Counter-Memorial of Bolivia

INTERNATIONAL COURT OF JUSTICE
DISPUTE OVER THE STATUS AND USE OF THE
WATERS OF THE SILALA
(CHILE v. BOLIVIA)
COUNTER-MEMORIAL OF
THE PLURINATIONAL STATE OF BOLIVIA
VOLUME 1 of 5
3 SEPTEMBER 2018

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COUNTER-MEMORIAL
OF THE PLURINATIONAL STATE OF BOLIVIA
VOLUME 1
TITLE PAGE N°
Counter-Memorial 3
List of Annexes 107
Certification 113
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3
INTERNATIONAL COURT OF JUSTICE
DISPUTE OVER THE STATUS AND USE OF THE
WATERS OF THE SILALA
(CHILE v. BOLIVIA)
COUNTER-MEMORIAL OF
THE PLURINATIONAL STATE OF BOLIVIA
3 SEPTEMBER 2018
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TABLE OF CONTENTS
CHAPTER 1. INTRODUCTION ..................................................................................... 9
A. Procedural History .......................................................................................................... 9
B. General Context .............................................................................................................. 9
C. Rejection of Chile’s Claims before the Court ............................................................... 12
D. Bolivia’s Counter-Claims ............................................................................................. 15
E. Structure of the Counter-Memorial ............................................................................... 16
CHAPTER 2. FACTUAL BACKGROUND OF THE SILALA WATERS .............. 17
A. Joint Efforts to Identify the Nature of the Silala Waters and Reach an Agreement
on its Utilization. ........................................................................................................... 17
B. State of Knowledge of the Silala. ................................................................................. 24
C. Artificial Enhancement of the Silala ............................................................................. 31
D. Effects and Consequences of the Artificial Enhancement of the Silala ....................... 45
E. Final Remarks ............................................................................................................... 55
CHAPTER 3. NATURE OF THE SILALA UNDER INTERNATIONAL LAW ..... 57
A. International Watercourses in Customary International Law ....................................... 57
B. Scope of Customary International Law on Naturally-Flowing Watercourses ............ 62
C. Regulation of the Artificially-Enhanced Silala Waters ............................................... 68
D. Final Remarks ............................................................................................................... 71
CHAPTER 4. LEGAL CONSEQUENCES OF THE SILALA AS AN
ARTIFICIALLY ENHANCED WATERCOURSE ..................................................... 73
A. The Right to Equitable and Reasonable Utilization of the Naturally-Flowing
Silala Waters ................................................................................................................. 75
B. Current Use of the Silala Waters by Chile .................................................................... 78
C. Obligation of the Parties to Take Appropriate Measures to Prevent Significant
Transboundary Environmental Harm ............................................................................ 81
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CHAPTER 5. ABSENCE OF BREACH OF THE OBLIGATION TO NOTIFY
AND CONSULT .............................................................................................................. 86
A. Bolivia Replied to Chile’s Requests on Matters Regarding the Silala Waters ............ 86
B. Bolivia did not Breach the Obligation to Provide Timely Notification
of Planned Measures in the Silala ............................................................................... 91
C. No Risk of Significant Adverse Effects by the Works at the Silala ............................ 95
D. Final Remarks ............................................................................................................... 97
CHAPTER 6. COUNTER-CLAIMS ............................................................................. 98
A. Bolivia’s Counter-Claims Fall within the Jurisdiction of the Court............................. 98
B. Admissibility of Bolivia’s Counter-Claims .................................................................. 99
C. Bolivia’s Counter-Claims ........................................................................................... 101
SUBMISSIONS .............................................................................................................. 105
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LIST OF FIGURES
Figure 1 Topographical catchment of the Silala in Bolivia (Source: Annex A, in
DHI, Final Report, p. 11)
Figure 2 “U” shaped profile of the Main Ravine of the Silala in Bolivia (Source:
DIREMAR, 2018)
Figure 3 An excavated section and vertical peat profile at the edge of an
undisturbed wetland patch in the North Bofedal (Source: Annex C, in
DHI, Final Report, p. 17)
Figure 4 South Bofedal in Bolivia (Source: DIREMAR, 2017)
Figure 5 North Bofedal in Bolivia (Source: DIREMAR, 2017)
Figure 6 Hydrological catchment of the Silala in Bolivia (Source: Annex A, in
DHI, Final Report, p. 12)
Figure 7 The Main Channel and desiltation chamber just below the confluence of
the secondary channels emerging from the North (Cajones) Ravine on
the left, and the South (Orientales) Ravine on the right (Source:
DIREMAR, 2018)
Figure 8 The technical stonework of the Main Channel as it receives water
transported by the two main subsidiary channels emerging from the
North (Cajones) Ravine and South (Orientales) Ravine (Source:
DIREMAR, 2018).
Figure 9 The Main Channel before it reaches the border (Source: DIREMAR,
2018)
Figure 10 Canal types constructed in the Silala (Source: DIREMAR, 2018)
Figure 11 Canal types constructed in the Silala depicted on a satellite image
(Source: DIREMAR, 2018)
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Figure 12 Distribution and dimensions of the channels in South (Orientales)
Ravine of the Silala in Bolivia (Source: Annex G, in DHI, Final Report,
p. 28)
Figure 13 Distribution and dimensions of the channels in the North (Cajones)
Ravine of the Silala in Bolivia (Source: Annex G, in DHI, Final Report,
p. 34)
Figure 14 Channel distribution and dimensions in the Main Channel below the
confluence of the two Silala ravines in Bolivia (Source: Annex G, in
DHI, Final Report, p. 31)
Figure 15 The extensive network of artificial drainage mechanisms crossing the
bofedales in the North (Cajones) Ravine of the Silala in Bolivia
(Source: DIREMAR, 2017)
Figure 16 Rectilinear channels with defined angles in the North (Cajones) Ravine
of the Silala and limited typical bofedal vegetation that would be
expected in thriving bofedales (Source: DIREMAR, 2017)
Figure 17 Silala spring directly connected to an artificial channel where the spring
emerges from the formation (Source: DIREMAR, 2016)
Figure 18 Drainage pipe adjacent to a Silala spring where the spring emerges from
the formation (Source: Annex C, in DHI, Final Report, p. 16)
Figure 19 Rocks adjacent to channels and drainage mechanisms providing
evidence of explosive blasts used to lower spring elevations and
increase spring discharge (Source: Annex F, in DHI, Final Report, p.
97)
Figure 20 Effects of desiccation on the South (Orientales) Silala Bofedal (Source:
DIREMAR, 2018)
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CHAPTER 1
INTRODUCTION
A. Procedural History
1. On 6 June 2016, the Republic of Chile (“Chile”) instituted proceedings before the
International Court of Justice against the Plurinational State of Bolivia (“Bolivia”)
in relation to the status and use of the waters of the Silala. Chile invokes as a basis
for jurisdiction the American Treaty on Pacific Settlement, the “Pact of Bogotá”, of
30 April 1948.1
2. In its Order of 1 July 2016, the Court fixed 3 July 2017 for the filing of the
Memorial of Chile. In response to the Memorial of Chile, Bolivia submits the
present Counter-Memorial in accordance with the Order of the Court dated 23 May
2018 fixing 3 September 2018 as the time-limit for the filing of the present written
pleading.
B. General Context
3. Bolivia is located in the center of South America and is part of one of the great
hydrographic basins and sub-basins of the continent. This situation causes Bolivia to
maintain relations of friendship, cooperation and integration with its five neighbors
with which it shares water resources, in some cases as the upstream State and in
others as the downstream State. As a result of this geographical condition, Bolivia
has entered into diverse forms of cooperation agreements with its neighbors to
achieve the sustainable use of water resources. Bolivia and Chile have not yet been
able to conclude such agreements between them.
1 Application instituting proceedings (hereinafter “Application”), 6 June 2016, p. 6, para. 5.
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4. In June 2017, on the occasion of an important meeting of the United Nations
Security Council dedicated to “Preventive Diplomacy and Transboundary Waters”,
the United Nations Secretary-General noted that,
“With demand for freshwater projected to grow by more than 40 per
cent by the middle of the century, and with climate change having a
growing impact, water scarcity is a growing concern. (…) By 2050,
at least one in four people will live in a country where the lack of
fresh water is chronic or recurrent. Strains on water access are
already rising in all regions. Without effective management of our
water resources, we risk intensified disputes between communities
and sectors and even increased tensions among nations.”2
5. The United Nations Secretary-General, Antonio Guterres, stressed that “it is
essential that nations cooperate to ensure that water is shared equitably and used
sustainably”, bearing in mind that “water has proven to be a catalyst for cooperation
among nations, even those that are not on good terms.” For instance, “in South
America, Lake Titicaca, the largest freshwater lake on the continent, has long been a
source of cooperation between Bolivia and Peru.”3
6. At that meeting, the President of Bolivia, Evo Morales, stated that the “2030
Agenda for Sustainable Development has deepened our understanding of the need to
achieve universal access to water and sanitation that is equitable for all.”4 The
Bolivian Representative observed that in Bolivia many indigenous peoples live in
rural areas and “our people have always considered water to be the source of life
and a public good that belongs to everyone, not just to one set of people in
2 United Nations, Security Council, 7959th meeting, 6 June 2017, S/PV.7959, p. 2.
3 United Nations, Security Council, 7959th meeting, 6 June 2017, S/PV.7959, p. 2.
4 United Nations, Security Council, 7959th meeting, 6 June 2017, S/PV.7959, p. 3.
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particular. It is a nutrient that Mother Earth produces and should be respected and
conserved.”5 He also pointed out that “water is vital to sustaining the life of all
peoples and living beings and for maintaining balance on Mother Earth” and “must
be conserved and safeguarded against pollution, the effects of climate change and
overuse in activities that are not essential.”6 In addition, the President of Bolivia
noted that “States should consider entering into governance agreements that
emphasize the sustainability of transboundary water resources and provide for the
establishment of institutional mechanisms that ensure the reasonable use of such
resources.”7
7. The 2009 Constitution of Bolivia states that its natural resources are of strategic
character and of public interest, recognizing water as a fundamental right for life
within the framework of the sovereignty of the people and in harmony with Mother
Earth.8 The State shall conserve, preserve, and guard these resources to guarantee
priority use of water for life.9 Its water resources, whether surface or subterranean
waters, constitute vulnerable and strategic finite resources. In relation to fossil,
glacial, wetland, and subterraneous waters, the State must guarantee their
conservation, protection, preservation, restoration, sustainable use and complete
management.10
8. The Bolivian Constitution also affirms that as a sovereign State “Bolivia is a pacifist
State that promotes the culture of peace (…) as well as cooperation among the
5 United Nations, Security Council, 7959th meeting, 6 June 2017, S/PV.7959, p. 4.
6 United Nations, Security Council, 7959th meeting, 6 June 2017, S/PV.7959, pp. 4-5.
7 United Nations, Security Council, 7959th meeting, 6 June 2017, S/PV.7959, p. 5.
8 Arts. 348.II, 16.I, 373.I of the Constitution of the Plurinational State of Bolivia adopted on 7 February
2009, Official Gazette. Available at: https://www.constituteproject.org/constitution/Bolivia_2009.pdf
9 Art. 374.I of the Constitution of the Plurinational State of Bolivia adopted on 7 February 2009,
Official Gazette. Available at: https://www.constituteproject.org/constitution/Bolivia_2009.pdf
10 Art. 374.III of the Constitution of the Plurinational State of Bolivia adopted on 7 February 2009,
Official Gazette. Available at: https://www.constituteproject.org/constitution/Bolivia_2009.pdf
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peoples of the region and the World, for the purpose of contributing to mutual
understanding, equitable development, (…) with full respect for the sovereignty of
States.”11 In the conduct of its international relations, the Constitution expressly
states as one of its guiding principles that of “[c]ooperation and solidarity among
states and peoples.”12
C. Rejection of Chile’s Claims before the Court
9. In its Application, Chile indicates that the present dispute concerns “the nature of
the Silala River system as an international watercourse and Chile’s rights as a
riparian State”13 and that it is “seeking declarations concerning the nature of the
Silala River system as an international watercourse and resulting rights and
obligations of the Parties under international law.”14 According to Chile’s
Memorial,
“Chile asks the Court to declare that Chile is entitled to the equitable
and reasonable use of the waters of the Silala River and, in addition,
to declare that – pursuant to the standard of equitable and reasonable
utilization – Chile is entitled to its current use. The dispute also
concerns the obligations of Bolivia that arise by virtue of the status
of the Silala River system as an international watercourse.”15
10. Bolivia in the present Counter-Memorial will demonstrate that Chile’s case is based
on both a mischaracterization and an over-simplification of the real nature of the
Silala waters and springs. Chile alleges that they constitute in their entirety an
11 Art. 10.I of the Constitution of the Plurinational State of Bolivia adopted on 7 February 2009, Official
Gazette. Available at: https://www.constituteproject.org/constitution/Bolivia_2009.pdf
12 Art. 255.II.5 of the Constitution of the Plurinational State of Bolivia adopted on 7 February 2009,
Official Gazette. Available at: https://www.constituteproject.org/constitution/Bolivia_2009.pdf
13 Application, p. 20, para. 41.
14 Application, p. 4.
15 Memorial of Chile (hereinafter “CM”), p. 3, para. 1.5.
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international watercourse. In doing so, Chile disregards that these waters, which largely
originate from springs located in Bolivia’s territory, have been artificially drained
and channelized in order to generate their present, man-made rate and volume of
flow. Chile fails to take into account the complexity and specific nature of the
waters of the Silala as well as the impact of that nature on the rules which are
applicable to these waters under customary international law.
11. Bolivia will also explain that the determination of the nature of the waters of the
Silala depends on technical and scientific assessments conducted in relation to the
relevant definitions and understandings of what constitutes an international
watercourse under customary international law.16
12. The relevant scientific studies, in particular the experts’ reports submitted by
Bolivia and Chile, show evidence of artificial enhancements leading to the
conclusion that the waters of the Silala are part of an artificially enhanced
watercourse.
13. A recent study by the Danish Hydraulic Institute (hereinafter “DHI”) commissioned
by Bolivia indicates in particular that current surface flows across the Bolivian-
Chilean frontier have been assessed to average 160-210 liters per second (l/s). Of
this flow, it is estimated that 30-40%, or as much as 64-84 l/s, can be directly
attributed to enhancements created by the artificial channels and drainage
mechanisms installed in the Silala within Bolivia.17
14. Given that under customary international law an international watercourse
designates the transboundary natural flow of waters, customary international rules
16 Bolivian Counter-Memorial (hereinafter “BCM”), para. 24.
17 Danish Hydraulic Institute (DHI), Study of the Flows in the Silala Wetlands and Springs System, 16
July 2018, p. 41, BCM, Vol. 2, Annex 17.
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on the use of international watercourses do not apply to the artificially-flowing
Silala waters.18
15. In the Memorial, Chile adds that it “is entitled to the equitable and reasonable
utilization of the waters of the Silala River system in accordance with customary
international law” and that “under the standard of equitable and reasonable
utilization, Chile is entitled to its current use of the waters of the Silala River”.19
16. Concerning the equitable and reasonable utilization of the Silala waters, Bolivia
submits that Chile’s claims should be dismissed. Not only do they seek to
indiscriminately apply to all Silala waters rather than only those flowing naturally,
they also fail to take into account Bolivia’s rights in relation to those waters. The
current use of the naturally-flowing Silala waters by Chile is without prejudice to
Bolivia’s concurrent right to their equitable and reasonable use.20
17. Further, Chile claims that under customary international law on international
watercourses, “Bolivia has an obligation to take all appropriate measures to prevent
and control pollution and other forms of harm to Chile resulting from its activities in
the vicinity of the Silala River”21 and that “Bolivia has an obligation to cooperate to
provide Chile with timely notification of planned measures which may have an
adverse effect on shared water resources, to exchange data and information and to
conduct where appropriate an environmental impact assessment.”22
18 BCM, paras. 80-108.
19 CM, p. 107, Submissions b) and c).
20 In the Memorial, Chile admits that it has “obligations owed to Bolivia” (CM, p. 92, para. 5.3), and
that its claims are without prejudice to “any future use by Bolivia of the Silala River” (CM, p. 2, para.
1.3 d) and p. 106, para. 6.5). However, Chile’s submissions do not make any reference to Bolivia’s
rights.
21 CM, p. 107, Submission d).
22 CM, p. 107, Submission e).
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18. These claims should also be dismissed. Bolivia instead asks the Court to declare that
Bolivia and Chile each have an obligation to take all appropriate measures to
prevent the causing of significant transboundary environmental harm, and that each
have an obligation to cooperate and to provide the other State with timely
notification of planned measures which may have a significant adverse effect on
naturally-flowing Silala waters, and to exchange data and information and where
appropriate, to conduct environmental impact assessments.
19. Contrary to Chile’s allegation that Bolivia has breached “its obligation to notify and
consult Chile with respect to activities that may affect the waters of the Silala River
or the utilization thereof by Chile,”23 Bolivia will demonstrate Chile’s failure to
credibly prove such claim.
D. Bolivia’s Counter-Claims
20. Bolivia, in accordance with Article 80 of the Rules of Court, is submitting three
Counter-Claims in this Counter-Memorial that are directly connected with the
subject-matter of the claims of Chile and that come within the jurisdiction of the
Court. Bolivia’s Counter-Claims are: (i) Bolivia has sovereignty over the artificial
channels and drainage mechanisms in the Silala that are located in its territory and
has the right to decide whether and how to maintain them; (ii) Bolivia has
sovereignty over the artificial flow of Silala waters engineered, enhanced, or
produced in its territory and Chile has no right to any part of that artificial flow; and
(iii) any delivery from Bolivia to Chile of artificially-flowing waters of the Silala,
and the conditions and modalities thereof, including the compensation to be paid for
said delivery, are subject to the conclusion of an agreement with Bolivia.
23 CM, p. 107, Submission e).
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21. Bolivia also notes that its submissions are without prejudice to any other claim that
Bolivia may formulate in relation to past use of the Silala waters by Chile.
E. Structure of the Counter-Memorial
22. This Counter-Memorial consists of a Volume 1 divided into six chapters with
annexes in the accompanying 4 Volumes.
23. Following this introductory chapter, Chapter 2 presents the relevant facts as regards
the nature of the waters of the Silala. Chapter 3 characterizes the Silala waters under
the relevant rules of international law. Chapter 4 defines the legal consequences of
the status of the Silala as an artificially-enhanced watercourse under customary
international law. Chapter 5 shows that Bolivia did not breach the obligation to
notify and consult Chile concerning activities that may significantly affect the
naturally-flowing Silala waters. Chapter 6 presents Bolivia’s Counter-Claims. The
Counter-Memorial concludes with Bolivia’s Submissions to the Court.
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CHAPTER 2
FACTUAL BACKGROUND OF THE SILALA WATERS
24. The determination of whether certain waters constitute an international watercourse
under international law depends on their “geographical characteristics” and other
“physical factors.”24 It is thus necessary to define the physical nature of the Silala
waters to identify the rules that are applicable to them.
A. Joint Efforts to Identify the Nature of the Silala Waters and Reach an Agreement
on its Utilization
25. Chile’s Memorial relies on inaccurate interpretations of Bolivian cartography,
minutes, and statements regarding the Silala waters. Bolivia cannot accept these
characterizations. At the time these documents were produced, both States lacked
sufficient scientific evidence to accurately determine the nature of the Silala waters.
Therefore, Bolivia will emphasize the more recent efforts by the Parties to ascertain
the nature of the waters in question.
26. The efforts by Bolivia and Chile to identify the exact nature of the Silala waters are
part of a continuing process, which started before the present proceedings. As Chile
itself acknowledges in its Memorial, the exact nature of these waters has been an
issue between both countries since 1999.25
24 Yearbook of the International Law Commission, 1994, Volume II, Part 2, p. 90, paras. 2-3 of the
commentary on Draft Article 2. On the definition of international watercourses under customary
international law, BCM, paras. 93-102.
25 CM, p. 40, paras. 3.8 ff. For those diplomatic exchanges between the Parties which started in 1999
see CM, Vol. II, Annexes 27 ff.
