RCW 87.22.160: Interest on unpaid bond installments—When payable.

All unpaid installments on account of the principal of said refunding bonds shall bear interest from the date of the bonds at a rate or rates as authorized by the board of directors of the district. Different installments of the principal of said bonds may bear different rates of interest if it is so provided in the bond plan. Interest shall be payable semiannually on the first day of January and July of each year.