Wash. Rev. Code § 87.04.050
If the number of directors is changed for a district which is divided into director divisions or new lands outside of existing director divisions are included into a district but cannot be added to director divisions as provided in RCW 87.04.055 due to geographic limitations, a petition for redivision or addition shall be filed with the board of county commissioners by the directors of the district and all proceedings thereon shall be conducted in the manner as provided in RCW 87.04.060 and 87.04.070: PROVIDED, That even if objections are filed at the hearing on said petition, no election shall be held but the board of county commissioners shall make such division or addition that they determine to be fair and equitable to the electors of the district.
RCW 87.04.050