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27. In September 1999, following a Note Verbale from Chile asserting that the Silala is
“an international river of a successive course, the use of which is governed by
International Law,”26 Bolivia replied that the waters of the Silala springs, from
which the surface flow emerges, as creating “wetlands, from where the waters are
caught and conducted by means of artificial work, generating a system that lacks
any characteristic of a river, let alone of an international river of a successive
course.”27 In response, Chile asserted that the waters of the Silala constitute “a
binational river or a shared river (...) that naturally responds to the definition that
international law gives for that purpose”.28
28. This divergence of views led Bolivia and Chile to initiate, in Chile’s own words, a
“collaborative relationship” that resulted in the establishment of a “joint technical
commission” in 2000.29 Discussions continued in 2004 “within the framework of the
Working Group on the Silala Issue” during which, “[a]gain, both States agreed to
carry out joint technical and scientific studies to determine the nature, origin and
flow of the waters of the Silala”.30
29. In March 2004, the Ministers of Foreign Affairs of the two countries agreed to
establish a Joint Technical Commission to exchange their views on the Silala. The
26 Note N° 474/71 from the General Consulate of Chile in La Paz to the Ministry of Foreign Affairs of
Bolivia, 20 May 1999, CM, Vol. 2, Annex 26.
27 Note N° GMI-656/99 from the Ministry of Foreign Affairs of Bolivia to the General Consulate of
Chile in La Paz, 3 September 1999, CM, Vol. 2, Annex 27.
28 Note N° 017550 from the Ministry of Foreign Affairs of Chile to the Ministry of Foreign Affairs of
Bolivia, 15 September 1999, CM, Vol. 2, Annex 28.
29 CM, p. 43, paras. 3.16 ff.
30 CM, pp. 45-46, para. 3.22. See also pp. 43-44, paras. 3.17-3.18 with regard to the work done in 2000
and 2001.
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first meeting of this Commission took place in May 2004.31 On that occasion, the
Parties:
“(…) agreed on the need to conduct technical and scientific studies
that allow determining the nature, origin, and flows of the Silala
waters, in order to thus establish a scientific basis that shall be made
available to their respective governments. Additionally, the
Delegations informed each other about the conclusions reached by
their respective preliminary studies to date.
Furthermore, both Delegations agreed that technical organisations
from both countries should conduct as of now joint studies in the
Silala area regarding the following aspects:
1. Topography, geodesics, and cartography, to be executed by the
corresponding Directorates of Boundaries
2. Geological analysis
3. Geomorphological analysis
4. Hydrological analysis
5. Hydraulic evaluation of existing works
6. Geophysical and hydrogeological explorations.”32
30. Both delegations also agreed that:
“the technical and scientific studies would be aimed at determining
the nature of the waters of the Silala and its flows. It is expected that
these studies shall issue conclusions on the following aspects:
1. Origin of the water resources of the Silala
2. Impact of the hydraulic works executed therein
3. Determination of the flows and volumes of the surface and
underground waters of the Silala
31 Minutes of the First Meeting of the Bolivia-Chile Working Group on the Silala Issue, 6 May 2004,
CM, Vol. 2, Annex 21.
32 Minutes of the First Meeting of the Bolivia-Chile Working Group on the Silala Issue, 6 May 2004
(emphasis added), CM, Vol. 2, Annex 21. See also Press Release from the Ministry of Foreign
Affairs of Bolivia, 1 October 2010, CM, Vol. 3, Annex 52.
20
4. Potential of the water resources of the Silala
5. Environmental impact
6. Water balance
7. Recharge and discharge volumes
8. Flow direction and velocity
9. Relation between surface and underground waters
10. Recharge and discharge areas of the Silala aquifer.”33
31. At the same meeting,
“The Chilean Delegation (…) expressed that the nature of the waters
would be determined by the pertinent studies, the study that the
IAEA could undertake being a good alternative to support the agreed
studies. This, without detriment to the possibility of resorting to
other trustworthy organisations such as the UNESCO, or other
entities of a good reputation, to achieve the set objectives.
Both Delegations agreed that the technical and scientific study
should be titled ‘The Nature and Characteristics of the Water
Resources of the Silala’, and that the study would be coordinated by
the Foreign Ministries of both nations”.34
32. In August of 2004, Chile proposed a joint study profile to explore the nature and
characteristics of the Silala water resources, including the impact of the hydraulic
infrastructure on water flow in the Silala.35 Based on that understanding, in January
2005 the Parties reiterated their commitment to move forward “in a joint work
program that will include technical-scientific studies on both sides of the border
necessary to determine the nature, origin and flows of the waters of Silala, both on
33 Minutes of the First Meeting of the Bolivia-Chile Working Group on the Silala Issue, 6 May 2004,
CM, Vol. 2, Annex 21.
34 Minutes of the First Meeting of the Bolivia-Chile Working Group on the Silala Issue, 6 May 2004,
CM, Vol. 2, Annex 21.
35 Joint Study Profile submitted by Chile in August of 2004, pp. 20 ff, BCM, Vol. 2, Annex 4.
21
the surface and underground.”36 This approach was again pursued in July 2006 with
the objective of reaching a final, practical and satisfactory solution for both Parties
in the form of a Preliminary Agreement on the issue of the use of the Silala waters.37
33. To that end, on 10 June 2008, the Parties determined to work towards “[o]n the one
hand, deepening the joint and coordinated study of the technical aspects and, on the
other hand, seeking an immediate basic agreement on the topics on which there is
consensus.”38 They also “agreed to formulate and implement a joint scheme of work
in the Silala area, to determine the water balance, hydrometric behaviour, water
dating, surface flows, influence of the waterworks on the streamflow, among other,
using a scientifically valid and agreed methodology.”39
34. A week later, on 17 June 2008, the Parties agreed “that in the next 60 days, the
contents will be exchanged for an immediate basic agreement, that takes into
account the water resource in its existing uses, the rights of each country, and the
means and mechanisms for its use in order to generate economic benefits for
Bolivia, considering the sustainability of the resource.”40
35. Later that year, on 14 November 2008, both countries met again to consider
developing a provisional agreement regarding the utilization of the waters that
would serve as basis for a definite agreement by which the Parties were to determine
36 Minutes of the II Meeting of the Bolivia-Chile Working Group on the Silala Issue, 20 January 2005,
BCM, Vol. 2, Annex 5.
37 Minutes of the Second Meeting of the Bolivia-Chile Working Group on Bilateral Affairs, 17 July
2006, CM, Vol. 2, Annex 22.
38 Minutes of the Third Meeting of the Bolivia-Chile Working Group on the Silala Issue, 10 June 2008,
CM, Vol. 2, Annex 23.
39 Minutes of the Third Meeting of the Bolivia-Chile Working Group on the Silala Issue, 10 June 2008.
CM, Vol. 2, Annex 23.
40 Minutes of the XVIII Meeting of the Bolivia-Chile Political Consultation Mechanism, 17 June 2008,
BCM, Vol. 2, Annex 6.
22
the percentages of waters freely available to each of the Parties, agreeing that: “[t]he
waters that are freely available in Bolivia and that were not used in that country,
may be made available for use in Chile, for which a mechanism must be agreed
upon that allows the constitution of exploitation rights in the border, as well as the
value that corresponds for its exclusive use.”41
36. On 28 July 2009, Bolivia and Chile reached a consensus on the text of an “Initial
Agreement” on the Silala42 in which they provisionally agreed, in particular: (a) the
use of the Silala waters that are freely available to Bolivia, abstracted in its territory
and transported to Chile should be compensated to Bolivia by the Chilean legal
entities43; (b) a percentage (50%) of the surface waters of the Silala correspond to
Bolivia and are freely available to this country, this percentage may be increased on
the basis of future joint studies44; (c) the Parties shall determine the influence of
waterworks on the flow before reaching a final agreement 45; (d) Bolivia shall give
its authorization for the waters of Silala that are freely available to it to be used in
Chilean territory, and any dispute that may arise between the legal Chilean entity
and Bolivia shall be resolved in accordance with Bolivian rules and before Bolivian
authorities.46
37. In that Initial Agreement, the Parties also made clear that further studies on the
nature of the “hydric system of the Silala” were expected and needed, and would be
undertaken jointly “in order to achieve a better understanding of its functioning and
nature”47. Finally, in the fourth paragraph of its preamble, the Parties determined
41 Minutes of the IV Meeting of the Bolivia-Chile Working Group on the Silala Issue, 14 November
2008, BCM, Vol. 2, Annex 7.
42 Initial Agreement [Silala or Siloli], Agreed Draft, 28 July 2009, BCM, Vol. 2, Annex 8.
43 Initial Agreement [Silala or Siloli], Agreed Draft, 28 July 2009, Art 3. BCM, Vol. 2, Annex 8.
44 Initial Agreement [Silala or Siloli], Agreed Draft, 28 July 2009, Art 6. BCM, Vol. 2, Annex 8.
45 Initial Agreement [Silala or Siloli], Agreed Draft, 28 July 2009, Art 9. BCM, Vol. 2, Annex 8.
46 Initial Agreement [Silala or Siloli], Agreed Draft, 28 July 2009, Art 15. BCM, Vol. 2, Annex 8.
47 Initial Agreement [Silala or Siloli], Agreed Draft, 28 July 2009, Art 5. BCM, Vol. 2, Annex 8.
23
that any other issue related to the Silala would be addressed in the future
agreement.48
38. In November 2009, the Bolivia-Chile Working Group on the Silala issue modified
the Initial Agreement and prepared a second draft, in which both Parties left open
“other issues that each of the parties might have an interest in addressing when
negotiating the new long-term Agreement”49 regarding the Silala, and decided,
among others, to conduct joint studies to define the nature of the Silala water
system.
39. The draft agreement could not be finalized and concluded. In accordance with the
fourth preamble of the Initial Agreement, in July 2010 Bolivia raised the aspect of
compensation that Chile would pay to Bolivia for past use of Silala waters.50 The
Parties determined that the Silala Working Group should be informed of, analyze,
and respond to all the proposals arising from the process of dissemination of the
Initial Agreement and submit a report to the Political Consultation Mechanism.51
The meeting of this Working Group was held in October 2010. Bolivia suggested
that the Agreement should incorporate a transitory article allowing the negotiations
on compensation for Chile’s past use of Silala waters. Chile refused to sign the
minutes of the meeting52 and did not convene the Third Meeting of the Political
48 Initial Agreement [Silala or Siloli], Agreed Draft, 28 July 2009, preamble, para. 4. BCM, Vol. 2,
Annex 8.
49 Initial Agreement [Silala or Siloli], Agreed Draft, Santiago, 13 November 2009, BCM, Vol. 2,
Annex 9.
50 La Razón, “Everything will be done after signing the Initial Agreement”, La Paz, 30 August 2009,
BCM, Vol. 2, Annex 16.
51 Minutes of the Twenty-Second Meeting of the Bolivia-Chile Political Consultation Mechanism, 14
July 2010, CM, Vol. 2, Annex 24.
52 Minutes of the First Part of the VIII Meeting of the Bolivia-Chile Working Group on the Silala Issue,
1 October 2010. BCM, Vol. 2, Annex 8.
24
Consultation Mechanism, despite previous agreement to hold this meeting in
November 2010.
40. Bolivia then invited Chile to hold a meeting of the Working Group on 12 September
2011 in La Paz.53 That invitation was not answered by Chile. Another invitation sent
in May 2012,54 which proposed a joint technical visit to Silala, was also ignored.
B. State of Knowledge of the Silala
41. The Silala constitutes a complex system of channelized surface and subsurface
water resources that traverse the Bolivian-Chilean border. Based on the above
account, it is evident that, in order to settle the dispute concerning the nature and use
of the Silala and to define their respective rights and obligations, the Parties have
considered it necessary and have been attempting for many years to improve their
knowledge of the nature of the Silala waters and to determine the influence of the
artificial installations.
42. The experts’ reports submitted by both Parties in the present proceedings certainly
have helped to further improve understanding of the Silala, on which the
identification of the rules applicable to it under international law depends. Based on
these reports, what is known today about the Silala waters and the impact of
artificial installations on their flow confirms to a large extent, as this Chapter will
53 Note Nº VRE-DGRB-UAM-018880/2011 from the Ministry of Foreign Affairs of Bolivia to the
General Consulate of Chile in La Paz, 29 August 2011. BCM, Vol. 2, Annex 11.
54 Note Nº VRE-DGRB-UAM-009901/2012 from the Ministry of Foreign Affairs of Bolivia to the
General Consulate of Chile in La Paz, 24 May 2012. BCM, Vol. 2, Annex 12.
25
show, Bolivia’s position according to which the Silala constitutes an artificiallyenhanced
watercourse.55
43. The Silala is located in the high altitude Altiplano, a dry puna mountain zone,
adjacent to the highly arid Atacama Desert. The region is characterized by low
precipitation, low temperatures, and high potential evaporation56. The Silala
topographical catchment of an approximate area in Bolivia of 59.1 km2 is dominated
by groundwater flows that generate negligible surface runoff57 (Figure 1).
55 Bolivia does not consider it necessary to respond to all the hydrological, hydrogeological,
topographic, ecological and other characterizations of the Silala that Chile included in its Memorial.
Bolivia will only address those that are relevant for the understanding and identification of the nature
of the Silala under international law.
56 Recent studies carried out in Bolivia have determined that the annual rainfall in the Silala is
significantly low and reaches an approximate average of 125 mm/year. The average annual
temperature is 2.2° C and the annual potential evapotranspiration is of approximately 1472 mm/year.
See Danish Hydraulic Institute (DHI), Study of the Flows in the Silala Wetlands and Springs System,
2018, p. 14. BCM, Vol. 2, Annex 17. See also Annex B: Climate Analysis, in Danish Hydraulic
Institute (DHI), Study of the Flows in the Silala Wetlands and Springs System, 2018, pp. 17-18, 21.
BCM, Vol. 2, Annex 17.
57 Danish Hydraulic Institute (DHI), Study of the Flows in the Silala Wetlands and Springs System, p.
25. BCM, Vol. 2, Annex 17. See also Annex A: The Silala Catchment in Danish Hydraulic Institute
(DHI), Study of the Flows in the Silala Wetlands and Springs System, 2018, p.10. BCM, Vol. 2,
Annex 17.
26
Figure 1: Topographical catchment of the Silala in Bolivia (Source: Annex A,
in DHI, Final Report, p. 11)
44. In Bolivian territory, the Silala Ravine was formed by fluvio-glacial erosion,
presenting a “U” shaped profile58 (Figure 2). It crosses the border between Chile
and Bolivia about 4 km downstream from the South Bofedal at an altitude of 150 m,
which is lower when compared to the upper springs59 and equivalent to an
approximate gradient of 3.7%. The topography and geology of the Altiplano are
dominated by volcanoes and thick deposits of pyroclastic material known as
ignimbrites. Due to both climate and altitude, the vegetation is characterized by
sparse and scattered grasses on the plains and volcano slopes.60
58 Ramsar Convention Secretariat, Report Ramsar Advisory Mission Nº 84, Ramsar Site Los Lípez,
Bolivia, 2018, p. 16. BCM, Vol. 5, Annex 18.
59 Annex A: The Silala Catchment, in Danish Hydraulic Institute (DHI), Study of the Flows in the Silala
Wetlands and Springs System, 2018, p. 6. BCM, Vol. 2, Annex 17.
60 Appendix A2: Final Report, Annex D: Soil Analyses, p. 3, p. 19 in Danish Hydraulic Institute (DHI),
Study of the Flows in the Silala Wetlands and Springs System, 2018. BCM, Vol. 3, Annex 17.
27
Figure 2: “U” shaped profile of the Main Ravine of the Silala in Bolivia
(Source: DIREMAR, 2018)
45. The wetlands found in the Silala catchment area within Bolivia are located at an
elevation of more than 4.320 meters above sea level. They are described as cushion
bogs, known as bofedales in the Andean region, with peat layers formed from
decaying Distichia plants (Figure 3). With time, these wetlands build peat layers of
organic deposits that can be several meters deep.61 The bofedales have been
described by researchers as “peatlands (…) like no other in the world”, and as
“unique, extremely fragile water features sensitive to climate changes and human
disturbances.”62 In their natural state, the bofedales “are indicative of elevated
groundwater tables and a permanently inundated valley floor.”63
61 G. Skrzypek, Z. Engel, T. Chuman, L. Šefrna, “Distichia Peat — A New Stable Isotope Paleoclimate
Proxy for the Andes”, Earth and Planetary Science Letters, 2011, Vol. 307, pp. 298-308.
62 A. F Squeo, G. B. Warner, R. Aravena, D. Espinoza, “Bofedales: High Altitude Peatlands of the
Central Andes”, Revista Chilena de Historia Natural, 2006, Vol. 79, at p. 245.
63 C. Latorre and M. Frugone, Holocene Sedimentary History of the Río Silala (Antofagasta Region,
Chile), 2017, CM, Vol. 5, Annex IV.
28
Figure 3: An excavated section and vertical peat profile at the edge of an
undisturbed wetland patch in the North Bofedal (Source: Annex C, in DHI, Final
Report, p. 17)
46. These wetlands are vulnerable to changing climatic and other conditions and rely on
a long-term, steady and reliable water supply to maintain suitable hydrological
conditions. In the Silala catchment area within Bolivia, bofedales are found in both
the South Ravine (Orientales) (Figure 4) and North Ravine (Cajones) (Figure 5),
which are controlled by the topography and groundwater discharges emerging
primarily from springs.64
64 Danish Hydraulic Institute (DHI), Study of the Flows in the Silala Wetlands and Springs System,
2018, p. 12. BCM, Vol. 2, Annex 17.
29
Figure 4: South Bofedal in Bolivia (Source: DIREMAR, 2017)
30
Figure 5: North Bofedal in Bolivia (Source: DIREMAR, 2017)
31
47. The Silala is a groundwater-fed water resource where contributions from surface
catchment runoff are small in comparison to the stationary or slowly varying
groundwater flow contributions. The potential area that stores and supplies
groundwater to the Silala comes from a hydrological catchment of approximately
234.2 km2 located in the Silala area65 (Figure 6). These waters have an approximate
age between 1,000 to 11,000 years,66 and it has not been ruled out that these waters
are non-renewable fossil groundwater.67 Water on the surface and in the subsurface
generally flows in a westward direction.68 Currently, water flows through an
artificially enhanced channel across the border from Bolivia into Chile at a variable
flow rate of approximately 160-210 l/s.69 The water flow in the subsurface of the
Silala catchment area is believed to have a rate of 100 l/s.70
C. Artificial Enhancement of the Silala
48. In 1908, The Antofagasta (Chili) and Bolivia Railway Company Limited (‘the
Railway Company’), a Chilean owned private company incorporated in the United
Kingdom, secured a concession from the Department of Potosi Prefecture in
65 Annex A: The Silala Catchment in Danish Hydraulic Institute (DHI), Study of the Flows in the Silala
Wetlands and Springs System, 2018, p. 12. BCM, Vol. 2, Annex 17.
66 Danish Hydraulic Institute (DHI), Study of the Flows in the Silala Wetlands and Springs System,
2018, p. 2. BCM, Vol. 2, Annex 17.
67 Appendix A2: Final Report, Annex D: Soil Analyses in Danish Hydraulic Institute (DHI), Study of
the Flows in the Silala Wetlands and Springs System, 2018, p. 85. BCM, Vol. 3, Annex 17.
68 Danish Hydraulic Institute (DHI), Study of the Flows in the Silala Wetlands and Springs System,
2018, p. 28. BCM, Vol. 2, Annex 17.
69 Danish Hydraulic Institute (DHI), Study of the Flows in the Silala Wetlands and Springs System,
2018, p. 26 and p. 41. BCM, Vol. 2, Annex 17.
70 “The model results of the Near Field suggest the present cross border groundwater flows over a 450m
wide section around the ravine to be in the order of 100 l/s” in Danish Hydraulic Institute (DHI),
Study of the Flows in the Silala Wetlands and Springs System, 2018, p. 41. BCM, Vol. 2, Annex 17.
32
Bolivia.71 In order to implement their concession, in 1910 the Railway Company
built a desiltation chamber (Figure 7) and installed a 56 km72 pipeline to convey an
approximate water flow of 76 l/s73 from the confluence of the North and South
Ravines in Bolivia to the San Pedro station in Chile.74
Figure 6: Hydrological catchment of the Silala in Bolivia (Source:
Annex A, in DHI, Final Report, p. 12)
71 Deed of Concession by the State of Bolivia of the Waters of the Siloli (N° 48) to The Antofagasta
(Chili) and Bolivia Railway Company Limited, 28 October 1908. CM, Vol. 3, Annex 41.
