Wash. Rev. Code § 14.07.020
Such municipalities may also acquire by purchase, condemnation or lease, lands and other property for said purpose and dispose of such lands and other property, including property acquired by tax foreclosure proceedings, by sale or gift for public use to any city, town, port district, county, the state of Washington or the United States of America. Any city, town, port district and county is hereby empowered to acquire lands and other property for said purpose by the exercise of the power of eminent domain under the procedure that is or shall be provided by law for the condemnation and appropriation of private property for any of their respective corporate uses, and no property shall be exempt from such condemnation, appropriation or disposition by reason of the same having been or being dedicated, appropriated, or otherwise held to public use: PROVIDED, HOWEVER, That nothing in this chapter shall authorize or entitle any city, town, port district or county to acquire by eminent domain any site or other facilities for landings, terminals, housing, repair and care of dirigibles, airplanes, and seaplanes for aerial transportation of persons, property, mail or military or naval aircraft, now or hereafter owned by any other city, town, port district or county.
RCW 14.07.020