The board of county commissioners of Okanogan county entered into a contract with the Puget Sound Bridge & Dredging Company and Charles Ostenberg for the construction of a bridge across the Okanogan river, for a stated consideration, to be paid in part from moneys *314belonging to Okanogan county and in part from moneys subscribed for that purpose and turned over to the county by citizens of Okanogan city, a town situated on the Okanogan river at the point where it was proposed to construct the bridge. After the contract had been let, the present action was begun to enjoin its execution, the plaintiff, appellant here, making parties defendant thereto all of the principals to the contract, including the members of the board of county commissioners as individuals. The contract was attacked on the ground that the commissioners had not complied with the requirements of the statute in its execution. The trial judge held against the contention of the plaintiff, and entered a judgment dismissing the action. This appeal was taken therefrom.
The respondents moved to dismiss the appeal, on the ground that there has been a cessation of the controversy. It appears from affidavits filed subsequent to the perfection of the appeal, that the board of county commissioners executed the contract after the dismissal of the action in the court below, and it is contended that now there is nothing upon which the injunction can operate, as the acts of the defendants sought, to be enjoined have been fully performed. But this contention mistakes the power of the court. It is true that when, pending an appeal from the judgment of the lower court, and without any fault on the part of the respondent, an event occurs which renders it impossible to enter a judgment in favor of the appellant which will give any effectual relief, the court will not proceed to a formal judgment but will dismiss the appeal; and it is held, also, that the same result will follow if the intervening event is owing to some voluntary act of the appellant. But no such result follows merely because the respondent has changed the status of the subject-matter in litigation. So in this case, if it appears that the contract entered into was subject to be enjoined because in violation of the statutes, the court may now inquire into the subsequent acts of the respondents and *315compel them to undo what they have wrongfully done, in so far as it is capable of undoing, and to answer in damages for anything that cannot be undone.
This principle was announced in the early case from this court of Hartson v. Dale, 9 Wash. 379, 37 Pac. 475. There an action was begun to enjoin a county treasurer from paying a county warrant which had been unlawfully issued. The relief was denied in the court below, and pending the appeal, the warrant was paid by its treasurer. This fact was shown to this court and a motion to dismiss the appeal on that ground was made. But the court denied the motion, reversed the judgment of the court below, and sent the case back for further proceedings. But while this case was correctly decided, it is probable that a wrong reason was given in support of the conclusion of the court. The decision was rested on the ground that it would be highly inequitable to allow any subsequent action of the respondent to have the effect of subjecting the appellant to the costs of a meritorious appeal, while the decision ought to have been rested on the ground we have before indicated; namely, that the court had power to enter an effectual decree by compelling the parties to undo what they had wrongfully done, or compel them to answer in damages therefor. In Farnsworth v. Wilbur, 49 Wash. 416, 95 Pac. 642, it was held that the court, in an action of equitable cognizance, had power to issue mandatory as well as prohibitory injunctions, and could, in virtue of its powers, compel the undoing of those acts which have been illegally done — in that case, to compel the vacation of an illegal transaction in which a judgment had been satisfied and discharged of record in consideration of a payment less than the whole. In Mills v. Green, 159 U. S. 651, the court used this language:
“If a defendant, indeed, after notice of the filing of a bill in equity for an injunction to restrain the building of a house, or of a railroad, or of any other structure, persists in completing the building, the court nevertheless, is not deprived *316of the authority, whenever in its opinion justice requires it, to deal with the rights of the parties as they stood at the commencement of the suit, and to compel the defendant to undo what he has wrongfully done since that time, or to answer in damages.”
See, also, Tucker v. Howard, 128 Mass. 361; Pennsylvania Co. v. Bond, 99 Ill. App. 535; Tate v. Field, 56 N. J. Eq. 35. The fact that no temporary injunction has been granted does not affect the kind or the extent of the remedy to which the plaintiff is entitled upon establishing his right at the hearing on the merits. Tucker v. Howard, supra. The motion to dismiss will be denied.
