Wash. Rev. Code § 53.34.020
The district shall have the power to enter into a contract or contracts for the use of said projects, their approaches and equipment and from time to time to amend such contracts, with persons and with private and public corporations, and by said contracts to give such persons or corporations the right to use said projects, their approaches and equipment for the transmission of power for telephone and telegraph lines, for the transportation of water, gas, petroleum, and other products, for railroad and railway purposes, and for any other purpose to which the same may be adapted: PROVIDED, That no such contract shall be for a period longer than ninety-nine years, and that the projects shall be put to the largest possible number of uses consistent with the purposes for which such projects are constructed.
In making such contract or contracts and providing for payments and rentals thereunder the port district shall determine the value of the separate and different uses to which the projects are to be put and shall apportion the annual rentals and charges as nearly as possible according to the respective values of such uses. No such contract shall be made with any person or corporation unless and until such person or corporation shall bind himself or herself or itself to pay as rental therefor an amount determined by the port district and specified in the contract which shall be a fair and just proportion of the total amount required to pay interest on the bonds provided for in this chapter, plus a just proportion of the amount necessary for their retirement, and plus the cost of maintenance of the projects, their approaches and equipment.
The port district may require any of such contracts to be entered into before beginning the construction of said projects or before the expenditure of funds under the provisions of this chapter if in its judgment it is deemed expedient.
There shall be no monopoly of the use of said projects, and their approaches by any one use, or by any person or corporation, private or public, in respect to the several uses, and the port district may continue to make separate, additional, and supplemental contracts for one or more uses until in the judgment of said port district the capacity of the projects and approaches for any such use has been reached. When such capacity has been reached contracts for the use of said projects shall be given preference in regard to such uses according to the public interest as determined by the port district, and subsequent contracts shall be subject to all existing and prior contracts. The port district shall have the power to prescribe regulations for the use of such facilities by the parties to contracts for such use, or any of them, and to hear and determine all controversies which may arise between such parties, under such rules as the port district may from time to time promulgate; and all contracts shall expressly reserve such power to the port district.
RCW 53.34.020