72 Robert H. Fox, “The Waterworks Department of the Antofagasta (Chili) & Bolivia Railway
Company”, South African Journal of Science, 1922, p. 124. CM, Vol. 3, Annex 75.
73 A discharge of 6.600 m3 per day, equivalent to 76 l/s approximately, has been registered. See: Robert
H. Fox, “The Waterworks Department of the Antofagasta (Chili) & Bolivia Railway Company”,
South African Journal of Science, 1922, p. 124. CM, Vol. 3, Annex 75.
74 See also Robert H. Fox, “The Waterworks Department of the Antofagasta (Chili) & Bolivia Railway
Company”, South African Journal of Science, 1922, p. 124. CM, Vol. 3, Annex 75.
33
Figure 7: The Main Channel and desiltation chamber just below the
confluence of the secondary channels emerging from the North
(Cajones) Ravine on the left, and the South (Orientales) Ravine on the
right (Source: DIREMAR, 2018)
49. In the 1920s, the Railway Company began to channelize the Silala waters by
installing engineered infrastructure in the headwaters of the Bolivian bofedales and
digging earthen channels from the upper springs of the two ravines to the border
with Chile in order to artificially draw the water from the surrounding springs and
bofedales and convey it more efficiently across the border into Chile.75
50. The artificial infrastructure includes a Main Channel that begins in Bolivia at the
confluence of the two Silala ravines the North and South Ravines (Figures 8 and 9)
and crosses the border into Chile. The Main Channel is connected to two subsidiary
main channels constructed in each of the two ravines and a desiltation chamber
located 700 m from the border inside Bolivian territory. Within the two ravines, the
75 Muñoz, J. F., Suárez, F., Fernández, B., Maass, T., 2017. Hydrology of the Silala River Basin, pp. 16-
23. CM, Vol. 5, Annex VII.
34
two subsidiary main channels are connected to several artificial minor lateral
channels and drainage mechanisms that crisscross throughout the bofedales. These
lateral channels and drainage mechanisms are directly connected to each of the more
than one hundred Silala springs and guide the spring flows to the subsidiary main
channels in each of the two ravines, thereby bypassing most of the bofedal habitat
(Figures 10 and 11).
Figure 8: The technical stonework of the Main Channel as it receives water
transported by the two main subsidiary channels emerging from the North (Cajones)
Ravine and South (Orientales) Ravine (Source: DIREMAR, 2018).
35
Figure 9: The Main Channel before it reaches the border (Source: DIREMAR,
2018)
51. The main artificial channels of the Silala vary in depth and width.76 There are also
second and third level channels that were dug out by hand to develop an extensive
drainage network that could reach the full extent of the bofedales. In all, the
Railway Company installed approximately 6.600 meters of channels, pipes, and
lined ditches,77 in Bolivia’s Silala basin that artificially enhanced the flow of water
to Chile (Figures 12, 13 and 14).
76 Annex G: Integrated Surface Water – Groundwater Modelling, in Danish Hydraulic Institute (DHI),
Study of the Flows in the Silala Wetlands and Springs System, 2018, pp. 24-27. BCM, Vol. 5, Annex
17.
77 Annex G: Integrated Surface Water – Groundwater Modelling, in Danish Hydraulic Institute (DHI),
Study of the Flows in the Silala Wetlands and Springs System, 2018, p. 24. BCM, Vol. 5, Annex 17.
36
Figure 10: Canal types constructed in the Silala (Source: DIREMAR, 2018)
37
Figure 11: Canal types constructed in the Silala depicted on a satellite image (Source: DIREMAR, 2018)
38
Figure 12: Distribution and dimensions of the channels in South (Orientales) Ravine of the Silala in Bolivia
(Source: Annex G, in DHI, Final Report, p. 28)
39
Figure 13: Distribution and dimensions of the channels in the North (Cajones) Ravine of the Silala in Bolivia
(Source: Annex G, in DHI, Final Report, p. 34)
40
Figure 14: Channel distribution and dimensions in the Main Channel below the confluence of
the two Silala ravines in Bolivia (Source: Annex G, in DHI, Final Report, p. 31)
41
52. The artificiality of the hydraulic infrastructure installed in Bolivian territory can be
evidenced from the rectilinear and angular design that these works comprise in the
area (Figures 15 and 16). In addition, by 1942, the Railway Company had
completed 13 km of yet a second Silala pipeline from the desiltation chamber built
in Chilean territory 40 meters from the border78 to San Pedro Station to convey the
waters generated by the channelization into Chilean territory.
Figure 15: The extensive network of artificial drainage mechanisms crossing the bofedales
in the North (Cajones) Ravine of the Silala in Bolivia (Source: DIREMAR, 2017)
78 Letter from the General Manager of the FCAB in Chile to the President of the Board of Directors of
the FCAB in London, 3 September 1942. CM, Vol. 3, Annex 68.
42
Figure 16: Rectilinear channels with defined angles in the North (Cajones)
Ravine of the Silala and limited typical bofedal vegetation that would be expected
in thriving bofedales (Source: DIREMAR, 2017)
53. The channelization system was installed to improve the transport of Silala water into
Chile, originally with the sole purpose to supply water for the Railway Company’s
steam locomotives.79 By the early 1960s, these had been replaced by diesel
locomotives. However, Chile had already unilaterally altered its initial use into the
water intensive mining industries, in particular copper mining, and use by some
nearby towns.80 The scheme of water distribution was exploited by private
operators. The infrastructure was necessary to create a more consistent and
voluminous flow of water from the Silala springs in Bolivia, through the dense
bofedales, and across the border into Chile.
79 Deed of Concession by the State of Bolivia of the Waters of the Siloli (N° 48) to The Antofagasta
(Chili) and Bolivia Railway Company Limited, 28 October 1908. CM, Vol. 3, Annex 41.
80 C. R. Rossi, “The Transboundary Dispute over the Waters of the Silala/Siloli: Legal Vandalism and
Goffmanian Metaphor”, Stanford Journal of International Law, Vol. 53, 2017, pp. 62-63.
43
54. To increase and maximize water flow rates within the channels and drainage
mechanisms, some parts of the infrastructure were lined with large, flat stones at the
base of each channel and conduit, as well as on the sides (Figure 17). In some cases,
the channels and drainage mechanisms were also covered with flat stone roofs, or
replaced with a steel pipe, to further minimize losses due to leakage and
evaporation81 (Figure 18).
Figure 17: Silala spring directly connected to an
artificial channel where the spring emerges from
the formation (Source: DIREMAR, 2016)
81 Hauser, A. 2004. Morphological, Geological, Tectonic, Hydrogeological and Hydrochemical
Context: Morphogenesis, Evolution and Modalities of Use of the Shared Chilean-Bolivian
Hydropgrahic System. National Geology and Mining Service (SERNAGEOMIN). CM, Vol. IV,
Annex II, Appendix A, pp. 21-22.
44
Figure 18: Drainage pipe adjacent to a Silala
spring where the spring emerges from the
formation (Source: Annex C, in DHI, Final
Report, p. 16)
55. The Railway Company carried out maintenance on the artificial infrastructure in
Bolivia until 1997, completely removing the surrounding vegetation.82
82 Expert Report 1, Fig. 7, p. 20, CM, Vol. 1.
45
D. Effects and Consequences of the Artificial Enhancement of the Silala
56. As shown above,83 since 1999 Bolivia and Chile have considered that to settle the
controversy it is necessary to determine the influence of the artificial installations in
the Silala on the flow of its waters. In its Memorial, Chile’s experts estimate that
“the channels in Bolivia have had limited effect on the extent of the Orientales and
Cajones wetlands in Bolivia, due to the shallow depth of the channels.”84 While the
extent of the effects of the channelization on Bolivia’s Silala springs, water flow,
and wetlands have still not been fully ascertained, their implementation, operation,
and maintenance have clearly and significantly altered the entire hydrology,
hydrogeology, and ecology of the Silala in Bolivia.
57. In its Memorial, Chile claims that “[t]he waters of the Silala River have flowed and
continue to flow naturally from Bolivian territory into Chile, before, after and
independently of the construction of these channels.”85 It further asserts that the
network of channels and drainage mechanisms was constructed “for sanitary
reasons”86 and that the “effect of the channels on the cross-boundary flow, due to
reduced evaporation in the wetlands, is therefore very limited and calculated to be
less than 3.4 l/s or 2% of the annual average flow.”87
58. Simplistic and categorical in form, Chile’s assertions are based on conjecture and an
incorrect factual and technical background. In particular, Chile ignores the very
purpose and justification for the construction of the channels, as well as the reality
that channelization of the Silala in Bolivia has substantially modified the Silala
83 BCM, paras. 26-39.
84 CM, pp. 32-33, para. 2.27.
85 CM, p. 32, para. 2.26.
86 CM, p. 32, para. 2.25.
87 CM, p. 33, para. 2.27.
46
basin and had a significant influence on the rate and volume of flow of Silala waters
in Bolivia.
59. Channelization of the Silala in Bolivia increased the discharge of spring water
emerging from the Silala springs and other diffuse sources due to the lowering of
the hydraulic head.88 Nearly all of the upstream ends of the artificial drainage
network constructed within both the North and South Ravines of Bolivia originate in
an identifiable spring. At these spring discharge points, the soil and any underlying
layers of coarser material and rocks, were completely removed, sometimes with
explosives,89 in order to increase drainage into the channels. As a result, the natural
resistance to the emerging groundwater was considerably reduced and spring flow
rates were boosted.
60. Under natural, pre-channelization conditions, less water emerged from the springs
on the surface, as compared to the present, and more groundwater would have been
retained in the subsurface formation than is currently being retained.90 The artificial
channels and drainage mechanisms effectively created a more direct and efficient
means of drawing water from the springs and bofedales to the Main Channel of the
Silala and across the Bolivian-Chilean border.91
88 Appendix A2: Final Report, Annex D: Soil Analyses in Danish Hydraulic Institute (DHI), Study of
the Flows in the Silala Wetlands and Springs System, 2018, p. 18, BCM, Vol. 3, Annex 17.
89 BCM, para. 61.
90 Chile’s own experts assert that the “constructed channels (…) act as drains and are able to receive
water from the wetland soils.” Expert Report 1, Sec. 2, p. 6, CM, Vol. 1. The logical conclusion
from this assertion is that the channelization of the Silala increased the rate and volume of water flow
from Bolivia’s springs and bofedales to Chile.
91 Danish Hydraulic Institute (DHI), Study of the Flows in the Silala Wetlands and Springs System,
2018, p. 81. BCM, Vol. 2, Annex 17.
47
61. Many of the spring discharge points in Bolivia still clearly evidence the use of
explosives.92 Such blasting methods appear to have been used to stimulate spring
flows by reducing or eliminating the resistance from narrow fissures, vegetation,
and peat layers that naturally constrained the flow of water from the spring. As a
result, many spring discharge points were altered substantially by lowering the
discharge point and increasing the rate and volume of water flowing from the
springs. These changes in turn lowered the water table in the immediate vicinity of
each spring, and increased the capture area contributing water to the springs.93
While the changes in the Silala springs cannot be precisely calculated today given
the absence of baseline data, evidence from a case study in which blasting was used
to enhance water flow through similarly fractured igneous and metamorphic rock
indicates that such techniques can increase yield from wells by a factor of 6 to 2094
(Figure 19).
92 Annex F: Hydrogeology in Danish Hydraulic Institute (DHI), Study of the Flows in the Silala
Wetlands and Springs System, 2018, pp. 97-98. BCM, Vol. 4, Annex 17.
93 Annex F: Hydrogeology in Danish Hydraulic Institute (DHI), Study of the Flows in the Silala
Wetlands and Springs System, 2018, pp. 97-98. BCM, Vol. 4, Annex 17.
94 F. G. Driscoll, “Blasting – It Turns Dry Holes into Wet Ones”, Johnson Drillers’ Journal, Nov/Dec
1978, Johnson Division, UOP, Inc. St. Paul, MN, p. 3.
48
Figure 19: Rocks adjacent to channels and drainage mechanisms
providing evidence of explosive blasts used to lower spring elevations
and increase spring discharge (Source: Annex F, in DHI, Final Report,
p. 97)
62. In addition, and contrary to Chile’s assertion that “the water that rises from springs
in Bolivia cannot flow anywhere else but downhill into Chile,”95 prior to the
installation of the artificial channels, Silala waters within Bolivia’s bofedales region
was relatively stagnant, with a considerably reduced cross-border water flow on the
surface as compared to the present. This is evident from the various actions taken by
the Railway Company when it secured its concession from Bolivia to draw water
from Bolivia’s Silala region and into Chile.
63. In particular, by installing an intake mechanism and a complex system of artificial
channels and drainage mechanisms within Bolivian territory near the bofedales, it is
apparent that the Railway Company sought to reach slow-flowing and otherwise
95 CM, p. 23, para. 2.8, in fine.
49
unreachable Silala waters and enhance their flow toward Chile. As recorded in the
1908 concession agreement, the Railway Company’s official representative,
Benjamín Calderón, asserted that:
“The Company that I represent is in need of those waters that are
relatively adequate to feed its locomotives (…) By building intake
and channeling works, the previously mentioned springs could be
used, even if at increased cost; and the Company plans to execute
such works to use the waters for its railroad services.”96
64. If, prior to channelization, the Silala had flowed across the Bolivian-Chilean border
in adequate volume and rate of flow to satisfy the Railway Company’s needs and
ambitions, it is inexplicable why the Railway Company would have needed to
construct and install all of this infrastructure inside Bolivia’s territory, in a region on
the edge of the Atacama Desert that even today is exceptionally isolated and highly
arid. In other words, in its pre-channelized natural condition, the Silala in Bolivia
did not flow in the manner, rate, or volume that met the needs of the Railway
Company; hence, their need to artificially modify and enhance it.
65. This conclusion is further supported by the assertion in the 1908 concession
agreement, which explicitly states that only “[b]y building intake and channeling
works, the previously mentioned springs could be used, even if at increased cost.”97
Considering that the concession agreement called for channelization work to take
place in Bolivia in order to facilitate use of Silala water in Chile, this provision is
based on two elements: (a) without the intake and channelization within Bolivia, the
96 Deed of Concession by the State of Bolivia of the Waters of the Siloli (N° 48) to The Antofagasta
(Chili) and Bolivia Railway Company Limited, 28 October 1908 (emphasis added). CM, Vol. 3,
Annex 41.
97 Deed of Concession by the State of Bolivia of the Waters of the Siloli (N° 48) to The Antofagasta
(Chili) and Bolivia Railway Company Limited, 28 October 1908 (emphasis added). CM, Vol. 3,
Annex 41.
50
natural water flow and volume in Bolivia’s Silala waters was not adequate to
achieve the Railway Company’s intended purpose of using Bolivia’s waters in
Chile; and (b) prior to channelization, the waters of the Silala did not flow naturally
across the border in the rate and volume adequate for the Railway Company’s
intended purposes. The channelization was manifestly done to secure additional
water for use in Chile.
66. Further, if prior to channelization sufficient water flowed across the Bolivian-
Chilean border, there would have been no need to line the base and the sides of
portions of the artificial channels and lateral drainage mechanisms with flat stones
(or fit them with steel piping, as was done with some of the channels). Again, the
only plausible explanation is that, prior to channelization, Bolivia’s Silala waters
stagnated in the ravines containing Bolivia’s Silala wetlands causing volumes of
water to evaporate and partially infiltrate prior to reaching the Bolivian-Chilean
border. Contrary to what Chile suggests, as a result of the Railway Company’s
installation of the infrastructure, the flow and volume of the Silala waters increased
considerably, making the costly investment worthwhile.
67. Bolstering this conclusion is the fact that the 1908 concession agreement also
provides that “the projected work shall make usable waters that are currently being
lost benefitting no one.”98 It would have been illogical for the Railway Company to
assert that the water was “being lost benefitting no one” unless (1) some of the
Silala waters within Bolivia were not flowing naturally across the border into Chile,
and (2) the pre-channelization flow rate and volume of water coursing across the
98 Deed of Concession by the State of Bolivia of the Waters of the Siloli (N° 48) to The Antofagasta
(Chili) and Bolivia Railway Company Limited, 28 October 1908 (emphasis added). CM, Vol. 3,
Annex 41.
51
Bolivian-Chilean border were substantially less than those occurring after
installation of the artificial channels and drainage mechanisms.99
68. In its Memorial, Chile now suggests that the construction of the artificial channels
and drainage mechanisms in Bolivia was principally set up for “sanitary reasons, to
inhibit breeding of insects at the Silala River headwaters and avoid contamination of
the potable water supply to Antofagasta.”100 Not only does this claim ignore the
original purpose of the channelization recorded in the 1908 concession
agreement,101 it also disregards the fact that the additional infrastructure was
implemented in 1928 to “renew[] and improve[e] the existing intake works” which
“have been in use for the last 17 years (…) [and which] had become deteriorated
and badly requires renewal.”102
69. In addition, the “sanitary” objective cannot detract from the fact that the installation
of the infrastructure increased the rate and volume of water flowing from Bolivia’s
Silala wetlands area into Chile. To destroy conditions that favored insect breeding,
the Railway Company had to eliminate or substantially reduce standing water and
vegetation in the bofedales.103 Channelization achieved that exact objective. Even
Chile’s own experts recognized this impact. In describing the channel infrastructure,
Expert Report 1 annexed to the Chilean Memorial asserts: “[t]he aim seems to have
been to formalize the natural channel system to minimize erosion and to drain
99 This was admitted by the Chilean Vice-Chancellor Mariano Fernandez in 1996 when he stated that
the Silala “is a ravine from which waters that would be useless if they were not canalized fall (…)
what was done is to prevent these waters from being lost into wetlands by building rock-canals for the
water to run in a more organized fashion”. See El Diario, “The Silala is not a matter of discussion for
Chile”, La Paz, 28 May 1996, BCM, Vol. 2, Annex 14.
100 CM, p. 32, para. 2.25.
101 BCM, para. 63.
102 Letter from the General Manager of FCAB in Chile to the Secretary of the Board of Directors of
FCAB in London, 27 January 1928. CM, Vol. 3, Annex 67.1.
103 E. Oyague Passuni and M. S. Maldonado Fonkén, “Relationships between Aquatic Invertebrates,
Water Quality and Vegetation in an Andean Peatland System, Mires and Peat, Volume 15 (2014/15),
Article 14, pp. 1-21.
52
standing water,”104 and the “constructed channels (…) act as drains and are able to
receive water from the wetland soils.”105 As explained below, the artificial channels
and drainage mechanisms that were installed within the bofedales significantly and
intentionally depleted those fragile wetlands,106 thereby affecting the habitat.
70. In developing their conceptual model for the Silala, Bolivia’s experts have sought to
estimate the impact of channelization on surface water and groundwater flows.
However, because of the lack of pre-channelization baseline data, and the fact that
channelization of the Silala has substantially modified the basin, the model was
based on present-day Silala conditions without the existing artificial
infrastructure.107 Under current conditions, if the channels and drainage mechanisms
were removed,108 Silala surface flows would be expected to decrease by 30-40% as
compared to current surface flows. In other words, of the current surface flows, as
much as 64-84 l/s can be directly attributed to the artificial enhancements installed
in the Silala within Bolivia. This estimate includes a 20-30% increase in
evapotranspiration that would occur from the larger bodies of standing waters in the
bofedales, as well as 8-12% (with a maximum potential of 25%) increase in losses
due to infiltration.109 In contrast, if the artificial infrastructure were to be removed,
sub-surface groundwater flow through the 450 m wide cross section of the Silala
104 Expert Report 1, pp. 18-19. CM, Vol. 1, pp. 146-147.
105 Expert Report 1, Sec. 2, p. 6. CM, Vol. 1, p. 134.
106 BCM, paras. 72-73.
107 Danish Hydraulic Institute (DHI), Study of the Flows in the Silala Wetlands and Springs System,
2018, p. 6. BCM, Vol. 2, Annex 17.
