California Code, Public Utilities Code - PUC § 101270

Annually at the time of levying county taxes, the board of supervisors shall levy a tax upon all the taxable real and personal property within the district.  Subject to the maximum limits prescribed by Section 101265, the rate shall be such as will produce, after due allowance for delinquency and cost of collection, the amounts determined by the board of directors as necessary to be raised by taxation and as set forth in the statement required by Section 101269.  The tax rate so levied shall apply to all the taxable real and personal property within the district as they appear on the assessment roll of the county.