” 739 As made clear earlier,

anthropogenic sediment is, in fact, “pollution.” Furthermore, while Costa Rica

says there is no proof that hazardous substances have made their way across the

border into the river from the Road project, 740as the Court is aware the rains in

the region, which have been only mild to date, have brought insufficiently moored

741
culverts into the river. Given the unstable condition of sections of the Road

there is an unac ceptable risk of a major spill into the river from a truck carrying

hazardous materials. Yet, there is no indication that Costa Rica plans to take the

kinds of preventive measures required by the Regional Agreement on the

Transboundary Movement of Hazardous Wastes. For its part, Nicaragua prohibits

the transport of hazardous materials on the San Juan River. 742

4. Agreement on Border Protected Areas

6.134 This bilateral treaty, known as the “SI -A-PAZ” agreement, was

signed by the Presidents of Costa Rica and Nicaragua in 1990. 743 In its Memorial,

739
Regional Agreement on the Transboundary Movement of Hazardous Wastes, op. cit. supra ,
740icle 3(3).
741CRCM, p. 125, para. 5.39.
See Figure 2.5, above, showing Nicaraguan civil servants attempting to remove a plastic
culvert from the river, into which it had washed from the Road project. See also 2014 Kondolf
Report, Section 3 (NR, Vol. II, Annex 1).
742See Article 70 (8) of the Decree 79/2009: “ … In relation to vessels, the following is forbidden:
….8. Transport, trade and use on the San Juan River of the following pesticides as raw material,

formulated products and any other mixture: 2,4,5 -T (trichlorophenoxyacetic acid), aldrin,
dieldrin, endrin, chlordane, chlordimeform, DBCP (Dibromochlorpropane -Nemagon), DDT
(Dichloride Diphenyl Trichloroethane), Dinoseb, EDB (Ethylene dibromide), ethyl parathion,
HCB (hex chlorobenzene), heptachlor, Lindane, Pentachlorophenol, Percloropentano cyclohexane
(Dichloride or Mirex), toxaphene, Methyl parathion, methamidophos (MTD) and Monocrotophos.
Without prejudice to the prohibitions and restrictions established in official document s.”available
in original language at http://www.cancilleria.gob.ni/diferendos/Gaceta_RegRSJNCR.pdf.
743
Agreement on Border Protected Areas, the “SI-A-PAZ” agreement, signed at Puntarenas, Costa
Rica, 15 December 1990. (NM, Vol. II, Annex 7).

248and precautionary approach to pollution problems.” 739 As made clear earlier,

anthropogenic sediment is, in fact, “pollution.” Furthermore, while Costa Rica

says there is no proof that hazardous substances have made their way across the

border into the river from the Road project, 740 as the Court is aware the rains in

the region, which have been only mild to date, have brought insufficiently moored

741
culverts into the river. Given the unstable condition of sections of the Road

there is an unac ceptable risk of a major spill into the river from a truck carrying

hazardous materials. Yet, there is no indication that Costa Rica plans to take the

kinds of preventive measures required by the Regional Agreement on the

Transboundary Movement of Hazardous Wastes. For its part, Nicaragua prohibits

the transport of hazardous materials on the San Juan River. 742

4. Agreement on Border Protected Areas

6.134 This bilateral treaty, known as the “SI -A-PAZ” agreement, was

signed by the Presidents of Costa Rica and Nicaragua in 1990. 743 In its Memorial,

739
Regional Agreement on the Transboundary Movement of Hazardous Wastes, op. cit. supra ,
740icle 3(3).
741CRCM, p. 125, para. 5.39.
See Figure 2.5, above, showing Nicaraguan civil servants attempting to remove a plastic
culvert from the river, into which it had washed from the Road project. See also 2014 Kondolf
Report, Section 3 (NR, Vol. II, Annex 1).
742See Article 70 (8) of the Decree 79/2009: “ … In relation to vessels, the following is forbidden:
….8. Transport, trade and use on the San Juan River of the following pesticides as raw material,

formulated products and any other mixture: 2,4,5 -T (trichlorophenoxyacetic acid), aldrin,
dieldrin, endrin, chlordane, chlordimeform, DBCP (Dibromochlorpropane -Nemagon), DDT
(Dichloride Diphenyl Trichloroethane), Dinoseb, EDB (Ethylene dibromide), ethyl parathion,
HCB (hex chlorobenzene), heptachlor, Lindane, Pentachlorophenol, Percloropentano cyclohexane
(Dichloride or Mirex), toxaphene, Methyl parathion, methamidophos (MTD) and Monocrotophos.
Without prejudice to the prohibitions and restrictions established in official document s.”available
in original language at http://www.cancilleria.gob.ni/diferendos/Gaceta_RegRSJNCR.pdf.
743
Agreement on Border Protected Areas, the “SI-A-PAZ” agreement, signed at Puntarenas, Costa
Rica, 15 December 1990. (NM, Vol. II, Annex 7). was, and continues to be constructed bre aches treaties to which both States are

parties. Costa Rica seems blind to the intent of many of these agreements,

beginning with the Convention on Biological Diversity, to safeguard areas within

a State party as well as those in other States. It is ines capable that Costa Rica’s

unplanned Road project ran roughshod not only over its legal obligations to

protect the environment, but also over protected areas of exceptional value and

sensitivity within its own borders. For this reason alone, Costa Rica can not rely

on its favorite defense : that its Road project did not cause significant harm to

Nicaragua.

G. CONCLUSIONS

6.137 The following conclusions may be drawn from the foregoing.

6.138 First, the fact that the Border Road is being constructed in Costa

Rican territory has no bearing on its obligations addressed in this Chapter. The

obligation of a State not to use or permit the use of its territory in such a way as to

harm its neighbour is venerable. Costa Rica’s insinuation that this is not the case

is not supported in international law and thus without merit.

6.139 Second, Costa Rica’s Emergency Decree is ineffective to release

Costa Rica from its international obligations, including those owed to Nicaragua

in respect of the Road project. By its own actions Costa Rica d emonstrated that it

did not believe that there was an “emergency” created by Nicaragua’s activities in

the disputed area that required initiating work on the Road project immediately,

250was, and continues to be constructed bre aches treaties to which both States are

parties. Costa Rica seems blind to the intent of many of these agreements,

beginning with the Convention on Biological Diversity, to safeguard areas within

a State party as well as those in other States. It is ines capable that Costa Rica’s

unplanned Road project ran roughshod not only over its legal obligations to

protect the environment, but also over protected areas of exceptional value and

sensitivity within its own borders. For this reason alone, Costa Rica can not rely

on its favorite defense : that its Road project did not cause significant harm to

Nicaragua.

G. CONCLUSIONS

6.137 The following conclusions may be drawn from the foregoing.

6.138 First, the fact that the Border Road is being constructed in Costa

Rican territory has no bearing on its obligations addressed in this Chapter. The

obligation of a State not to use or permit the use of its territory in such a way as to

harm its neighbour is venerable. Costa Rica’s insinuation that this is not the case

is not supported in international law and thus without merit.

6.139 Second, Costa Rica’s Emergency Decree is ineffective to release

Costa Rica from its international obligations, including those owed to Nicaragua

in respect of the Road project. By its own actions Costa Rica d emonstrated that it

did not believe that there was an “emergency” created by Nicaragua’s activities in

the disputed area that required initiating work on the Road project immediately, law. Costa Rica was on notice of the possibi lity that the project would cause

significant adverse effects upon Nicaragua due to the magnitude of the project and

its proximity to the San Juan River, and it is this possibility, not whether

significant harm actually resulted from the project, that triggered the obligation to

notify. Even if, quod non, the project qualified as one of “utmost urgency,” Costa

Rica failed to comply with the requirements of communicating to Nicaragua (i) a

formal declaration of the urgency, and (ii) the relevant data and in formation

concerning the Road project. In addition, even in such a situation Costa Rica

would remain under its other international obligations, including that of

prevention of significant harm to Nicaragua.