108 Because of the substantial changes made to the Silala basin resulting from the channelization works,
present-day conditions without the channels and drainage mechanisms are not equivalent to prechannelization
conditions. Nonetheless, such a comparison can provide insight and estimates into prechannelization
circumstances.
109 Danish Hydraulic Institute (DHI), Study of the Flows in the Silala Wetlands and Springs System,
2018, pp. 41-42. BCM, Vol. 2, Annex 17.
53
catchment area at the Bolivian-Chilean border would be expected to increase by 7-
11% as compared to present subsurface flows.110
71. Channelization of the Silala in Bolivia for the purpose of increasing the volume and
rate of its flow has had a profound and long-lasting impact on the Silala bofedal
ecosystem.
72. The artificial drainage network constructed within both the North and South
Bolivian Silala Ravines effectively diverted water into the subsidiary main channels
of the two ravines and then to the Main Channel, thereby preventing the water from
slowly filtering naturally through the wetlands. As a result, the bofedales were
substantially dewatered thereby affecting the natural habitat.
73. According to the 2018 Ramsar Convention Secretariat Report on the site Los Lípez
in Bolivia, “[t]he wetlands found in the Silala area have been highly affected by the
construction of the water-catchment canals started in 1908. At present, there are
only vestiges of the original wetlands that used to cover an area of about 141,200
m2, or 14.1 hectares. The current surface area of the wetlands covers only about
6,000 m2, or 0.6 ha., which are surrounded by the water catchment works and
artificial canals.”111 Today, a narrow riparian fringe of vegetation suggests
accessibility to water only in close proximity of the canal112 (Figure 20).
110 Danish Hydraulic Institute (DHI), Study of the Flows in the Silala Wetlands and Springs System,
2018, p. 41. BCM, Vol. 2, Annex 17.
111 Ramsar Convention Secretariat, Report Ramsar Advisory Mission Nº 84, Ramsar Site Los Lípez,
Bolivia, 2018, p. 38. BCM, Vol. 5, Annex 18.
112 Annex C: Surface Waters, in Danish Hydraulic Institute (DHI), Study of the Flows in the Silala
Wetlands and Springs System, 2018, pp. 8-9. BCM, Vol. 2, Annex 17.
54
Figure 20: Effects of desiccation on the South (Orientales) Silala Bofedal (Source:
DIREMAR, 2018)
74. As a result of the considerable alteration of the Silala, the present-day rate and
volume of water flowing on the surface and through the subsurface of the basin are
of a combined natural and artificial origin. Some of the water coursing through the
Silala, including some of the water flowing across the Bolivian-Chilean border, can
be described as occurring naturally. However, contrary to Chile’s assertions, the rest
of that water flows solely as a result of the implementation of the drainage network
that crisscrosses the two Silala ravines in Bolivia and that enhances the flow of the
water by draining the springs and wetlands in Bolivia and transporting their waters
into channels that flow into Chile. The proportions of natural versus artificial flows
and volumes have been estimated in Bolivia’s studies. As mentioned above,113 under
current conditions, if the channels and drainage mechanisms were removed, the
113 BCM, para. 70.
55
Silala surface flows would be expected to decrease by 30-40% as compared to
current surface flows.
E. Final Remarks
75. The Silala basin comprises a highly complex system of springs, surface waters, and
groundwaters, as well as groundwater-dependent ecosystems in the form of the
bofedales. Over many decades, both Bolivia and Chile, through joint and
independent efforts, have endeavored to gain a better understanding of the
intricacies of the basin including its origin, geographic extent, capacity, and flow
regime, as well as the influence that the artificial channels and drainage installations
have on the flow. Most recently, additional data and information have been obtained
allowing further knowledge about the hydrology and hydrogeology of the region.
76. Today, it is known that drainage and channelization of the Silala in Bolivia has had
a considerable impact on the discharge of spring water emerging from the Silala
springs, as well as the rate of flow and volume of water traversing the Bolivian-
Chilean border. By evaluating the Silala without the presence of the artificial
infrastructure, the most recent expert study conducted by the Danish Hydraulic
Institute in 2018 suggests that surface flows would decline by 30-40% below current
surface flow rates, while groundwater flows would increase by 7-11% as compared
to present subsurface flows.
77. In addition, said report indicates that the water in the Silala currently flows across
the Bolivian-Chilean border on the surface and through subsurface formations at a
variable flow rate of approximately 160-210 l/s. Moreover, the evidence is clear that
this flow comprises both natural and artificial flows, the latter being the direct
product of the artificial drainage and channelization of the waters of the Silala.
56
78. Finally, evidence shows that the bofedales that occupy portions of the two Silala
ravines in Bolivia are critically dependent on the waters of the Silala, primarily
groundwater, and that they are vulnerable to changing climatic and other conditions.
Moreover, these fragile wetlands have suffered considerable degradation and
reduction in geographic scope as a direct result of the drainage and channelization
mechanisms installed throughout the ravines.
57
CHAPTER 3
NATURE OF THE SILALA UNDER INTERNATIONAL LAW
79. In the present Chapter, Bolivia will show that the Silala and its waters, whose
factual nature and characteristics were identified in the previous chapter, do not
qualify, in their entirety, as an international watercourse under customary
international law. They do not for two reasons. Customary international law on the
non-navigational uses of international watercourses only applies to the natural flow
of watercourses. And, as shown in the previous chapter, the waters of the Silala are
part of an artificially enhanced watercourse that includes both naturally- and
artificially-flowing water.
A. International Watercourses in Customary International Law
80. Under customary international law, the obligations that States have to each other in
relation to non-navigational uses of international watercourses are limited to the
natural flow of the waters. As authoritative doctrine states, “[t]he flow of boundary,
or international, rivers is not within the arbitrary power of one of the riparian states,
for it is a rule of international law that no state is allowed to alter the natural
conditions of its own territory to the disadvantage of the natural condition of the
territory of a neighbouring state.”114 In a similar vein, it has been considered that
“[e]very state must allow rivers (…) to flow naturally.”115 In relation to the Silala, it
has been observed accordingly that “[a] manufactured river, in the form of canals or
other man-made systems, would not fall within the rubric of international water law,
114 R. Jennings and A. Watts (eds.), Oppenheim’s International Law, Longman, 9th ed., 1996, p. 585
(emphasis added).
115 M. Huber, Ein Beitrag zur Lehre von der Gbietshoheit an Grenzflüssen, Zeitschrift für Volkerrecht
und Bundesstaatsrecht, 1907, pp. 29 ff. and 159 ff., translated in S. McCaffrey, The Law of
International Watercourses, Oxford University Press, 2007, p. 132 (emphasis added).
58
since, by definition, such water bodies are proprietary and subject to the agreements
that created them.”116
81. International and domestic judicial decisions also recognize the legal relevance of
the distinction between the existence of natural and artificial flows. For instance, in
the Lake Lanoux arbitration, it was specified that what was relevant in terms of
obligations related to uses of transboundary waters was “le volume qui corresponde
aux apports naturels du Lanoux au Carol.”117 It has also been decided by domestic
courts that “[n]o State may substantially impair the natural use of the flow of such a
river by its neighbor” and that “every State must submit to the natural flow of the
water in spite of its consequences.”118 In Gabcikovo-Nagymaros, Hungary’s claim
was limited to its right “to 50% of the natural flow of the Danube,” by virtue of the
1976 Convention on Regulation of Water Management Issues of Boundary
Waters.119
82. State practice confirms that under international law, in situations of watercourses
involving naturally and artificially flowing waters, States consider their obligations
and rights distinctly. Various agreements explicitly limit their application to the
natural flow of a shared watercourse. For example, Article 7 of the 1996 Mahakali
Treaty stipulates that “[i]n order to maintain the flow and level of the waters of the
Mahakali River, each Party undertakes not to use or obstruct or divert the waters of
the Mahakali River adversely affecting its natural flow and level except by an
116 B. Mulligan and G. Eckstein, “The Silala/Siloli Watershed: Dispute Over the Most Vulnerable Basin
in South America”, International Journal of Water Resources Development, Vol. 27(3), 2011, pp.
595-606.
117 Affair du Lac Lanoux (Spain v. France), Award of 16 November 1957, Reports of International
Arbitral Awards, Vol. XII, p. 303 (emphasis added).
118 S. McCaffrey, The Law of International Watercourses, Oxford University Press, 2007, pp. 242-244
(emphasis added), citing Württemberg and Prussia v Baden (Donauversinkung case), German
Staatsgerichtshof, 18 June 1927, pp. 131-132.
119 Gabcikovo-Nagymaros Project (Hungary/Slovakia), Judgment, I.C.J. Reports 1997, p. 73, para. 125
(emphasis added).
59
agreement between the Parties.”120 Article 6 of the 1995 Mekong River Agreement
obligates the Parties to ensure in the mainstream of the Mekong River a “minimum
monthly natural flow during each month of the dry season,” and a “natural reverse
flow of the Tonie Sap to take place during the wet season.”121 Article XIII of the
Columbia River Treaty restricts diversions of “any water from its natural channel in
a way that alters the flow of any water as it crosses the Canada-United States of
America boundary within the Columbia River basin.”122 The Canada-United States
Boundary Waters Treaty similarly limits its applicability to the “natural channels” of
tributaries and the “natural level or flow of boundary waters.”123
83. Considering that customary international law only imposes obligations in relation to
the natural flow of international watercourses, under customary international law,
there is therefore no obligation to install or to maintain infrastructures for the
purposes of increasing the flow and enhancing the use of transboundary waters.
There is no right for a State to require another State to install or maintain such
infrastructures for its benefit. This is reflected, a contrario, in Article 26 of the
United Nations Watercourses Convention (hereinafter “UNWC”) which deals with
“installations” only to the extent that they may cause significant adverse effects.124
120 Treaty between His Majesty’s Government of Nepal and the Government of India concerning the
Integrated Development of the Mahakali Barrage Including Sarada Barrage, Tanakpur Barrage and
Pancheshwar Project, 12 February 1996 (emphasis added). According to M. M. Rahaman, “[t]his
means each Party has an obligation to maintain the natural flow of the river.” See M. M. Rahaman
“Principles of Transboundary Water Resources Management and Ganges Treaties: An Analysis”,
Water Resources Development, Vol. 25, No. 1, March 2009, at p. 165.
121 Art. 6 of the Agreement for the Cooperation of the Sustainable Development of the Mekong River
Basin, 5 April 1995, UNTS, Vol. 2069, No. 35844, p. 7.
122 Art. XIII, Treaty Relating to Cooperative Development of the Water Resources of the Columbia
River Basin, 17 January 1961, 542 UNTS 244, pp. 264-266 (emphasis added).
123 Arts. II and III, Treaty between the United States and Great Britain relating to Boundary Waters, and
Questions Arising Between the United States and Canada, 11 January 1909, T.S. No. 548, 36 Stat.
2448.
124 For the relevant State practice on security and safety of hydraulic installations, see Mr. Stephen C.
McCaffrey, Special Rapporteur, Sixth report on the law of the non-navigational uses of international
60
84. Distinguishing artificial and natural conditions of geographic or geologic features to
determine their legal effects is not limited to international watercourses. It
constitutes a general approach in international law, in particular in relation to natural
resources and allocation of rights over land or maritime areas.
85. For example, under the law of the sea, artificial structures are not subject to the
same regime as natural features. Article 11 of the United Nations Convention on the
Law of the Sea (‘UNCLOS’) provides that “artificial islands shall not be considered
as permanent harbour works,” while Article 60(8) provides that “[a]rtificial islands,
installations and structures do not possess the status of islands. They have no
territorial sea of their own, and their presence does not affect the delimitation of the
territorial sea, the exclusive economic zone or the continental shelf.”125
86. Following these provisions, an arbitral tribunal recently concluded that the
UNCLOS requires that “the status of a feature be ascertained on the basis of its
earlier, natural condition, prior to the onset of significant human modification.”126
As a result, the arbitral tribunal determined that it “will therefore reach its decision
on the basis of the best available evidence of the previous status of what are now
heavily modified coral reefs.”127 The Tribunal also asserted that “[j]ust as a low-tide
elevation or area of seabed cannot be legally transformed into an island through
human efforts, (…) a rock cannot be transformed into a fully entitled island through
watercourses, U.N. Doc. A/CN.4/427 and Add.l, Yearbook of the International Law Commission,
1990, Vol. II (Part One), pp. 53-57, paras. 20-36. This practice does not reveal the existence of any
obligation under customary international law to install or maintain artificial infrastructures for the
purposes of increasing the flow and enhancing the use of transboundary waters. For the Convention
see UN Doc. A/RES/51/266, 21 May 1997.
125 Art. 60, United Nations Convention on the Law of the Sea, 3 December 1982, 1833 UNTS 3.
126 The South China Sea Arbitration (The Republic of Philippines v. The People’s Republic of China),
PCA Case No. 2013-19, Award of 12 July 2016, p. 132, para. 306.
127 The South China Sea Arbitration (The Republic of Philippines v. The People’s Republic of China),
PCA Case No. 2013-19, Award of 12 July 2016, pp. 131-132, para. 306.
61
land reclamation. The status of a feature must be assessed on the basis of its natural
condition.”128
87. In another case interpreting the UNCLOS and international law, the Court in
Maritime Delimitation in the Black Sea concluded that the landward end (rather than
the seaward end) of the Sulina Dyke “where it joins the Romanian mainland should
be used as a base point for the establishment of the provisional equidistance line.”129
Highlighting its artificial nature, the Court asserted, “[a]s a relevant base point for
the purposes of the first stage of delimitation, it has the advantage, unlike the
seaward end of the dyke, of not giving greater importance to an installation than to
the physical geography of the landmass.”130
88. In Qatar/Bahrain, the Court similarly observed that, since “Bahrain undertook
reclamation works for the construction of a petrochemical plant, during which an
artificial channel was dredged connecting the waters on both sides of Fasht al Azm,”
there was a dispute on whether or not “Fasht al Azm must be deemed to be part of
the island of Sitrah or whether it is a low-tide elevation which is not naturally
connected to Sitrah Island.”131
128 The South China Sea Arbitration (The Republic of Philippines v. The People’s Republic of China),
PCA Case No. 2013-19, Award of 12 July 2016, p. 214, para. 508.
129 Maritime Delimitation in the Black Sea (Romania v. Ukraine), Judgment, I.C.J. Reports 2009, p. 108,
para. 140.
130 Maritime Delimitation in the Black Sea (Romania v. Ukraine), Judgment, I.C.J. Reports 2009, p. 108,
para. 139.
131 Maritime Delimitation and Territorial Questions between Qatar and Bahrain, Merits, Judgment,
I.C.J. Reports 2001, p. 97, para. 188. The Court eventually decided that “[a]fter careful analysis of the
various reports, documents and charts submitted by the Parties, the Court has been unable to establish
whether a permanent passage separating Sitrah Island from Fasht al Azm existed before the
reclamation works of 1982 were undertaken. For the reasons explained below, the Court is
nonetheless able to undertake the requested delimitation in this sector without determining the
question whether Fasht al Azrn is to be regarded as part of the island of Sitrah or as a low-tide
elevation” (p. 98, para. 190).
62
89. Along the same lines, the Court observed in the Fisheries case in 1951 that “the
Indreleia is not a strait at all, but rather a navigational route prepared as such by
means of artificial aids to navigation provided by Norway.”132 In these
circumstances, it could on its own not create specific consequences under
international law.
90. With regard to boundary rivers, in Land and Maritime Boundary between Cameroon
and Nigeria, the Court “has first examined” whether “the course of the Keraua
River has been diverted by Nigeria as a result of an artificial channel constructed by
it in the vicinity of the village of Gange” before determining whether that channel, if
not artificial, could be deemed to be the river designated as the boundary in the
Thomson-Marchand Declaration.133
91. In light of the above, under general international law, an international watercourse
designates a natural flow of waters.
B. Scope of Customary International Law on Naturally-Flowing Watercourses
92. To support its assertion that customary international law applies to the Silala as a
whole, including the artificial channels and drainage mechanisms, Chile refers in its
Memorial to the broad definition of “watercourse” provided in the 1994 Draft
Articles on the Non-Navigational Uses of International Watercourses adopted by the
132 Fisheries case (United Kingdom v. Norway), Judgment, I.C.J. Reports 1951, p. 132. See similarly,
expressing the view that a strait under the law of the sea only refers to a natural outlet and that any
outlet which is the product of artificial, human work is not a strait, but a canal which is not regulated
by the general law of the sea but either by specific agreements or by domestic law: S. Karagiannis,
“Les détroits”, in M. Forteau, J.-M. Thouvenin (dirs.), Traité du droit international de la mer,
Pedone, Paris, 2017, p. 446.
133 Land and Maritime Boundary between Cameroon and Nigeria (Cameroon v. Nigeria: Equatorial
Guinea intervening), Judgment, I.C.J. Reports 2002, p. 365, para. 95.
63
ILC:134 “a system of surface waters and groundwaters constituting by virtue of their
physical relationship a unitary whole and normally flowing into a common
terminus.”135 The 1994 Draft Articles also define an international watercourse as: “a
watercourse, parts of which are situated in different States.”136
93. Bolivia disagrees with Chile’s indiscriminate application of the terms and
definitions of the 1997 UNWC to the Silala. On the one hand, the specifics of the
Silala do not allow a broad application of the definitions for “watercourse” and
“international watercourse” incorporated in this Convention to the Silala as they do
not reflect customary international law on the use of artificially enhanced
watercourses. On the other hand, State practice and case law confirms that an
“international watercourse” only refers to the natural flow of that water body under
customary international law.
94. In order to advance the applicability of the Convention to the specific circumstances
of the Silala, Chile relies on definitions of the term ‘international watercourse’,
which fail to reflect the actual text as finally approved.137 An illustration of this
misrepresentation is Chile’s attempt to include canals in the definition by using a
mere “working hypothesis” adopted by the International Law Commission (ILC) in
1980,138 which was not ultimately accepted.
134 CM, pp. 52-53, paras. 4.3-4.4 and pp. 54-55, paras. 4.7-4.10. See also, implicitly, pp. 1-2, para. 1.3 (a)
and pp. 29, para. 2.17.
135 Report of the Commission to the General Assembly on the Work of its Forty-Sixth Session, The Law of
the Non-Navigational Uses of International Watercourses, UN Doc. A/49/10, Yearbook of the
International Law Commission, 1994, Vol. II (Part Two), p. 90, Draft Article 2 (b).
136 Report of the Commission to the General Assembly on the Work of its Forty-Sixth Session, The Law of
the Non-Navigational Uses of International Watercourses, UN Doc. A/49/10, Yearbook of the
International Law Commission, 1994, Vol. II (Part Two), p. 90, Draft Article 2 (a).
137 CM, p. 52, para 4.3.
138 CM, pp. 52-53, para. 4.3, footnote 106. As Special Rapporteur S. Schwebel noted, “No definite
definition was attempted. Instead, a working hypothesis subject to refinement and change, was
arrived at.” Yearbook of the International Law Commission, 1982, Vol. II, Part 1, p. 68, para. 7.
64
95. In its Commentaries on its 1994 Draft Articles, the ILC referenced “canals” in its
understanding that the components of “system of surface and ground waters” can
include “rivers, lakes, aquifers, glaciers, reservoirs and canals.”139 That statement,
however, was immediately qualified in the next paragraph of the Commentary. The
ILC explained that “certain members of the Commission expressed doubts about the
inclusion of “canals” among the components of a watercourse because, in their
view, the draft had been elaborated on the assumption that a ‘watercourse’ was a
natural phenomenon.”140
96. For example, during the ILC’s 1987 session, Special Rapporteur on the Law of the
Non-Navigational Uses of International Watercourses, Stephen McCaffrey, stated
that “[t]he term ‘international watercourse’ was normally used to refer to a
watercourse created by nature and not to any artificial diversions.”141
97. In the context of non-navigational uses, the definition of watercourse in Article 2 of
the 1994 Draft Articles was described as the “most significant, but also the most
controversial aspect of this part [of the Draft Articles].”142
139 Report of the Commission to the General Assembly on the Work of its Forty-Sixth Session, The Law of
the Non-Navigational Uses of International Watercourses, UN Doc. A/49/10, Yearbook of the
International Law Commission, 1994, Vol. 2 (Part Two), p. 90, Commentary (4) to Article 2
(emphasis added).
