California Code, Water Code - WAT § 36420

(a) After adopting the resolution ordering the improvement district formed, the board may provide for and call a special bond election within such improvement district to submit to the voters of the improvement district a proposition of whether or not an indebtedness of the district shall be incurred and bonds issued therefor in an amount not exceeding the estimate stated in the resolution ordering the improvement district formed.

(b) If such bonds are to be general obligation bonds, such indebtedness and the bonds shall be payable from assessments to be levied and collected upon lands within said improvement district.

(c) If such bonds are to be revenue bonds only revenues derived from the operation of the improvement district works shall be pledged to the payment or redemption thereof and the payment of interest thereon, and such revenue bonds shall not be a general debt liability or obligation of the district.