In Kansas v. Colorado24 the question was raised whether one State has the right, by the construction of its irrigation works, seriously to deplete the water supply of a river which, rising in the defendant State, by nature flows into and through the plaintiff State. The case thus involved not only the technical question of the rights of riverain States to the water of rivers flowing into and through their respective territories, but whether the conflict of interests was one justiciable in the Supreme Court. The court means usually resorted to by independent sovereignties to terminate their differences can be invoked, it must appear that the States are in direct antagonism as States. Clearly this bill makes out no such state of case.
"If, however, on the case presented, it was competent for Missouri to implead the State of Illinois the only ground on which it can be rested is to be found in the allegation that its governor was about to authorize the water to be turned into the drainage channel.
"The sanitary district was created by an act of the general assembly of Illinois, and the only authority of the State having any control or supervision over the channel is that corporation. Any other control or supervision lies with the lawmaking power of the State of Illinois, and I cannot suppose that complainant seeks to coerce that. It is difficult to conceive what decree could be entered in this case which could bind the State of Illinois or control its action.
"The governor, it is true, was empowered by the act to authorize the water to be let into the channel on the receipt of a certificate, by commissioners appointed by him to inspect the work, that the channel was of the capacity and character required. This was done, and the water was let in on the day when the application was made to this court for leave to file the bill. The governor had discharged his duty, and no official act of Illinois, as such, remained to be performed.
"Assuming that a bill could be maintained against the sanitary district in a proper case, I cannot agree that the State of Illinois would be a necessary or proper party, or that this bill can be maintained against the corporation as the case stands.
"The act complained of is not a nuisance per se, and the injury alleged to be threatened is contingent. As the channel has been in operation for a year, it is probable that the supposed basis of complaint can now be tested. But it does not follow that the bill in its present shape should be retained.
"In my opinion both the demurrers should be sustained, and the bill dismissed, without prejudice to a further application, as against the sanitary district, if authorized by the state of Missouri."
24 185 U. S. 125; 22 Sup. Ct. Rep. 552; 46 L. ed. 838.
After a review of the authorities, the court show that the interests involved are substantial ones, ones which, as between sovereign States, would furnish sufficient ground for controversy, and that, therefore, the individual States being unable to deal with one another, either by diplomatic negotiation, treaty, or war, the General Government must have the right to intervene. The opinion declares:
"The action complained of is state action, and not the action of state officers in abuse or excess of their powers.
"The State of Colorado contends that, as a sovereign and independent State, she is justified, if her geographical situation and material welfare demand it in her judgment, in consuming for beneficial purposes all the waters within her boundaries; and that, as the sources of the Arkansas river are in Colorado, she may absolutely and wholly deprive Kansas and her citizens of any use of or share in the waters of that river. She says that she occupies toward the State of Kansas the same position that foreign States occupy toward each other, although she admits that the Constitution does not contemplate that controversies between members of the United States may be settled by reprisal or force of arms, and that to secure the orderly adjustment of such differences power was lodged in this court to hear and determine them. The rule of decision, however, it is contended, is the rule which controls foreign and independent States in their relations to each other; that by the law of nations the primary and absolute right of a State is self-preservation: that the improvement of her revenues, arts, agriculture, and commerce are incontrovertible rights of sovereignty; that she has dominion over all things within her territory, including all bodies of water, standing or running, within her boundary lines; that the moral obligations of a State to observe the demands of comity cannot be made the subject of controversy between states; and that only those controversies are justiciable in this court which, prior to the Union, would have been just cause for reprisal by the complaining State; and that, according to international law, reprisal can only be made when a positive wrong has been inflicted or rights stricti juris withheld.
"But when one of our States complains of the infliction of such wrong or the deprivation of such rights by another State, how shall the existence of cause of complaint be ascertained, and be accommodated if well founded ? The States of the Union cannot make war upon each other. They cannot 'grant letters of marque and reprisal.' They cannot make reprisal on each other by embargo. They cannot enter upon diplomatic relations, and make treaties.
"As Mr. Justice Baldwin remarked in Rhode Island v. Massachusetts : 'Bound hand and foot by the prohibitions of the Constitution, a complaining State can neither treat, agree, or fight with its adversary, without the consent of Congress. A resort to the judicial power is the only means left for legally adjusting or persuading a State which has possession of disputed territory to enter into an agreement or compact relating to a controverted boundary. Few, if any, will be made when it is left to the pleasure of the State in possession; but when it is known that some tribunal can decide on the right, it is most probable that controversies will be settled by compact.' 12 Pet. 657; 9 L. ed. 1233. . . ." 25
25 For a discussion of the legal points involved in this case see Journal of Political Economy, XI, 273, article, "The Present Status of Rights to Interstate Streams;" and Columbia Law Review, II, 364, article, "Notes on Suit9 Between States."