Separate opinion of Judge ad hoc Dugard

S EPARATE OPINION OF J UDGE AD HOC D UGARD

Table of Contents

Paragraphs

I. Separate opinion.....................................................................1-2.............................

II. Territorial integrity................................................................3................................

III. Protection of the environment.......................................................4-5......................

IV. The principle of prevention and the source of the environmental impact
assessment obligation................................................................6-11.........................

V. Environmental impact assessment: general rule or customary rule......................12-17

VI. Rules relating to an environmental impact assessment................................18-19.....

VII. Construction of a Road and the obligation to conduct an environmental impact
assessment............................................................................20................................

VIII. Certain Activities and the obligation to conduct an environmental impact

assessment in respect of Costa Rica’s wetlands......................................21-35..........

IX. Ramsar Convention...................................................................36-45........................

I. Separate opinion

1. I am in agreement with the Court’s decisions on what I consider to be three of the
principal issues: Nicaragua’s violation of Costa Rica’s territorial sovereignty; Costa Rica’s failure
to perform an environmental impact assessment before embarking on the construction of
Route 1856 along the San Juan River; and the failure of Nicaragua to prove that the construction of
Route 1856 caused significant transboundary harm. I dissent from the Court’s decision on two
issues: first, the rejection of Costa Rica’s complaint that Nicaragua failed to carry out a proper

environmental impact assessment for its programme of dredging of the San Juan River and to
consult with Costa Rica on this subject, as required by the Ramsar Convention; second, the
rejection of Costa Rica’s request for an order of costs arising from Nicaragua’s construction of two
caños in 2013. As I am in broad agreement with the Court, I consider that my opinion is more
accurately to be viewed as a separate opinion.

2. I will address the first issue on which I dissent below, after some comments on
Nicaragua’s violation of Costa Rica’s territorial integrity. In the case of the second issue I join
Judges Tomka, Greenwood and Sebutinde in a joint declaration on the ordering of costs.

II. Territorial integrity

3. I agree with the Court’s finding that Nicaragua has violated Costa Rica’s territorial

sovereignty by excavating three caños and establishing a military presence in part of that territory.
I believe that Nicaragua further violated Costa Rica’s territorial sovereignty by encouraging
members of the Guardabarranco Environmental Movement to trespass on Costa Rican territory.
(See my dissenting opinion in Certain Activities carried out by Nicaragua in the Border Area - 2 -

(Costa Rica v. Nicaragua); Construction of a Road in Costa Rica along the San Juan River
(Nicaragua v. Costa Rica), Order of 16 July 2013, Provisional Measures, I.C.J. Reports 2013,

pp. 275-276, paras. 13-14.) The Court has on previous occasions emphasized that the principle of
territorial integrity is an important feature of the international legal order (Accordance with
International Law of the Unilateral Declaration of Independence in respect of Kosovo, Advisory
Opinion, I.C.J Reports 2010 (II), p. 437, para. 80). This principle is enshrined in the Charter of the
United Nations and the Charter of Organization of American States and was reiterated by the
General Assembly in resolution 2625 (XXV) on the Declaration of Principles of International law
concerning Friendly Relations and Cooperation among States. In these circumstances I believe that

the Court should have placed greater emphasis on the serious nature of Nicaragua’s violation of the
territorial integrity of Costa Rica.

III. Protection of the environment

4. The protection of the environment featured prominently in both Certain Activities and
Construction of a Road. In both cases the Court was required to address the questions of action

that might result in significant transboundary harm and the failure to produce an environmental
impact assessment in respect of projects that risk causing significant transboundary harm. I agree
with the Court that neither Costa Rica nor Nicaragua proved that the actions of their neighbour had
caused significant transboundary harm. I also agree with the finding of the Court, and its reasoning
for this finding, that the evidence showed that Costa Rica had breached a rule of international law
by failing to carry out an environmental impact assessment when it embarked on the construction
of the Road along the San Juan River. I disagree, however, with the finding of the Court that

Nicaragua was not obliged to conduct an environmental impact assessment in respect of its project
for dredging the San Juan River and that it was not obliged to consult with Costa Rica on this
subject. This disagreement, which relates to both the factual findings and the reasoning of the
Court, provides the basis for my dissent. In summary, I believe that the Court erred in its findings
of fact and that it failed to apply the same reasoning in Certain Activities that it applied in
Construction of a Road. I also believe that the Court erred in its interpretation of the
Ramsar Convention on the duty to consult.

5. Before examining the Court’s finding and reasoning on the absence of an obligation on the
part of Nicaragua to conduct an environmental impact assessment when it embarked on the
dredging of the San Juan River it is necessary to consider the source, nature and content of the
obligation to conduct an environmental impact assessment.

IV. The principle of prevention and the source of the environmental impact assessment

obligation

6. The main purpose of environmental law is to prevent harm to the environment. This is
because of the “often irreversible character of damage to the environment and of the limitations
inherent in the very mechanism of reparation of this type of damage” (Gabčíkovo-Nagymaros
Project (Hungary/Slovakia), Judgment, I.C.J. Reports 1997, p. 78, para. 140). A cluster of
principles seek to achieve this goal, including the principle of prevention, the precautionary
principle, the principle of co-operation, notification and consultation and the obligation of due

diligence.

7. The obligation of due diligence flows from the principle of prevention. This is
emphasized by the International Law Commission’s Commentary on Article 3 of its Draft Articles
on the Prevention of Transboundary Harm from Hazardous Activities which declares “[t]he
obligation of the State of origin to take preventive or minimization measures is one of due - 3 -

diligence” (Yearbook of the International Law Commission (YILC), 2001, Vol. II, Part Two, p. 154,

para. 7; see too, p. 155, para. 17). The duty of due diligence therefore is the standard of conduct
required to implement the principle of prevention.

8. The principle of prevention is also implemented through a number of specific obligations,
which include the obligation to carry out an environmental impact assessment. These obligations

must be carried out in accordance with the due diligence standard. Thus if an environmental
impact assessment has been carried out, but not with sufficient care in the circumstances,1a State
may be found to be in breach of it obligation to do an environmental impact assessment . That due
diligence and the obligation to conduct an environmental impact assessment are legal tools
employed to ensure the prevention of significant transboundary harm is confirmed by the Court in
its present Judgment when it states that “a State’s obligation to exercise due diligence in preventing

significant transboundary harm” requires it to conduct a screening exercise to determine whether it
is required to do an environmental impact assessment prior to undertaking an activity. Such an
obligation will arise if it ascertains that such activity has “the potential adversely to affect the
environment of another State” (Judgment, paragraph 153; see too, paragraph 104).

