California Code, Water Code - WAT § 79142.4

(a) The board may establish the interest rate for a loan made pursuant to this article at a rate equal to 50 percent of the interest rate paid by the state on the most recent sale of state general obligation bonds, to be computed according to the true interest cost method.

(b) If the interest rate so determined is not a multiple of one-tenth of 1 percent, the interest rate shall be set at the next higher multiple of one-tenth of 1 percent.

(c) The interest rate set for each contract shall be applied throughout the repayment period of the contract. There shall be a level annual repayment of principal and interest on the loans.