The Law of Nations or the Principles of Natural Law (1758)

Emmerich de Vattel

Of Rivers, Streams, and Lakes

§ 266. A river that separates two territories.
WHEN a nation takes possession of a country, with a view to settle there, it takes possession of every thing included in it, as lands, lakes, rivers, etc. But it may happen that the country is bounded and separated from another by a river; in which case, it is asked, to whom this river belongs. It is manifest, from the principles established in Chap. XVIII., that it ought to belong to the nation who first took possession of it. This principle cannot be denied; but the difficulty is, to make the application. It is not easy to determine which of the two neighboring nations was the first to take possession of a river that separates them. For the decision of such questions, the rules which may be deducted from the principles of the law of nations are as follows: —

1. When a nation takes possession of a country bounded by a river, she is considered as appropriating to herself the river also: for, the utility of a river is too great to admit a supposition that the nation did not intend to reserve it to herself. Consequently, the nation that first established her dominion on one of the banks of the river is considered as being the first possessor of all that part of the river which bounds her territory. When there is a question of a very broad river, this presumption admits not of a doubt, so far, at least, as relates to a part of the river’s breadth; and the strength of the presumption increases or diminishes in an inverse ratio with the breadth of a river; for, the narrower the river is, the more does the safety and convenience of its use require that it should be subject entirely to the empire and property of that nation.1

2. If that nation has made any use of the river, as, for navigating or fishing, it is presumed with the greatest certainty that she has resolved to appropriate the river to her own use.

3. If, of two nations inhabiting the opposite banks of the river, neither party can prove that they themselves, or those whose rights they inherit, were the first settlers in those tracts, it is to be supposed that both nations came there at the same time, since neither of them can give any reason for claiming the preference; and in this case the dominion of each will extend to the middle of the river.2

4. A long and undisputed possession establishes the right of nation,3 otherwise there could be no peace, no stability between them; and notorious facts must be admitted to prove the possession. Thus, when from time immemorial a nation has, without contradiction, exercised the sovereignty upon a river which forms her boundary, nobody can dispute with that nation the supreme dominion over the river in question.

5. Finally, if treaties determine any thing on this question, they must be observed. To decide it by accurate and express stipulations, is the safest mode; and such is, in fact, the method taken by most powers at present.

§ 267. Of the bed of a river which is dried up, or takes another course.
If a river leaves its bed, whether it be dried up or takes its course elsewhere, the bed belongs to the owner of the river; for, the bed is a part of the river; and he who had appropriated to himself the whole, had necessarily appropriated to himself all its parts.

§ 268. The right of alluvion.4
If a territory which terminates on a river has no other boundary than that river, it is one of those territories that have natural or indeterminate bounds (territoria arcifinia), and it enjoys the right of alluvion; that is to say, every gradual increase of soil, every addition which the current of the river may make to its bank on that side, is an addition to that territory, stands in the same predicament with it, and belongs to the same owner. For, if I take possession of a piece of land, declaring that I will have for its boundary the river which washes its side, — or if it is given to me upon that footing, — I thus acquire, beforehand, the right of alluvion; and, consequently, I alone may appropriate to myself whatever additions the current of the river may insensibly make to my land: — I say “insensibly,”; because in the very uncommon case called avulsion, when the violence of the stream separates a considerable part from one piece of land and joins it to another, but in such manner that it can still be identified, the property of the soil so removed naturally continues vested in its former owner. The civil laws have thus provided against and decided this case, when it happens between individual and individual; they ought to unite equity with the welfare of the state, and the care of preventing litigations.

In case of doubt, every territory terminating on a river is presumed to have no other boundary than the river itself: because nothing is more natural than to take a river for a boundary, when a settlement is made; and wherever there is a doubt, that is always to be presumed which is most natural and most probable.

§ 269. Whether alluvion produces any change in the right to a river.
As soon as it is determined that a river constitutes the boundary line between two territories, whether it remains common to the inhabitants on each side of its banks, or whether each shares half of it, or, finally, whether it belongs entirely to one of them, their rights with respect to the river are in no wise changed by the alluvion. If, therefore, it happens that, by a natural effect of the current, one of the two territories receives an increase, while the river gradually encroaches on the opposite bank, the river still remains the natural boundary of the two territories, and notwithstanding the progressive changes in its course, each retains over it the same rights which it possessed before; so that, if, for instance, it be divided in the middle between the owners of the opposite banks, that middle, though it changes its place, will continue to be the line of separation between the two neighbors. The one loses, it is true, while the other gains; but nature alone produces this change: she destroys the land of the one, while she forms new land for the other. The case cannot be otherwise determined, since they have taken the river alone for their limits.

§ 270. What is the case when the river changes its bed.
But if, instead of a gradual and progressive change of its bed, the river, by an accident merely natural, turns entirely out of its course, and runs into one of the two neighboring states, the bed which it has abandoned becomes, thenceforward, their boundary, and remains the property of the former owner of the river (§ 267); the river itself is, as it were, annihilated in all that part, while it is reproduced in its new bed, and there belongs only to the state in which it flows.