9. A State’s obligation to conduct an environmental impact assessment is an independent
obligation designed to prevent significant transboundary harm that arises when there is a risk of
such harm. It is not an obligation dependent on the obligation of a State to exercise due diligence
in preventing significant transboundary harm. Due diligence is the standard of conduct that the
State must show at all times to prevent significant transboundary harm, including in the decision to
conduct an environmental impact assessment, the carrying out of the environmental impact

assessment and the continued monitoring of the activity in question. The International Law
Commission views the obligation to conduct an environmental impact assessment as an
independent obligation (Draft Articles on Prevention of Transboundary Harm from Hazardous
Activities, YILC, 2001, Vol. II, Part Two, Art. 7, p. 157), as do the Rio Declaration (Principle 17),
the Convention on Biological Diversity (Art. 14) and the Convention on Environmental Impact
Assessment in a Transboundary Context (“Espoo Convention”) (Art. 2). None of these instruments

mentions due diligence in their formulation of the obligation to conduct an EIA. The decision of
the Court in Pulp Mills on the River Uruguay invokes the principles of prevention, vigilance and
due diligence as a basis for an environmental impact assessment when it states that “due diligence,
and the duty of vigilance and prevention which it implies” would not have been exercised if a State
embarking on an activity that might cause significant transboundary harm failed to carry out an
environmental impact assessment (Pulp Mills on the River Uruguay, (Argentina v. Uruguay),

Judgment, I.C.J. Reports 2010 (I), p. 83, para. 204). But the Court then explains that the content of
the environmental impact assessment obligation is to be assessed “having regard . . . to the need to
exercise due diligence in conducting such an assessment” (ibid., para. 205). This means that the
due diligence obligation informs the environmental impact assessment obligation, so that, in
assessing whether the duty of prevention has been satisfied, and in determining its necessary
content, the Court will apply a due diligence standard. Due diligence is therefore the standard of

care required when carrying out the environmental impact assessment and not the obligation itself.

10. The danger of viewing the due diligence obligation as the source of the obligation to
perform an environmental impact assessment is that it allows a State to argue, retrospectively, that
because no harm has been proved at the time of the legal proceedings, no duty of due diligence

arose at the time the project was planned. This backward looking approach was adopted by the
Court in Certain Activities but not in Construction of a Road. If the obligation to perform an
environmental impact assessment is viewed as an independent obligation it is clear that a State

See Responsibilities and Obligations of States with respect to Activities in the Area, Advisory Opinion,
1 February 2011, ITLOS Reports 2011, p. 49, para. 141. - 4 -

must ascertain the risk at the time the project is planned and prior to embarking upon the project.
Moreover, it is clear that the threshold for making such a decision is not the high standard for

determining whether significant transboundary harm has been caused but the lower standard of risk
assessment  even if it is proved later that no significant transboundary harm has been caused.
An environmental impact assessment not only ensures that the principle of prevention is adhered to
but also encourages environmental consciousness on the part of States by requiring them to assess
the risk of harm even if no harm is proved after the project has been undertaken.

11. As the Court here has affirmed, Pulp Mills makes clear that the obligation to do an
environmental impact assessment exists as a separate legal obligation from due diligence.
Moreover, policy considerations confirm that the obligation to perform an environmental impact
assessment must be viewed as an obligation separate from that of due diligence. The obligation of
due diligence is vague and lacking in clear content or procedural rules. It is an obligation that can
be applied either prospectively or retrospectively  as shown by the reasoning in
Certain Activities. The obligation to conduct an environmental impact assessment, on the other

hand, imposes a specific obligation on States to examine the circumstances surrounding a particular
project when it is planned and before it is implemented. It is characterized by certainty whereas
due diligence is a more open-textured obligation that could potentially be satisfied in a number of
different ways.

V. Environmental impact assessment: general rule or customary rule

12. The Court has chosen to describe the obligation to conduct a transboundary
environmental impact assessment concerning activities carried out within a State’s jurisdiction that
risk causing significant harm to other States as an obligation under “general international law”.
This term is used in both Certain Activities (paras. 101, 104) and Construction of a Road
(paras. 152, 162, 168, 229 (6)). In so doing the Court has carefully followed the language
employed by the Court in Pulp Mills when it stated

“it may now be considered a requirement under general international law to undertake

an environmental impact assessment where there is a risk that the proposed industrial
activity may have a significant adverse impact in a transboundary context in particular
on a shared resource” (Pulp Mills on the River Uruguay (Argentina v. Uruguay), I.C.J.
Reports 2010 (I), p. 83, para. 204).

13. As the term “general international law” does not appear in the sources of international

law listed in Article 38 (1) of the Court’s Statute there will inevitably be some debate about the
precise meaning to be attached to the term.

14. “General international law” cannot be equated with “general principles of law recognized
by civilized nations” referred to in Article 38 (1) (c) in the present context as the Court has
accepted the obligation to conduct an environmental impact assessment as an obligation that gives
rise to a cause of action (Judgment, paragraph 162). Were the term to be interpreted as

synonymous with “general principles of law” the question would be raised whether such a “general
principle of law” might found a cause of action and require the Court to enter this jurisprudential
minefield.

15. General principles fall largely into the categories of rules of evidence or procedure or are
used as a defence (e.g., res judicata). Abuse of procedure has been invoked as a general principle
in a number of cases before the Court but the Court has never found the conditions for an - 5 -

2
application of the principle to be fulfilled . That a general principle of law might give rise to a
cause of action cannot be discounted. In Factory at Chorzów the Court declared that “it is a
principle of international law, and even a general conception of law, that any breach of an
engagement involves an obligation to make reparation” (Factory at Chorzów, Merits,
Judgment No. 13, P.C.I.J, Series A, No 17, 1928, p. 29). However, that obligation to pay reparation

was not an independent cause of action but a secondary obligation that arose only after the
determination of a breach of some other obligation. On the other hand, there is some authority for
the proposition that a general principle cannot be construed as a separate obligation. In
Mavrommatis Jerusalem Concessions (Greece v. United Kingdom), the Permanent Court of

International Justice stated:

“It is true that the Claimant has maintained that the provision of the Protocol
should be supplemented by certain principles taken from general international law; the
Court, however, considers that Protocol XII is complete in itself, for a principle taken
from general international law cannot be regarded as constituting an obligation

contracted by the Mandatory except in so far as it has been expressly or implicitly
incorporated in the Protocol.” (P.C.I.J., Series A, No 5, 1925, p. 27.)