140 Report of the Commission to the General Assembly on the Work of its Forty-Sixth Session, The Law of
the Non-Navigational Uses of International Watercourses, UN Doc. A/49/10, Yearbook of the
International Law Commission, 1994, Vol. 2 (Part Two), p. 90, Commentary (5) to Article 2
(emphasis added).
141 Draft Articles proposed by the Drafting Committee, The Law of the Non-Navigational Uses of
International Watercourses, UN Doc. A/CN.4/ L.411, Yearbook of the International Law
Commission, 1987, Vol. I, p. 220, para. 75 (emphasis added).
142 Comments and observations received from Governments, The Law of the Non-Navigational Uses of
International Watercourses, A/CN.4/447 and Add. 1-3, Yearbook of the International Law
Commission, 1993, Vol. II (Part One), p. 165, para. 2 (Poland). The “draft articles” to which Poland
referred to are the 1994 Draft Articles that predated and led to the United Nations Watercourses
Convention.
65
98. As to State practice, the most that can be deduced related to the definition of an
international watercourse is that it limits that definition to the natural flow
contained within the main channel of a river that traverses an international
boundary.143
99. Legal doctrine also disqualifies Chile’s construction of the definition of an
international watercourse. For instance, according to the Max Planck Encyclopedia
of Public International Law:144
“Canals are artificial waterways that for purposes of international
legal regulation (…) must be distinguished from natural waterways
such as international watercourses or international straits (…)”
“Differences in use and in geographical situation make it impossible
to identify general rules of customary international law applicable to
all canals of international concern. (…) Moreover, in most cases the
use and administration of canals serving more than one State or
affecting the interests of more than one State are regulated by way of
a conventional regime. Therefore, the relevant rules are to be
ascertained with reference both to the specific use to which a canal is
dedicated and to the existing treaty provisions applying to it.”
And it continues:
“Internal canals that are totally confined to the territory of one State
are subject to the exclusive sovereignty of that State. Lacking
unilateral or conventional commitment to that effect, there is no
international obligation for a State to build a canal on its territory,
143 A. Tanzi, “The UN Convention on International Watercourses as a Framework for the Avoidance and
Settlement of Waterlaw Disputes,” Leiden Journal of International Law, Vol. 11, Issue 3, 1998, p.
447.
144 M. Arcari, “Canals”, Max Planck Encyclopedia of Public International Law, online version, last
updated October 2007, para. 1 and paras. 4-6 (emphasis added).
66
nor to maintain or operate an internal canal in the interest of other
States.”
“Unlike international watercourses which separate or traverse the
territories of different States, a canal lying across national
boundaries consists of two national sections, each remaining an
internal waterway of the State where it is situated. Yet interested
States can regulate via conventions their respective rights and
obligations relating to transboundary canals.”
100. Chile’s own insistence in the Memorial on the Silala as a natural flow of waters is
consistent with the fact that under general international law, the concept of
international watercourses is generally considered as referring to the natural flow of
waters. On many occasions in the Memorial, Chile puts the emphasis on this natural
element. For instance, Chile alleges that “the waters of the Silala River have flowed
and continue to flow naturally from” Bolivia to Chile145 and that the artificial
installations have nearly no effect on the natural flow.146 In the “summary” of its
case, Chile further states that the Silala is a watercourse because it is a “naturally
flowing body of water.”147 Chile quotes in particular the Note Verbale of 15
September 1999 in which it considered that the Silala is an international watercourse
because it has “a permanent natural runoff” which flows from Bolivia to Chile.148 In
a press release dated 4 March 2002, Chile again “can only reiterate its formal
reservation regarding its rights over the Silala River, due to its nature as a shared
water resource that has its origins in Bolivia and flows naturally into Chilean
145 CM, p. 32, para. 2.26 (emphasis added).
146 CM, p. 32, para. 2.27
147 CM, p. 7, para. 1.16 (a) (emphasis added).
148 CM, pp. 40-41, para. 3.10 (emphasis added).
67
territory.”149 In other paragraphs of the Memorial, Chile refers to the status of the
Silala as a watercourse on the ground that it is “naturally flowing.”150
101. In conclusion, the lack of support and the uncertainty surrounding the inclusion of
artificial canals within the concept of a watercourse indicate that the use of “canals”
by the ILC in its commentaries to the 1994 Draft Articles is not based on customary
international law applicable to international watercourses. Rather, the evidence
indicates that the accepted norm is to exclude artificial conveyance mechanisms like
canals and drainage mechanisms from the scope of customary international law
applicable to transboundary watercourses.
102. The foregoing examination demonstrates that the definitions for “watercourse” and
“international watercourse” proffered by Chile are not supported by the existing
applicable customary international law on the use of transboundary watercourses
when referring to artificially enhanced water flows. Chile’s preferred terminologies
and definitions not only do not apply to the circumstances of the Silala, but are
inconsistent with its official position at the time of the ILC discussions.151
149 Press Release from the Ministry of Foreign Affairs of Chile, 4 March 2002. CM, Vol. 3, Annex 60
(emphasis added).
150 CM, p. 75, paras. 4.37 ff (emphasis added). See also, for instance, CM, p. 90, para. 4.66 (“the Silala is
a watercourse that follows the natural course downhill”), or CM, p. 100, para. 5.23.
151 Chile did not agree with the expression “international watercourse” during the negotiation of the 1997
United Nations Convention. During the debate sessions on Article 2 the Chilean delegation stated
that: “the term ʽwatercourseʼ was confusing, as shown by the fact that some delegations wished to
replace it with ʽriverʼ, which was far too restrictive a term. His delegation proposed that ʽwatercourseʼ
should be replaced by ʽhydrographic systemʼ, ʽinternational watercourseʼ by ʽhydrographic system
with shared water resourcesʼ and ʽwatercourse Stateʼ by ʽState belonging to a hydrographic system
with shared water resourcesʼ”. United Nations, Sixth Committee, Summary Record of the 23rd
meeting, 17 October 1996, A/C.6/51/SR.23, p. 11, para. 78, BCM, Vol. 2, Annex 1.
68
C. Regulation of the Artificially-Enhanced Silala Waters
103. As discussed in Chapter 2 of this Counter-Memorial, the scientific assessment and
factual characteristics of the Silala clearly establish that the Silala, including the
water that emanates from springs located within Bolivia, forms an artificially
enhanced watercourse –one that has been modified by human engineering in a
manner that substantially augments the flow and volume of the water that crosses
the border. Today, the Silala contains both naturally- and artificially-flowing water.
104. Customary international law on the use of transboundary watercourses does not
apply to the artificial components of a watercourse that is wholly or partly artificial.
As already demonstrated, for that legal regime to apply to an artificially created or
enhanced watercourse, there would need to be an agreement between the Parties,
including a compromise on the adjustments required to take into account the
artificial nature of the water body. Unfortunately, Bolivia and Chile thus far have
been unable to reach such an agreement.
105. State practice shows that a watercourse that traverses an international boundary
through artificial means, whether in whole or in part, can only create rights and
obligations under international law through an agreement between two or more
riparian States.152 The same can be said for a manufactured water flow that is
152 M. Arcari, “Canals”, Max Planck Encyclopedia of Public International Law, online version, last
updated October 2007, para. 6 (recognizing that a canal crossing national boundaries effectively
consists of two national sections, with each maintaining its domestic waterway character in the State
where it is situated). In addition, Article 5, of the International Law Association’s 1980 Regulation of
the Flow of Water of International Watercourses provides: “The construction of dams, canals,
reservoirs or other works and installations and the operation of such works and installations required
for regulation by a basin State in the territory of another can be carried out only by agreement
between the basin States concerned.” (International Law Association, Report of the fifty-ninth
conference, Belgrade, 1980 (Resolution of approval, p. 4; Report of the Committee on the
International Water Resources Law, Part II-Regulation of the flow of water of international
watercourses, pp. 362-373; Rapporteur: Judge E. J. Manner)). Similarly, Article 3 of the 1923
69
diverted into either a natural or artificial waterway traversing an international
border. Absent an agreement authorizing the transfer of artificial water across the
frontier, the State from whose territory the water originates has no obligation under
international law to implement or maintain such a conveyance.
106. Moreover, when an agreement for such a transfer of manufactured water is
terminated or is otherwise no longer operational, States have no obligation under
international law to maintain the artificial drainage and other infrastructure within
their territory for the benefit of other States.153 As demonstrated elsewhere in this
Counter-Memorial154 the Parties made an attempt to agree on the nature and the use
of the Silala waters. However, given the absence of such an agreement in the present
case, Bolivia has the sole authority to decide on the artificial channels and drainage
mechanisms within its sovereign territory.
107. This perspective on engineered flows and infrastructure and national sovereignty
has long been recognized in customary international law. In its judgment on
Diversion of Water from the Meuse, the Permanent Court of International Justice
concluded:
“The Court finds nothing either in the arguments of the Netherlands
or in the text of the Treaty of 1863 which would prevent either the
Netherlands or Belgium from making such use as they may see fit of
the canals covered by the Treaty in so far as concerns canals which
Convention relating to the Development of Hydraulic Power affecting more than one State provides:
“If a Contracting State desires to carry out operations for the development of hydraulic power, partly
on its own territory and partly on the territory of another Contracting State or involving alterations on
the territory of another Contracting State, the States concerned shall enter into negotiations with a
view to the conclusion of agreements which will allow such operations to be executed.”
153 Diversion of Water from the Meuse (Netherlands v. Belgium), Judgment, 28 June 1937, P.C.I.J. Series
A/B No. 70, p. 26; see also Art 5, of the International Law Association’s 1980 Regulation of the Flow
of Water of International Watercourses.
154 BCM, paras. 36-40.
70
are situated in Netherlands or Belgian territory, as the case may be,
and do not leave that territory. As regards such canals, each of the
two States is at liberty, in its own territory, to modify them, to
enlarge them, to transform them, to fill them in and even to increase
the volume of water in them from new sources.”155
108. Further, State practice abundantly shows that dam and hydroelectric facilities
constructed along international watercourses needed the conclusion of a formal
agreement authorizing the creation of those structures, or engaging the Parties in
negotiation over expected benefits and detriments.156 These agreements govern the
155 Diversion of Water from the Meuse (Netherlands v. Belgium), Judgment, 28 June 1937, P.C.I.J. Series
A/B No. 70, p. 26.
156 For example, Amistad Dam and Falcon Dam on the Rio Grande, which forms the border between
Mexico and the United States, are managed jointly by both countries under the Treaty between the
United States of America and Mexico relating to the utilization of the Waters of the Colorado and
Tijuana Rivers and of the Rio Grande (3 February 1944), along with supplemental Minutes Nos. 182,
187, 190, 192, 199, 202, 205, 207, 210, 213, 215, 232, 235, 292, and 308. The Kariba Dam on the
Zambezi River is owned and operated equally by Zimbabwe and Zambia through the Zambezi River
Authority under Agreement between the Republic of Zimbabwe and the Republic of Zambia
concerning the utilization of the Zambezi River (28 July 1987), with Annexure I (Article 22).
Working arrangements for the operation and maintenance of the interconnected systems, and
Annexure I (Article 23). Working arrangements for the sharing of energy from Kariba Dam. The
Columbia River Agreement entered into by Canada and the United States implemented three dams in
British Columbia, Canada (Duncan Dam, Mica Dam, and Keenleyside Dam) and one in Montana in
the United States (Libby Dam) providing a complex series of power generation, flood control and
water storage benefits. Treaty relating to cooperative development of the water resources of the
Columbia River Basin (17 January 1961); Exchange of Notes Constituting an Agreement between
Canada and the United States of America regarding Disposal within the United States of the Canadian
Entitlement to Downstream Power Benefits Under the Columbia River Treaty (31 March 1999);
Exchange of Notes Constituting an Agreement between Canada and the United States of America
regarding Sale of Canada’s Entitlement to Downstream Benefits Under the Treaty Relating to Cooperative
Development of the Water Resources of the Columbia River Basin (17 November 1961);
Exchange of Notes Constituting An Agreement Between Canada and the United States of America
Authorizing the Canadian Entitlement Purchase Agreement Provided for Under the Treaty Relating to
Co-Operative Development of the Water Resources of the Columbia River Basin (17 January 1961
and 16 September 1964). While the treaty between Brazil and Paraguay on the Parana River that
resulted in the Itaipú Dam and its vast energy generation capacities sparked several disputes with
Argentina, the Three Party Corpus and Itaipú Treaty between Argentina, Brazil and Paraguay
eventually resolved those differences. Treaty of Itaipú between Brazil and Paraguay (26 April 1973);
Argentina-Brazil-Paraguay: Agreement on Parana River Projects. Done at President Stroessner City,
71
artificial aspects that have been implemented, including the location of artificial
infrastructure, management of the engineered works, and rates and volumes of
artificial flows. While customary international legal norms apply to those
components of the watercourse that remain natural, the agreements apply to those
aspects that are the product of human engineering.
D. Final Remarks
109. As demonstrated by the various expert reports, the Silala springs and waters today
are part of an artificially enhanced watercourse that includes both naturally and
artificially flowing water.157 The artificial infrastructure and drainage mechanisms
installed within Bolivia’s borders have modified Bolivia’s Silala springs and
bofedales and enhanced the rate and volume of flow of Silala water coursing from
Bolivia into Chile.158
110. As such, the Silala and its waters are not governed exclusively by customary
international law on the use of transboundary watercourses. Rather, that law is
relevant only to the rate and volume of Silala water that flows naturally across the
Bolivian-Chilean border. In contrast, given the absence of an agreement between
Bolivia and Chile on the management or distribution of the Silala and its waters,
Bolivia has full rights and authority over the artificially created flows and volumes
of Silala water coursing across that frontier.
Paraguay (19 October 1979). The Indus Waters Treaty is a water distribution agreement between
India and Pakistan that, when entered into in 1960, took into account existing and future artificial
diversions, enhancements, and modifications to the river and its tributaries. Indus Waters Treaty 1960
Between the Government of India, the Government of Pakistan and the International Bank for
Reconstruction and Development. Signed at Karachi (19 September 1960).
157 BCM, Chapter 2.
158 BCM, Chapter 2.
72
111. In addition, absent a specific obligation or agreement to the contrary, States have no
obligation to maintain artificial infrastructure within their territory for the benefit of
other States. Accordingly, Bolivia may decide whether and how to maintain the
artificial channels and drainage mechanisms within its sovereign territory.
73
CHAPTER 4
LEGAL CONSEQUENCES OF THE SILALA
AS AN ARTIFICALLY ENHANCED WATERCOURSE
112. Having demonstrated in the previous Chapters that the Silala springs and waters are
part of an artificially enhanced watercourse, and that therefore the rules invoked by
Chile do not apply to the artificially flowing Silala waters, the present Chapter will
discuss the legal consequences arising from the nature of the Silala as an artificially
enhanced watercourse.
113. Chile acknowledges in the Memorial that, once the status of the Silala is clarified, it
would not be over-complicated for the Parties to agree on suitable rules for the
management of the Silala. Chile states:
“It is Chile’s position that, once the status of the Silala River has
been confirmed, the issues of use and restrictions on use can be
decided with little difficulty.”159
114. Bolivia agrees with Chile’s statement, which echoes the discussions and joint works
that the Parties initiated after 1999 to identify the nature of the Silala waters and the
efforts they made to reach an initial agreement on their use, which unfortunately has
not yet been concluded.160
115. In the face of Chile’s indiscriminate treatment of the Silala waters, the present
Chapter will clarify the different and separate legal regimes that must be considered
and that Chile systematically ignores. First, Bolivia has full sovereignty over the use
of the artificial flow of waters which in absence of an agreement between Bolivia
159 CM, p. 4, para. 1.6.
160 BCM, paras. 27-40.
74
and Chile is to be regulated by Bolivian domestic law. Second, given the absence of
an agreement between Bolivia and Chile on the naturally flowing waters of the
Silala, these are regulated by customary international law. Unless an agreement is
reached by the two States crafting a different set of rules for the ad hoc management
of any component of or the entire Silala and its waters, which comprise water that
flows naturally as well as water that is the result of artificial engineering, these two
different and separate legal regimes each apply to the overall management of this
unique and fragile, artificially enhanced watercourse.
116. Contrary to its present position, the application of two such distinct regimes was
acknowledged by Chile in 1997. As was reported on 17 May 1997, at that time,
Chile considered the annulment of the Concession on the Silala161 as an issue
governed by domestic law, not international law:
“The Chilean Government said last night that there is no controversy
with the Government of Bolivia regarding the use of the Silala River
waters that supply the northern populations of our country and said
that the issue is subject to a contract of International Private Law,
which should be discussed in those terms. (…) According to the
acting Minister of Foreign Affairs, Mariano Fernández, this is a
contract of International Private Law and therefore follows the rules
of all contracts. (…) “For now I have to say that there is no
161 Administrative Resolution No 71/97 by the Prefecture of the Department of Potosi, 14 May 1997,
CM, p. 32, para. 2.24. CM, Vol. 3, Annex 46. The concession was revoked and annulled in 1997 on
the grounds that its object, cause and purpose disappeared “by decisive supervening factors, such as
the technological conversion of the locomotives of the concessionaire company, eliminating their
need for water, for the steam power that previously propel them, to which must be added the nonexistence
of the concessionaire itself as an active corporate in Bolivian territory” and that “there has
been evidence of the improper use of said waters by third Parties outside the granting of their use,
with prejudice to the interests of the State and in clear violation of Articles 136 and 137 of the State
Political Constitution.” For the Bolivian Supreme Decree N° 24660, 20 June 1997, see BCM, Vol. 2,
Annex 13.
75
controversy between the Bolivian Government and the Chilean
Government in this matter.”162
A. The Right to Equitable and Reasonable Utilization of Naturally-Flowing Silala
Waters
117. In its Application and Memorial, Chile requests the Court to adjudge and declare
that “Chile is entitled to the equitable and reasonable use of the waters of the Silala
River system in accordance with customary international law.”163 It also requests the
Court to declare that – pursuant to the “standard of equitable and reasonable
utilization – Chile is entitled to its current use.”164 The latter request, if accepted,
could impede the exercise by Bolivia of its right under international law to make use
of the waters of the Silala in the future.
118. With respect to the equitable and reasonable utilization of the Silala waters, Bolivia
considers that Chile’s submissions should be dismissed as they purport to apply to
all the Silala waters, including those artificially flowing. In addition, Chile’s
submissions should be dismissed to the extent that they only concern Chile’s rights
and disregard Bolivia’s rights. Chile’s current use of naturally flowing Silala waters
can be recognized only where and to the extent that Bolivia’s right to an equitable
and reasonable use of these waters is not prejudiced.
119. Starting with the first claim according to which “Chile is entitled to the equitable
and reasonable utilization of the waters of the Silala River system in accordance
with customary international law,” Bolivia agrees with Chile that the principle of
162 El Mercurio, “Clarification from the Chilean Chancellery: There is no conflict with Bolivia over the
Silala River,” Santiago, 17 May 1997. BCM, Vol. 6, Annex 15.
163 Application, p. 22, para. 50 b); CM, p. 107, b).
164 Application, p. 22, para. 50 c); CM, p. 107, c).
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equitable and reasonable use, as reflected in Articles 5 and 6 of the UNWC,165 is “a
cornerstone” of the law on international watercourses.166 In practical terms, “[w]hat
is an equitable and reasonable utilization in a specific case will (…) depend on a
weighing of all relevant factors and circumstances.”167 As emphasized by Chile in
its Memorial, the equitable and reasonable utilization is a “flexible standard that
must be adapted to fit the facts and circumstances of each case.”168 The rule
reflected in Article 6 of the UNWC presents an indicative and non-exhaustive list of
factors that must be taken into account in determining the equitable and reasonable
utilization of an international watercourse.169 Moreover, all factors need to be
165 Article 5 of the UNWC provides:
“1. Watercourse States shall in their respective territories utilize an international watercourse in an
equitable and reasonable manner. In particular, an international watercourse shall be used and
developed by watercourse States with a view to attaining optimal and sustainable utilization thereof
and benefits therefrom, taking into account the interests of the watercourse States concerned,
consistent with adequate protection of the watercourse. 2. Watercourse States shall participate in the
use, development and protection of an international watercourse in an equitable and reasonable
manner. Such participation includes both the right to utilize the watercourse and the duty to cooperate
in the protection and development thereof, as provided in the present Convention.”