This case is very different from that of a river which changes its course without going out of the same state. The latter, in its new course, continues to belong to its former owner, whether that owner be the state, or any individual to whom the state has given it; because rivers belong to the public in whatever part of the country they flow. Of the bed which it has abandoned, a moiety accrues to the contiguous lands on each side, if they are lands that have natural boundaries, with the right of alluvion, That bed (notwithstanding what we have said in § 267) is no longer the property of the public, because of the right of alluvion vested in the owners of its banks, and because the public held possession of the bed only on account of its containing a river. But if the adjacent lands have not natural boundaries, the public still retains the property of the bed. The new soil over which the river takes its course is lost to the proprietor, because all the rivers in the country belong to the public.

§ 271. Works tending to turn the current.5
It is not allowable to raise any works on the bank of a river, which have a tendency to turn its course, and to cast it upon the opposite bank: this would be promoting our own advantage at our neighbor’s expense. Each can only secure himself, and hinder the current from undermining and carrying away his land.6

§ 272. or, in general, prejudicial to the rights of others.7
In general, no person ought to build on a river, any more than elsewhere, any work that is prejudicial to his neighbor’s rights. If a river belongs to one nation, and another has an incontestible right to navigate it, the former cannot erect upon it a dam or a mill which might render it unfit for navigation. The right which the owners of the river possess in this case is only that of a limited property; and, in the exercise of it, they are bound to respect the rights of others.

§ 273. Rules in relation to interfering rights.
But, when two different rights to the same thing happen to clash with each other, it is not always easy to determine which ought to yield to the other: the point cannot be satisfactorily decided, without attentively considering the nature of the rights and their origin. For example, a river belongs to me, but you have a right to fish in it: and the question is, whether I may erect mills on my river, whereby the fishery will become more difficult and less advantageous? The nature of our rights seems to determine the question in the affirmative. I, as proprietor, have an essential right over the river itself: — you have only a right to make use of it — a right which is merely accessory, and dependent on mine; you have but a general right to fish as you can in my river, such as you happen to find it, and in whatever state I may think fit to possess it. I do not deprive you of your right by erecting my mills: it still exists in the general view of it; and, if it becomes less useful to you, it is by accident, and because it is dependent on the exercise of mine.8

The case is different with respect to the right of navigation, of which we have spoken. This right necessarily supposes that the river shall remain free and navigable, and therefore excludes every work that will entirely interrupt its navigation.

The antiquity and origin of the rights serve, no less than their nature, to determine the question. The more ancient right, if it be absolute, is to be exerted in its full extent, and the other only so far as it may be extended without prejudice to the former; for, it could only be established on this fooling, unless the possessor of the first right has expressly consented to its being limited.

In the same manner, rights ceded by the proprietor of any thing are considered as ceded without prejudice to the other rights that belong to him, and only so far as they are consistent with these latter, unless an express declaration, or the very nature of the right, determine it otherwise. If I have eded to another the right of fishing in my river, it is manifest that I have ceded it without prejudice to my other rights, and that I remain free to build on that river such works as I think proper, even though they should injure the fishery, provided they do not altogether destroy it.9 A work of this latter kind, such as a dam that would hinder the fish from ascending it, could not be built but in case of necessity, and on making, according to circumstances, an adequate compensation to the person who has a right to fish there.

§ 274. Lakes.
What we have said of rivers and streams, may be easily applied to lakes. Every lake, entirely included in a country, belongs to the nation that is the proprietor of that country; for in taking possession of a territory, a nation is considered as having appropriated to itself every thing included in it; and, as it seldom happens that the property of a lake of any considerable extent falls to the share of individuals, it remains common to the nation. If this lake is situated between two states, it is presumed to be divided between them at the middle, while there is no title, no constant and manifest custom, to determine otherwise.

§ 275. Increase of a lake.
What has been said of the right of alluvion, in speaking of rivers, is also to be understood as applying to lakes. When a lake which bounds a state belongs entirely to it, every increase in the extent of that lake falls under the same predicament as the lake itself; but it is necessary that the increase should be insensible, as that of land in alluvion, and moreover that it be real, constant, and complete. To explain myself more fully. — 1. I speak of insensible increase: this is the reverse of alluvion; the question here relates to the increase of a lake, as in the other case, to an increase of soil. If this increase be not insensible, — if the lake, overflowing its banks, inundates a large tract of land, this new portion of the lake, this tract thus covered with water, still belongs to its former owner. Upon what principles can we found the acquisition of it in behalf of the owner of the lake? The space is very easily identified, though it has changed its nature: and it is too considerable to admit a presumption that the owner had no intention to preserve it to himself, notwithstanding the changes that might happen to it.

But 2. If the lake insensibly undermines a part of the opposite territory, destroys it, and renders it impossible to be known, by fixing itself there, and adding it to its bed, that part of the territory is lost to its former owner; it no longer exists; and the whole of the lake thus increased still belongs to the same state as before.

