Protection of international watercourses

Protection of international watercourses

Malgosia Fitzmaurice
Professor of Public International Law, Queen Mary, University of London


I am very honoured to be asked to participate in the liber amicorum for Professor Attard whose contribution to the development of the law of the sea is of great and lasting significance and whose pioneering work on the legal character of exclusive economic zones opened a new era in international law.

This chapter will deal with another important aspect of international law – the law of international watercourses, a subject which is very controversial and certain aspects of which remain still unresolved, despite the existence of a significant case law, which crystallized many of the contentious issues and the signing of the 1997 Convention on the Non-Navigational Uses of International Watercourses (see below).

This chapter will be divided in three main parts: the general principles of water cooperation between states and watercourse protection; the protection of international watercourses: general considerations; and the protection of international watercourses and sustainable development: theoretical framework.

It is an incontrovertible statement that in the contemporary world, international environmental protection, including the protection of watercourses, is part and parcel of the process of sustainable development. Therefore, the protection of international watercourses will also be analysed from the point of view of sustainable development.

There are certain general principles of international water law, which also relate to the management of shared water resources which contribute to the implementation of the protection of watercourses. An example of such a principle is the prohibition on causing significant harm to watercourses.

The main substantive principles underlying watercourse cooperation

The main principles underlying international watercourse cooperation are those of equitable utilization and no-significant harm. These are also the fundamental principles of the 1997 Watercourses Convention.1 The text of the Convention is the result of an uneasy compromise achieved between conflicting interests of riparian and non-riparian states, upper riparian states and lower riparian states. Support for either of these principles depended on the geographical position of a state. The core provisions of the Convention are contained in Art. 5 (equitable utilization and participation)2 and Art. 7 (obligation not to cause significant harm). Art. 6 lists all the factors relevant to equitable and reasonable utilization that must be considered in order to determine whether the utilization of an international watercourse is conducted in an ‘equitable and reasonable’ manner.3 Art. 6(2)

1 The text of the Convention was adopted by the UNGA on 21 May 1997 and opened for signature. The text is available in ILM 36, 1997, p. 700. Available on-line at: It was the final product of 25 years of work of the International Law Commission (ILC). In Resolution 2669, XXV, which was adopted on 8 December 1970, the UNGA recommended that the ILC should study the law of non-navigational uses of international watercourses. On the Convention, see: M. Fitzmaurice, ‘Convention on Non-Navigational Uses of International Watercourses’, Leiden Journal of International Law 10(3), pp. 501–8; S. McCaffrey and M. Sinjela, ‘The 1997 United Nations Convention on International Watercourses’, Am. J. Int’l L. 92, 1998, 97–107; A. Tanzi and M. Arcari The United Nations Convention on the Law of International Watercourses. A Framework for Cooperation (London, Boston and The Hague: Kluwer Law International, 2001).

2 Art. 5:

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 the development thereof, as provided in the present Convention.

See on the fundamental principles: M. Fitzmaurice, ‘General principles governing the cooperation between states in relation to non-navigational uses of international watercourses’, Yearbook of International Environmental Law 14, 2003, pp. 3–45.

3 Art. 6:

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 circumstance, including:

(a) Geographic, hydrographic, hydrological, climatic, ecological and other factors of natural character;

(b) The social and economic needs of the watercourse States concerned;

(c) The population dependent on the watercourse in each watercourse States;

(d) The effects of the use or uses of the watercourse State on other watercourse States;

(e) Existing and potential uses of the watercourses;

(f) Conservation, protection, development and economy of the use of the water resources of the watercourse and the cost measures taken to this effect;

(g) Availability of alternatives, of comparable value, to a particular planned or existing use.

2 In application of article 5 or paragraph 1 of this article watercourse States concerned shall, when the need arises, enter into consultations in the spirit of cooperation.

