The information is filed at the relation of the harbor commissioners of the Commonwealth to restrain the rebuilding of a dam across Mystic River, a small stream flowing into Boston harbor. It has been used from time immemorial for pleasure boating between the harbor and Mystic Pond, which is situated a short distance above the dam. Since 1851, pleasure boats have passed the dam daily during the summer, and their passage has been seriously obstructed by the dam.
It is denied by the defendant that the river at this place is within tide water, because, it is said, although the rise and fall there is two feet, it is occasioned by the meeting of the salt water of the tide with the fresh water which comes down the stream. But the law on this point is well settled. It is the rise and fall of the water, and not the proportion of salt water to fresh, that determines whether a particular portion of a stream is within tide water. This was settled in The King v. Smith, 2 Doug. 441, in application to the Thames at London ; in Peyroux v. Howard, 7 Pet. 324, 338, in respect to the Mississippi at New Orleans ; and in Lapish v. Bangor Bank, 8 Maine, 85, in respect to the Penobscot at Bangor. The same doctrine must apply to small streams as to large ones. We have no doubt that the defendant’s dam is within tide water.
It is also denied that the stream is navigable, although it is about two feet deep at low water, because it is not proved to be used for the purposes of navigation except with pleasure boats. The case of Rowe v. Granite Bridge Co. 21 Pick. 344, 347, is cited to sustain this position. Chief Justice Shaw there says: “ It is not every small creek in which a fishing skiff or gunning canoe can be made to float at high water, which is deemed navigable.. But in order to have this character it must be navigable to some purpose useful to trade or agriculture.” The same thing, in substance, is stated in Charlestown v. County Commissioners, 3 Met. 202, and Murdock v. Stickney, 8 Cush. 113, 115. But this language is applied to the capacity of the stream, and is not intended to be a strict enumeration of the uses to which it must be actually applied in order to give it this character. Navigable streams are highways; and a traveller for pleasure is as fully en*440titled to protection in using a public way, whether by land or by water, as a traveller for business. Certainly fishing and fowling are as really regarded, on navigable waters, as trade and agriculture, though not mentioned in the case cited above; and in West Roxbury v. Stoddard, 7 Allen, 158, 171, it is said that the use of great ponds, which are public property, may as well be for bathing, boating, skating, fishing and fowling, as for business, and is entitled to equal consideration. If water is navigable for pleasure boating, it must be regarded as navigable water, though no craft has ever been upon it for the purposes of trade or agriculture. The purpose of the navigation is not the subject of inquiry, but the fact of the capacity of the water for use in navigation. The use that is actually made of Mystic River proves that it is navigable. The dam is within the public domain, for at the point where the tide, from natural causes, ebbs the lowest, is the boundary of the flats beyond which private titles do not reach. Sparhawk v. Bullard, 1 Met. 95, 107. Beyond that point the legislature has control, for the common benefit of the public, and structures that interfere with the common right of navigation are a nuisance at common law. The legislature has a right to make reasonable restraints for the protection of the public, and enforce them by reasonable penalties. Commonwealth v. Alger, 7 Cush. 53, 92.
By the St. of 1866, e. 149, the legislature has made provision for these public interests. It creates a board of harbor commissioners, and confers on them the general care and supervision of all our harbors and tide waters, and the flats and lands flowed by such tide waters, except the Back Bay lands, respecting which other provisions are made. It designates particularly some of the duties of the commissioners. By § 5, all erections and works made without authority from the legislature, or in any manner not sanctioned by the commissioners, when their direction is required as provided in the statute, within tide waters flowing into or through any harbor, shall be considered public nuisances, and liable to indictment as such. The prohibition extends to ordinary high water mark. Commonwealth v. Roxbury, 9 Gray, 451. Commonwealth v. Charlestown, 1 Pick. 180. The defend*441ant’s dam is within this clause, there being no authority for its erection, derived either from the legislature or the commissioners.
This section further provides that the commissioners shall have power to order suits on behalf of the Commonwealth to prevent or stop, by injunction or otherwise, any such erection or other nuisance in the tide waters which flow into or through any harbor in the Commonwealth. The attorney general and district attorneys are directed to commence and conduct such suits.
It is contended that no remedy in equity exists, if there is a full, adequate and complete remedy at law; and that an injunction should not issue unless it appears that irreparable injury is to be prevented; and authorities which are applicable to ordinary suits in equity are cited to sustain these positions. But the statute gives special remedies, and designates the cases to which this shall be applied. The remedy by injunction is cumulative.
The purpose of the statute is, not only to punish all encroachments upon this portion of the public domain, but to furnish means for their prevention or removal. It cannot be doubted that the legislature has power to do this, and to prohibit all invasions of the rights of the public without regard to the amount of damage occasioned by them. But in the present case the report finds that the obstruction to the navigation of the river by the defendant’s dam is such as to create a nuisance of a serious character, Injunction to issue.