Whenever a city or town annexes an area, or a city or town incorporates an area, and the county has issued revenue bonds or general obligation bonds to finance storm or surface water drains or facilities that are payable in whole or in part from rates or charges imposed in the area, the county shall continue imposing all portions of the rates or charges that are allocated to payment of the debt service on bonds in that area after the effective date of the annexation or official date of the incorporation until:
The provisions of this section apply whether or not the bonds finance facilities that are geographically located within the area that is annexed or incorporated.
RCW 36.94.470