16. What meaning then is to be attached to the term “general international law” which the

International Court has used in Pulp Mills and other decisions? Possibly it includes general
international conventions, particularly those that codify principles of international law; and widely
accepted judicial decisions, particularly decisions of the International Court of Justice. Certainly it
includes both customary international law and general principles of law within the meaning of
Article 38 (1) (c) and (d) of the Court’s Statute. In the present case I understand the term “general

international law” to denote a rule of customary international law requiring an environmental
impact assessment to be carried out where there is a risk of transboundary harm.

17. There can be little doubt that there is an obligation under customary international law to
conduct an environmental impact assessment when there is a risk of significant transboundary

harm. The ITLOS Seabed Disputes Chamber has held that there is3a “general obligation under
customary international law” to conduct such an assessment . Fourteen years ago, the International
Law Commission stated in its Draft Articles on Prevention of Transboundary Harm from
Hazardous Activities that “the practice of requiring an environmental impact assessment has
become very prevalent”, citing the laws of several developed States in support of such an

obligation and declaring that some 70 developing countries had legislation of some kind on this
subject (Commentary on Article 7, para. 4, YILC, 2001, Vol. II, Part Two, p. 158). These Draft
Articles have been commended by the General Assembly of the United Nations (resolution of
6 December 2007, UN doc A/Res/62/68, para. 4). In addition, a growing number of multilateral
conventions recognize the obligation to conduct an environmental impact assessment. See, in

particular, the Convention of Environmental Impact Assessment in a Transboundary Context
(“Espoo Convention”), the Antarctic Treaty on Environmental Protection (the Antarctic Protocol),
the Convention on the Protection and Use of Transboundary Watercourses and Lakes
(Art. 6 (1) (b)), the Convention on Biological Diversity (Art. 14), and the Convention of the Law of
the Sea (Art. 206). The writings of jurists lend strong support to such an obligation under

customary international law. Significantly, neither Costa Rica or Nicaragua has denied such an
obligation as binding on them although in their pleadings they followed Pulp Mills and used the
language of “general international law”. There was no argument as to what this term meant and it
was apparently assumed that it was a synonym for custom.

2
A. Zimmermann et al. (eds.), Statute of the International Court of Justice: A Commentary, 2nd ed., 2012,
pp. 904-905.
Responsibilities and Obligations of States with respect to Activities in the Area, Advisory Opinion,
1 February 2011, ITLOS Reports 2011, p. 50, para. 145. - 6 -

VI. Rules relating to an environmental impact assessment

18. In Pulp Mills the Court stated that general international law does not “specify the scope
and content of an environmental impact assessment” with the result “that it is for each State to
determine in its domestic legislation or in the authorization process for the project, the specific
content of the environmental impact assessment required in each case” (I.C.J. Reports 2010 (I),
p. 83, para. 205). This dictum, which is reaffirmed by the Court in the present case (Judgment,

paragraph 104), has on occasion been interpreted as meaning that the environmental impact
assessment obligation has no independent content and that there is simply a renvoi to domestic
law . This is incorrect. Obviously there are some matters relating to the carrying out of an
environmental impact assessment which must be left to domestic law. These include the identity of
the authority responsible for conducting the examination, the format of the assessment, the time
frame and the procedures to be employed. But there are certain matters inherent in the nature of an

environmental impact assessment that must be considered if it is to qualify as an environmental
impact assessment and to satisfy the obligation of due diligence in the preparation of an
environmental impact assessment. This is made clear by the International Law Commission in its
Commentary on Article 7 of its Draft Articles on the Prevention of Transboundary Harm from
Hazardous Activities which declares that an environmental impact assessment should relate the risk

involved in an activity “to the possible harm to which the risk could lead”, contain “an evaluation
of the possible transboundary harmful impact of the activity”, and include an assessment of the
“effects of the activity not only on persons and property, but also on the environment of other
States” (YILC, 2001, Vol. II, Part Two, pp. 158-159, paras. 6-8).

19. In the present case the Court has recognized that the following rules are inherent in the

nature of an environmental impact assessment. An environmental impact assessment must be
undertaken prior to the implementation of the activity in question (Judgment, paragraphs 104, 153,
159, 161, 168). The State undertaking an activity must assess the risk of significant transboundary
harm prior to implementing the activity “on the basis of an objective evaluation of all the relevant
circumstances” (Judgment, paragraph 153). The burden of proof in showing that an environmental
impact assessment or similar preliminary assessment of the risk involved has been done is upon the

State undertaking the activity (Judgment, paragraph 154). The circumstances of the particular
environment must be considered in assessing the threshold for deciding whether an environmental
impact assessment is required (Judgment, paragraphs 104, 155). The fact that the activity is
conducted in a Ramsar protected site “heightens the risk of significant damage because it denotes
that the receiving environment is particularly sensitive” (Judgment, paragraph 155). (From this it
follows that the threshold for deciding whether to conduct an environmental impact assessment is

lower in the case of a wetland of international significance protected by the Ramsar Convention.)
A State must exercise due diligence in carrying out an environmental impact assessment with
regard to the nature and magnitude of the activity and its likely impact on the environment
(Judgment, paragraphs 104, 155). In determining the need for an environmental impact assessment
it is necessary to have regard to the risk of harm being caused (Judgment, paragraphs 104, 153).

(By necessary implication, this rejects that argument that the test is not the risk of transboundary
harm but the likelihood or probability of such harm occurring. It is also recognition of the fact that
there is a lower standard  risk  that triggers the obligation to conduct an environmental impact
assessment than the higher standard required for proving that significant transboundary harm has
actually been caused. This is confirmed by the finding of the Court that Costa Rica was required to
conduct an environmental impact assessment because of the risk its activity posed to Nicaragua’s

See, for instance, the statement of the Seabed Disputes Chamber of ITLOS in its Advisory Opinion of 2011
(footnote 1 above), p. 51, para. 149. - 7 -

environment, despite the fact that Nicaragua failed to prove that significant transboundary harm

had in fact occurred.) Finally, the Court affirmed that a subsequent finding of an absence of
significant transboundary harm does not exonerate the State that carries out an activity that risks
causing such harm for its failure to carry out an environmental impact assessment when the activity
was planned.

