Opinion of the Court. docks, landing places, piers and wharves out to navigable waters if the river is navigable in fact, but if it is not so navigable he may construct anything he pleases to the thread of the stream, unless it injures some other riparian proprietor, or those having the superior right to use the waters for hydraulic purposes. Subject to these restrictions, he has the right to use his land under water the same as above water. It is his private property under the protection of the constitution, and it cannot be taken, or its value lessened or impaired, even for public use, without compensation,' or 'without due process of law,' and it cannot be taken at all for any one's private use." With respect to such rights, we have held that the law of the State, as declared by its Supreme Court is controlling as a rule of property. Barney v. Keokuk, 94 U. S. 324; Packer v. Bird, 137 U. S. 661; Hardin v. Jordan, 140 U. S. 371. There is no doubt, under the facts of this case, that the owner of lot 5 was entitled to compensation for the land appropriated by the State in the construction of the dam and of the embankment in front of the lot. To what extent he was entitled to the use of the water power created by the dam, as against the public and the other riparian owners, may be difficult of ascertainment, depending as it does largely upon the number of proprietors, the width and depth of the river, the volume of the water, the amount of fall, and the character of the manufactures to which it was applicable. Nor is it necessary to answer the question in this case, since it appears that, whatever this property is, it has been appropriated and no provision made for the compensation of the owner. The case of the plaintiff Canal Company depends primarily, as stated above, upon the legality of the legislative act of 1848, whereby the State assumed to reserve to itself any water power which should be created by the erection of the dam across the river at this point. No question is made of the power of the State to construct or authorize the construction of this improvement, and to devote to it the proceeds of the land grant of the United States. The improvement of the navigation of a river is a public purpose, and the sequestration or appropriation of land or other property, therefore, for such Opinion of the Court. purpose, is doubtless a proper exercise of the authority of the State under its power of eminent domain. Upon the other hand, it is probably true that it is beyond the competency of the State to appropriate to itself the property of individuals for the sole purpose of creating a water power to be leased for manufacturing purposes. This would be a case of taking the property of one man for the benefit of another, which is not a constitutional exercise of the right of eminent domain. But if, in the erection of a public dam for a recognized public purpose, there is necessarily produced a surplus of water, which may properly be used for manufacturing purposes, there is no sound reason why the State may not retain to itself the power of controlling or disposing of such water as an incident of its right to make such improvement. Indeed, it might become very necessary to retain the disposition of it in its own hands, in order to preserve at all times a sufficient supply for the purposes of navigation. If the riparian owners were allowed to tap the pond at different places, and draw off the water for their own use, serious consequences might arise, not only in connection with the public demand for the purposes of navigation, but between the riparian owners themselves as to the proper proportion each was entitled to draw controversies which could only be avoided by the State reserving to itself the immediate supervision of the entire supply. As there is no need of the surplus running to waste, there was nothing objectionable in permitting the State to let out the use of it to private parties, and thus reimburse itself for the expenses of the improvement. The value of this water power created by the dam was much greater than that of the river in its unimproved state in the hands of the riparian proprietors who had not the means to make it available. These proprietors lost nothing that was useful to them except the technical right to have the water flow as it had been accustomed and the possibility of their being able some time to improve it. If the State could condemn this use of the water with the other property of the riparian owner it might raise a revenue from it sufficient to complete the work which might otherwise fail. There was VOL. CXLII-18 Opinion of the Court. every reason why a water power thus created should belong to the public rather than to the riparian owners. Indeed, it seems to have been the practice, not only in New York but in Ohio, in Wisconsin, and perhaps in other States, in authorizing the erection of dams for the purpose of navigation or other public improvement, to reserve the surplus of water thereby created to be leased to private parties under authority of the State; and where the surplus thus created was a mere incident to securing an adequate amount of water for the public improvement, such legislation, it is believed, has been uniformly sustained. Thus, in Cooper v. Williams, 4 Ohio, 253, the law authorizing the construction of the Miami Canal, from Dayton to Cincinnati, empowered the canal commissioners to dispose of the surplus water power of the feeder for the benefit of the State, and their action in so disposing of the water was justified. The ruling was repeated in the same case, 5 Ohio, 391. In Buckingham v. Smith, 10 Ohio, 288, it was held that, if the water of private streams should be taken by the State for the mere purpose of creating hydraulic