Wash. Rev. Code § 35.92.090
The total general indebtedness incurred under this chapter, added to all other indebtedness of a city or town at any time outstanding, shall not exceed the amounts of indebtedness authorized by chapter 39.36 RCW, as now or hereafter amended, to be incurred without and with the assent of the voters: PROVIDED, That a city or town may become indebted to a larger amount, but not exceeding the amount authorized therefor by chapter 39.36 RCW, as now or hereafter amended, for supplying it with water, artificial light, and sewers when works for supplying such water, light, and sewers are owned and controlled by the city or town.
RCW 35.92.090
Limitations upon indebtedness: State Constitution Art. 7 s 2 (Amendments 55, 59), Art. 8 s 6 (Amendment 27), RCW 84.52.050.