VII. Construction of a Road and the obligation to conduct an environmental impact
assessment

20. Here the Court scrupulously applied the principles governing an environmental impact
assessment that it had expounded in the present case (see para. 19 above). First, it held that
Costa Rica had breached its obligation to conduct an environmental impact assessment by failing to
carry out such an assessment prior to embarking on the construction of the Road (Judgment,
paragraphs 153, 159, 161, 168). The fact that it later carried out an environmental diagnostic
assessment and other studies on the impact of the Road did not suffice (Judgment, paragraph 161).
Second, it held that Costa Rica had failed to prove that it had carried out a preliminary assessment

before embarking on the construction of the Road (Judgment, paragraph 154). Third, it held that
the geographic conditions of the river basin where the Road was to be built were to be considered
in assessing the risk involved in the activity (Judgment, paragraph 155). The Court made a careful
examination of these conditions and the proximity of the Road to the San Juan River in order to
show that the Road posed a risk to Nicaragua’s environment (Judgment, paragraph 155). Fourth,
the Court held that the fact that the Road was built in the proximity of Nicaragua’s Ramsar
protected wetland of Refugio de Vida Silvestre Río San Juan heightened the risk of significant

impact because of the sensitive nature of the environment (Judgment, paragraph 155). Fifth, it held
that in determining the need for an environmental impact assessment it was necessary for
Costa Rica to have regard to the risk of significant transboundary harm being caused by the
construction of the Road (Judgment, paragraph 153). Sixth, it held that the fact that Nicaragua did
not prove that significant transboundary harm had in fact been caused by the construction of the
Road did not absolve Costa Rica from its obligation to conduct an environmental impact
assessment prior to commencing this activity.

VIII. Certain Activities and the obligation to conduct an environmental impact assessment in
respect of Costa Rica’s wetlands

21. The reasoning and fact-finding of the Court on the need for an environmental impact
assessment in Construction of a Road must be compared to the approach it adopted in
Certain Activities.

22. In its application and subsequent submissions Costa Rica made it clear that it had two
main concerns about Nicaragua’s plan to dredge the Lower San Juan River: first, the impact it
might have on Costa Rica’s Ramsar protected wetlands and, second, the damage it might cause to
the Colorado River. In the course of the oral proceedings, on 28 April 2015, Costa Rica asked the
Court to adjudge and declare that Nicaragua had breached “the obligation to respect Costa Rica’s
territory and environment, including its wetland of international importance under the Ramsar

Convention ‘Humedal Caribe Noreste’, on Costa Rican territory”; and “the obligation to carry out
an appropriate transboundary environmental assessment, which takes account of all potential
significant adverse impacts on Costa Rican Territory” (Judgment, paragraph 49). Costa Rica also
requested the Court to find that Nicaragua had breached it obligation to refrain from any activity
that might cause damage to the Colorado River. This opinion will focus entirely on Costa Rica’s
submissions in respect of its wetlands. This is done for the sake of brevity. The expert witnesses
of both Parties agreed in 2015 that Nicaragua’s dredging programme was not likely to affect the - 8 -

flow of water to the Colorado River. Whether the dredging as initially planned in 2006 posed a
risk to the Colorado River, warranting an environmental impact assessment, remains unanswered.

23. The Court’s response to Costa Rica’s submissions was terse. First, it stated that

“[i]n 2006 Nicaragua conducted a study of the impact that the dredging programme

would have on its own environment, which also stated that the programme would not
have a significant impact on the flow of the Colorado River. This conclusion was
later confirmed by both Parties’ experts.” (Judgment, paragraph 105; emphasis
added.)

This passage indicates that the Court was aware that Nicaragua’s study of 2006 dealt only with the
likely impact of dredging “on its own environment” and that the Court was satisfied, in the light of
the “later” evidence of experts of both Parties, that the dredging programme would have no impact
on the Colorado River. Then came the Court’s finding on both the flow of the Colorado River and

the impact on Costa Rica’s wetlands:

“Having examined the evidence in the case file, including the reports submitted
and testimony given by experts called by both Parties, the Court finds that the

dredging programme planned in 2006 was not such as to give rise to a risk of
significant transboundary harm, either with respect to the flow of the Colorado River
or to Costa Rica’s wetland. In light of the absence of risk of significant transboundary
harm, Nicaragua was not required to carry out an environmental impact assessment.”

(Judgment, paragraph 105.)

24. In order to compare and contrast the reasoning employed by the Court in
Certain Activities with its reasoning in Construction of a Road it is necessary to examine the

evidence in the case file of the Court, particularly “the reports submitted and the testimony given
by experts called by both Parties” (Judgment, paragraph 105), upon which the Court bases its
finding that the Nicaraguan dredging programme planned in 2006 was not such as to give rise to a
risk of significant transboundary harm with respect to Costa Rica’s wetland, the Humedal Caribe

Noreste.

25. There are four important documents dealing with the impact of Nicaragua’s dredging

programme: th5 terms of reference of the Ministry of the Environment and Na6ural Resources
(MARENA) , Nicaragua’s environmental impact study (EIS) of 2006 , the Project Design Study
attached as an annexure to the environmental impact study and the Report of the Ramsar Advisory
Mission No. 72 on the impact of the dredging programme on Nicaragua’s wetland, the Refugio de
8
Vida Silvestre del Río San Juan . The first three documents prepared by Nicaragua have one thing
in common: they carefully examine the impact of the dredging programme on Nicaragua’s own
environment but make no mention of its possible impact on the territory of Costa Rica, least of all
on its wetland. The terms of reference of MARENA, which define the scope of the study, do not

direct any transboundary impacts to be studied. The environmental impact study mentions only
Nicaragua’s Ramsar protected wetland. The Project Design Study is concerned only with the

Ministry of the Environment and Natural Resources (MARENA), Specific Terms of Reference for the
Preparation of the Environmental Impact Study for the Project “Dredging of the San Juan River” (undated),
Counter-Memorial of Nicaragua (CMN), Vol. II, Ann. 9, p. 221.
6
Environmental Impact Study for Improving Navigation on the San Juan de Nicaragua River, September 2006,
CMN, Vol. II, Ann. 7, p. 77.
Project Design Study, September 2006, CMN, Vol. II, Ann. 8, p. 213.
8
Ramsar Report of 18 April 2011. - 9 -

increase in the flows of the channel bed of the San Juan River and makes no mention of any
possible transboundary impact of the dredging programme. The Court is therefore correct in

stating that Nicaragua’s study considered only the “impact that the dredging programme would
have on its own environment” (Judgment, paragraph 105).