power, and rented to an individual, the transaction would be illegal, and no title would pass as against the owner; but it was intimated that in conducting water through a feeder, a discretionary power must necessarily rest in the agents of the State, and in making provision for a supply, it must frequently occur that a surplus will accumulate, and that such surplus might be subject to lease by the commissioners. In Little Miami Elevator Co. v. Cincinnati, 30 Ohio St. 629, 643, the right to lease surplus water for private use was recognized as an incident to the public use of a canal for the purpose of navigation; but it was held that such use was a subordinate one, and that the right to the same might be terminated whenever the State, in the exercise of its discretion, abandoned or relinquished the public use. It was doubted whether the State could, after abandoning the canal as a public improvement, still reserve to itself the right to keep up a water power solely for private use and as a source of revenue. "By, so doing," said the court, "the water power would cease to be an incident to the public use, and the State would be engaged in the private enterprise of Opinion of the Court. keeping up and renting water power after it ceased to act as a government in keeping up the public use." The same ruling was made by this court in Fox v. Cincinnati, 104 U. S. 783. See also Hubbard v. City of Toledo, 21 Ohio St. 379. In Spaulding v. Lowell, 23 Pick. 71, 80, it was held that, where a town built a market house two stories high, and appropriated the lower story for a market, it being bona fide their principal and leading object in erecting the building, the appropriation of the upper story to other subordinate purposes was not such an excess of authority as to render the erection of the building and the raising of money therefor illegal. Chief Justice Shaw, in delivering the opinion of the court, said: "If this had been a colorable act, under the pretence of exercising a legal power, looking to other and distinct objects beyond the scope of the principal one, it might be treated as an abuse of power, and a nullity. But we perceive no evidence to justify such a conclusion in the present case. The building of a market house was the principal and leading object, and everything else seems to have been incidental and subordinate. If the accomplishment of the object was within the scope of the corporate powers of the town, the corporation itself was the proper judge of the fitness of the building for its objects, and it is not competent in this suit to inquire whether it was a larger and more expensive building, than the exigencies of the city required." See also French v. Inhabitants of Quincy, 3 Allen, 9. In Attorney General v. Eau Claire, 37 Wisconsin, 400, it was broadly held that where the State was authorized to erect and maintain a dam for a public municipal use, the legislature might also empower it to lease any surplus water power created by such dam. The ruling was repeated in State v. Eau Claire, 40 Wisconsin, 533. The true distinction seems to be between cases where the dam is erected for the express or apparent purpose of obtaining a water power to lease to private individuals, or where in building a dam for a public improvement, a wholly unnecessary excess of water is created, and cases where the surplus is a mere incident to the public improvement and a reasonable provision for securing an adequate supply of water at all times for such Opinion of the Court. improvement. No claim is made in this case that the water power was created for the purpose of selling or leasing it, or that the dam was erected to a greater height than was reasonably necessary to create a depth of water sufficient for the purposes of navigation at all seasons of the year. So long as the dam was erected for the bona fide purpose of furnishing an adequate supply of water for the canal and was not a colorable device for creating a water power, the agents of the State are entitled to great latitude of discretion in regard to the height of the dam and the head of water to be created; and while the surplus in this case may be unnecessarily large, there does not seem to have been any bad faith or abuse of discretion on the part of those charged with the construction of the improvement. Courts should not scan too jealously their conduct in this connection if there be no reason to doubt that they were animated solely by a desire to promote the public interests, nor can they undertake to measure with nicety the exact amount of water required for the purposes of the public improvement. Under the circumstances of this case, we think it within the power of the State to retain within its immediate control such surplus as might incidentally be created by the erection of the dam. So far, however, as land was actually taken for the purpose of this improvement, either for the dam itself or the embankments, or for the overflow, or so far as water was diverted from its natural course, or from the uses to which the riparian owner would otherwise have been entitled to devote it, such owner is undoubtedly entitled to compensation. So far as concerns lots 6 and 7, no such compensation could be claimed, since the Supreme Court held, and we think correctly, that the release executed by Hunt to the Fox and Wisconsin Improvement Company in 1854, in which he granted to that company and its representatives "the right to erect and forever maintain an embankment of the dimensions as surveyed by the engineer of said company," operated as a surrender of all riparian rights appertaining to such lots not reserved in the instrument. No such grant, however, was proven to have been made with respect to lot 5, then owned by one Beardsley, to which the |