166 CM, p. 93, para. 5.6.
167 Report of the Commission to the General Assembly on the Work of its Forty-Sixth Session, The Law of
the Non-Navigational Uses of International Watercourses, UN Doc. A/49/10, Yearbook of the
International Law Commission, 1994, Vol. II (Part Two), p. 101, Commentary 1 to Article 6.
168 CM, p. 94, para. 5.9.
169 A non-exhaustive list of applicable factors is articulated in Article 6 of the UNWC under the title of
“Factors relevant to equitable and reasonable utilization:”
“1. Utilization of an international watercourse in an equitable and reasonable manner within the
meaning of article 5 requires taking into account all relevant factors and circumstances, including:
(a) Geographic, hydrographic, hydrological, climatic, ecological and other factors of a natural
character;
(b) The social and economic needs of the watercourse States concerned;
(c) The population dependent on the watercourse in each watercourse State;
(d) The effects of the use or uses of the watercourses in one watercourse State on other watercourse
States;
(e) Existing and potential uses of the watercourse;
(f) Conservation, protection, development and economy of use of the water resources of the
watercourse and the costs of measures taken to that effect;
(g) The availability of alternatives, of comparable value, to a particular planned or existing use.”
77
considered together and no factor is to be given priority,170 although “special
regard” should be “given to the requirements of vital human needs.”171
120. On the other hand, Bolivia disagrees with Chile with regard to the scope of
application of this principle in the present case. Bolivia considers that both Chile
and Bolivia are each entitled to equitable and reasonable use, but only in relation to
the naturally flowing waters of the Silala. In contrast, as explained previously in this
Counter-Memorial,172 Bolivia has full sovereignty over the artificial flow of waters
of the Silala on the ground that, absent any drainage and channelization
mechanisms, waters that are mechanically induced or created would not naturally
flow to the territory of Chile. The principle of equitable and reasonable use under
customary international law does not apply to the artificial flow of the Silala waters.
121. A further consequence of Bolivia’s sovereignty over the artificial flow of waters of
the Silala is that any use of such flow by Chile depends on Bolivia’s consent.173
170 While the relative weight of the various factors is not delineated in the principle, the ILC asserted
that: “[s]ome of the factors listed may be relevant in a particular case while others may not be, and
still other factors may be relevant which are not contained in the list. No priority or weight is assigned
to the factors and circumstances listed, since some of them may be more important in certain cases
while others may deserve to be accorded greater weight in other cases.” Report of the Commission to
the General Assembly on the Work of its Forty-Sixth Session, The Law of the Non-Navigational Uses
of International Watercourses, UN Doc. A/49/10, Yearbook of the International Law Commission,
Vol. II (Part Two), 1994, p. 101, Commentary 3 to Article 6 (emphasis added).
171 Art. 10 of the UNWC provides: “1. In the absence of agreement or custom to the contrary, no use of
an international watercourse enjoys inherent priority over other uses, 2. In the event of a conflict
between uses of an international watercourse, it shall be resolved with reference to articles 5 to 7, with
special regard being given to the requirements of vital human needs” (emphasis added).
172 BCM, Chapter 3.
173 BCM, Chapter 6. It is important to point out that during the negotiation of the 1997 United Nations
Convention, Chile maintained a favorable position for the States to exercise sovereignty over the part
of a watercourse located in their territory. For example, in the explanation of its vote for the approval
of the draft Convention, the Delegation of Chile stated that it “[...] had voted in favour of the draft
Convention, despite its reservations with regard to some of its provisions. For example, the deletion
of the reference to the sovereignty of the watercourse States over the part of the watercourse situated
in their national territory was a serious omission, since the principle of State sovereignty was the
point of departure for the whole process.” See: United Nations, Sixth Committee, Summary Record of
78
B. Current Use of the Silala Waters by Chile
122. Chile’s second claim relating to equitable and reasonable utilization requests the
Court to adjudge and declare that: “Under the standard of equitable and reasonable
utilization, Chile is entitled to its current use of the waters of the Silala River.”174
123. A literal interpretation of this claim seems to suggest that Chile requests the Court to
declare that the use of the Silala it currently enjoys should be secured in perpetuity.
In other words, it suggests that the current rate and volume of water flow from
Bolivia to Chile should not be subject to future modification and that any
subsequent alteration in favor of Bolivia violates Chile’s right to its Court-adjudged
equitable and reasonable current use. Such claim is plainly contrary to international
law and violates Bolivia’s equal right to an equitable and reasonable share of the
naturally-flowing waters of the Silala, as well as its exclusive rights over the
artificial flow of Silala waters. This leads to the result that a State (in this case
Chile) would be able to “unilaterally assum[e] control of a shared resource, and
thereby depriv[e] [another State] of its right to an equitable and reasonable share of
the natural resources of the [shared resource].”175 This position is clearly untenable.
the Second Part of the 62nd meeting, 4 April 1997, A/C.6/51/SR.62/Add.1, pp. 6-7, para. 24. BCM,
Vol. 2, Annex 3.
174 Application, p. 22, para. 50 c); CM, p. 107, c).
175 Gabcikovo-Nagymaros Project (Hungary/Slovakia), Judgment, I.C.J. Reports 1997, p. 56, para. 85.
This quotation is relied on by Chile in its Memorial at para. 5.3. In most cases, it is upstream States
whose actions are challenged for possible violations of international law in relation to alleged harm to
a downstream State. However, if a downstream State were to follow the interpretation suggested
above, it would effectively foreclose any future use of the transboundary watercourse by the upstream
State. That foreclosure of use, in turn, could be deemed to cause harm to the upstream State by
impeding that upper riparian from enjoying its right to use the waters in an equitable and reasonable
manner. See S. Salman, “Downstream Riparians Can Also Harm Upstream Riparians: The Concept of
Foreclosure of Future Uses”, Water International, 2010, pp. 350-364.
79
124. In the Memorial, Chile admits that Bolivia equally has rights to reasonable and
equitable use:
“(…) once the Silala River is held to be an international watercourse,
shared by Bolivia and Chile, each of those States has this “basic
right” and obligation of equitable and reasonable utilization of its
waters.”176
125. Equitable and reasonable utilization is a flexible principle not only because it is
context-specific,177 but also because it can change over time depending on new
circumstances, needs, and uses of the international watercourse that riparian States
may justify.
126. Indeed, according to Chile’s own interpretation, the equitable and reasonable nature
of its current use of the waters of the Silala depends on the absence of counterpoised
uses in Bolivia. As Chile asserts in its Memorial,
“In the absence of countervailing uses in Bolivia, it inevitably
follows that all use by Chile, as downstream riparian State, of the
170 l/s flow of the Silala River that crosses the international
boundary from Bolivia into Chile, has been, and cannot but be,
equitable and reasonable vis-à-vis Bolivia.”178
127. Moreover, if Bolivia were to exercise its right to a reasonable and equitable use of
the naturally flowing waters of the Silala in the future, Chile would then not be
176 CM, p. 93, para. 5.5 (emphasis added). See also CM, p. 92, para. 5.3: “[i]n accordance with the
principle of equitable and reasonable utilization, Chile has the right to utilize the waters of the Silala
and to be free from significant harm caused by Bolivia. Chile also has corresponding obligations
owed to Bolivia. Bolivia has the same rights, as well as corresponding obligations owed to Chile”
(emphasis added).
177 BCM, para. 119.
178 CM, p. 96, para. 5.13.
80
entitled to the entirety of its current use of the naturally flowing waters. Otherwise,
Bolivia would effectively be impeded from using the naturally flowing waters of the
Silala.
128. Interpreting Chile’s request to the Court to mean that any future action taken by
Bolivia would be unlawful if it negatively impacted the natural flow of water into
Chile would be contrary to international law. As set out above,179 this cannot be
right.
129. In light of the above, Bolivia concludes with respect to the claims made by Chile in
the Application and Memorial in relation to the equitable and reasonable use of the
Silala waters that:
a) Customary international rules on the use of international watercourses do not
apply to the artificially-flowing Silala waters;
b) Bolivia and Chile are each entitled to the equitable and reasonable utilization of
the naturally-flowing Silala waters in accordance with customary international
law;
c) The current use of the naturally-flowing Silala waters by Chile is without
prejudice to Bolivia’s ongoing right to an equitable and reasonable use of these
waters.
179 BCM, para. 118.
81
C. Obligation of the Parties to Take Appropriate Measures to Prevent Significant
Transboundary Environmental Harm
130. In its Submissions, Chile has asked the Court to adjudge and declare that “Bolivia
has an obligation to take all appropriate measures to prevent and control pollution
and other forms of harm to Chile resulting from its activities in the vicinity of the
Silala River.”180
131. Chile’s claim, however, is not consistent. In Chapter 5 of the Memorial, Chile
advances a different, narrower claim, according to which “Bolivia is under an
obligation to take all appropriate measures to prevent the causing of significant
harm to Chile.”181 According to Chile, that obligation (“to prevent the causing of
significant harm”) is based on the “rule enshrined in Article 7 of the UNWC” and
applies to “States sharing an international watercourse.”182
132. Chile also invokes “measures Bolivia must take to give full effect to article 7 of the
UNWC.”183 Yet, in another paragraph of the same section of the Memorial, Chile
contends that Bolivia has an obligation to prevent “any other kind of harm in
Chile”184 and requests the Court to “reaffirm that Bolivia has an obligation to take
all appropriate measures to prevent and control pollution and other forms of harm to
Chile resulting from the activities in the vicinity of the Silala River.”185 In addition,
Chile invokes Article 7 of the UNWC to claim the existence of an obligation not to
carry out activities “in the vicinity of the Silala” which may affect the quality of the
180 Application, p. 22, para. 50 d); Memorial, p. 107, Submission d).
181 CM, p. 96, section C (emphasis added).
182 CM, p. 96, para. 5.14.
183 CM, p. 97, para. 5.17.
184 CM, p. 97, para. 5.16.
185 CM, p. 97, para. 5.17 (emphasis added).
82
waters,186 while said Article 7 only concerns significant harms resulting from the
utilization of the international watercourse.
133. Chile’s claim, as it is articulated in the Submissions of the Memorial, should be
dismissed. Bolivia is not bound by the UNWC as such, but only by those provisions
that reflect customary international law. In addition, the law on international
watercourses only applies to the naturally-flowing waters of the Silala. Since the
Silala springs and waters are part of an artificially enhanced watercourse, customary
international rules on the use of international watercourses do not apply to the
artificially flowing Silala waters.
134. Moreover, the ‘no significant harm’ principle applies under customary international
law only to significant environmental harms and not, as Chile alleges in its
Submissions, to “prevent and control pollution and other forms of harm” without
qualifications. The ‘no significant harm’ principle is deeply rooted in international
environmental law. In Legality of the Threat or Use of Nuclear Weapons, the Court
applied to the environment the latin maxim sic utere tuo ut alienum non laedas187
and asserted that:
“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 control is
186 CM, p. 97, paras. 5.16-5.17.
187 The maxim reads as “Use your own property in such a way that you do not injure other people’s”
according to J. Law and E. A. Martin, A Dictionary of Law, 7th ed., Oxford University Press, 2014.
An early decision of the Court referred to this maxim, although not in an environmental context: “It is
every State’s obligation not to allow knowingly its territory to be used for acts contrary to the rights
of other States” (Corfu Channel (United Kingdom v. Albania), Merits, Judgment, ICJ Reports 1949,
p. 22).
83
now part of the corpus of international law relating to the
environment.”188
135. According to the Court, the scope and content of the rule is clear:
“As the Court restated in the Pulp Mills case, under customary
international law, “[a] State is (…) obliged to use all the means at its
disposal in order to avoid activities which take place in its territory,
or in any area under its jurisdiction, causing significant damage to
the environment of another State” (I.C.J. Reports 2010 (I), p. 56,
para. 101; see also Legality of the Threat or Use of Nuclear
Weapons, Advisory Opinion, I.C.J. Reports 1996 (I), pp. 241-242,
para. 29).”189
136. All cases involving environmental questions before this Court over the past twenty
years have referred to the ‘no significant harm’ rule as reflecting customary
international law.190
137. The obligation to prevent such significant harm is not absolute, it is a due diligence
obligation couched in terms of taking “all appropriate measures.” According to the
ILC:
“The obligation of due diligence contained in article 7 sets the
threshold for lawful State activity (…) It is an obligation of conduct,
188 Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, I.C.J. Reports 1996, pp. 241-
242, para. 29.
189 Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v. Nicaragua) and
Construction of a Road in Costa Rica along the San Juan River (Nicaragua v. Costa Rica), Judgment,
I.C.J. Reports 2015, pp. 711-712, para. 118.
190 Gabcikovo-Nagymaros Project (Hungary/Slovakia), Judgment, I.C.J. Reports 1997, pp. 67-68, para.
112; Case concerning Pulp Mills on the River Uruguay (Argentina v Uruguay), Judgment, I.C.J.
Reports 2010, p. 78, para. 193; Certain Activities Carried Out by Nicaragua in the Border Area
(Costa Rica v. Nicaragua) and Construction of a Road in Costa Rica along the San Juan River
(Nicaragua v. Costa Rica), Judgment, I.C.J. Reports 2015, pp. 711-712, para. 118.
84
not an obligation of result. What the obligation entails is that a
watercourse State whose use causes significant harm can be deemed
to have breached its obligation to exercise due diligence so as not to
cause significant harm only when it has intentionally or negligently
caused the event which had to be prevented or has intentionally or
negligently not prevented others in its territory from causing that
event or has abstained from abating it.”191
138. The due diligence nature of the ‘no significant harm’ obligation was confirmed by
the Court in Pulp Mills. In that case, the Court maintained that it was “an obligation
to act with due diligence in respect of all activities which take place under the
jurisdiction and control of each party.”192 Such an obligation is breached if a State
“fail[s] to act diligently and thus take all appropriate measures to enforce its relevant
regulations on a public or private operator under its jurisdiction.”193 Evidence
supporting the due diligence nature of the ‘no significant harm’ rule and its
consequences can be found also in the ILC Draft Articles on the Prevention of
Transboundary Harm from Hazardous Activities.194
191 Report of the Commission to the General Assembly on the Work of its Forty-Sixth Session, The Law of
the Non-Navigational Uses of International Watercourses, UN Doc. A/49/10, Yearbook of the
International Law Commission, 1994, Vol. II (Part Two), p. 103, para. 4.
192 Pulp Mills on the River Uruguay (Argentina v. Uruguay), Judgment, I.C.J. Reports 2010, p. 79, para.
197. The Court further clarifies that “[i]t is an obligation which entails not only the adoption of
appropriate rules and measures, but also a certain level of vigilance in their enforcement and the
exercise of administrative control applicable to public and private operators, such as the monitoring of
activities undertaken by such operators, to safeguard the rights of the other party.”
193 Pulp Mills on the River Uruguay (Argentina v. Uruguay), Judgment, I.C.J. Reports 2010, p. 79, para.
197.
194 “The obligation of the State of origin to take preventive or minimization measures is one of due
diligence. It is the conduct of the State of origin that will determine whether the State has complied
with its obligation under the present articles. The duty of due diligence involved, however, is not
intended to guarantee that significant harm be totally prevented, if it is not possible to do so. In that
eventuality, the State of origin is required, as noted above, to exert its best possible efforts to
minimize the risk. In this sense, it does not guarantee that the harm would not occur.” Commentary to
Draft Article 3, para. 7, Draft Articles on Prevention of Transboundary Harm from Hazardous
Activities, U.N. Doc A/56/10, Yearbook of the International Law Commission, 2001, Vol. II, Part
Two, p. 154.
85
139. In conclusion, only the use of the naturally flowing waters of the Silala is regulated
by customary international law on the use of international watercourses. The ‘no
significant harm’ principle under customary international law only applies to
significant harm. This principle applies to both States. Bolivia accordingly requests
the Court to dismiss Chile’s claim and to declare that Bolivia and Chile each have
an obligation under customary international law to take all appropriate measures to
prevent the causing of significant transboundary environmental harm.
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CHAPTER 5
ABSENCE OF BREACH OF THE OBLIGATION TO NOTIFY AND CONSULT
140. In its Memorial, Chile alleges that Bolivia violated the procedural obligations to
provide Chile with timely notification of any planned measures which may have an
adverse effect on the shared water resource and to exchange data and information in
relation to these measures.195 Chile’s submission requests the Court to declare that
“Bolivia has breached (…) its obligations to notify and consult” without asking for
any other remedies.196 In this Chapter, Bolivia will demonstrate that Chile did not
establish such a breach.
A. Bolivia Replied to Chile’s Requests on Matters Regarding the Silala Waters
141. According to Chile, “Bolivia has announced certain measures including in May
2012 the construction of a fish farm, a dam and a mineral water bottling plant while,
more recently, it has constructed ten houses close to the river.” 197 It continues:
195 In summarizing its claims in the Memorial, Chile describes “the legal consequences that flow from
the status of the Silala River as an international watercourse.” It identifies one of those consequences
as follows: “The third consequence is that Bolivia is also subject to a series of procedural obligations.
It has an obligation to cooperate and to provide Chile with timely notification of any planned
measures which may have an adverse effect on the shared water resource, to exchange data and
information and to conduct, where appropriate an environmental impact assessment, in order to
enable Chile to evaluate the possible effects of any such planned measures (...)” (CM, pp. 8-9, para.
1.17, c)) (emphasis added). In its Submissions, Chile asserts under Submission e) that: “Bolivia has
an obligation to cooperate and to provide Chile with timely notification of planned measures which
may have an adverse effect on shared water resources, to exchange data and information and to
conduct where appropriate an environmental impact assessment, in order to enable Chile to evaluate
the possible effects of such planned measures. Obligations that Bolivia has breached so far as
concerns its obligation to notify and consult Chile with respect to activities that may affect the waters
of the Silala River or the utilization thereof by Chile” (CM, p. 107, Submission e)) (emphasis added).
196 CM, p. 107, Submission e). At p. 6, paras. 1.13 and p. 105, paras. 6.1-6.2 of the Memorial, Chile
mentions reparation and restitution. But it then indicates (para. 6.1) that it considers that its rights
“will be adequately protected by a series of declaratory orders.”
197 CM, p. 10, para. 1.17 c).
87
“Given the relatively low flow of the Silala River, and its location in
such an arid area, such measures might readily have an adverse
effect on the shared water resource. However, although Chile has
repeatedly sought information from Bolivia as to the nature and
extent of the measures announced and has specifically sought
information with respect to the use of the river for sanitary
arrangements with respect to the recent new constructions, Bolivia
has provided no substantive response.”198
142. In the same paragraph, Chile specifies:
“Until such time as Bolivia provides information showing the
absence of risk of adverse impact and/or confirmation that the
announced measures will not in fact proceed, Chile considers that
Bolivia is in breach of its procedural obligations and seeks a
declaration accordingly.”199
143. Chile maintains in its Memorial that on 7 May 2012 it requested information from
Bolivia but that Bolivia never replied.200 This is not correct. Chile omits to mention
that in a Note Verbale dated 24 May 2012, Bolivia responded that “the Government
of Chile is once again invited to carry out a joint visit to that region.”201 In
concluding its Note, Bolivia stated that “in accordance with a culture of dialogue
(…) [it] expresses its willingness to continue exploring the necessary instances that
lead to a common understanding to continue moving forward in the treatment of the
matter.”202
198 CM, p. 10, para. 1.17 c).
199 CM, p. 10, para. 1.17 c).
200 CM, p. 98, para. 5.19.
201 Note No VRE-DGRB-UAM-009901/2012 from the Ministry of Foreign Affairs of Bolivia to the
General Consulate of Chile in La Paz, 24 May 2012, BCM, Vol. 2, Annex 12.
202 Note No VRE-DGRB-UAM-009901/2012 from the Ministry of Foreign Affairs of Bolivia to the
General Consulate of Chile in La Paz, 24 May 2012, BCM, Vol. 2, Annex 12.
