Wash. Rev. Code § 37.08.240
That in aid of the construction, maintenance and operation of a ship canal, by the United States of America, to connect the waters of Lakes Union and Washington, in King county, with Puget Sound, together with all necessary and convenient locks, landways, spillways, buildings, power plant and other proper appurtenances, there be and hereby is granted by this state to said United States the right to place, construct, maintain, and operate, such ship canal, landways, spillways, buildings, power plant and other proper appurtenances, upon, along, through and over any and all lands belonging to and waters of this state in said King county, within such limits as shall be defined by the plans and specifications for such improvement as the same shall be approved by the United States secretary of war, and the right to raise the waters of Salmon Bay and the right to lower the waters of Lake Washington, in prosecution of such improvement, and this state hereby releases the United States from all liability to damages to this state, its successors or assigns, that shall or might arise from such lowering or raising of waters, or otherwise from such improvement. But nothing in this section contained shall operate as an assumption of nor create any liability on the part of the state, for any damages which may result to any person, company or corporation.
RCW 37.08.240