26. The Ramsar Report of 2011, on the other hand, is concerned with the wetlands of the
Lower San Juan River basin belonging to both Nicaragua and Costa Rica. It states that because any
changes to the fluvial dynamics of the river due to dredging will alter the dynamics of the

Nicaraguan and Costa Rican wetlands and “the distribution and abundance of the species living
there” it is “important to perform studies of the relevant environmental impacts prior to its
implementation” . It adds that:

“Considering the main role of the San Juan River basin on the entire dynamics
of the San Juan River as well as the Ramsar sites Refugio de Vida Silvestre and Caribe
Nordeste, it is essential to develop joint actions of cooperation between Nicaragua and
Costa Rica, enabling compliance with their international commitments within the

framework of the Ramsar Conve10ion, and particularly the maintenance of the
ecological characteristics.”

The report then recommends “strong cooperation” between Nicaragua and Costa Rica “for a more

integrated management of activi11es that may potentially affect the river” and “its related wetlands
of international importance” . Finally it recommends the monthly monitoring of the hydrometric
levels, the concentration of suspended solids in the water column and the groundwater levels of the
12
river at least during the construction phase of the dredging .

27. Not surprisingly, the Ramsar Report of 2011 was not produced by Nicaragua until
13
requested by Costa Rica. Nicaragua wrote a hostile reply to the Ramsar Secretariat criticizing the
actions of Costa Rica and requesting, inter alia, the deletion of the report’s conclusion that any
changes to the fluvial dynamics of the river due to dredging will alter the dynamics of the wetlands
of Nicaragua and Costa Rica and the species living there, resulting in the need “to perform studies

of the relevant environmental impacts prior to its implementation”. In the oral proceedings
Nicaragua dismissed the Ramsar Report as only a draft report which the Ramsar Secretariat never
finalized. In the light of the concern expressed by the Ramsar Report over the impact that dredging
might have on the wetlands of both Nicaragua and Costa Rica it is unlikely that this was one of the

reports “in the case file” of the Court (Judgment, paragraph 105) which led it to conclude that the
dredging programme planned in 2006 was not such as to give rise to a risk of significant
transboundary harm.

28. The principal witnesses called by Nicaragua in Certain Activities were
Professors Kondolf and van Rhee. Kondolf’s report in Nicaragua’s Counter-Memorial is largely 14

concerned with the clearing of the caño and does not consider the impact of dredging on the
wetlands other than in the vicinity of the caño. His Written Statement is likewise focused mainly

9Ramsar Report, Conclusions, para. 5.

1Ibid., para. 6.
11
Ramsar Report, Recommendations, para. 1.
1Ibid., para. 3.
13
Considerations and Changes of the Government of the Republic of Nicaragua to the draft Ramsar Mission
Report No. 72.
14
“Distributary Channels of the Rio San Juan, Nicaragua and Costa Rica: Review of Reports by Thorne,
UNITAR, Ramsar, Meet, and Araya Montero”, CMN, Vol. I, p. 461. - 10 -

on the clearing of the caño but he does state that the contemplated diversion of the
Colorado River’s flow into the San Juan River “does not risk harming the Colorado or the wetlands
it feeds”. There is no indication of the wetlands to which he refers. Kondolf’s oral testimony was

again centred on the clearing of the caño without mention of the impact of the dredg15g upon the
wetlands. Professor van Rhee’s report in Nicaragua’s Counter-Memorial is about the dredging
programme itself but it does state that it “helps to ensure the survival of the wetlands of

internati16al importance”, including the Refugio de Vida Silvestre and the Humedal Caribe
Noreste . In a subsequent report, Professor van Rhee makes the important point that the dredging
project described in the environmental impact study of 2006 “has since been reduced in scope. As

such, even 17e small impact of the dredging project on the environment . . . will likely be
reduced.” In his Written Statement van Rhee states that dredging is an “effective technique for
maintaining flows to wetlands” which serves to preserve the ecological health of the

environmentally sensitive wetlands of the Lower San Juan River. Professor van Rhee’s oral
testimony was hampered by the fact that he had not seen the 2011 Ramsar Report No. 72 on which
he was cross-examined.

29. Costa Rica’s main witness was Professor Thorne. He was unable to access the San Juan
River in person as the Nicaraguan authorities denied such access. In contrast to the reports of
18
Professors Kondolf and van Rhee, his report in Costa Rica’s Memorial had much to say about the
impact of dredging on Costa Rica’s wetlands. In the executive summary of his report, he states that
the wetland of Humedal Caribe Noreste that could be indirectly impacted by the dredging

“provides habitats for a wide array of plants, birds, fish, amphibians, reptiles and mammals,
including many iconic and endangered species” . Risks to such species “include the possibility of
20
extinction of those already threatened or endangered” . The report itself declares that dredging has
“direct, short-term impacts on river environments and ecosystems through disturbing aquatic flora
and fauna, destroying benthic communities and, potentially, increasing turbidity and reducing water
21
quality, with impacts that will be felt throughout the trophic network” . The report spells out the
potential environmental impacts on the wetlands of dredging on such issues as surface drainage,
water quality, vegetation, fish, aquatic plant life, birds and fauna . The report concludes that the

evidence suggests that the “morphological, environmental a23 ecological risks associated with
continuing the dredging programme are serious” . Professor Thorne’s Written Statement was
largely concerned with maps and the construction of the three caños. He did, however, state that

“disturbance to the environment and ecosystem at each dredging site are inherent and inevitable”.
Significantly, Professor Thorne accepts Professor van Rhee’s assessment that Nicaragua’s reduced
dredging programme is likely to cause less environmental damage to the wetlands. He warns,

however, that if the dredging programme were to be expanded to achieve its initial goal of greater
navigability of the river this would have adverse impacts. Professor Thorne’s testimony in the oral
proceedings was largely devoted to maps and the cutting of the caños. However, when he testified

15Van Rhee and De Vriend, “The Influence of Dredging on the Discharge and Environment of the San Juan
River,” CMN, Vol. I, p. 525.
16
Ibid., p. 540, para. 3.2.
17
Van Rhee and De Vriend, “Morphological Stability of the San Juan River Delta, Nicaragua/Costa Rica,”
CMN, Vol. IV, pp. 19, 23.
18“Assessment of the physical impact of works carried out by Nicaragua since October 2010 on the

geomorphology, hydrology and sediment dynamics of the San Juan River and the environmental impacts on Costa Rican
territory”, Memorial of Costa Rica, Vol. I, p. 307.
19Ibid., p. 313.