6.142 Fifth, Costa Rica’s Road project breached, and continues to breach,

the obligation to prevent the causing of significant harm to Nicaragua. The Road

project has added significant quantities of anthropogenic sediment, a pollutant, to

the San Juan River, whether measured in absolute or relative quantit ies. Costa

Rica was obligated to prevent the introduction of these additional quantities into

the San Juan River, Nicaragua’s territory. These additional quantities have

caused, and continue to cause, significant harm to Nicaragua. Costa Rica is also

responsible to Nicaragua for the harmful effects of the substantial increases in

sediment yields from Costa Rican tributaries to the San Juan due to substandard

land use practices in Costa Rica. Finally, Costa Rica’s obligation to prevent harm

to Nicaragua re quires that Costa Rica refrain from transporting or allowing the

252law. Costa Rica was on notice of the possibi lity that the project would cause

significant adverse effects upon Nicaragua due to the magnitude of the project and

its proximity to the San Juan River, and it is this possibility, not whether

significant harm actually resulted from the project, that triggered the obligation to

notify. Even if, quod non, the project qualified as one of “utmost urgency,” Costa

Rica failed to comply with the requirements of communicating to Nicaragua (i) a

formal declaration of the urgency, and (ii) the relevant data and in formation

concerning the Road project. In addition, even in such a situation Costa Rica

would remain under its other international obligations, including that of

prevention of significant harm to Nicaragua.

6.142 Fifth, Costa Rica’s Road project breached, and continues to breach,

the obligation to prevent the causing of significant harm to Nicaragua. The Road

project has added significant quantities of anthropogenic sediment, a pollutant, to

the San Juan River, whether measured in absolute or relative quantit ies. Costa

Rica was obligated to prevent the introduction of these additional quantities into

the San Juan River, Nicaragua’s territory. These additional quantities have

caused, and continue to cause, significant harm to Nicaragua. Costa Rica is also

responsible to Nicaragua for the harmful effects of the substantial increases in

sediment yields from Costa Rican tributaries to the San Juan due to substandard

land use practices in Costa Rica. Finally, Costa Rica’s obligation to prevent harm

to Nicaragua re quires that Costa Rica refrain from transporting or allowing the 6.145 Costa Rica is also dismissive of the Judgment of the Central

American Court of Justice on the grounds that the Court lacked jurisdiction over it

and based its Judgment on “no scientific evidence of harm whatever.” These

claims have are without merit. The Court determined it had jurisdiction, as it is

entitled to do, that the subject matter was enti rely within its competence, and

based its Judgment on scientific and technical evidence submitted by the

plaintiffs.

6.146 For all of these reasons , Nicaragua requests that the Court hold

Costa Rica responsible for its breaches of environmental obligations under

international law.

254 6.145 Costa Rica is also dismissive of the Judgment of the Central

American Court of Justice on the grounds that the Court lacked jurisdiction over it

and based its Judgment on “no scientific evidence of harm whatever.” These

claims have are without merit. The Court determined it had jurisdiction, as it is

entitled to do, that the subject matter was enti rely within its competence, and

based its Judgment on scientific and technical evidence submitted by the

plaintiffs.

6.146 For all of these reasons , Nicaragua requests that the Court hold

Costa Rica responsible for its breaches of environmental obligations under

international law. responsible for an internationally wrongful act is under an obligation to cease that

751
act, if it is continuing.” In the presen t case, Costa Rica’s internationally

wrongful acts are indeed continuing. This has been both noted by Nicaragua’s

scientific experts and recognized by Costa Rica itself.

7.4 Thus, in his most recent rep ort, Dr Kondolf has noted that:

“Erosion has visibly worse ned since I first observed Rte 1856 in October

2012.” 752 Similarly, Mr. Hagans and Dr. Weaver, two consulting

geomorphologists, note that:

“A review of paired oblique aerial photographs taken from
helicopters in October 2012 and May 2014 illustrates the
widespread, ongoing and persistent erosion occurring along

portions of the route from a combination of landslide, 753
fluvial (gully) and surface erosional processes.”

7.5 Interestingly, Costa Rica itself accepts that the effects on the River

are continuing and that measures have not been taken in order to remediate it. As

the Court observed in its Order of 13 December 2013 on the Request Presented by

Nicaragua for the Indication of Provisional Measures , Costa Rica recognized the

need for remediation and mitigation measures 754, but, at the same time, “explained

that, under the updated version of the schedule, the resumption of construction

751
I.C.J., Judgment, 3 February 2012, Jurisdictional immunities of the State (Germany v. Italy:
Greece intervening), Reports 2012 , p. 153, para. 137.See also I.C.J., Judgment, 20 July 2012,
Questions relating to the obligation to prosecute or extradite (Belgium v. Senegal), Reports 2012,
p. 461, para. 121; I.C.J., Judgment, 31 March 2014, Whaling in the Antarctic (Australia v. Japan:
New Zealand intervening), paras. 245-246 or ILC, Article 3 0 of the Articles on responsibility of
States for internationally wrongful acts and its commentary,Yearbook of the International Law
Commission, 2001, vol. II, Part Two, pp. 88-91.
7522014 Kondolf Report, Section 3 (NR, Vol. II, Annex 1).
753
754Hagans & Weaver Report, Section 1 (NR, Vol. II, Annex 2).
I.C.J., Order, 13 December 2013, Construction of a Road in Costa Rica along the San Juan
River (Nicaragua v. Costa Rica), para. 37.

256responsible for an internationally wrongful act is under an obligation to cease that

751
act, if it is continuing.” In the presen t case, Costa Rica’s internationally

wrongful acts are indeed continuing. This has been both noted by Nicaragua’s

scientific experts and recognized by Costa Rica itself.

7.4 Thus, in his most recent rep ort, Dr Kondolf has noted that:

“Erosion has visibly worse ned since I first observed Rte 1856 in October

2012.” 752 Similarly, Mr. Hagans and Dr. Weaver, two consulting

geomorphologists, note that:

“A review of paired oblique aerial photographs taken from
helicopters in October 2012 and May 2014 illustrates the
widespread, ongoing and persistent erosion occurring along

portions of the route from a combination of landslide, 753
fluvial (gully) and surface erosional processes.”

7.5 Interestingly, Costa Rica itself accepts that the effects on the River

are continuing and that measures have not been taken in order to remediate it. As

the Court observed in its Order of 13 December 2013 on the Request Presented by

Nicaragua for the Indication of Provisional Measures , Costa Rica recognized the

need for remediation and mitigation measures 754, but, at the same time, “explained

that, under the updated version of the schedule, the resumption of construction

751
I.C.J., Judgment, 3 February 2012, Jurisdictional immunities of the State (Germany v. Italy:
Greece intervening), Reports 2012 , p. 153, para. 137.See also I.C.J., Judgment, 20 July 2012,
Questions relating to the obligation to prosecute or extradite (Belgium v. Senegal), Reports 2012,
p. 461, para. 121; I.C.J., Judgment, 31 March 2014, Whaling in the Antarctic (Australia v. Japan:
New Zealand intervening), paras. 245-246 or ILC, Article 3 0 of the Articles on responsibility of
States for internationally wrongful acts and its commentary,Yearbook of the International Law
Commission, 2001, vol. II, Part Two, pp. 88-91.
7522014 Kondolf Report, Section 3 (NR, Vol. II, Annex 1).
753
754Hagans & Weaver Report, Section 1 (NR, Vol. II, Annex 2).
I.C.J., Order, 13 December 2013, Construction of a Road in Costa Rica along the San Juan
River (Nicaragua v. Costa Rica), para. 37. negative impact on the River, but the reinstatement of a situation as proximate as

possible to the one existing before the construction of the road.

