Wash. Rev. Code § 86.15.020
The board may initiate, by affirmative vote of a majority of the board, the creation of a zone or additional zones within the county, and without reference to an existing zone or zones, for the purpose of undertaking, operating, or maintaining flood control projects or stormwater control projects or groups of projects that are of special benefit to specified areas of the county. Formation of a zone may also be initiated by a petition signed by twenty-five percent of the electors within a proposed zone based on the vote cast in the last county general election. If the formation of the zone is initiated by petition, the board shall incorporate the terms of the petition in a resolution within forty days after receiving the petition from the county auditor. Thereafter, the procedures for establishing a zone shall be the same whether initiated by motion of the board or by a petition of electors.
Petitions shall be in a form prescribed and approved by the county auditor and shall include the necessary legal descriptions and other information necessary for establishment of a zone by resolution. When the sponsors of a petition have acquired the necessary signatures, they shall present the petition to the county auditor who shall thereafter certify the sufficiency of the petition within forty-five days. If the petition is found to meet the requirements specified in this chapter, the auditor shall transmit the petition to the board for their action; if the petition fails to meet the requirements of this chapter, it shall be returned to the sponsors.
RCW 86.15.020
Severability-1983 c 315: See note following RCW 90.03.500.