3 The weight to be given to each factor is to be determined by its importance in comparison with that or other relevant factors. In determining what is reasonable and equitable use, all relevant factors are to be considered together and a conclusion reached on the basis of the whole.

specifies that in the application of Art. 5 and paragraph 1 of Art. 6 ‘watercourse States concerned shall when the need arises enter into consultations in a spirit of cooperation’. Art. 6(3) stipulates that the weight given to each factor is to be established by its importance in comparison with other factors. In the determination of what is reasonable and equitable use, all relevant factors are to be considered together and a conclusion reached on the basis of the whole. Art. 8 containing the general obligation to cooperate is linked to Art. 5.4

The second crucial provision contained in Art. 7 of the Watercourses Convention concerns the issues of no-significant harm.5 The so-called no-harm principle is derived from the maxim sic utere tuo ut alienum non laedas (use your property in such a manner as not to harm that of others).6 The terminology is not accurate as not all harm is prohibited and a degree of harm is permitted. The threshold of permissible harm is one of the unresolved issues in international environmental law. In relation to the Watercourses Convention it was formulated at the level of ‘non-significant’. Support for the application of this principle in general international law derives from the 1941 Trail Smelter arbitration (United States v. Canada).7 This case involved transboundary air pollution. Nonetheless, its findings also apply to the transboundary pollution of waters. Moreover, the Tribunal reached its decision drawing on practice regarding transboundary

4 Art. 8:

1 Watercourse States shall cooperate on the basis of sovereign equality, territorial integrity, mutual benefits and good faith in order to attain optimal utilization and adequate protection of an international watercourse.

2 In determining the manner of such cooperation, watercourse States may consider the establishment of joint mechanism or commissions, as deemed necessary by them, to facilitate cooperation on relevant measures and procedures in light of experience gained through cooperation in existing joint mechanisms and commissions in various regions.

5 Art. 7:

1 Watercourse States shall, in utilizing an international watercourse in their territories, take all appropriate measures to prevent the causing of significant harm to other watercourse States.

2 When significant harm nevertheless is caused to another watercourse State, the States whose use causes such harm shall, in the absence of agreement to such uses, take all appropriate measures, having due regard for the provisions of Articles 5 and 6, in consultation with the affected State, to eliminate or mitigate such harm and, where appropriate, to discuss the question of compensation.

6 L. Caflisch, ‘Sic utere tuo ut alienum non laedas: Règle prioritaire ou element pour determine le droit d’utilisation equitable et raisonnable d’un cours d’eau international?’ in A. von Ziegler et al., International les Recht auf See und Binnengwässern, Festschrift für Walter Müller (Zurich: Schulthess, 1993), pp. 27–47; L. Caflisch, ‘Règles générales du droit des cours des eaux internation-aux’, Recueil des Cours 219, 1989, pp. 9–226.

7 Trail Smelter Case (United States, Canada), 16 April 1938 and 11 March 1941, Reports of International Arbitral Awards, vol. III, pp. 1905–82; see also Am. J. Int’l L. 35, 1941, p. 684.

pollution of waters between states in the USA. The most often cited statement is as follows:

[n]o State has the right to use or permit to use of its territory in such a manner as to cause injury by fumes in or to the territory of another of properties or persons therein, when the case is of serious consequence and the injury is established by clear and convincing evidence.

As can be seen, the threshold of harm in this case, is set at the level of ‘seriousness’.

The 1949 Corfu Channel case was another general decision, which is interpreted as formulating the prohibition of transboundary harm.8 The Court enunciated the very well-known principle that ‘every State’s obligation not to allow knowingly its territory to be used for acts contrary to the rights of other States’. It appears that to link this statement directly to the law of international watercourses, or even to international environmental law, is somewhat stretched, as the Court did not specify what rights of a state it had in mind. An alternative perspective on the Court’s statement is that a state’s right to use its territory is not unlimited and ‘the view may thus be taken as supporting the doctrine of equitable utilisation as much as that of no-harm’.9 The no-harm principle was incorporated into numerous international instruments of hard and soft character, one of the best known being Principle 21 of the Stockholm Declaration on Human Environment. It provides in its first paragraph the following:

States, have in accordance with international law, the sovereign right to exploit their own resources pursuant to their own environmental policies, and the responsibility to ensure that activities within their jurisdiction or control do not cause damage to the environment of other States or areas beyond the limits of national jurisdiction.