7.9 As made clear in the Memorial, “[t]his implies that Costa Rica shall

at least:

 plant trees in order to re -establish the ravaged vegetation and

landscape [serious plantation made by qualified personnel and not
761
by children ]

 rebuild the right bank of the San Juan River where it has been

affected by construction works and

 compensate Nicaragua for restoring the natural flow of the waters

that flow through the south basin to the San Juan River which has

been modified as a consequence of the construction works which

also have modified the drainage of t he surrounding wetlands in the

lower San Juan and its delta;
762
 and comply with the recommendations of the experts on the
763
works necessary for full restoration of the status quo ante.”

7.10 This of course includes the “mitigation” works which Costa Rica

has pled ged to undertake. 764 But, as shown above, 765 those announced by the

Respondent are far from sufficient to permit a real re -establishment of the pre -

existing situation. These measures should include all the recommendations made

761
762See CODEFORSA Report, pp. 10, 15 (CRCM, Vol. II, Annex 2).
763See NM, paras. 3.96-3.98 and the 2012 Kondolf Report, Section 5.6 (NM, Vol. II, Annex 1).
764NM, para. 6.31.
See CRCM, paras. 2.38-2.41.
765See para. 1.16 and Chapter 3 Section B.

258negative impact on the River, but the reinstatement of a situation as proximate as

possible to the one existing before the construction of the road.

7.9 As made clear in the Memorial, “[t]his implies that Costa Rica shall

at least:

 plant trees in order to re -establish the ravaged vegetation and

landscape [serious plantation made by qualified personnel and not
761
by children ]

 rebuild the right bank of the San Juan River where it has been

affected by construction works and

 compensate Nicaragua for restoring the natural flow of the waters

that flow through the south basin to the San Juan River which has

been modified as a consequence of the construction works which

also have modified the drainage of t he surrounding wetlands in the

lower San Juan and its delta;
762
 and comply with the recommendations of the experts on the
763
works necessary for full restoration of the status quo ante.”

7.10 This of course includes the “mitigation” works which Costa Rica

has pled ged to undertake. 764 But, as shown above, 765 those announced by the

Respondent are far from sufficient to permit a real re -establishment of the pre -

existing situation. These measures should include all the recommendations made

761
762See CODEFORSA Report, pp. 10, 15 (CRCM, Vol. II, Annex 2).
763See NM, paras. 3.96-3.98 and the 2012 Kondolf Report, Section 5.6 (NM, Vol. II, Annex 1).
764NM, para. 6.31.
See CRCM, paras. 2.38-2.41.
765See para. 1.16 and Chapter 3 Section B.  despite the fact that Costa Rica indic ated to the Court that the road

construction works will not recommence “before late 2014 or early
772 773
2015,” it would appear that they have never been suspended.

For instance, Costa Rica announced to have awarded millions of
774
colones for the construction of b ridges and President Chinchilla
775
declared that “works are underway.”

7.13 This corresponds precisely to a circumstance when such measures

are required. 776

7.14 In the letter transmitting the present Reply to the Registrar of the

Court, Nicaragua suggests that the Court appoint an expert who could assist it “in

evaluating the scientific evidence submitted by the Parties and, after the

Judgment, to assist the Parties in its implementation. In Nicaragua’s view, such an

expert should be a geomorphologist or geotechnical e ngineer with expertise on

road construction and road impacts. If the Court appoints such an expert,

Nicaragua further suggests that the Parties could be called to share his or her fees

and expenses.” Such an appointment would provide the Court with valuabl e

assistance in the pre -Judgment phase, and reinforce the guarantee to have the

772CR 2013/31, 8 November 2013, morning, p. 15, para. 22 (Ms. Parlett).
773Note from the Minister of Foreign Affairs of Costa Rica, to the Minister of Foreign Affairs of
Nicaragua, Ref.: DM-AM-704-13, 19 December 2013. (NR, Vol. II, Annex 8).
774See “Trail Construction Will Restart at the End of the Chinchilla Administration”,Diario
Extra, 13 December 2013 (http://www.crhoy.com/precio-total-de-la-trocha-fronteriza-se-estima-
en-mas-de-50-mil-millones/) (NR, Vol. II, Annex 17) an d “‘Trail’ Will Be a Project for the Next
Governement”, La Prensa , 21 February 2014

(http://www.prensaescrita.com/adiario.php?codigo=AME&pagina=http://www.p…)
775, Vol. II, Annex 19).
“Visit by the President Two Days Before Delivering the Command”, La Nación (Costa Rica), 6
May 2014. (NR, Vol. II, Annex 20). See also R. Madrigal, “Works on the Trail Paralyzed while
Waiting for Designs and Modular Bridges”, crhoy.com, 10 July 2014. (NR, Vol. II, Annex 21).
776See NM, para. 6.24.

260  despite the fact that Costa Rica indic ated to the Court that the road

construction works will not recommence “before late 2014 or early
772 773
2015,” it would appear that they have never been suspended.

For instance, Costa Rica announced to have awarded millions of
774
colones for the construction of b ridges and President Chinchilla
775
declared that “works are underway.”

7.13 This corresponds precisely to a circumstance when such measures

are required. 776

7.14 In the letter transmitting the present Reply to the Registrar of the

Court, Nicaragua suggests that the Court appoint an expert who could assist it “in

evaluating the scientific evidence submitted by the Parties and, after the

Judgment, to assist the Parties in its implementation. In Nicaragua’s view, such an

expert should be a geomorphologist or geotechnical e ngineer with expertise on

road construction and road impacts. If the Court appoints such an expert,

Nicaragua further suggests that the Parties could be called to share his or her fees

and expenses.” Such an appointment would provide the Court with valuabl e

assistance in the pre -Judgment phase, and reinforce the guarantee to have the

772CR 2013/31, 8 November 2013, morning, p. 15, para. 22 (Ms. Parlett).
773Note from the Minister of Foreign Affairs of Costa Rica, to the Minister of Foreign Affairs of
Nicaragua, Ref.: DM-AM-704-13, 19 December 2013. (NR, Vol. II, Annex 8).
774See “Trail Construction Will Restart at the End of the Chinchilla Administration”,Diario
Extra, 13 December 2013 (http://www.crhoy.com/precio-total-de-la-trocha-fronteriza-se-estima-
en-mas-de-50-mil-millones/) (NR, Vol. II, Annex 17) an d “‘Trail’ Will Be a Project for the Next
Governement”, La Prensa , 21 February 2014

(http://www.prensaescrita.com/adiario.php?codigo=AME&pagina=http://www.p…)
775, Vol. II, Annex 19).
“Visit by the President Two Days Before Delivering the Command”, La Nación (Costa Rica), 6
May 2014. (NR, Vol. II, Annex 20). See also R. Madrigal, “Works on the Trail Paralyzed while
Waiting for Designs and Modular Bridges”, crhoy.com, 10 July 2014. (NR, Vol. II, Annex 21).
776See NM, para. 6.24. were derived from monitoring at different stations, at different depths, and

on different dates. Similarly, with respect to water quality, the Parties used

different sampling techniques at different locations and depths, to obtain
the data presented to the Court, thus complicating the comparability of the

results submitted by them.

