RCW 85.18.180: Levy is exclusive method for raising revenue—Exception.

Any diking district operating under this chapter shall not use the processes provided for raising revenue under any other law: PROVIDED, That any such other method of raising revenue provided by law may be used concurrently for the sole purpose of extinguishing indebtedness incurred before the district adopts the procedure of this chapter, and no funds raised hereunder shall be used to pay such prior indebtedness.