Wash. Rev. Code § 35.23.452
The city council of such city shall have power to purchase, lease, or otherwise acquire real estate and personal property necessary or proper for municipal purposes and to control, lease, sublease, convey or otherwise dispose of the same; to acquire and plat land for cemeteries and parks and provide for the regulation thereof, including but not limited to the right to lease any waterfront and other lands adjacent thereto owned by it for manufacturing, commercial or other business purposes; including but not limited to the right to lease for wharf, dock and other purposes of navigation and commerce such portions of its streets which bound upon or terminate in its waterfront or the navigable waters of such city, subject, however, to the written consent of the lessees of a majority of the square feet frontage of the harbor area abutting on any street proposed to be so leased. No lease of streets or waterfront shall be for longer than ten years and the rental therefor shall be fixed by the city council. Every such lease shall contain a clause that at intervals of every five years during the term thereof the rental to be paid by the lessee shall be readjusted between the lessee and the city by mutual agreement, or in default of such mutual agreement that the rental shall be fixed by arbitrators to be appointed one by the city council, one by the lessee and the third by the two thus appointed. No such lease shall be made until the city council has first caused notice thereof to be published in the official newspaper of such city at least fifteen days and in one issue thereof each week prior to the making of such lease, which notice shall describe the portion of the street proposed to be leased, to whom, for what purpose, and the rental to be charged therefor. The city may improve part of such waterfront or street extensions by building inclines, wharves, gridirons and other accommodations for shipping, commerce and navigation and may charge and collect for service and use thereof reasonable rates and tolls.
RCW 35.23.452