20Ibid., p. 315.
21
Ibid., pp. 443-444.
22
Ibid., pp. 454-458.
23Ibid., p. 461. - 11 -

in Construction of a Road, in response to a question by Judge Tomka, he issued the stark warning
that “[t]he dredging programme, if it cuts off the sediment supply, will starve the delta, the
Caribbean Sea will take it away, we will lose hundreds of hectares of wetland due to coastal

erosion” (CR 2015/12, p. 52).

30. Only one expert on environmental impact assessments testified in the joined cases. He

was Dr. William Sheate, who was called as a witness by Nicaragua in the Construction of a Road
to give evidence on the question whether Costa Rica had breached its obligation to conduct an
environmental impact assessment when it embarked on the construction of a road along the
San Juan River. Although he did not provide evidence in Certain Activities there is no reason why

his evidence should not be considered in that case as the two cases were joined and the issue of the
obligation of a State to conduct an environmental impact assessment prior to embarking on an
activity that risks causing significant transboundary harm arose in both cases. In his report in
Nicaragua’s Reply in the Construction of a Road , Dr. Sheate repeatedly stresses the sensitivity of

the two wetlands, the Refugio de Vida Silvestre and the Humedal Caribe Noreste, the fact that they
are designated by Ramsar as wetlands of international importance and the need to conduct an
environmental impact assessment in respect of any activity in the region. He declares that “[t]he
Ramsar and UNESCO designations covering the San Juan River and adjacent areas should have

been sufficient triggers on their own for an enviro25ental impact assessment or some form of
advance assessment to have been undertaken” . Later he goes further in saying that Ramsar
designation should “alone” be sufficient reason to require an environmental impact assessment . 26
Referring to the designation of an area as a Ramsar protected site, he states that “[t]he likelihood

of significant effects is increased because of the sensitive nature of the designated environment and
the habitats and wildlife for which the area has been designated  the threshold for triggering an
environmental impact assessment is therefore rightly expected to be much lower than if the
receiving environment were not a Ramsar designated area” . These opinions were restated by

Dr. Sheate in his Written Statement and his oral evidence.

31. It is difficult to conclude that an examination of the “reports submitted and testimony
given by experts called by both Parties” indicates that there was support for the finding that “the

dredging programme planned in 2006 was not such as to give rise to a risk of significant
transboundary harm . . . with respect to Costa Rica’s wetland” (Judgment, paragraph 105). The
documents/reports submitted by Nicaragua failed to examine the impact of the dredging
programme on Costa Rica’s wetlands at all. The fact that Nicaragua felt obliged to conduct an

environmental impact study in respect of its own territory, however, suggests that it had cause for
concern about the environmental impacts of its dredging on the area. The report of the Ramsar
Advisory Mission No. 72 of 2011 stated that dredging presented a risk of environmental impact on
the wetlands of both Costa Rica and Nicaragua and suggested that a new environmental impact

study be carried out. It also recommended that there be regular monthly monitoring of the
situation. Professor Kondolf had little to say about the impact of the dredging on the wetlands
while Professor van Rhee merely affirmed that dredging would promote the flow of water in the
river which would be beneficial to the wetlands. Moreover, he was unable to respond to questions

2“Comments on the Lack of EIA for the San Juan Border Road in Costa Rica, July 2014”, Reply of Nicaragua
(RN), Vol. II, Ann. 5, p. 281.
25
Ibid., pp. 284, 297.
2Ibid., p. 296.
27
Ibid., p. 297. - 12 -

about the Ramsar Report of 2011 because Nicaragua had failed to provide him with this important
report. Professor Thorne, on the other hand, made it clear that the dredging programme had serious
consequences for the wetlands. The only expert witness on environmental impact assessments,
Dr. Sheate, testified that the fact that an area had been designated a Ramsar site of international
importance was alone sufficient to trigger the need for an environmental impact assessment and
that there was a lower threshold for the assessment of risk of harm in such a designated area.

32. Rather than showing that there was no need for Nicaragua to conduct an environmental
impact assessment in respect of the risk of significant transboundary harm to Costa Rica’s
wetlands, the evidence contained in the reports and testimonies of witnesses called by both Parties
shows that there was a risk of harm to Costa Rica’s Ramsar-designated site at the time the dredging

was planned regardless of the fact that no harm was later proved. The Court should have held that
in a Ramsar-designated wetland there was a lower threshold of risk, that Nicaragua had failed to
show that it had considered the question of transboundary harm at all and that the risk to the
wetland was sufficient for Nicaragua to have conducted an environmental impact assessment that
examined the risk that its dredging programme posed to Costa Rica’s wetlands.

33. The temporal factor is important in assessing Nicaragua’s obligation to conduct an
environmental impact assessment. The planned aim of the dredging in 2006 was to improve
navigability on the San Juan River by deepening and widening the navigation channel . Both 28
van Rhee (above para. 28) and Thorne (above para. 29) testified that Nicaragua had reduced the
scale of the dredging programme that was planned in 2006. As a result of this the risk of harm to
the wetlands had been diminished. However, in assessing the risk for the purpose of deciding

whether Nicaragua should have conducted an environmental impact assessment, it is necessary to
have regard to the dredging programme as it was planned in 2006. This was the question that
required consideration and not the question whether the evidence of the implementation of the
dredging in 2015 showed that the dredging programme planned in 2006 was not such as to give rise
to a risk of significant transboundary harm. The evidence of Professor Thorne is important in this