This principle with some changes was incorporated in the 1992 Rio Declaration on Environment and Development.10 This threshold of harm was set at ‘significant’ in the 1997 Watercourses Convention. It was reached after many heated discussions within the ILC during which other limits were debated such as ‘substantial’ or ‘appreciable’. The Memorandum of Understanding attached to the 1997 Convention explains that

the term ‘significant’ is not used in the present Convention in the sense of ‘substantial’. What are to be avoided are localized agreements, or agreements concerning a particular project, programme or use, which have a significant adverse effect upon third watercourse States. While such effect must be

8 Corfu Channel case, judgment of 15 December 15 1949: ICJ Reports 1949, p. 244.

9 S. McCaffrey, The Law of International Watercourses, Non-Navigational Uses (Oxford: Oxford University Press, 2001), p. 355.

10 The ICJ in the Advisory Opinion on the Legality of the Threat or Use of Nuclear Weapons stated that this legal principle was codified in Principle 21 of the Stockholm Declaration. See Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, ICJ Reports 1996, p. 226, p. 241, para. 27.

capable of being established by objective evidence and not trivial in nature, it need not rise to the level of being substantial.11

The relationship between the principle of equitable utilization, the no-harm rule and the principle of due diligence – ‘all appropriate measures’ – has had a long and troubled history and was exacerbated by the lack of clarity as to the legal nature of each of these three elements. The ILC struggled to link them together in a coherent manner without much success. In particular, the question as to which element – equitable utilization or the prohibition of significant harm – has priority, was not fully clarified. The awkward drafting of Arts. 5 and 7 in the Watercourses Convention did little to disperse doubts and confusion surrounding the relationship between principles of no-significant harm, equitable utilization and due diligence (appropriate measures standard).12 However, it must also be noted that this Convention contains a very extensive set of procedural obligations, which include, inter alia, notification of planned measures, adequate notice to give time for response and regular exchange of available data.

The protection of international watercourses: general considerations

The most important development is the inclusion of the protection of international watercourses into the legal structure of the law of international watercourses. Traditionally, international water law was focused of the apportionment of water rights between private entities and states at the international level. However, the 1966 ILA Helsinki Rules already included Articles on the protection against pollution.13

Article IX states: ‘As used in this chapter, the term “water pollution” refers to any detrimental change resulting from human conduct in the natural composition, content, or quality of the waters of an international drainage basin.’ It has to be noted that these Rules linked the protection against pollution with the rules of the equitable utilization. Article X provided that:

1 Consistent with the principle of equitable utilization of the waters of an international drainage basin, a State:

(a) Must prevent any new form of water pollution or any increase in the degree of existing water pollution in an international drainage basin which would cause substantial injury in the territory of a co-basin State;

11 Statements of Understanding Pertaining to Certain Articles of the Convention, ILM 36, 1997, p. 719.

12 However, please note also that Tanzi and Arcari claim that the Convention has the perfect balance between the principles of equitable utilization and no harm, A. Tanzi and M. Arcari, The United Nations Convention on the Law of International Watercourses. A Framework for Cooperation (London, Boston and The Hague: Kluwer Law International, 2001), p. 178.

13 The Helsinki Rules on the Uses of the Waters of International Rivers adopted by the International Law Association at the 52nd conference, held at Helsinki in August 1966. Report of the Committee on the Uses of the Waters of International Rivers, London: ILA, 1967.

The 1997 United Nations Watercourses Convention developed these provisions and added a new Part on Protection, Preservation and Management. Article 20 (Protection and preservation of ecosystems) states: ‘Watercourse States shall, individually and, where appropriate, jointly, protect and preserve the ecosystems of international watercourses.’ This provision is styled on the UNCLOS,15 which in Article 192 includes an obligation on states to protect the marine environment.16 Despite the use of the term ‘shall’ the obligation contained both in the UNCLOS and the Watercourses Convention is not absolute but of due diligence character.

