State Jurisdiction over Water

• Author: John H. Currie; Craig Forcese; Joanna Harrington; Valerie Oosterveld
• Pages: 373-449

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CHAPTER 5

State Jurisdiction over Water

Water covers more than  percent of the Earth’s surface. Human beings obviously do not

inhabit this “territory” in the same way they do land. Yet the oceans, rivers, and lakes of

the world are an important source of resources, both biotic and mineral. They also provide

fundamentally important means of transportation that are vital to travel, trade, and security.

States therefore have an intense interest in the jurisdictional regimes applicable to the water

regions of the world.

In our discussion of state jurisdiction over water, we rst examine “inland” waterways

and then turn to oceans.

A. INLA ND WATERWAYS

Inland waterways are those bodies of water or watercourses, such as lakes and rivers, that

are enclosed by land. It is dicult to extract generic rules of international law from the many

legal regimes that govern the world’s inland waterways. Most signicant rivers and lakes that

are bounded by more than one state are regulated by treaty, the specic terms of which vary.

Consider, for example, comments made by the International Court of Justice (ICJ) in a case

concerning rights of navigation along one particular inland waterway:

Dispute Regarding Navigational and Related Rights (Costa Rica v Nicaragua), Judgment, []

ICJ Rep 

. According to Costa Rica, its right of free navigation on the part of the San Juan river

that is in dispute derives on the one hand from certain treaty provisions in force between

the Parties, primarily but not exclusively the Treaty of Limits of  April , and on the

other hand from the rules of general international law that are applicable, even in the

absence of treaty provisions, to navigation on “international rivers”. The San Juan is said

to fall into this category, at least as regards the section whose course follows the border,

with Costa Rica thus possessing a customary right of free navigation in its capacity as a

riparian State.

. According to Nicaragua, on the contrary, the San Juan is not an “international river”,

since it ows entirely within the territory of a single country by virtue of the provisions

of the  Treaty of Limits, which establish the border in such a way that no part of the

river falls under the sovereignty of a State other than Nicaragua. Moreover, Nicaragua

challenges the existence of a general régime that might be applicable, under customary

international law, to rivers whose course, or one of whose banks, constitutes the bor-

der between two States, and more widely to “international rivers”. Lastly, according to

 INTERNATIONAL LAW: DOCTRINE, PRACTICE, AND THEORY

Nicaragua, even if such a régime were to exist, it would be superseded in this case by the

treaty provisions which dene the status of the San Juan river and govern the riparian

States’ right of navigation. It is these special provisions which should be applied in order

to settle the present dispute, in any event that part of it relating to the right of navigation

on the river.

. The Court does not consider that it is required to take a position in this case on

whether and to what extent there exists, in customary international law, a régime applic-

able to navigation on “international rivers”, either of universal scope or of a regional

nature covering the geographical area in which the San Juan is situated. Nor does it con-

sider, as a result, that it is required to settle the question of whether the San Juan falls

into the category of “international rivers”, as Costa Rica maintains, or is a national river

which includes an international element, that being the argument of Nicaragua.

. Indeed, even if categorization as an “international river” would be legally relevant in

respect of navigation, in that it would entail the application of rules of customary inter-

national law to that question, such rules could only be operative, at the very most, in

the absence of any treaty provisions that had the eect of excluding them, in particular

because those provisions were intended to dene completely the régime applicable to

navigation, by the riparian States on a specic river or a section of it.

. That is precisely the case in this instance. The  Treaty of Limits completely

denes the rules applicable to the section of the San Juan river that is in dispute in

respect of navigation. Interpreted in the light of the other treaty provisions in force

between the Parties, and in accordance with the arbitral or judicial decisions rendered on

it, that Treaty is sucient to settle the question of the extent of Costa Rica’s right of free

navigation which is now before the Court. Consequently, the Court has no need to con-

sider whether, if these provisions did not exist, Costa Rica could nevertheless have relied

for this purpose on rules derived from international, universal or regional custom. . . .

Given the situation-specic nature of most inland waterway legal regimes, we can only

make a few general observations about the international law governing these regimes, and

then turn to one specic example: the Canada–US inland waterways regime.

) General Observations

In simple terms, we can divide inland waterways into three categories: those that are entirely

within the territory of a single state; those that ow from one state to another; and those

that lie or ow along a border between states. Inland waterways completely enclosed by a

single state present relatively few diculties in international law: “Where a river lies wholly

within the territory of one state, it belongs entirely to that state, and generally speaking no

other state is entitled to rights of navigation on it.” In other words, such inland waterways

are part of a state’s sovereign territory in much the same way as its land territory. The state

enjoys plenary jurisdiction over these waterways.

Rivers and lakes that straddle or demarcate international borders cause greater compli-

cations. Consider this discussion of navigation rights:

Also where a river passes through several states, each state owns that part of the river

which runs through its territory, but controversy has centred round the question of the

 Ivan A Shearer, Starke’s International Law, th ed (Toronto: Butterworths, ) at .

Chap ter : State Juris diction over Water 

rights of riparian and other states to navigate along the whole length of the river. Several

writers on international law . . . have been of the opinion that there is a general right of

passage for all states along such international rivers, but this view has never been gen-

erally accepted in practice, and is certainly not recognized as a customary principle of

international law. . . . [S]uch measures of freedom of navigation as become established

on international waterways [are] almost entirely the creation of treaty.

Water in international inland waterways is also a key resource, use of which may cause

frictions between states. Consider these observations:

It is believed that there is a general readiness of states to admit that any . . . use or diver-

sion [of,] or interference [with, water ow] by one riparian state injuring the free navig-

ability of a navigable international waterway to the detriment of a co-riparian state is a

breach of international law. Short of this, it is perhaps only possible to say that there is

a duty on a riparian state not, by any use of the river waters under its control to cause

grievous or irreparable damage of an economic character on other riparian states, for

example pollution, which might reasonably have been prevented. . . . Where the rivers

concerned form part of a drainage basin, each riparian state is entitled to a reasonable

and equitable share in the benecial uses of the waters of the basin, a principle applied

in numerous treaties.

The International Law Commission (ILC) has attempted to give eect to some of these

general principles, with its eorts reected in the following treaty:

Convention on the Law of the Non-Navigational Uses of International Watercourses,  May ,

 UNTS  in force  August 

PART II .

GENERAL PR INCIPLES

Article 

Equitable and reasonable utilizat ion and participation

. Watercourse States shall in their respective territories utilize an international water-

course in an equitable and reasonable manner. In particular, an international water-

course shall be used and developed by watercourse States with a view to attaining optimal

and sustainable utilization thereof and benets therefrom, taking into account the inter-

ests of the watercourse States concerned, consistent with adequate protection of the

watercourse.

. 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 protec-

tion and development thereof, as provided in the present Convention.

Article 

Factors relev ant to equitable and reasonable utilization

. Utilization of an international watercourse in an equitable and reasonable manner

within the meaning of article  requires taking into account all relevant factors and cir-

cumstances, including:

 Ibid.

 Ibid at .