regard. In his first report, included in Costa Rica’s Memorial, he provides a comprehensive
account of the potential environmental impact of the dredging as planned in 2006. But in his
Written Statement of 2015 he is less critical of this impact on account of the reduction of the
dredging that had been planned (above para. 29). That the original dredging plan of 2006 held a
risk of transboundary harm was confirmed by the Ramsar Report of 2011. Moreover, the clear
implication of Dr. Sheate’s evidence is that an environmental impact assessment was without doubt

required when a Ramsar-designated wetland was at risk. The Court’s pronouncement that “the
dredging programme planned in 2006 was not such as to give rise to a risk of significant
transboundary harm . . . with respect to . . . Costa Rica’s wetland” (Judgment, paragraph 105) based
on the reports submitted and the testimony given by experts called by both Parties takes no account
of the fact that Nicaragua’s documents/reports had nothing to say on this subject, that the Ramsar
Report of 2011 expressed serious concern about the risk to the environment and that the testimony

of witnesses showed on a balance of probabilities (and possibly beyond reasonable doubt) that
there was a risk to Costa Rica’s wetland in 2006. Furthermore it takes no account of the fact that
Costa Rica was prevented by Nicaragua from measuring the flow of water in the river to provide
proof of the impact of the dredging on its wetlands; and that Nicaragua had itself either not taken
such measurements or refused to disclose them. Such conduct on the part of Nicaragua affects the
burden of proof as was stated by the Court in the Corfu Channel case:

2See Environmental Impact Study for Improving Navigation on the San Juan de Nicaragua River,
September 2006, CMN, Vol. II, Ann. 7, para. 2.1.3. - 13 -

“exclusive territorial control exercised by a State within its frontiers has a bearing
upon the methods of proof available . . . By reason of this exclusive control, the other

State, the victim of a breach of international law, is often unable to furnish direct proof
of facts giving rise to responsibility. Such a State should be allowed a more liberal
recourse to inferences of fact and circumstantial evidence.” (Corfu Channel
(United Kingdom v. Albania), Merits, Judgment, I.C.J. Reports 1949, p. 18.)

34. The fact-finding of the Court cannot be substantiated. To make matters worse the
decision of the Court cannot be reconciled either with the reasoning on the obligation to conduct an

environmental impact assessment employed by the Court in Construction of a Road or with the
rules relating to environmental impact assessments expounded by the Court and set out in
paragraph 19 above. First, there is no examination of the factual situation of Costa Rica’s wetlands
of the kind carried out by the Court in respect of the road along the San Juan River (Judgment,
paragraph 155). Second, there is no suggestion that Nicaragua carried out “an objective evaluation
of all the relevant circumstances” (Judgment, paragraph 153). On the contrary, the Court itself
states that Nicaragua’s environmental study was confined to “its own environment” (Judgment,

paragraph 105). This flies in the face of the statement of the International Law Commission that an
environmental impact assessment should include an assessment of the effects of the activity “on the
environment of other States” (see above, para. 18). In these circumstances it is impossible to
conclude that Nicaragua had discharged the burden of proof in showing that it had carried out an
adequate preliminary assessment of the impact of its dredging programme on Costa Rica’s
wetlands. Third, the Court’s finding fails to take into account the circumstances affecting the
environment of the Lower San Juan River. In particular it does not mention that the Costa Rican

wetland in question  the Humedal Caribe Noreste  like the Nicaraguan wetland  the Refugio
de Vida Silvestre Río San Juan, invoked in the Construction of a Road, is a Ramsar Convention
protected wetland “which heightens the risk of significant damage because it denotes that the
receiving environment is particularly sensitive” (Judgment, paragraph 155). Fourth, the Court
disregards its requirement that a State must exercise due diligence in ascertaining whether there is a
risk of significant transboundary harm prior to undertaking an activity having the potential

adversely to affect the environment of another State (Judgment, paragraph 153). Nicaragua’s
environmental impact study which took no account of transboundary harm clearly failed to meet
the standard of due diligence. Fifth, the Court seems to have reached its conclusion that there was
no risk of significant transboundary harm when the dredging programme was planned in 2006 on
the basis of the evidence of witnesses testifying on the impact of the dredging in 2015. This
inference is drawn from the fact that the Court examined the impact of the dredging in its
consideration of the question whether it had caused significant transboundary harm in 2015 but not

the risk  a lower threshold  that it might cause significant transboundary harm in 2006. This
finding differs fundamentally from that of the Court in Construction of a Road where it was careful
to distinguish between the risk of transboundary harm when the Road was planned and the question
whether such harm had been proved in 2015. If the Court’s conclusion was reached in some other
way, it was careful to conceal this in paragraph 105.

35. The evidence examined shows that there was a risk of significant transboundary impacts

to Costa Rica’s wetlands arising from the dredging project as planned in 2006. This risk was not as
obvious or as great as that posed by the construction of Route 1856 in Construction of a Road.
Nevertheless there was a risk and Nicaragua had an obligation to carry out an environmental
impact assessment that examined not only the impact of the dredging on its own territory but also
the impact on Costa Rica’s territory. By failing to do so it breached its obligation under general
international law to conduct an environmental impact assessment. - 14 -

IX. Ramsar Convention

36. Certain Activities and Construction of a Road are both concerned with the protection of
the environment of wetlands and the Ramsar Convention is the most important multilateral
convention on this subject. It was the first conservation convention that focused exclusively on the
habitat. Both Parties appreciated the importance of the Ramsar Convention and accused each other
of violating its terms by failing to notify and consult each other in respect of potential
environmental impacts. In these circumstances one might have expected the Court to have more
seriously considered the relevance of the Convention to the two cases before it.

37. Two wetlands in the vicinity of the disputed territory and the Lower San Juan River are
listed with the Secretariat of Ramsar as Wetlands of International Importance: the Humedal Caribe
Noreste wetland of Costa Rica and the Refugio de Vida Silvestre San Juan of Nicaragua. Wetlands
are selected for listing on account of their international significance in terms of ecology, botany,
zoology, limnology or hydrology. Both wetlands include estuaries, lagoons and marshes and are
home to migratory birds, salamanders and aquatic life.

38. The legal provisions of the Ramsar Convention relating to notification and consultation
invoked by both Parties are Articles 3 (1) and 5 (1):

“Article 3

1. The Contracting Parties shall formulate and implement their planning so as to
promote the conservation of the wetlands included in the List, and as far as possible

the wise use of wetlands in their territory.

