Wash. Rev. Code § 53.34.090
It is the intention hereof that any pledge of revenues, income, receipts, profits, charges, fees, or other moneys made by a district for the payment of bonds shall be valid and binding from the time of the adoption of any resolution or the execution of any trust agreement making such pledge notwithstanding the fact that there may not then be any simultaneous delivery thereof, that the revenues, income, receipts, profits, charges, fees, and other moneys so pledged shall as soon as received by the district immediately be subject to the lien of such pledge without the physical delivery thereof and without further act, and that the lien of any such pledge shall be valid and binding as against all parties having claims of any kind in tort, contract, or otherwise against the district irrespective of whether such parties have notice thereof. Neither the resolution, resolutions, or trust agreement authorizing revenue bonds or notes nor any other instrument by which such a pledge is created need be recorded to be effective.
RCW 53.34.090