[…]

5. It is of course true that it is the responsibility of the Court to determine

the facts and to assess their probative value, but this does not prevent it

from taking advantage of its powers to order an enquiry or to seek expert

opinion in the handling of the complex technical and scie ntific material
submitted to it in this case. The Court, in order to exercise its function of

resolving disputes, needs to ensure not only to be in possession of all the

available facts relevant to the issues before it, but also to understand fully

their actual meaning for the proper application of the law to those facts.

The rationale behind the provisions on enquiry and the seeking of an
expert opinion in the Statute and in the Rules of Court is to allow the Court

to obtain the necessary assistance and su pport in acquiring such full

knowledge of the facts.

6. This case offered a unique opportunity for the Court to use the powers

granted to it by Article 50 of its Statute, as well as by Article 67 of the

Rules of Court. It is a case where the decisions and conclusions of the

Court largely depend on a correct appreciation of the scientific and
technical facts. It is true that on many occasions in the past the Court was

able to resolve complex and contested factual issues without resorting to

Article 50 of th e Statute. Yet, in a case such as this one concerning the

protection of the environment and the prevention of pollution, specialized

scientific expertise can provide the Court with the insights necessary to

262were derived from monitoring at different stations, at different depths, and

on different dates. Similarly, with respect to water quality, the Parties used

different sampling techniques at different locations and depths, to obtain
the data presented to the Court, thus complicating the comparability of the

results submitted by them.

[…]

5. It is of course true that it is the responsibility of the Court to determine

the facts and to assess their probative value, but this does not prevent it

from taking advantage of its powers to order an enquiry or to seek expert

opinion in the handling of the complex technical and scie ntific material
submitted to it in this case. The Court, in order to exercise its function of

resolving disputes, needs to ensure not only to be in possession of all the

available facts relevant to the issues before it, but also to understand fully

their actual meaning for the proper application of the law to those facts.

The rationale behind the provisions on enquiry and the seeking of an
expert opinion in the Statute and in the Rules of Court is to allow the Court
detail on Nicaragua’s request for provisional measures (A.). But Costa Rica’s
to obtain the necessary assistance and su pport in acquiring such full

knowledge of the facts. allegations concerning the other Nicaraguan requests deserve some rebuttal,

whether they concern:
6. This case offered a unique opportunity for the Court to use the powers

granted to it by Article 50 of its Statute, as well as by Article 67 of the

Rules of Court. It is a case where the decisions and conclusions of the

Court largely depend on a correct appreciation of the scientific and
technical facts. It is true that on many occasions in the past the Court was

able to resolve complex and contested factual issues without resorting to

Article 50 of th e Statute. Yet, in a case such as this one concerning the

protection of the environment and the prevention of pollution, specialized 778
I.C.J., Judgment, 20 April 2010,
scientific expertise can provide the Court with the insights necessary to Declaration of Judge Yusuf, Reports 2010, p. 216, paras. 2-3 and p. 217, paras. 5-7. 1. Nicaragua’s former request for Provisional Measures

7.17 Nicaragua had suggested that the Court order provisional measures

proprio motu under Article 75 of its Rules. The Court declined to do it 779 and

decided not to uphold Nicaragua’s express request for provisional measures of 11

October 2013 by its Order of 13 December 2013. The Court based its ruling on

the information available at the time and on the (late) announcement by Costa

Rica that “the resumption of construction works on the section of the road along

the south bank of the San Juan River would not begin “before late 2014 or early

2015.” 780 However, “[h]aving concluded that no provisional measures should be

indicated,” the Court observed:

“nevertheless that Costa Rica acknowledged during the

course of the oral proceedings that it has a duty not to cause
any significant transb oundary harm as a result of the
construction works on its territory, and that it would take
the measures that it deemed appropriate to prevent such

harm. The Court further observes that Costa Rica has in any
event recognized the necessity of remediation wo rks, in
order to mitigate damage caused by the effects of poor
planning and execution of the road works in 2011, and has

indicated that a number of remediation measures to that end
have already been undertaken. Finally, the Court notes that
Costa Rica anno unced, during the same oral proceedings,
that, with its Counter -Memorial, due to be filed by 19

December 2013, it would submit what it described as an
‘Environment Diagnostic’ study covering the stretch of the
road running along the bank of the San Juan River.” 781

779See I.C.J., Order, 17 April 2013.
780Order, 13 December 2013, para. 33.
781Ibid., para. 37.

264 1. Nicaragua’s former request for Provisional Measures

7.17 Nicaragua had suggested that the Court order provisional measures

proprio motu under Article 75 of its Rules. The Court declined to do it 779and

decided not to uphold Nicaragua’s express request for provisional measures of 11

October 2013 by its Order of 13 December 2013. The Court based its ruling on

the information available at the time and on the (late) announcement by Costa

Rica that “the resumption of construction works on the section of the road along

the south bank of the San Juan River would not begin “before late 2014 or early

2015.” 780 However, “[h]aving concluded that no provisional measures should be

indicated,” the Court observed:

“nevertheless that Costa Rica acknowledged during the

course of the oral proceedings that it has a duty not to cause
any significant transb oundary harm as a result of the
construction works on its territory, and that it would take
the measures that it deemed appropriate to prevent such

harm. The Court further observes that Costa Rica has in any
event recognized the necessity of remediation wo rks, in
order to mitigate damage caused by the effects of poor
planning and execution of the road works in 2011, and has

indicated that a number of remediation measures to that end
have already been undertaken. Finally, the Court notes that
Costa Rica anno unced, during the same oral proceedings,
that, with its Counter -Memorial, due to be filed by 19

December 2013, it would submit what it described as an
‘Environment Diagnostic’ study covering the stretch of the
road running along the bank of the San Juan River.” 781

779See I.C.J., Order, 17 April 2013.
780Order, 13 December 2013, para. 33.
781Ibid., para. 37. they cannot have a retroactive effect and, therefore, will not make good the harm

already suffered. 785As a consequence these damages must be compensated. 786

7.20 Costa Rica’s sole an swer to this claim is that “[n]one of the

paragraphs or documents cited by Nicaragua established that it has suffered any

787
compensable loss.” As is apparent from Chapter 2 of this Reply, the damage

caused to the San Juan River by the misconceived road works done by Costa Rica

is all too well established:

 Road construction works have caused pollution to the San Juan

River through massive delivery of road -derived sediments to the

River;

 Road-derived sediments have caused morphological changes of the

San Juan River (creation of or enlargement of existing deltas of

sediments) and

 have affected San Juan River water quality and aquatic life;

 have significantly affected Nicaragua’s dredging needs.

788 Nicaragua
7.21 In accordance with a well -established practice,

requests that the amount of the compensation be assessed in a separate phase of

the proceedings insofar as the Parties cannot reach an agreement in this respect.

785
786See NM, para. 6.32.
See ibid. and Article 36, para. 1, of the ILC Articles on the Responsibility of States for
internationally wrongful acts: “The State responsible for an internatiowrongful act is under
an obligation to compensate for the damage caused thereby, insofar as such damage is not made
good by restitution.”
787CRCM, para. 6.13.
788See NM, p. 243, fn. 610.

266they cannot have a retroactive effect and, therefore, will not make good the harm

already suffered. 785As a consequence these damages must be compensated. 786

7.20 Costa Rica’s sole an swer to this claim is that “[n]one of the

paragraphs or documents cited by Nicaragua established that it has suffered any

787
compensable loss.” As is apparent from Chapter 2 of this Reply, the damage

caused to the San Juan River by the misconceived road works done by Costa Rica

is all too well established:

 Road construction works have caused pollution to the San Juan

River through massive delivery of road -derived sediments to the

River;

 Road-derived sediments have caused morphological changes of the

San Juan River (creation of or enlargement of existing deltas of

sediments) and

 have affected San Juan River water quality and aquatic life;

 have significantly affected Nicaragua’s dredging needs.