Article 5

The Contracting Parties shall consult with each other about implementing
obligations arising from the Convention especially in the case of a wetland extending
over the territories of more than one Contracting Party or where a water system is
shared by Contracting Parties. They shall at the same time endeavour to coordinate

and support present and future policies and regulations concerning the conservation of
wetlands and their flora and fauna.”

39. In Certain Activities Costa Rica alleged that Nicaragua had violated Article 5 (1) of the
Ramsar Convention by refusing to provide it with information about its dredging programme or to
inform it about the environmental impact study that it had conducted so that Costa Rica would have
been able to consider the impacts of the proposed works on its territory (Memorial of Costa Rica,

Vol. I, para. 5.17). Nicaragua contested this, arguing that the obligation to notify, consult or
provide an environmental impact assessment arose only under general international law where
there was a risk of a significant transboundary impact, but failed to address the obligation to
consult under Article 5 (1) of the Ramsar Convention which is not restricted to situations involving
a risk of significant transboundary impact. However, Nicaragua changed its position on this in the
Construction of a Road when it stated that “there is no requirement in this article [Art. 5 (1)] that a
party’s activities cause or risk causing significant harm to another party” (RN, Vol. I, para. 6.114).

40. Article 5 (1) requires States to consult with each other on the implementation of
“obligations arising from the Convention especially in the case of a wetland extending over the
territories of more than one Contracting State or where a water system is shared by Contracting - 15 -

Parties”. As the listed wetlands of Costa Rica and Nicaragua share a common water system it
follows that there is an obligation on both Parties to consult with each other on issues affecting this

shared water system.

41. Article 5 (1) must be read with Article 3 (1) which provides: “The Contracting Parties
shall formulate and implement their planning so as to promote the conservation of the wetlands

included in the List, and as far as possible the wise use of wetlands in their territory.” While the
“wise use of wetlands in their territory” obligation is limited to Nicaragua’s territory and thus may
not give rise to a specific obligation to consult, the same cannot be said of the first half of
Article 3 (1) dealing with listed wetlands. According to Lyster’s International Wildlife Law there is
“some form of collective responsibility for such sites” . Their designation as sites of international

importance30eans that they are “resources of ‘common concern’ to the international community as
a whole” . The obligation to formulate and implement planning so as to promote the conservation
of wetlands applies generally to all wetlands included in the List, and thus has extraterritorial
effect. “The precise nature and extent of their responsibility towards sites designated by other

States 31 uncertain, but should at least involve an obligation to avoid causing them significant
harm.”

42. Article 3 (1) should therefore be read as imposing an obligation to undertake planning

“to promote the conservation of the wetlands included in the List” which clearly covers the
wetlands of Costa Rica and Nicaragua that share the same water system. Thus it may convincingly
be argued that when Nicaragua planned its dredging programme in 2006 and carried out an
environmental impact study it was bound to “formulate and implement” its planned environmental

assessment study in such a way as to promote the conservation not only of its own wetland, the
Refugio de Vida Silvestre Río San Juan, but also of Costa Rica’s Humedal Caribe Noreste.
Article 3 (1) thus enlivens the procedural obligation to conduct an environmental impact
assessment under general international law, giving it a substantive content requirement  namely

to promote the conservation of the wetlands. It does not stipulate the circumstances in which such
planning is to take place, and is not subject to any separate threshold requirement. But it makes it
clear that the planning must be formulated and implemented to promote the conservation of
wetlands.

43. Nicaragua does not deny that there is a relationship between the environmental impact
assessment obligation and Article 3 (1). In its Memorial in Construction of a Road, alleging that
Costa Rica had breached Article 3 (1), it noted that Article 3 (1) applied whether or not the affected

wetland was within Costa Rican territory, and explained that conservation of wetlands “is premised
upon appropriate planning, something Costa Rica did not do in respect of its Road project”
(Memorial of Nicaragua (MN), Vol. I, paras. 5.74-5.75). Nicaragua accepted that the obligation
under Article 3 (1) applies equally to both Costa Rican and Nicaraguan wetlands (MN, Vol. I,
para. 5.74) and acknowledged the link between Article 3 (1) and the obligation to conduct an

environmental impact assessment (RN, Vol. I, paras. 6.112-6.115). As shown in paragraph 39
above, Nicaragua recognized that Article 5 (1) does not require proof of significant transboundary
harm to bring it into operation (RN, Vol. I, para. 6.114).

29
M. Bowman, P. Davies and C. Redgwell, Lyster’s International Wildlife Law, Cambridge, Cambridge
University Press, 2nd ed., 2010, p. 420.
3Ibid., p. 420.

3Ibid., p. 424. - 16 -

44. When read in conjunction with Article 3 (1), Nicaragua was obliged to consult with

Costa Rica on the promotion of conservation in both its own wetland and that of Costa Rica in its
planning of activities affecting the wetlands. This included the carrying out of an environmental
impact assessment. To effectively consult in the implementation of Article 3 (1), Nicaragua was
required at a minimum to provide a draft copy of its 2006 environmental impact study to
Costa Rica and to seek its input before finalizing its plans. Nicaragua does not contest that it failed
to do so, although it says that the information was publicly available, at least in summary form,
through Nicaraguan press sources. This is not sufficient to constitute consultation. It therefore

appears that Nicaragua is in breach of its obligations under Article 5 (1) of the Ramsar Convention
in that it failed to consult with Costa Rica on the implementation of Article 3 (1).

45. This final part of my opinion is concerned with Nicaragua’s failure to conduct an
adequate environmental impact assessment and to consult with Costa Rica in respect of its dredging
programme as required by the Ramsar Convention. It should, however, be made clear that

Costa Rica likewise breached its obligations under the Ramsar Convention by failing to conduct an
environmental impact assessment for the construction of a road along the San Juan River, which
forms part of Nicaragua’s wetland. It is in breach of Article 3 (1) because by not carrying out an
environmental impact assessment it failed to take measures to promote the conservation of the
listed wetlands. Costa Rica is also in breach of Article 5 (1) of the Ramsar Convention because it
failed to consult with Nicaragua on its planned activities involving the construction of the Road.

Paragraph 172 of the Judgment wrongly seems to assume that the obligation to consult under
Article 5 (1) of the Ramsar Convention only comes into operation when there is proof of significant
transboundary harm. As shown above, in paragraph 39, Article 5 (1) contains no such requirement.

(Signed) John D UGARD .

___________