Wash. Rev. Code § 35.42.200
Any city or town may execute leases for a period of years with or without an option to purchase with the state or any of its political subdivisions, with the government of the United States, or with any private party for the lease of any real or personal property, or property rights: PROVIDED, That with respect only to leases that finance the acquisition of property by the lessee, the aggregated portions of lease payments over the term of the lease which are allocable to principal shall constitute debt, which shall not result in a total indebtedness in excess of one and one-half percent of the taxable property of such city or town computed in accordance with RCW 39.36.030, unless a proposition in regard to whether or not such a lease may be executed is submitted to the voters for their approval or rejection in the same manner that bond issues for capital purposes are submitted, and the voters approve the same.
RCW 35.42.200