788 Nicaragua
7.21 In accordance with a well -established practice,

requests that the amount of the compensation be assessed in a separate phase of

the proceedings insofar as the Parties cannot reach an agreement in this respect.

785
786See NM, para. 6.32.
See ibid. and Article 36, para. 1, of the ILC Articles on the Responsibility of States for
internationally wrongful acts: “The State responsible for an internatiowrongful act is under
an obligation to compensate for the damage caused thereby, insofar as such damage is not made
good by restitution.”
787CRCM, para. 6.13.
788See NM, p. 243, fn. 610. - these declarations are also necessary in order to regulate the

future conduct of the Parties and

- the declarations ar e necessary to prevent further future

irreparable harms to be caused to the River.

(a) A Declaration Concerning the Violations of Costa
Rica’s Obligations vis-à-vis Nicaragua

7.24 Nicaragua’s first submission aims at obtaining a declaration from

the Court “that, by its conduct, Costa Rica has breached

(i) Its obligation not to violate the integrity of
Nicaragua’s territory as delimited by the 1858

Treaty of Limits, the Cleveland Award of 1888 and
the five Awards of the Umpire EP Alexander of 30
September 1897, 20 December 1897, 22 March
1898, 26 July 1899 and 10 March 1900.

(ii) Its obligation not to damage Nicaraguan territory;

(iii) Its obligations under general international law and
the relevant environmental conventions, including
the Ramsar Convention on Wetl ands, the
Agreement over the Border Protected Areas

between Nicaragua and Costa Rica (International
System of Protected Areas for Peace [SI -A-PAZ]
Agreement), the Convention on Biological Diversity
and the Convention for the Conservation of the

Biodiversity and Protection793 the Main Wild Life
Sites in Central America”.

7.25 Here again, Costa Rica’s sole answer is that “Nicaragua has not

demonstrated that any such internationally wrongful acts have occurred.” 794

793
794M, Submissions, p. 251, para. 1 (i), (ii) and (iii).
CRCM, para. 6.8.

268 - these declarations are also necessary in order to regulate the

future conduct of the Parties and

- the declarations ar e necessary to prevent further future

irreparable harms to be caused to the River.

(a) A Declaration Concerning the Violations of Costa
Rica’s Obligations vis-à-vis Nicaragua

7.24 Nicaragua’s first submission aims at obtaining a declaration from

the Court “that, by its conduct, Costa Rica has breached

(i) Its obligation not to violate the integrity of
Nicaragua’s territory as delimited by the 1858

Treaty of Limits, the Cleveland Award of 1888 and
the five Awards of the Umpire EP Alexander of 30
September 1897, 20 December 1897, 22 March
1898, 26 July 1899 and 10 March 1900.

(ii) Its obligation not to damage Nicaraguan territory;

(iii) Its obligations under general international law and
the relevant environmental conventions, including
the Ramsar Convention on Wetl ands, the
Agreement over the Border Protected Areas

between Nicaragua and Costa Rica (International
System of Protected Areas for Peace [SI -A-PAZ]
Agreement), the Convention on Biological Diversity
and the Convention for the Conservation of the

Biodiversity and Protection 793the Main Wild Life
Sites in Central America”.

7.25 Here again, Costa Rica’s sole answer is that “Nicaragua has not

demonstrated that any such internationally wrongful acts have occurred.” 794

793
794NM, Submissions, p. 251, para. 1 (i), (ii) and (iii).
CRCM, para. 6.8. industries are being established as well as petroleum concessions are being

granted in this area. 797

7.28 Costa Rica does not deny the fact that it has not prepared (and, as a

consequence, not notified to Nicaragua) an environment impact assessment.

Costa Rica argues: “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.” 798 Moreover, it adds

that: “So far as concerns construction of the Road, neither of the [threshold

requirements in respect of the obligation to conduct an environmental impact

assessment] was met such as to require Costa Rica to carry out an environmental

impact assessment.” 799

7.29 Here again, Costa Rica’s sole defence is summary and beside the

800
point. It consists of invoking the Court’s Order on Provisional Measures of 13

December 2013 by which th e Court held that “[a] decision by the Court to order

Costa Rica to provide Nicaragua with such an Environmental Impact Assessment

Study as well as technical reports at this stage of the proceedings would therefore

801
amount to prejudging the Court’s decision on the merits of the case.”

797
Information available at http://www.semanariouniversidad.ucr.cr/ind ex.php/noticias/pais/7356-
construccion-de-trocha-fronteriza-favoreceria-a-grandes-empresarios-de-la-zona-y-a-petrolera-
798lon-oil.html
799CRCM, para. 2.34; see also NM, paras. 2.22-2.25 and 5.13-5.14.
800Ibid., para. 5.12.
Ibid, para. 6.6.
801I.C.J., Order, 13 December 2013, 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, para. 39.

270industries are being established as well as petroleum concessions are being

granted in this area. 797

7.28 Costa Rica does not deny the fact that it has not prepared (and, as a

consequence, not notified to Nicaragua) an environment impact assessment.

Costa Rica argues: “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.” 798 Moreover, it adds

that: “So far as concerns construction of the Road, neither of the [threshold

requirements in respect of the obligation to conduct an environmental impact

assessment] was met such as to require Costa Rica to carry out an environmental

impact assessment.” 799

7.29 Here again, Costa Rica’s sole defence is summary and beside the

800
point. It consists of invoking the Court’s Order on Provisional Measures of 13

December 2013 by which th e Court held that “[a] decision by the Court to order

Costa Rica to provide Nicaragua with such an Environmental Impact Assessment

Study as well as technical reports at this stage of the proceedings would therefore

801
amount to prejudging the Court’s decision on the merits of the case.”

797
Information available at http://www.semanariouniversidad.ucr.cr/ind ex.php/noticias/pais/7356-
construccion-de-trocha-fronteriza-favoreceria-a-grandes-empresarios-de-la-zona-y-a-petrolera-
798lon-oil.html
799CRCM, para. 2.34; see also NM, paras. 2.22-2.25 and 5.13-5.14.
800Ibid., para. 5.12.
Ibid, para. 6.6.
801I.C.J., Order, 13 December 2013, 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, para. 39. Costa Rica produce and EIA and notify it to Nicaragua so that it does not conceal

its intention to conduct new road construction works along the River. 804

7.33 The situation is very similar to that met by the Arbitral Tribunal in

the recent Indus Waters Kishenganga Arbitration. The Tribunal recalled:

“The International Court of Justice affirmed that ‘due
diligence, and the duty of vigilance and prevention which it

implies, would not be considered to have been exercised , if
a party planning works liable to affect the regime of the
river or the quality of its waters did not undertake an
environmental impact assessment on the potential effects of
805
such works.’ Finally, the International Court of Justice
emphasized that such duties of due diligence, vigilance and
prevention continue ‘once operations have started and,
806 807
where necessary, throughout the life of the project.’ ”

This also holds true in the present case.

7.34 This said, Nicaragua wishes to specify that Costa Rica cannot

invoke the necessity to establish an adequate Environment Impact Assessment in

order to delay the urgent/prevention/emergency remediation measures that are

indispensable to mitigate the harm which has already occurred or which threatens

to occur imminently if they are not undertaken.