3. if some of the lands bordering on the lake are only overflowed at high water, this transient accident cannot produce any change in their dependence. The reason why the soil which the lake invades by little and little belongs to the owner of the lake and is lost to its former proprietor, is, because the proprietor has no other boundary than the lake, nor any other marks than its banks, to ascertain how far his possessions extend. If the water advances insensibly, he loses; if it retires in like manner, he gains; such must have been the intention of the nations who have respectively appropriated to themselves the lake and the adjacent lands: — it can scarcely be supposed that they had any other intention. But a territory overflowed for a time is not confounded with the rest of the lake: it can still be recognized; and the owner may still retain his right of property in it. Were it otherwise, a town overflowed by a lake would become subject to a different government during the inundation, and return to its former sovereign as soon as the waters were dried up.

4. For the same reasons, if the waters of the lake, penetrating by an opening into the neighboring country, there form a bay, or new lake, joined to the first by a canal, this new body of water and the canal belong to the owner of the country in which they are formed, For the boundaries are easily ascertained: and we are not to presume an intention of relinquishing so considerable a tract of land in case of its happening to be invaded by the waters of an adjoining lake.

It must be observed that we here treat the question as arising between two states: it is to be decided by other principles when it relates to proprietors who are members of the same state. In the latter case, it is not merely the bounds of the soil, but also its nature and use, that determine the possession of it. An individual who possesses a field on the borders of a lake, cannot enjoy it as a field when it is overflowed; and a person who has, for instance, the right of fishing in the lake, may exert his right in this new extent: if the waters retire, the field is restored to the use of its former owner. If the lake penetrates by an opening into the low lands in its neighborhood, and there forms a permanent inundation, this new lake, belongs to the public, because all lakes belong to the public.

§ 276. Land formed on the banks of a lake.
The same principles show, that if the lake insensibly forms an accession of land on its banks, either by retiring or in any other manner, this increase of land belongs to the country which it joins, when that country has no other boundary than the lake. It is the same thine as alluvion on the banks of the river,

§ 277. Bed of a lake dried up.
But, if the lake happened to be suddenly dried up, either totally or in a great part of it, the bed would remain in the possession of the sovereign of the lake; the nature of the soil, so easily known, sufficiently marking out the limits.

§ 278. Jurisdiction over lakes and rivers.
The empire or jurisdiction over lakes and rivers is subject to the same rules as the property of them, in all the cases which we have examined. Each state naturally possesses it over the whole or the part of which it possesses the domain. We have seen (§ 245) that the nation, or its sovereign, commands in all places in its possession.


     1.    As regards private rights, there is no legal presumption that the soil of a navigable river belongs to the owners of the adjoining lands, ex utraque parte, or otherwise, Rex v. Smith, 2 Doug. 411. {Palmer v. Hicks, 66 Johns Rep. 133.}
     2.    5 Wheat. Rep. 374, 379; 3 Mass, Rep. 147.
     3.    As to what is a sufficiently long and undisturbed possession, by the law of France, Jersey, and England, in general, see Benest v. Pipon, Knapp’s Rep. 67.
     4.    As to the rights of alluvion, or sudden derelict in general, see The King v. Yarborough, 1 Dow Rep. New Series, 178; 4 Dowl. & Ry. 799; 3 Barn. & Cres. 91, S.C.; 5 Bing. 163, 169; 1 Thomas Co. Lit. 47, in note; Scuites on Aquatic Rights; Chitty’s General Practice, 199, 200. {2 Johns. Rep. 322; 3 Mass. Rep. 325; 2 Hall’s L. Journ. 307; 5 Hall’s L. Journ. 1, 113.)
     5.    This principle of the law of nations has been ably discussed as part of the municipal law of Scotland and England in Menzies v. Breadalbone, 3 Wils. & Shaw, 235; and see The King v. Lord Yarborough, 1 Dow. Rep., New Series, 179; and Wright v. Howard. 1 Sim. & Stu. 190; Rex v. Trafford, 1 Barn. & Adolph. 874, and Chitty’s General Practice, 610. {4 Dall. Rep. 211; 13 Mass. 420, 507; 3 Har. & McHen. 441; 2 Conn. Rep. 584; Coxe’s Rep, 460.)
     6.    That is permitted as well as a bank or groove to prevent an alteration in the current. Rex v. Pagham, 8 Barn. & Cress. 355; Rex v. Trafford, 1 Barn. & Adolph. 874; 2 Man. & Ryl, 468; 1 Moore & Scott, 401; 8 Bing. 204. (in error.)
     7.    Ibid.
     8.    But this doctrine seems questionable. See Wright v. Howard, 1 Sim. & Stu. 190; and Mason v. Hill, 3 Barn. & Adolph. 304; Chitty’s General Prac. 191, 192. Even a right of irrigating at reasonable times may qualify the absolute and general right to the use of the water for working a mill.
     9.    Ibid.