88
144. Chile itself acknowledges this reply when on 9 October 2012 Chile accepts this
invitation and expressed its wish to “concretize this activity as soon as possible,”
indicating the need for agreement on the dates, delegation members and their
mandate.203 Contrary to what Chile alleges, Bolivia again responded by Note
Verbale of 25 October 2012 stating:
“With respect to the invitation of 13 September 2011, made by the
Government of the Plurinational State of Bolivia to carry out a “Joint
Visit” to said region, the Ministry of Foreign Affairs deems that it
should be coordinated and planned with the “Chile-Bolivia Political
Consultations Mechanism”, wherein this matter can be jointly
pursued.”204
145. It should be noted that at this time the Parties were already in disagreement on the
nature of the Silala waters205 and had already agreed, in particular in 2004, to
proceed to joint studies and to discuss the matter in order “to determine the nature,
origin and flow of the waters of the Silala.”206 As Chile points out in the Memorial,
Bolivia’s position at that time, as expressed in the letters responding to Chile’s
request for information, was that the waters of the Silala as a whole do not qualify as
an international watercourse.207
203 Note N° 389/149 from the General Consulate of Chile in La Paz to the Ministry of Foreign Affairs of
Bolivia, 9 October 2012, CM, Vol. 2, Annex 35.
204 Note No VRE-DGRB-UAM-020663/2012 from the Ministry of Foreign Affairs of Bolivia to the
General Consulate of Chile in La Paz, 25 October 2012, CM, Vol. 2, Annex 36.
205 BCM, paras. 26-37.
206 CM, p. 46, para. 3.22. In the two letters of May and October 2012 through which Chile requested
information, Chile reaffirmed the need “to continue developing studies, field observations and joint
works related to” the waters of the Silala (Annex 34) and called for “a future visit to carry out field
observations and schedule joint works” (Annex 35). See Note N° 199/39 from the General Consulate
of Chile in La Paz to the Ministry of Foreign Affairs of Bolivia, 7 May 2012, CM, Vol. 2, Annex 34;
Note N° 389/149 from the General Consulate of Chile in La Paz to the Ministry of Foreign Affairs of
Bolivia, 9 October 2012, CM, Vol. 2, Annex 35.
207 CM, pp. 47-48, paras. 3.27-3.29 and p. 98, para. 5.20.
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146. It should be emphasized that, even though both Parties disagreed on the status and
nature of the waters, Bolivia in response to Chile’s requests for information
repeatedly stated in various Notes Verbales sent to Chile between January 2013 and
April 2014, that:
“(…) in accordance with the culture of dialogue that characterises
the Plurinational State of Bolivia, the Ministry of Foreign Affairs
expresses its predisposition to begin conversations about this and
other bilateral topics through the Political Consultations Mechanism
that was agreed by our Governments.”208
147. It is thus not true to allege, as Chile does, that Bolivia repeatedly “fail[s] to respond
to requests from Chile for information.”209 This is simply incorrect. In addition,
Bolivia’s proposal was consistent with the view that it is necessary “to create the
conditions for successful co-operation between the parties.”210 Chile never replied to
Bolivia on this issue.211
208 Note N° VRE-DGLF-UMA-000715/2013 from the Ministry of Foreign Affairs of Bolivia to the
General Consulate of Chile in La Paz, 17 January 2013, CM, Vol. 2, Annex 37.2 (emphasis added).
See also Note No VRE-DGLF-UMA-008107/2013 from the Ministry of Foreign Affairs of Bolivia to
the General Consulate of Chile in La Paz, 9 May 2013, CM, Vol. 2, Annex 37.4; Note No VREDGLF-
UMA-017599/2013 from the Ministry of Foreign Affairs of Bolivia to the General Consulate
of Chile in La Paz, 2 October 2013, CM, Vol. 2, Annex 37.6; Note No VRE-DGLF-UMA-
020899/2013 from the Ministry of Foreign Affairs of Bolivia to the General Consulate of Chile in La
Paz, 19 November 2013, CM, Vol. 2, Annex 37.8; Note No VRE-DGLF-UMA-022856/2013 from
the Ministry of Foreign Affairs of Bolivia to the General Consulate of Chile in La Paz, 16 December
2013, CM, Vol. 2, Annex 37.10; Note No VRE-DGLFAIT-UAIT-Nv-7/2014 from the Ministry of
Foreign Affairs of Bolivia to the General Consulate of Chile in La Paz, 19 February 2014, CM, Vol.
2, Annex 37.12; and Note No VRE-DGLFAIT-UAIT-Cs-136/2014 from the Ministry of Foreign
Affairs of Bolivia to the General Consulate of Chile in La Paz, 10 April 2014, CM, Vol. 2, Annex
38.2.
209 CM, p. 103, paras. 5.31-5.32.
210 Pulp Mills on the River Uruguay (Argentina v. Uruguay), Judgment, I.C.J. Reports 2010, p. 58, para.
113; see also p. 59, para. 115.
211 Note No 003933 from the Ministry of Foreign Affairs of Chile to the General Consulate of Bolivia in
Santiago, 9 April 2013, CM, Vol. 2, Annex 37.3; Note No 269/134 from the General Consulate of
Chile in La Paz to the Ministry of Foreign Affairs of Bolivia, 25 September 2013, CM, Vol. 2,
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148. Further, as set out above,212 the relevant scientific studies that both Parties have
submitted in the course of the present proceedings demonstrate that the waters of the
Silala constitute an artificially enhanced watercourse. The procedural obligations to
notify and consult are only applicable to the naturally-flowing Silala waters,
according to customary international law. They do not apply to the artificiallyflowing
waters, unless an agreement to this effect exists between the Parties. In the
present case, no such agreement exists between Bolivia and Chile. Even if these
procedural obligations were considered as being applicable to the Silala waters as a
whole, as will be shown below, it is manifest that Bolivia did not breach any alleged
obligations.
149. Bolivia has always expressed its willingness to cooperate, even in circumstances
that involved the use of the waters of an artificially enhanced watercourse. In its
Memorial, Chile states that “Bolivia has recently adopted the position that the Silala
is not an international watercourse and that it therefore has no obligation to cooperate
with Chile in managing and utilizing its waters.”213 However, official
correspondence shows otherwise.214
Annex 37.5; Note No 323/157 from the General Consulate of Chile in La Paz to the Ministry of
Foreign Affairs of Bolivia, 29 October 2013, CM, Vol. 2, Annex 37.7; Note No 362/180 from the
General Consulate of Chile in La Paz to the Ministry of Foreign Affairs of Bolivia, 28 November
2013, CM, Vol. 2, Annex 37.9; and Note No 63/51 from the General Consulate of Chile in La Paz to
the Ministry of Foreign Affairs of Bolivia, 12 February 2014, CM, Vol. 2, Annex 37.11.
212 BCM, para. 42.
213 CM, p. 101, para. 5.26.
214 Notes Verbales sent to Chile between January 2013 and April 2014, state that:
“(…) in accordance with the culture of dialogue that characterises the Plurinational State of Bolivia,
the Ministry of Foreign Affairs expresses its predisposition to begin conversations about this and
other bilateral topics through the Political Consultations Mechanism that was agreed by our
Governments.” Note N° VRE-DGLF-UMA-000715/2013 from the Ministry of Foreign Affairs of
Bolivia to the General Consulate of Chile in La Paz, 17 January 2013. (emphasis added) CM Annex
37.2. See also Note No VRE-DGLF-UMA-008107/2013 from the Ministry of Foreign Affairs of
Bolivia to the General Consulate of Chile in La Paz, 9 May 2013, CM, Vol. 2, Annex 37.4; Note No
VRE-DGLF-UMA-017599/2013 from the Ministry of Foreign Affairs of Bolivia to the General
Consulate of Chile in La Paz, 2 October 2013, CM, Vol. 2, Annex 37.6; Note No VRE-DGLF-UMA91
B. Bolivia did not Breach the Obligation to Provide Timely Notification of Planned
Measures in the Silala
150. Although Chile invokes in Chapter 5 of its Memorial the procedural obligations to
provide Chile with timely notification of planned measures, to exchange data and
information and to conduct an environmental impact assessment, the only alleged
violation of a procedural duty that Chile substantiates concerns an obligation to
provide timely notification of planned measures. Moreover, in Chapter 6 of Chile’s
Memorial, where it articulates its submissions, it simply requests from the Court “a
declaration with respect to a breach by Bolivia of its obligations of notification and
consultation.”215
151. In relation to the duty to provide timely notification of, and to consult on, planned
measures, Chile claims that this obligation applies to “the construction of a fish
farm, a weir, and a mineral water bottling plant”216 and “the recent construction of
ten houses near the Bolivian Military Post.”217 According to Chile’s submission e),
“Bolivia has breached (…) its obligation to notify and consult Chile with respect to
activities that may affect the waters of the Silala River or the utilization thereof by
Chile.”218
020899/2013 from the Ministry of Foreign Affairs of Bolivia to the General Consulate of Chile in La
Paz, 19 November 2013, CM, Vol. 2, Annex 37.8; Note No VRE-DGLF-UMA-022856/2013 from
the Ministry of Foreign Affairs of Bolivia to the General Consulate of Chile in La Paz, 16 December
2013, CM, Vol. 2, Annex 37.10; Note No VRE-DGLFAIT-UAIT-Nv-7/2014 from the Ministry of
Foreign Affairs of Bolivia to the General Consulate of Chile in La Paz, 19 February 2014, CM, Vol.
2, Annex 37.12; and Note No VRE-DGLFAIT-UAIT-Cs-136/2014, from the Ministry of Foreign
Affairs of Bolivia to the General Consulate of Chile in La Paz, 10 April 2014, CM, Vol. 2, Annex
38.2.
215 CM, p. 106, para. 6.6 (emphasis added).
216 CM, p. 98, para. 5.19.
217 CM, p. 99, para. 5.21.
218 CM, p. 107, Submission e).
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152. By referring to the obligation to “notify and consult,” Chile seems to refer to, and
conflate, the obligations set out in Articles 11219 and 12220 of the UNWC on
information concerning planned measures. Chile’s Memorial relies and expands on
the content of both Articles, considering that the duty to “notify and consult (…) is
set out in detail in articles 11 to 18 of the UNWC.”221
153. Considering that neither Bolivia nor Chile are Parties to this Convention, Articles 11
and 12 only apply to the extent that these provisions reflect customary international
law. As explained below, Article 12 reflects customary international law, but Article
11 does not.
154. The duty under Article 11 is broader than the notification obligation under Article
12 of the UNWC. Article 11 concerns any “(…) possible effects of planned
measures on the condition of an international watercourse.” In interpreting what
became Article 11, the International Law Commission explained that “[t]he
expression ‘possible effects’ includes all potential effects of planned measures,
whether adverse or beneficial.”222 In addition, the language of the provision
indicates that the “effect” must be “on the condition of an international watercourse”
and not necessarily to any particular riparian State. As such, it requires notification,
219 Art. 11 of the UNWC reads:
“Watercourse States shall exchange information and consult each other and, if necessary, negotiate on
the possible effects of planned measures on the condition of an international watercourse.”
220 Art. 12 of the UNWC reads:
“Before a watercourse State implements or permits the implementation of planned measures which
may have a significant adverse effect upon other watercourse States, it shall provide those States with
timely notification thereof. Such notification shall be accompanied by available technical data and
information, including the results of any environmental impact assessment, in order to enable the
notified States to evaluate the possible effects of the planned measures.”
221 CM, pp. 101-102, paras. 5.27-5.28. Article 18 of the UNWC concerns the procedure applicable in
relation to notifications under Article 12.
222 Report of the Commission to the General Assembly on the Work of its Forty-Sixth Session, The Law of
the Non-Navigational Uses of International Watercourses, UN Doc. A/49/10, Yearbook of the
International Law Commission, 1994, Vol. II (Part Two), p. 111, Commentary 3 to Article 11.
93
consultation, and exchange of information about all possible positive and negative
effects of planned measures that a State is contemplating and not only about
“significant adverse effects” as is the case under Article 12.223
155. In sharp contrast with the ILC Commentaries on Article 12,224 the Commentaries on
Article 11 make no reference to the status of the obligation under Article 11 in
customary international law. Following an extensive analysis of State practice and
case-law on the obligation to notify and consult, the fourth Special Rapporteur on
the topic at the ILC concluded that there exists “a widespread practice of States of
agreeing to notify and consult with other States with regard to proposed uses that
could significantly affect the other States’ use of or interest in an international
watercourse.”225 Surely, agreements may adopt a lower standard, but in light of
State practice and case-law adopting the “significant adverse effect” standard, the
conclusion of the Special Rapporteur reflects the position under customary
international law.226 Article 11 is therefore not applicable in the present case.
223 During the negotiations of the 1997 Convention, Chile stressed that Article 12 only applies to
“significant adverse effects”. See United Nations, Sixth Committee, Summary Record of the 53rd
meeting, 31 March 1997, A/C.6/51/SR.53, p. 8, para. 47: “Mr. SALINAS (Chile) said that his
delegation had no objections regarding the text of article 12, although the title did not match the
content. Therefore, he suggested that ‘significant’ should be inserted before ‘adverse effects’”. At p.
9, para. 53: “Mr. SALINAS (Chile) said that the Netherlands proposal did not agree exactly with the
content of the articles. Article 11 referred to planned measures without qualifying the possible
adverse effects, while article 12 stipulated the obligation to give notification of planned measures that
might have a significant adverse effect. Therefore, he maintained his proposal that ‘significant’
should be added to the title [of article 12]”. BCM, Vol. 2, Annex 2.
224 Report of the Commission to the General Assembly on the Work of its Forty-Sixth Session, The Law of
the Non-Navigational Uses of International Watercourses, UN Doc. A/49/10, Yearbook of the
International Law Commission, 1994, Vol. II (Part Two), pp. 112-113, Commentaries 6-13 to Article
12.
225 Third report on the law of the non-navigational uses of international watercourses, Mr. Stephen C.
McCaffrey, Special Rapporteur, A/CN.4/406 and Corr.1 and Add.1 & 2, Yearbook of the
International Law Commission, 1987, Vol. II (Part One), p. 30, para. 72 (emphasis added).
226 Third report on the law of the non-navigational uses of international watercourses, Mr. Stephen C.
McCaffrey, Special Rapporteur, A/CN.4/406 and Corr.1 and Add.1 & 2, Yearbook of the
International Law Commission, 1987, Vol. II (Part One), pp. 28-35, paras. 60-87. See also the
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156. Article 12 of the UNWC concerns planned measures that may have a significant
adverse effect upon other watercourse riparians. As noted above, this obligation is
widely acknowledged to be a principle of customary international law. The ILC
surveyed numerous examples in which the principle has been incorporated into
treaties, recognized by international bodies and conferences, adopted in codification
works, and addressed in judicial decisions.227 Moreover, as Chile points out in its
Memorial, the ICJ in the Pulp Mills case noted that the obligation to notify is “an
essential part of the process leading the parties to consult in order to assess the risks
of the plan and to negotiate possible changes which may eliminate those risks or
minimize their effects.”228
157. In presenting this provision, and specifically the notion of “significant adverse
effect,” which limits its scope of application, the ILC asserted that “[t]he threshold
established by this standard is intended to be lower than that of ‘significant harm’
under article 7.”229 Both obligations are triggered only when the possible effect is
negative. The “trigger” for the “may have” determination has to be evaluated before
the activity is authorized or implemented.
practice assessed in the Third report on the law of the non-navigational uses of international
watercourses, Mr. Stephen M. Schwebel, Special Rapporteur, A/CN.4/348. Yearbook of the
International Law Commission, 1982, Vol. II (Part One), pp. 105-110, paras. 170-186.
227 Report of the Commission to the General Assembly on the Work of its Forty-Sixth Session, The Law of
the Non-Navigational Uses of International Watercourses, UN Doc. A/49/10, Yearbook of the
International Law Commission, 1994, Vol. II (Part Two), pp. 112-113, Commentaries 6-12 to Article
12.
228 Pulp Mills on the River Uruguay (Argentina v. Uruguay), Judgment, I.C.J. Reports 2010, p. 59, para.
115; see also CM, p.102, para. 5.29.
229 Report of the Commission to the General Assembly on the Work of its Forty-Sixth Session, The Law of
the Non-Navigational Uses of International Watercourses, UN Doc. A/49/10, Yearbook of the
International Law Commission, 1994, Vol. II (Part Two), p. 111, Commentary 2 to Article 12.
95
C. No Risk of Significant Adverse Effects by the Works at the Silala
158. It is only when a proper analysis of the basis of Chile’s claims is made within the
context of the specifics of the Silala waters, that their artificiality becomes clear. For
instance, the construction of a fish farm never went forward beyond a failed
experimental stage. Regarding the possible constructions of a weir, and a mineral
water bottling plant, the obligation clearly was not triggered because those proposed
activities were never taken forward. The Memorial of Chile itself refers to these
activities as mere “projects in the Silala area that had been announced by the
governor of the Department of Potosi,” without mentioning that their consideration
went beyond contemplation.230 As for the construction of ten houses near the
Bolivian Military Post, in the planning of their construction it was evident that there
would be no significant adverse effect on Chile, and Chile has offered no evidence
of actual harm resulting from the project beyond a plain exaggeration to construct its
claims concerning the alleged breach.
159. In any event, Bolivia communicated to Chile the relevant information and the
reasons why there was no risk that significant adverse effect might be caused to
Chile or the waters of the Silala as a result of the construction of ten houses near the
Bolivian Military Post. In a Diplomatic Note dated 7 February 2017, Chile
requested from Bolivia:
“(…) information regarding the utilization of water of the Silala
River water system, as a consequence of the construction and
operation of the military base called “Silala Military Post” as well as
the ten houses built in the proximities of said watercourse.”231
230 CM, p. 98, para. 5.19.
231 Note N° 29/17 from the General Consulate of Chile in La Paz to the Ministry of Foreign Affairs of
Bolivia, 7 February 2017. CM, Vol. 2, Annex 39.1. It should be noted that in this note of 7 February
2017, Chile cites the “construction” of the Silala Military Post even though this Post had by then been
96
160. Specifically, the General Consulate requested information about the water supply, as
well as the disposal system of the wastewater from the above-mentioned
infrastructure works, on the ground that the potential uses of water of the system and
the discharge of wastewater therein, may have significant consequences on the
rights and legitimate interests that Chile has in the Silala.232
161. Bolivia responded with a Diplomatic Note dated 24 March 2017 stating that:
“On that matter and in the context of the principles of good faith and
neighbourliness, the Ministry communicates that as soon as the
requested information is available it will let the Honourable General
Consulate know.”233
162. Only two months later, on 25 May 2017, Bolivia sent Chile another Diplomatic
Note stating:
“(…) the Ministry of Foreign Affairs indicates that the scarce
Bolivian infrastructure that exists at the site does not constitute any
danger that would generate pollution or affects the water quality of
the Silala springs, given that the houses built are uninhabited.
With regard to the Military Post, appropriate mechanisms that
ensure the preservation and conservation of the aforementioned
waters have been provided, since they are a permanent concern of
Bolivia. Therefore the use of the waters is minimal and the disposal
in place for over a decade, since 2006, without ever leading to any request for information in regard
to the Silala waters.
232 Note N° 29/17 from the General Consulate of Chile in La Paz to the Ministry of Foreign Affairs of
Bolivia, 7 February 2017. CM, Vol. 2, Annex 39.1.
233 Note VRE-Cs-47/2017 from the Ministry of Foreign Affairs of Bolivia to the General Consulate of
Chile in La Paz, 24 March 2017. CM, Vol. 2, Annex 39.2.
97
thereof is controlled through a system of basic sanitation that
prevents contamination in the area.”234
163. This correspondence evidences that there was no risk of “a significant adverse effect
upon other watercourse States” under the rule reflected in Article 12 of the UNWC.
Consequently, the obligation contained in Article 12 was never triggered. In any
case, Bolivia provided Chile with the relevant information about the characteristics
of the ten houses and the Military Post through the above-mentioned Diplomatic
Note dated 25 May 2017.235
D. Final Remarks
164. In light of the above, Chile’s claim that Bolivia breached its obligations “to notify
and consult” should be dismissed. Chile has been unable to demonstrate not only the
lack of exchanges, but also the alleged unwillingness on the part of Bolivia to enter
into dialogue and cooperate with each other.
234 Note VRE-Cs-117/2017 from the Ministry of Foreign Affairs of Bolivia to the General Consulate of
Chile in La Paz, 25 May 2017. CM, Vol. 2, Annex 39.3 (emphasis added).
