Washington Revised Code Title 35. Cities and Towns § 35.55.120. Local improvement bonds--Terms

The city council shall have full authority to provide for the issuance of bonds against the improvement district fund in such denominations as the city council may provide which shall bear such rate of interest as the city council may fix. Interest shall be paid annually and the bonds shall become due and payable at such time, not exceeding ten years from the date thereof, as may be fixed by the council and shall be payable out of the local assessment district fund.

If so ordered by the council, the bonds may be issued in such a way that different numbers of the bonds may become due and payable at different intervals of time, or they may be so issued that all of the bonds against said district mature together.