Wash. Rev. Code § 79.120.050
All waterways excavated through any state-owned tidelands or shorelands by virtue of the provisions of chapter 99, Laws of 1893, so far as they run through the tidelands or shorelands, are declared to be public waterways, free to all citizens upon equal terms, and subject to the jurisdiction of the proper authorities, as otherwise provided by law. However, where tide gates or locks are considered by the contracting parties excavating any waterways to be necessary to the efficiency of the waterway, the department may, in its discretion, authorize tide gates or locks to be constructed and may authorize the parties constructing the waterway to operate them and collect a reasonable toll from vessels passing through the tide gates or locks. Further, the state of Washington or the United States of America can, at any time, appropriate the tide gates or locks upon payment to the parties erecting them of the reasonable value of the tide gates or locks at the date of the appropriation, reasonable value to be ascertained and determined as in other cases of condemnation of private property for public use.
RCW 79.120.050