Cal. WAT § 9260

Whenever any assessment levied by the board upon lands within the drainage district has been completed and all of the hearings before the board in regard thereto have been held and the board is ready to make its order approving the assessment as finally fixed pursuant to the provisions of Chapter 5, Part 4, of this division the board may at the time of making the order finally approving the assessment, also determine, and make a part of the order, that in its judgment it is for the best interests of the owners of land in the drainage district affected by the assessment to issue bonds for the purpose of obtaining money to pay the cost of the works or other expenses for which the assessment was levied.