Cal. Pub. Resources Code § 49140
At least 15 days before the first day of the month in which the board of supervisors of the county in which the district is situated is required by law to levy the amount of taxes required for county purposes, the district board shall furnish the board of supervisors and county auditor of the county an estimate in writing of the amount of money necessary for district's purposes during the next ensuing fiscal year.
The county tax collector shall collect the district taxes at the same time and in the same manner as the county taxes are collected. Unless the governing board has designated any depository pursuant to Section 49131, all money collected for district purposes shall be paid into the county treasury and paid out on warrants of the county auditor drawn on the county treasurer, upon order of the district board.
The amount of money necessary for the district's purposes may include a cash-basis fund.
Ca. Pub. Res. Code § 49140