235 Note VRE-Cs-117/2017 from the Ministry of Foreign Affairs of Bolivia to the General Consulate of
Chile in La Paz, 25 May 2017. CM, Vol. 2, Annex 39.3.
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CHAPTER 6
COUNTER-CLAIMS
165. In accordance with Article 80 of the Rules of Court, Bolivia submits three Counter-
Claims. As Bolivia will show, these Counter-Claims come under the jurisdiction of
the Court and are directly connected with the subject-matter of Chile’s claims. For
the reasons set out in this Chapter, Bolivia asks the Court to adjudge and declare
that:
a) Bolivia has sovereignty over the artificial channels and drainage mechanisms in
the Silala that are located in its territory and therefore has the right to decide
whether and how to maintain them;
b) Bolivia has sovereignty over the artificial flow of Silala waters engineered,
enhanced, or produced in its territory, and Chile has no right to that artificial
flow; and
c) Any delivery from Bolivia to Chile of artificially-flowing waters of the Silala,
and the conditions and modalities thereof, including the compensation to be paid
for said delivery, are subject to the conclusion of an agreement with Bolivia.
A. Bolivia’s Counter-Claims Fall within the Jurisdiction of the Court
166. According to Article 80, paragraph 1, of the Rules of Court, the Court “may
entertain a counter-claim only if it comes within the jurisdiction of the Court.” The
jurisdiction of the Court in the present case is based on Article XXXI of the Pact of
Bogotá,236 to which both States are Parties. There is no doubt that Bolivia’s
236 BCM, para. 1, and CM, pp. 5-6, paras. 1.10-1.13.
99
Counter-Claims come within the jurisdiction of the Court under that provision. They
are “questions of international law” through which Bolivia asks the Court to identify
rights and obligations of the Parties under customary international law in relation to
the artificial channels and drainage mechanisms and the artificial flow of waters of
the Silala.
B. Admissibility of Bolivia’s Counter-Claims
167. The Court may entertain Counter-Claims only if they are admissible under Article
80 of the Rules of the Court. According to the Court, two conditions have to be met
for that purpose. First, Counter-Claims must pursue “objectives other than the mere
dismissal of the claim of the Applicant in the main proceedings,”237 i.e. they must
constitute “a separate ‘claim’, that is to say an autonomous legal act the object of
which is to submit a new claim to the Court.”238 Second, under Article 80, paragraph
1, of the Rules of Court, they must be “directly connected with the subject-matter of
the claim of the other Party.” Both conditions are fulfilled in the present case.
168. First, Bolivia’s Counter-Claims are “distinguishable from a defense on the
merits.”239 Bolivia asks for something more than the mere rejection of Chile’s
claims. While in its submissions Chile addresses its own rights under international
customary rules applicable to international watercourses, Bolivia’s Counter-Claims
concern Bolivia’s rights under customary international rules applicable to waters
and their flow, and its rights in respect to artificial infrastructure, including artificial
237 Application of the Convention on the Prevention and Punishment of the Crime of Genocide, Counter-
Claims, Order of 17 December 1997, I.C.J. Reports 1997, p. 256, para. 27.
238 Application of the Convention on the Prevention and Punishment of the Crime of Genocide, Counter-
Claims, Order of 17 December 1997, I.C.J. Reports 1997, p. 256, para. 27.
239 Application of the Convention on the Prevention and Punishment of the Crime of Genocide, Counter-
Claims, Order of 17 December 1997, I.C.J. Reports 1997, p. 256, para. 27.
100
channels and drainage mechanisms in Bolivia’s own territory, that are not governed
by the law on international watercourses.
169. Second, Bolivia’s Counter-Claims are directly connected, “both in fact and in
law,”240 to Chile’s Application.
170. According to the Court’s jurisprudence,
“It is for the Court to assess ‘whether the counter-claim is
sufficiently connected to the principal claim, taking account of the
particular aspects of each case’ (see Certain Activities Carried Out
by Nicaragua in the Border Area (Costa Rica v. Nicaragua) and
Construction of a Road in Costa Rica along the San Juan River
(Nicaragua v. Costa Rica), Counter-Claims, Order of 18 April 2013,
ICJ Reports 2013, pp. 211-212, para. 32).”241
171. In the present case, Chile’s claims and Bolivia’s Counter-Claims “relate to the same
factual complex, including the same geographical area or the same time period.”242
They both seek a declaratory judgment concerning rights and obligations relating to
the waters of the Silala and its artificial installations. They also concern “similar
types of conduct.”243 They concern conduct in relation to the status and use of the
waters of the Silala and of the corresponding artificial channels and drainage
240 Application of the Convention on the Prevention and Punishment of the Crime of Genocide, Counter-
Claims, Order of 17 December 1997, I.C.J. Reports 1997, p. 258, para. 33.
241 Alleged Violations of Sovereign Rights and Maritime Spaces in the Caribbean Sea (Nicaragua v.
Colombia), Counter-Claims, Order of 15 November 2017, I.C.J. Reports 2017, p. 296, para. 22.
242 Alleged Violations of Sovereign Rights and Maritime Spaces in the Caribbean Sea (Nicaragua v.
Colombia), Counter-Claims, Order of 15 November 2017, I.C.J. Reports 2017, p. 297, para. 24.
243 Alleged Violations of Sovereign Rights and Maritime Spaces in the Caribbean Sea (Nicaragua v.
Colombia), Counter-Claims, Order of 15 November 2017, I.C.J. Reports 2017, p. 297, para. 24.
101
mechanisms. In addition, both Parties pursue “the same legal aim,”244 that is to say
the identification of the legal rules applicable under customary international law to
the Silala waters and their flow, and to the artificial installations in and around the
Silala springs.
172. In light of the above, there is no doubt that a decision of the Court on Bolivia’s
Counter-Claims within the context of the present proceedings will “ensure better
administration of justice” by enabling the Court “to have an overview of the
respective claims of the parties and to decide them more consistently.”245
C. Bolivia’s Counter-Claims
173. Bolivia’s Counter-Claims are based on the factual and legal conclusions drawn in
the previous Chapters of this Counter-Memorial.
174. In Chapter 2, Bolivia showed that artificial channels and drainage mechanisms have
been constructed in Bolivia’s territory by a foreign company.246 As Chile notes in its
Memorial, these artificial installations were built and are located “on” or “in”
Bolivian territory.247 As there is no agreement between Bolivia and Chile in relation
to the construction, maintenance or operation of the artificial installations located in
Bolivia, and since under customary international law there is no obligation for a
State to maintain artificial channels and drainage mechanisms within its territory for
244 Alleged Violations of Sovereign Rights and Maritime Spaces in the Caribbean Sea (Nicaragua v.
Colombia), Counter-Claims, Order of 15 November 2017, I.C.J. Reports 2017, p. 297, para. 25.
245 Application of the Convention on the Prevention and Punishment of the Crime of Genocide, Counter-
Claims, Order of 17 December 1997, I. C. J. Reports 1997, p. 257, para. 30.
246 BCM, paras. 48-49.
247 CM, pp. 87-88, paras. 4.59-4.61.
102
the benefit of other States,248 Bolivia has the right to decide whether and how to
maintain the artificial channels and drainage mechanisms in Bolivian territory.249
175. In the exercise of this prerogative, following a recent report by the Ramsar
Convention Secretariat, Bolivia may assess the convenience of adopting appropriate
actions involving the artificial channels and drainage mechanisms aimed at
preserving or restoring the bofedales of the Silala, in particular considering their
documented state of vulnerability.
176. The Silala wetlands in Bolivia have been identified as part of a Ramsar site and have
been designated for protection in accordance with the Ramsar Convention.250 As
shown in Chapter 2 of this Counter-Memorial, the artificial channels and drainage
network of the Silala substantially affected and degraded the bofedales and caused
the wetlands to recede and decline.251 According to the 2018 Report of the Ramsar
Convention Secretariat on the Ramsar Site Los Lipez in Bolivia,
“[t]he wetlands found in the Silala area have been highly affected by
the construction of the water-catchment canals started in 1908. At
present, there are only vestiges of the original wetlands that used to
cover an area of about 141,200 m2, or 14.1 hectares. The current
surface area of the wetlands covers only about 6,000 m2, or 0.6 ha.,
248 BCM, para. 83.
249 BCM, para. 106.
250 Ramsar Convention Secretariat, Report Ramsar Advisory Mission Nº 84, Ramsar Site Los Lípez,
Bolivia, 2018. BCM, Vol. 5, Annex 18. The Ramsar Convention on Wetlands of International
Importance especially as Waterfowl Habitat, 2 February 1971 (UNTS 1976, No. 14583, p. 246), is an
intergovernmental treaty that provides the framework for national action and international
cooperation for the conservation and wise use of wetlands and their resources. A Ramsar site is a
wetland that has been designated of international importance. Parties to the Ramsar Convention
commit to provide special protections under domestic law to Ramsar sites.
251 BCM, paras. 71-74.
103
which are surrounded by the water catchment works and artificial
canals.”252
177. It was in this context that said Secretariat concluded in the aforementioned Report
that the deterioration of the Silala Valley bofedales is derived from the construction
of the water diversion channels initiated in 1908.253
178. The Bolivian bofedales are heavily dependent on the waters of the Silala and are
vulnerable to changing climatic and other conditions.254 In the Guidelines for the
allocation and management of water resources in order to maintain the ecological
functions of wetlands adopted in 2002, the Conference of the Contracting Parties to
the Ramsar Convention observed in particular that:
“Insufficient water reaching wetlands, due to abstractions, storage
and diversion of water for public supply, agriculture, industry and
hydropower, is a major cause of wetland loss and degradation. A
key requirement for wetland conservation and wise use is to ensure
that adequate water of the right quality is allocated to wetlands at the
right time.”255
179. Accordingly, the Conference considered that “[t]o maintain the natural ecological
character of a wetland, it is necessary to allocate water as closely as possible to the
natural regime”256 and that “[f]lows should normally follow the natural regime as
252 Ramsar Convention Secretariat, Report Ramsar Advisory Mission Nº 84, Ramsar Site Los Lípez,
Bolivia, 2018, p. 38. BCM, Vol. 5, Annex 18.
253 Ramsar Convention Secretariat, Report Ramsar Advisory Mission Nº 84, Ramsar Site Los Lípez,
Bolivia, 2018, p. 39. BCM, Vol. 5, Annex 18.
254 BCM, para. 52.
255 Resolution VIII.1, Guidelines for the allocation and management of water for maintaining the
ecological functions of wetlands, Annex, para. 2, Ramsar COP8, Valencia, Spain, 18-26 November
2002 (emphasis added).
256 Resolution VIII.1, Guidelines for the allocation and management of water for maintaining the
ecological functions of wetlands, Annex, para. 5, Ramsar COP8, Valencia, Spain, 18-26 November
2002.
104
closely as possible to maintain the natural ecology.”257 In the case of the Silala,
Bolivia may have to modify the artificial channels and drainage mechanisms which
are located in its territory in order to fulfill that goal.
180. By virtue of Bolivia’s sovereignty over the artificial flow of Silala waters, any
delivery from Bolivia to Chile of artificially-flowing waters of the Silala, and the
conditions and modalities thereof, including the compensation to be paid for said
delivery, are subject to the conclusion of an agreement with Bolivia.
181. Bolivia therefore requests the Court to adjudge and declare that:
a) Bolivia has sovereignty over the artificial channels and drainage mechanisms in
the Silala that are located in its territory and has the right to decide whether and
how to maintain them;
b) Bolivia has sovereignty over the artificial flow of Silala waters engineered,
enhanced, or produced in its territory and Chile has no right to that artificial
flow; and
c) Any delivery from Bolivia to Chile of artificially-flowing waters of the Silala,
and the conditions and modalities thereof, including the compensation to be paid
for said delivery, are subject to the conclusion of an agreement with Bolivia.
257 Resolution VIII.1, Guidelines for the allocation and management of water for maintaining the
ecological functions of wetlands, Annex, para. 28, Ramsar COP8, Valencia, Spain, 18-26 November
2002.
105
SUBMISSIONS
1. Bolivia respectfully asks the Court to dismiss and reject the requests and submissions
of Chile and to adjudge and declare that:
a) The waters of the Silala springs are part of an artificially enhanced watercourse;
b) Customary international rules on the use of international watercourses do not apply
to the artificially-flowing Silala waters;
c) Bolivia and Chile are each entitled to the equitable and reasonable utilization of the
naturally-flowing Silala waters, in accordance with customary international law;
d) The current use of the naturally-flowing Silala waters by Chile is without prejudice
to Bolivia’s right to an equitable and reasonable use of these waters;
e) Bolivia and Chile each have an obligation to take all appropriate measures to
prevent the causing of significant transboundary environmental harm in the Silala;
f) Bolivia and Chile each have an obligation to cooperate and provide the other State
with timely notification of planned measures which may have a significant adverse
effect on naturally-flowing Silala waters, exchange data and information and conduct
where appropriate environmental impact assessments;
g) Bolivia did not breach the obligation to notify and consult Chile with respect to
activities that may have a significant adverse effect upon the naturally-flowing Silala
waters or the lawful utilization thereof by Chile.
106
2. As to Bolivia’s Counter-Claims, Bolivia respectfully requests the Court to adjudge
and declare that:
a) Bolivia has sovereignty over the artificial channels and drainage mechanisms in the
Silala that are located in its territory and has the right to decide whether and how to
maintain them;
b) Bolivia has sovereignty over the artificial flow of Silala waters engineered,
enhanced, or produced in its territory and Chile has no right to that artificial flow;
c) Any delivery from Bolivia to Chile of artificially-flowing waters of the Silala, and
the conditions and modalities thereof, including the compensation to be paid for said
delivery, are subject to the conclusion of an agreement with Bolivia.
3. The present submissions are without prejudice to any other claim that Bolivia may
formulate in relation to the Silala waters.
The Hague, 3 September 2018
Eduardo RODRÍGUEZ VELTZÉ
Agent of the Plurinational State of Bolivia
107
LIST OF ANNEXES TO THE COUNTER-MEMORIAL
OF THE PLURINATIONAL STATE OF BOLIVIA
VOLUMES 2 - 5
ANNEX Nº TITLE PAGE N°
VOLUME 2 (ANNEXES 1 – 17)
UNITED NATIONS DOCUMENTS (ANNEXES 1 – 3)
Annex 1 United Nations, Sixth Committee, Summary Record of the 23rd meeting,
17 October 1996, A/C.6/51/SR.23, p. 11, para. 78
(Original in English)
3
Annex 2 United Nations, Sixth Committee, Summary Record of the 53rd meeting,
31 March 1997, A/C.6/51/SR.53, p. 8, para. 47 and p. 9, para. 53
(Original in English)
19
Annex 3 United Nations, Sixth Committee, Summary Record of the Second Part
of the 62nd meeting, 4 April 1997, A/C.6/51/SR.62/ Add.1, pp. 6-7, para.
24
(Original in English)
39
DOCUMENTATION FROM THE BOLIVIA-CHILE SILALA WORKING GROUP
AND POLITICAL CONSULTATION MECHANISM (ANNEXES 4 - 10)
Annex 4 Joint Study Profile submitted by Chile in August 2004
(Original in Spanish, English translation)
55
Annex 5 Minutes of the II Meeting of the Bolivia-Chile Working Group on the
Silala Issue, 20 January 2005
(Original in Spanish, English translation)
105
Annex 6 Minutes of the XVIII Meeting of the Bolivia-Chile Political
Consultation Mechanism, 17 June 2008
(Original in Spanish, English translation)
115
108
Annex 7 Minutes of the IV Meeting of the Bolivia-Chile Working Group on the
Silala Issue, 14 November 2008
(Original in Spanish, English translation)
143
Annex 8 Initial Agreement [Silala or Siloli], Agreed Draft, 28 July 2009
(Original in Spanish, English translation)
157
Annex 9 Initial Agreement [Silala or Siloli], Agreed Draft, Santiago,13
November 2009
(Original in Spanish, English translation)
175
Annex 10 Minutes of the First Part of the VIII Meeting of the Bolivia-Chile
Working Group on the Silala Issue, October 2010 (unsigned)
(Original in Spanish, English translation)
195
BOLIVIA-CHILE DIPLOMATIC CORRESPONDENCE (ANNEXES 11 - 12)
Annex 11 Note Nº VRE-DGRB-UAM-018880/2011 from the Ministry of Foreign
Affairs of Bolivia to the General Consulate of Chile in La Paz, 29
August 2011
(Original in Spanish, English translation)
211
Annex 12 Note Nº VRE-DGRB-UAM-009901/2012 from the Ministry of Foreign
Affairs of Bolivia to the General Consulate of Chile in La Paz, 24 May
2012
(Original in Spanish, English translation)
215
BOLIVIAN OFFICIAL DOCUMENTS (ANNEX 13)
Annex 13 Bolivian Supreme Decree N° 24660, 20 June 1997
(Original in Spanish, English translation)
223
PRESS ARTICLES (ANNEXES 14 - 16)
Annex 14 El Diario, “The Silala is not a matter of discussion” for Chile, La Paz,
28 May 1996
(Original in Spanish, English translation)
231
109
Annex 15 El Mercurio, “Clarification from the Chilean Chancellery: There is no
conflict with Bolivia over the Silala River”, Santiago, 17 May 1997
(Original in Spanish, English translation)
237
Annex 16 La Razón, “Everything will be done after signing the initial
agreement”, La Paz, 30 August 2009
(Original in Spanish, English translation)
243
TECHNICAL DOCUMENTS (ANNEX 17)
Annex 17 Danish Hydraulic Institute (DHI), Study of the Flows in the Silala
Wetlands and Springs System, 2018
(Original in English)
255
Annex A: The Silala Catchment
(Original in English)
313
Annex B: Climate Analysis
(Original in English)
331
Annex C: Surface Waters
(Original in English)
357
110
ANNEX Nº TITLE PAGE N°
VOLUME 3 (ANNEX 17)
TECHNICAL DOCUMENTS (CONTINUED FROM ANNEX 17)
Annex 17 Danish Hydraulic Institute (DHI), Study of the Flows in the Silala
Wetlands and Springs System, 2018.
(Original in English)
Annex D: Soil Analyses
(Original in English)
1
Appendix A: “Results of Field and Laboratory Soil
Studies” - Characterization of the Silala Wetlands Area and
its Vicinities
23
Appendix A1: Preliminary Report
(Original in Spanish, English translation)
27
Appendix A2: Final Report
(Original in Spanish, English translation)
257
Annex E: Water Balances
(Original in English)
461
111
ANNEX Nº TITLE PAGE N°
VOLUME 4 (ANNEX 17)
TECHNICAL DOCUMENTS (CONTINUED FROM ANNEX 17)
Annex 17 Danish Hydraulic Institute (DHI), Study of the Flows in the Silala
Wetlands and Springs System, 2018
(Original in English)
Annex F: Hydrogeology
(Original in English)
1
Appendix a: Documentation of Wells and Piezometers
from the Field Investigation Program
111
Appendix b: Packer Test Analyses 423
Appendix c: Slug Test Analyses 431
Appendix d: Pumping Test Analyses 515
Appendix e: Water Quality Data for Silala Spring System 537
112
ANNEX Nº TITLE PAGE N°
VOLUME 5 (ANNEXES 17 - 18)
TECHNICAL DOCUMENTS ( CONTINUED FROM ANNEX 17 AND ANNEX 18)
Annex 17 Danish Hydraulic Institute (DHI), Study of the Flows in the Silala
Wetlands and Springs System, 2018
(Original in English)
Annex G: Integrated Surface Water / Groundwater Modelling
(Original in English)
1
Annex H: Natural Flow Scenarios
(Original in English)
57
Annex I: Questionnaire put by the Plurinational State of Bolivia to
DHI
(Original in English)
79
Annex 18 Ramsar Convention Secretariat, Report Ramsar Advisory Mission Nº
84, Ramsar Site Los Lipez, Bolivia, 2018
(Original in Spanish, English translation)
87
113
CERTIFICATION
I certify that the annexes and reports filed with this Counter-Memorial are true copies of
the documents referred to and that the translations provided are accurate.
Eduardo RODRÍGUEZ VELTZÉ
Agent of the Plurinational State of Bolivia