804CRCM, para. 2.41 (“Costa Rica will bring th e road works to completion…”). See also “Trail
Construction Will Restart at the End the Chinchilla Administration”, CR Hoy, 13 December 2013
(http://www.crhoy.com/precio-total-de-la-trocha-fronteriza-se-estima-en-…)

(NR, Vol.II, Annex 17) and “‘Trail’ Will Be a Project for the Next GovernmentLa Prensa, 21
February 2014
(http://www.prensaescrita.com/adiario.php?codigo=AME&pagina=http://www.p…)
805, Vol. II, Annex 19).
Fn. 600: “Pulp Mills on the River Uruguay (Argentina v. Uruguay) , Judgment, I.C.J. Reports
2010, p. 14, p. 83.”
806Fn. 661: “Ibid., at pp. 83-84.”
807Partial Arbitral Award, 18 February 2013, Indus Waters Kishenganga Arbitration (Pakistan v.
India), para. 450 (available at http://www.pca-cpa.org/showpage.asp?pag_id=1392

272Costa Rica produce and EIA and notify it to Nicaragua so that it does not conceal

its intention to conduct new road construction works along the River. 804

7.33 The situation is very similar to that met by the Arbitral Tribunal in

the recent Indus Waters Kishenganga Arbitration. The Tribunal recalled:

“The International Court of Justice affirmed that ‘due
diligence, and the duty of vigilance and prevention which it

implies, would not be considered to have been exercised , if
a party planning works liable to affect the regime of the
river or the quality of its waters did not undertake an
environmental impact assessment on the potential effects of
805
such works.’ Finally, the International Court of Justice
emphasized that such duties of due diligence, vigilance and
prevention continue ‘once operations have started and,
806 807
where necessary, throughout the life of the project.’ ”

This also holds true in the present case.

7.34 This said, Nicaragua wishes to specify that Costa Rica cannot

invoke the necessity to establish an adequate Environment Impact Assessment in

order to delay the urgent/prevention/emergency remediation measures that are

indispensable to mitigate the harm which has already occurred or which threatens

to occur imminently if they are not undertaken.

804CRCM, para. 2.41 (“Costa Rica will bring th e road works to completion…”). See also “Trail
Construction Will Restart at the End the Chinchilla Administration”, CR Hoy, 13 December 2013
(http://www.crhoy.com/precio-total-de-la-trocha-fronteriza-se-estima-en-…)

(NR, Vol.II, Annex 17) and “‘Trail’ Will Be a Project for the Next GovernmentLa Prensa, 21
February 2014
(http://www.prensaescrita.com/adiario.php?codigo=AME&pagina=http://www.p…)
805, Vol. II, Annex 19).
Fn. 600: “Pulp Mills on the River Uruguay (Argentina v. Uruguay) , Judgment, I.C.J. Reports
2010, p. 14, p. 83.”
806Fn. 661: “Ibid., at pp. 83-84.”
807Partial Arbitral Award, 18 February 2013, Indus Waters Kishenganga Arbitration (Pakistan v.
India), para. 450 (available at http://www.pca-cpa.org/showpage.asp?pag_id=1392). into account, for example, stages of conceptualization, feasibility, design and

management of the work.” 811 And Dr. Kondolf adds:

“Construction of Rte 1856 involved multiple cut and fill
roads across steep hillslopes, many underlain by weak rock
types or with unfavorable orientation of geologic structure,
resulting in inherently weak cutslopes. The material

removed from the cut was simply ‘sidecast’, i.e., pushed
down the slope by the blade, without first removing
vegetation from the slope and with neither engineering the

fill by compaction nor use of geotextiles. As a result, the
fillslopes are inherently unstable, no more than loose piles
of earth, easily eroded into rills and gullies by surface
runoff, and prone to landsliding. … Similarly, the stream

crossings consist of loose, unengineered fill dumped over
what most commonly appear to be undersized culvert pipes,
which are often not set at the base of the fill (along the
original grade of the stream) but higher in the fill, where

they are more812one to failure (as has occurred at many
crossings).”

As a result, the road is extremely dangerous for the users.

7.38 Several “portions of the road are unsafe because of steep slopes” or

because of substandard stream crossings which pose a risk of collapse. 813 “The

problems with unsafe and unstable slopes and poor stream crossings are

compounded by the extreme proximity to the Rio San Juan of most of the

route.”814 Given this proximity, “failure of these slopes and overturning of trucks

carrying hazardous material would be very likely to result in immediate

contamination of the Rio San Juan.” 815 Dr. Kondolf provides a map of potentially

811CONAVI Press Release, 25 May 2012, para. 3 (NM, Vol. II, Annex 34, p. 481).
8122014 Kondolf Report, Section 4 (NR, Vol. II, Annex 1).
813Ibid., Section 5.
814Ibid.
815Ibid.

274into account, for example, stages of conceptualization, feasibility, design and

management of the work.” 811 And Dr. Kondolf adds:

“Construction of Rte 1856 involved multiple cut and fill
roads across steep hillslopes, many underlain by weak rock
types or with unfavorable orientation of geologic structure,
resulting in inherently weak cutslopes. The material

removed from the cut was simply ‘sidecast’, i.e., pushed
down the slope by the blade, without first removing
vegetation from the slope and with neither engineering the

fill by compaction nor use of geotextiles. As a result, the
fillslopes are inherently unstable, no more than loose piles
of earth, easily eroded into rills and gullies by surface
runoff, and prone to landsliding. … Similarly, the stream

crossings consist of loose, unengineered fill dumped over
what most commonly appear to be undersized culvert pipes,
which are often not set at the base of the fill (along the
original grade of the stream) but higher in the fill, where

they are more812one to failure (as has occurred at many
crossings).”

As a result, the road is extremely dangerous for the users.

7.38 Several “portions of the road are unsafe because of steep slopes” or

because of substandard stream crossings which pose a risk of collapse. 813 “The

problems with unsafe and unstable slopes and poor stream crossings are

compounded by the extreme proximity to the Rio San Juan of most of the

route.” 814 Given this proximity, “failure of these slopes and overturning of trucks

carrying hazardous material would be very likely to result in immediate

contamination of the Rio San Juan.” 815 Dr. Kondolf provides a map of potentially

811CONAVI Press Release, 25 May 2012, para. 3 (NM, Vol. II, Annex 34, p. 481).
8122014 Kondolf Report, Section 4 (NR, Vol. II, Annex 1).
813Ibid., Section 5.
814Ibid.
815Ibid. 7.41 The danger of serious pollution by hazardous materials is all the

more likely to materialize because, in spite of C osta Rican denials, there exists an

important risk of hurricanes and earthquake. 820

7.42 This all justifies the Court’s Order banning any traffic of trucks or

engines transporting hazardous material, at least as long as Costa Rica will not

remediate and complete the works in accordance with the best standard practice in

the field in order to avoid exceptional risks of pollution as they now stand.

7.43 Indeed, such an Order can be seen as going further than a pure

declaration. But it is far from being unprecedented. Suf fices it to recall at this

stage that, in its recent Judgment in the Whaling case, the Court observed

“that JARPA II [the Japanese research programme declared
unlawful by the Court] is an ongoing programme. Under
these circumstances, measures that go beyon d declaratory
relief are warranted. The Court therefore will order that
Japan shall revoke any extant authorization, permit or

licence to kill, take or treat whales in relation to JARPA II,
and refrain from granting any further permits under Article
VIII, paragraph 1, of the Convention, in pursuance of that
programme.” 821

The purely preventive measures requested by Nicaragua in the present case are

more modest in scope.

