Cal. FAC § 6071

The board of directors of each district shall, on or before the first Monday in February of each year, prepare and file with the board of supervisors of the county in which the district is situated, a budget setting forth all estimated expenditures of the district for the fiscal year commencing on the first day of the month of April of that fiscal year. The budget shall include any estimated expenditures for special benefits which will affect only certain properties. The board of directors may submit the budget or a revised budget to the board of supervisors later than the first Monday in February, but not later than March 15, if necessary in order to properly reflect changes in the acreage involved between the preliminary estimate and the register prepared pursuant to Section 6070 and the costs of programs therefor. A copy of the budget shall, at the same time, be filed with the auditor of the county.