Wash. Rev. Code § 36.88.375
For the purpose of issuing bonds only, the governing body of any county may authorize the establishment of consolidated road improvement districts. The road improvements within such consolidated districts need not be adjoining, vicinal, or neighboring. If the governing body orders the creation of such consolidated road improvement districts, the money received from the installment payments of the principal of and interest on assessments levied within original road improvement districts shall be deposited in a consolidated road improvement district bond redemption fund to be used to redeem outstanding consolidated road improvement district bonds. The issuance of bonds of a consolidated road improvement district shall not change the number of assessment installments in the original road improvement districts, but such bonds shall run two years longer than the longest assessment installment of such original districts.
RCW 36.88.375
Severability-1981 c 313: See note following RCW 36.94.020.