Passing to the merits of the controversy, it remains to inquire whether or not there was a compliance with the statutes in the letting of the contract. That portion of the Okanogan river from its mouth to a point above the site of the bridge is navigable, being capable of floating water craft of considerable dimensions. In 1891 the legislature of this state passed an act relating to the construction of bridges across navigable streams by boards of county commissioners, the material part of which is found in § 5680 of Rem. & Bal. Code, which reads as follows:
. “Whenever the county commissioners of any county or counties desire to erect a bridge on any public highway across a navigable stream, under the provisions of this act, said board or boards shall cause to be published a notice in a newspaper of general circulation in the county or counties, if such there be; and if there be no newspaper published in the county or counties, then by posting three notices, one in the locality of the place to be bridged, and two in the most public places in the county or counties; such notice shall contain the name of the stream to be bridged and the exact point where such bridge is to be erected, and the date when the said board will determine the public necessity for the building of said bridge: Provided, that when such bridge is to be built by two counties, the notice shall be published in both counties. At the time fixed in such notice the board of county commissioners shall declare such public necessity by an order of record, which said order shall, in addition to the other *317facts, prescribe the width of the draw to be made, if any draw shall be considered necessary in such bridge, and also the length of span necessary to permit the free flow of water: Provided, that such bridges shall be so constructed as not to interfere with, impede, or obstruct the navigation of such streams.”
There is no pretense that the commissioners in letting the contract for the construction of this .bridge complied, or attempted to comply, with the provisions of this statute. The commissioners seek to excusé themselves, however, by asserting that the statute is no longer in force, it having been superseded, it is contended, both by subsequent state legislation and by Congressional enactments on the same subject. The state legislation referred to is the act of March 9, 1893 (Laws 1893, p. 147; Rem. & Bal. Code, § 5575), and the act of March 16, 1903 (Laws 1903, p. 225; Rem. & Bal. Code, § 5585). The first of these acts, while it relates to the construction, repair and improvement of public highways generally, contains no specific provision relating to contracts for the construction of bridges over navigable streams, nor does it purport to cover within itself the entire law on the subject-matter of which it treats; for example, it contains no provision relating to obtaining a right of way for public highways, or the construction of highways lying in two or more counties, or the construction or repair of bridges across streams which form the boundary line between two counties, or the manner of letting of contracts for the construction of bridges generally. These were matters perhaps that would fall within the title and spirit of the act, but since the act contains no provision relating to them, the act cannot be said to have been a complete act on the subject of roads and bridges; and consequently, since there is no direct conflict between the acts, there can be no implied repeal of the one by the other.
The second act cited is more to the point, as it does contain a specific provision with relation to the construction of bridges. But there is nevertheless no conflict between the. *318acts. The act thought to be superseded, it will be noticed, relates chiefly to the preliminary steps to be taken before any attempt is made to let the contract for the construction of the bridge, while the latter relates solely to the letting of the contract. It provides that bridge construction of which the estimated cost is more than one hundred and fifty dollars, except in cases of emergency, shall be let by contract by the county commissioners on plans and specifications previously prepared, etc. The later act, therefore, but supplements the earlier one, and cannot under any construction operate as a repeal of it.
The Federal statutes are intended to protect the rights of the public at large in navigable streams, or perhaps more accurately, the right of navigation thereon. In substance they provide that no navigable stream shall be bridged at all without the consent of Congress, and when consent is given, that the bridge constructed shall be according to plans and specifications approved by the chief of engineers and by the secretary of war. But it is manifest that these statutes in no way interfere with the operation of the state statutes. They impose an additional burden on the county commissioners, inasmuch as the plans adopted by them must meet the approval of the Federal authorities named, but they offer no other hindrance to the workings of the state statutes. We think, therefore, that the statute quoted was in force at the time the contract in question was entered into.
But the statutes of the state were also violated in another particular. The contract for the construction of the bridge-was let without calling for competitive bids, although the contract called for an expenditure in excess of one hundred and fifty dollars. This act on the part of the commissioners is sought to be excused by the plea that an emergency existed which would not permit of a delay long enough to do the necessary advertising. But we can find no support in the record for the contention. It might perhaps be that 'were all of the bridges across a stream lying between two *319populous centers to be destroyed by a sudden flood or other unlooked for catastrophe, that such an emergency would exist for the replacement of some one or more of them that the public authorities would be justified in entering upon the work of replacement without calling for competitive bids, but it is difficult to understand how any such necessity can arise with reference to entirely new construction. But be this’ as it may, there was clearly no such necessity in this instance. All of the means for crossing the river that had theretofore served the people were still intact, no sudden flood or other catastrophe had interfered with their operation, nor was there any sudden increase in the number of persons desiring to cross the river as to render the existing facilities inadequate; in fact, nothing necessitating the construction of the bridge was shown other than the fact that the increase in population was generally outgrowing the existing facilities. Under these circumstances it seems worse than idle to argue that the rush was so great as not to brook of a delay of three weeks, the time required to advertise for competitive bids.
