RCW 85.22.020

For the purpose of securing such reorganization, a petition shall be presented to the clerk of the board of county commissioners of the county in which such district is located, at a regular or special meeting of the board. The petition shall be signed by the board of commissioners of the district and shall state the number of the district seeking to reorganize, and shall pray that such district be reorganized as a drainage and irrigation improvement district or diking, drainage and irrigation improvement district.