Article 21 specifically addresses the prevention of pollution as one of the elements of the general environmental protection.17 Article 24 has significant

14 Of importance as well are para. 2 of Article X and Article XI. Article 10(2) provides that ‘The rule stated in paragraph 1 of this article applies to water pollution originating: (a) Within a territory of the State, or (b) Outside the territory of the State, if it is caused by the State’s conduct.’ Article XI then provides that:

1 In the case of a violation of the rule stated in paragraph 1(a) of article X of this chapter, the State responsible shall be required to cease the wrongful conduct and compensate the injured co-basin State for the injury that has been caused to it.

2 In a case falling under the rule stated in paragraph 1(b) of article X, if a State fails to take reasonable measures, it shall be required promptly to enter into negotiations with the injured State with a view towards reaching a settlement equitable under the circumstances.

15 United Nations Convention on the Law of the Sea, 1982.

16 Article 192 of the UNCLOS: ‘General Obligation: States have the obligation to protect and preserve the marine environment’.

17 Article 21 – Prevention, reduction and control of pollution:

1 For the purpose of this article, “pollution of an international watercourse” means any detrimental alteration in the composition or quality of the waters of an international watercourse which results directly or indirectly from human conduct.

2 Watercourse States shall, individually and, where appropriate, jointly, prevent, reduce and control the pollution of an international watercourse that may cause significant harm to other watercourse States or to their environment, including harm to human health or safety, to the use of the waters for any beneficial purpose or to the living resources of the watercourse. Watercourse States shall take steps to harmonize their policies in this connection.

3 Watercourse States shall, at the request of any of them, consult with a view to arriving at mutually agreeable measures and methods to prevent, reduce and control pollution of an international watercourse, such as:

(a) Setting joint water quality objectives and criteria;

(b) Establishing techniques and practices to address pollution from point and non-point sources;

(c) Establishing lists of substances the introduction of which into the waters of an international watercourse is to be prohibited, limited, investigated or monitored.

importance for the protection of international watercourses, as well as linking directly the protection of the riparian environment with sustainable development.18

The term ‘joint management mechanisms’, refers to river commissions which are the most commonly established mechanism for the management of joint watercourses. There are a multitude of examples of such bodies such as the Mekong River Commission or the Danube River Commission. The powers and scope of jurisdiction of such bodies varies greatly. The ICJ in the 1997 Gabcikovo-Nagymaros case supported the establishment of joint regime of the management between the parties to the dispute.19

Article 24 also states that the management is based on sustainable development. From this we may infer that, in general, the protection of watercourses should rely on this principle. The Court very forcefully emphasized in the Gabcikovo-Nagymaros case the necessity of placing international environmental law and the water law within the context of sustainable development.20

The new approach to the protection of watercourse resources was further strengthened by the Berlin Rules adopted in 2004 by the ILA.21 These Rules rely on the modern principles of watercourse management and sustainable development.

As it was stated by J. Delapenna, who was the Rapporteur of the ILA Water Resources Law Committee which adopted the Rules:

The new paradigm found in the Berlin Rules has gained acceptance in customary international law over the last 30 years or so without being fully identified or articulated before. This paradigm includes of five general principles that apply to States in the management of all waters, wholly national or domestic waters as well as internationally shared waters: 1. Participatory water management …; 2. Conjunctive management …; 3. Integrated management …; 4. Sustainability …; and 5. Minimization of environmental harm …22

18 Article 24 – Management:

1 Watercourse States shall, at the request of any of them, enter into consultations concerning the management of an international watercourse, which may include the establishment of a joint management mechanism.

2 For the purposes of this article, ‘management’ refers, in particular, to:

(a) Planning the sustainable development of an international watercourse and providing for the implementation of any plans adopted; and

(b) Otherwise promoting the rational and optimal utilization, protection and control of the watercourse.

19 Gabcikovo-Nagymaros Project (Hungary/Slovakia), judgment, ICJ Reports 1997, p. 7, e.g. paras 144 and 147.

20 Gabcikovo-Nagymaros Project (Hungary/Slovakia), judgment, ICJ Reports 1997, p. 7, para. 140.

21 ILA, Berlin Conference 2004, text of the Rules available on the ILA website.

22 J. Dellapenna, ‘The Berlin Rules on Water Resources: the new paradigm for international water law’. Available on-line at:

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