As boards of county commissioners themselves are but creatures of the statute, they must pursue and exercise the powers conferred on them in strict compliance with the statutes. Only by so doing, can they bind their principal. Contracts entered into in defiance of the manner pointed out by the statutes, or which have no support in the statutes, bind no one. Money paid out in pursuance of such contracts can be recovered back from any person into whose hands it can be traced. In fine, the proceedings, in so far as they affect the county, are nullities. Smith v. Lamping, 27 Wash. 624, 68 Pac. 195; Arnott v. Spokane, 6 Wash. 442, 33 Pac. 1063; Wrought Iron Bridge Co. v. Board of Comr’s., 19 Ind. App. 672; Commonwealth v. Baker, 212 Pa. 230, 61 Atl. 910.
From the foregoing considerations it necessarily follows that the contract in question was void, and affords no justification for the acts of the board of county commissioners, *320nor of the other parties to the contract who acted under it. But we cannot follow the appellant’s argument to the effect that such persons are jointly and severally liable to return to the county treasurer the money of the county directed to be paid out by the board and received by the persons building the bridge. While this may be the rule in some jurisdictions, this court has adopted the more equitable doctrine of allowing the parties, where the contract if entered into in conformity with the statutes' would not have been unlawful, to retain from the moneys received by them a sum equivalent to the reasonable value of the property the county acquires and retains in virtue of the execution of the void contract. Such, in substance, is the doctrine of the case of Criswell v. Directors School District No. 24, 34 Wash. 420, 75 Pac. 984. To the same effect is Chapman v. County of Douglas, 107 U. S. 348, cited in the case from this court. There a county had entered into an illegal contract for the purchase of a farm of which it had received a conveyance. The court held the county liable, independent of the contract, to make payment for the land or reconvey it to the vendors. In the course of the opinion, this language was used :
“The agreement, as we have assumed, so far as it relates to the time and mode of payment, is void; but the contract for. the sale itself has been executed on the part of the vendor by the delivery of the deed, and his title at law has actually passed to the county. As the agreement between the parties has failed by reason of the legal disability of the county to perform its part, according to its conditions, the right of the vendor to rescind the contract and to a restitution of his title would seem to be as clear as it would be just, unless some valid reason to the contrary can be shown. As was said by this court in Marsh v. Fulton County, 10 Wall. 676, 684, and repeated in Louisiana v. Wood, 102 U. S. 294, ‘the obligation to do justice rests upon all persons, natural and artificial, and if a county obtains the money or property of others without authority, the law, independent of any statute, will compel restitution or compensation.’ ”
So in this case, since the county has accepted and made use *321of the bridge, it is liable to the builders for its reasonable value, and it is entitled to recover only the difference between the reasonable value of the bridge and the amount paid for its construction.
As we have elsewhere stated, one-half the cost of the bridge was contributed by donations to the county from private parties interested in the construction of the bridge. It is suggested that in case it is found that the reasonable value of the bridge is less than the amount paid for its construction, only one-half of such difference should be refunded to the county. But we think the county entitled to the entire difference. The gift to induce the construction of the bridge was to the county and paid into the county treasury, not to the board of county commissioners nor to the contractors, and the county is entitled to its return if it has been wrongfully paid out.
The judgment appealed from is reversed, and the cause remanded with instructions to reinstate the case, take an accounting of the moneys paid out by the county in the construction of the bridge, and ascertain the reasonable value of the bridge, and if the amount paid by the county exceeds the reasonable value of the bridge, enter a judgment against the parties receiving the money for the difference; if the value of the bridge equals or exceeds the sum paid for its construction, then enter a judgment to the effect that the appellant take nothing by his action. Costs in this court will be allowed the appellant; costs in the court below to abide the event of the final hearing.
Morris, J., concurs.