Cal. Wat. Code § 36407
Warrants or negotiable notes issued under this chapter and authorized by the voters pursuant to Section 36402.1 shall constitute general obligations of the district for the payment of both principal and interest of which all land in the district subject to assessment by the district shall be assessed without limitation of rate or amount. It shall be the duty of the board to include in its annual estimate filed with the board of supervisors all sums necessary to pay the principal of, and interest on, all warrants or negotiable notes issued under this chapter coming due during the next year, and any sums that the board shall direct to be set aside in a special fund for the future payment of principal of and interest on any outstanding warrants or negotiable notes issued under this chapter which will come due in any year following the next year. It shall be the duty of the board of supervisors, at the time and in the manner provided in this division for making the annual assessment, to fix an ad valorem rate of assessment sufficient to pay the principal of and interest on all warrants or negotiable notes issued under this chapter as the same become due, and the sums required for the special fund established by the board. Such ad valorem assessment shall be in addition to all other assessments in this division provided for and when collected shall be used for no purpose other than the payment of said warrants or negotiable notes and the interest thereon.
Ca. Water Code § 36407