California Code, Harbors and Navigation Code - HNC § 7260

After the incurring of any general obligation indebtedness, evidenced by general obligation bonds, and annually thereafter until the indebtedness is paid or until there is a sum in the treasury of the district set apart for that purpose sufficient to meet all payments of principal of and interest on the indebtedness as it becomes due, the board shall cause a tax to be levied, as herein provided sufficient to pay the interest and principal as will become due before the proceeds of a tax levied at the next general tax levy will be available.