822014 Kondolf Report, Section 12 (NR, Vol. II, Annex 1).
821See I.C.J., Judgment, 31 March 2014, Whaling in the Antarctic (Australiv. Japan: New

Zealand intervening), para. 244; see also para. 247(7). See also I.C.J., Advisory Opinion, 9 July
2004, Legal Consequences of the Construction of a Wall in the Occupied Palestinian Terri,ory
Reports 2004, p. 201, para. 163(3)(B).

276 7.41 The danger of serious pollution by hazardous materials is all the

more likely to materialize because, in spite of C osta Rican denials, there exists an

important risk of hurricanes and earthquake. 820

7.42 This all justifies the Court’s Order banning any traffic of trucks or

engines transporting hazardous material, at least as long as Costa Rica will not

remediate and complete the works in accordance with the best standard practice in

the field in order to avoid exceptional risks of pollution as they now stand.

7.43 Indeed, such an Order can be seen as going further than a pure

declaration. But it is far from being unprecedented. Suf fices it to recall at this

stage that, in its recent Judgment in the Whaling case, the Court observed

“that JARPA II [the Japanese research programme declared
unlawful by the Court] is an ongoing programme. Under
these circumstances, measures that go beyon d declaratory
relief are warranted. The Court therefore will order that
Japan shall revoke any extant authorization, permit or

licence to kill, take or treat whales in relation to JARPA II,
and refrain from granting any further permits under Article
VIII, paragraph 1, of the Convention, in pursuance of that
programme.” 821

The purely preventive measures requested by Nicaragua in the present case are

more modest in scope.

8202014 Kondolf Report, Section 12 (NR, Vol. II, Annex 1).
821See I.C.J., Judgment, 31 March 2014, Whaling in the Antarctic (Australiav. Japan: New

Zealand intervening), para. 244; see also para. 247(7). See also I.C.J., Advisory Opinion, 9 July
2004, Legal Consequences of the Construction of a Wall in the Occupied Palestinian Terri,ory
Reports 2004, p. 201, para. 163(3)(B). concerning Certain Activities carried out by Nicaragua in the Border Area (Costa

Rica v. Nicaragua) with those in the case concerning Construction of a Road in

Costa Rica along the San Juan River (Nicaragua v. Costa Rica):

“Both cases are based on facts relating to works being
carried out in, along, or in close proximity to the San Juan

River, namely the dredging of the river by Nicaragua and
the construction of a road along its right bank by Costa
Rica. Both sets of proc eedings are about the effect of the

aforementioned works on the local environment and on the
free navigation on, and access to, the San Juan River. In
this regard, both Parties refer to the risk of sedimentation of
the San Juan River.

In the present case and in the Nicaragua v. Costa Rica case,
the Parties make reference, in addition, to the harmful
environmental effect of the works in and along the San Juan

River on the fragile fluvial ecosystem (inclu823g protected
nature preserves in and along the river).”

There is therefore nothing abnormal about making the same submission in both

cases.

7.47 As for the second argument advanced by Costa Rica, it is true that

the Court rejected a similar Nicaraguan request in the Navigational Rights case for

the reason that these issues were settled in the Cleveland Award. 824 But the fact is

that Costa Rica persistently contests Nicaragua’s right to dredge the San Juan

823I.C.J. Order, 22 Novem ber 2013, Certain Activities carried out by Nicaragua in the Border
Area (Costa Rica v. Nicaragua), Request for Provisional Measures , paras. 20 and 21, and I.C.J.,
Order, 13 December 2013, Construction of a Road in Costa Rica along the San Juan River
(Nicaragua v. Costa Rica), Request for Provisional Measures, paras. 14 and 15.
824I.C.J., Judgment, 13 July 2009, Dispute regarding Navigational and Related Rights (Costa Rica
v. Nicaragua), I.C.J. Reports 2009, p. 60, para. 155.

278concerning Certain Activities carried out by Nicaragua in the Border Area (Costa

Rica v. Nicaragua) with those in the case concerning Construction of a Road in

Costa Rica along the San Juan River (Nicaragua v. Costa Rica):

“Both cases are based on facts relating to works being
carried out in, along, or in close proximity to the San Juan

River, namely the dredging of the river by Nicaragua and
the construction of a road along its right bank by Costa
Rica. Both sets of proc eedings are about the effect of the

aforementioned works on the local environment and on the
free navigation on, and access to, the San Juan River. In
this regard, both Parties refer to the risk of sedimentation of
the San Juan River.

In the present case and in the Nicaragua v. Costa Rica case,
the Parties make reference, in addition, to the harmful
environmental effect of the works in and along the San Juan

River on the fragile fluvial ecosystem (inclu823g protected
nature preserves in and along the river).”

There is therefore nothing abnormal about making the same submission in both

cases.

7.47 As for the second argument advanced by Costa Rica, it is true that

the Court rejected a similar Nicaraguan request in the Navigational Rights case for

the reason that these issues were settled in the Cleveland Award. 824 But the fact is

that Costa Rica persistently contests Nicaragua’s right to dredge the San Juan

823I.C.J. Order, 22 Novem ber 2013, Certain Activities carried out by Nicaragua in the Border
Area (Costa Rica v. Nicaragua), Request for Provisional Measures , paras. 20 and 21, and I.C.J.,
Order, 13 December 2013, Construction of a Road in Costa Rica along the San Juan River
(Nicaragua v. Costa Rica), Request for Provisional Measures, paras. 14 and 15.
824I.C.J., Judgment, 13 July 2009, Dispute regarding Navigational and Related Rights (Costa Rica
v. Nicaragua), I.C.J. Reports 2009, p. 60, para. 155.280 SUBMISSIONS

1. For the reasons given in its Memorial and in th is Reply, the Republic of
Nicaragua requests the Court to adjudge and declare that, by its conduct, the

Republic of Costa Rica has breached:

(i) Its obligation not to violate the integrity of Nicaragua’s territory as

delimited by the 1858 Treaty of Limits as interpreted by the

Cleveland Award of 1888 and the five Awards of the Umpire

EP Alexander of 30 September 1897, 20 December 1897, 22
March 1898, 26 July 1899, and 10 March 1900;

(ii) Its obligation not to damage Nicaraguan territory;

(iii) Its obligations under general international law and the relevant

environmental conventions, including the Ramsar Convention

on Wetlands, the Agreement over the Border Protected Areas
between Nicaragua and Costa Rica (International System of

Protected Areas for Peace [SI -A-PAZ] Agreement), the

Convention on Biological Diversity and the Convention for the
Conservation of the Biodiversity and Protection of the Main

Wild Life Sites in Central America;

2. Nicaragua also requests the Court to adjudge and declare that Costa Rica must:

(i) Cease all its continuing internationally wrongful acts that affect or

are likely to affect the rights of Nicaragua.

281 (ii) Inasmuch as possible, restore the situation to the status quo ante, in
full respect of Nicaragua’s sovereignty over the San Juan de

Nicaragua River, including by taking the emergency measures

necessary to alleviate or mitigate the continuing harm being

caused to the River and the surrounding environment.

(iii) Compensate for all damages caused insofar as they are not made

good by restitution, including the costs added to the dredging of
the San Juan de Nicaragua River, with the amount of the

compensation to be determined in a subsequent phase of the

case.

3. Furthermore, Nicaragua requests the Court to adjudge and declare that Costa

Rica must:

(i) Not undertake any future development in the area without an

appropriate transboundary Environmental Impact Assessment

and that this assessment must be presented in a timely fashion

to Nicaragua for its analysis and reaction;

(ii) Refrain from using Route 1 856 to transport hazardous material as

long as it has not given the guarantees that the road complies
with the best construction practices and the highest regional

and international standards of security for road traffic in similar

situations;

4. The Rep ublic of Nicaragua further requests the Court to adjudge and declare

that Nicaragua is entitled:

282 (ii) Inasmuch as possible, restore the situation to the status quo ante, in
full respect of Nicaragua’s sovereignty over the San Juan de

Nicaragua River, including by taking the emergency measures

necessary to alleviate or mitigate the continuing harm being

caused to the River and the surrounding environment.

(iii) Compensate for all damages caused insofar as they are not made

good by restitution, including the costs added to the dredging of
the San Juan de Nicaragua River, with the amount of the

compensation to be determined in a subsequent phase of the

case.

3. Furthermore, Nicaragua requests the Court to adjudge and declare that Costa

Rica must:

(i) Not undertake any future development in the area without an

appropriate transboundary Environmental Impact Assessment

and that this assessment must be presented in a timely fashion

to Nicaragua for its analysis and reaction;

(ii) Refrain from using Route 1 856 to transport hazardous material as

long as it has not given the guarantees that the road complies
with the best construction practices and the highest regional

and international standards of security for road traffic in similar

situations;

4. The Rep ublic of Nicaragua further requests the Court to adjudge and declare

that Nicaragua is entitled:284 CERTIFICATION

I have the honour to certify that this Reply and the documents annexed in Volume

II are true copies and conform to the original documents and that the translations
into English made by the Republic of Nicaragua are accurate translations.

The Hague, 04 August 2014

Carlos J. Argüello Gómez

Agent of the Republic of Nicaragua

285286 LIST OF ANNEXES
VOLUME II

Annex Document Page
No.

EXPERT REPORTS

1 Dr. G. Mathias Kondolf, “Erosion and Sediment Delivery to 1
the Rio San Juan from Route 1856,” July 2014.

2 Mr. Danny Hagans & Dr. Bill Weaver, “Evaluation of Erosion,47
Environmental Impacts and Road Repair Efforts at Selected
Sites along Juan Rafael Mora Route 1856 in Costa Rica,
Adjacent the Río San Juan, Nicaragua,” July 2014.

3 Dr. Edmund D. Andrews, “An Evaluation of the Methods, 199
Calculations, and Conclusions Provided By Costa Rica
Regarding the Yield and Transport of Sediment in the Rio San
Juan Basin,” July 2014.

4 Dr. Blanca Ríos Touma, “Ecological Impacts of the Route 247
1856 on the San Juan River, Nicaragua”, July 2014

5 Dr. William R. Sheate, “Comments on the Lack of EIAfor the281

San Juan Border Road in Costa Rica,” July 2014.

6 Golder Associates, Inc., “The Requirements of Impact 339
Assessment for Large-Scale Road Construction Project in

Costa RicaAlong the San Juan River, Nicaragua,” July 2014.

DIPLOMATIC NOTES

7 Note from the Minister of Foreign Affairs of Nicaragua, 415

to the Minister of Foreign Affairs of Costa Rica,
Ref: MRE/DM/645//12/13, 17 December 2013.

287 8 Note from the Minister of Foreign Affairs of Costa 419
Rica, to the Minister of Foreign Affairs of Nicaragua,
Ref.: DM-AM-704-13, 19 December 2013.

CENTRALAMERICAN DOCUMENTS

9 RESOLUTION 03-99 (XXI COMITRAN), Guatemala, 423

18 November 1999.

10 Central American Manual of Environmental Norms for the 427
Design, Construction and Maintenance of Roads (2002)
(excerpts).

11 Central American Manual of Specifications for the 431
Construction of Regional Roads and Bridges (2nd. Edition
2004) (excerpts).

12 CentralAmerican Manual on the Maintenance of Roads (2010 437
Edition) (excerpts).

13 CentralAmerican Manual of Norms for the Geometric Design 443
of Roads (3rd. Edition 2011) (excerpts).

NICARAGUAN DOCUMENTS

14 Affidavit ofAna Isabel IzaguirreAmador, 18 July 2014. 447

15 Nicaraguan Law 274 regarding the regulation and control 457

of pesticides and toxic and dangerous substances, 1998,
Art. 23(2).

MEDIAREPORTS

16 “President Confirms Errors in Construction of Trail 1856”, 461
El Pais, 24 May 2014 (http://www.elpais.cr/frontend/noticia_
detalle/1/92093)

28817 “Trail Construction Will Restart at the End of the Chinchilla 465
Administration”, crhoy.com, 13 December 2013 (http://www.
crhoy.com/precio-total-de-la-trocha-fronteriza-se-estima-en-
mas-de-50-mil-millones/) (excerpts)

18 “Solis Commits to Finishing the Trail”, Diario Extra, 6 May 469
2014 (http://www.diarioextra.com/Dnew/noticiaDetalle
/231053) (excerpts)

19 “Trail Will Be a Project for the Next Government”,La Prensa 473
Libre, 21 February 2014 (http://www.prensaescrita.com/
adiario.php?codigo=AME&pagina=http://www.prensalibre.

cr)

20 “Visit by the President Two Days Before Delivering 477
the Command”, La Nación, 6 May 2014 (http://www.
nacion.com/nacional/Chinchilla-disculpa-vecinos-trocha-

fronteriza_0_1412858873.html) (excerpts)

21 “Works on the Trail Paralyzed while Waiting for Designs 481
and Modular Bridges”, crhoy.com, 10 July 2014 (http://www.

crhoy.com/trabajos-en-la-trocha-se-paralizan-a-la-espera-de-
disenos-y-puentes-modulares/)

22 Alberto Cabezas, Border Trail Case, published 4 June 2014 485

(http://revista-amauta.org/2014/06/caso-trocha-fronteriza/)

23 “Accident in Chaclacayo: Rímac River Fuel Spill Causes 491
Concern among Local Residents”,El Comercio, 31 December

2013), http://elcomercio.pe/lima/sucesos/accidente-
chaclacayo-derrame-combustible-al-rio-rimac-preocupa-
vecinos-noticia-1680548

24 “OEFAAssesses Impact of Oil Spill in the Rímac River”, 495
Mining Press Edición Perú, 1 February 2014, http://www.
miningpress.com.pe/nota/250217/oefa-evalua-impacto-de-
derrame-de-petroleo-en-el-rio-rimac-

289 25 “Oil Spilled into the Villalobos River”, La Nación 19 June 499
2012, http://www.lanacion.com.co/index.php/noticias-
judicial/item/156017-petroleo-cayo-al-rio-villalobos

26 “Ombudsman Investigates Mining Company Spillage into 503
River”, Los Andes, 26 August 2009 http://archivo.losandes.
com.ar/notas/2009/8/26/un-442539.asp

27 “Oil Spill Contaminates Lake”, Perú21, 9 May 2012, 507
http://peru21.pe/2012/05/09/impresa/derrame-crudo-
contamina-laguna-2023480

28 “Oil Truck Overturned near the Cruces River”, El Mercurio 511
Online, 3 January 2009, http://www.emol.com/noticias/
nacional/2009/01/03/338122/camion-con-petroleo-se-volco-
en-las-cercanias-del-rio-cruces.html

29 “Truck Spilled 9,000 Gallons of Fuel into Rivers”, 515
Enlace Nacional, 4 February 2008, http://enlacenacional.
com/2008/02/04/camion-derramo-9-mil-galones-de-petroleo-
en-rios/

30 “Truck Overturns - Severe Environmental Damage”, La 519
Angostura Digital, 23 July 2009), http://www.laangosturadigital.
com.ar/v3/home/interna.php?id_not=10282&ori=web

290

Document file FR
Document Long Title

Reply of Nicaragua

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