Cal. PRC § 5571

The board of supervisors of each county in which any part of the district is located, shall, at the time of making the general tax levy in each year, levy a tax upon all the real and personal property within the district and within their respective county at a rate sufficient to meet the proportion of taxes necessary to be raised in the county for the purpose of paying the principal and interest of the bonds and other indebtedness of the district and all other requirements of the district as shown by the estimate of the board of directors of the district. The amount of taxes to be raised in each county shall be in the same proportion as the assessed valuation of the taxable property in the district within the county is to the assessed valuation of all property in the district.

Such taxes shall be assessed, levied, and collected at the same time and in the same manner as other county taxes are assessed, levied, and collected, and shall, when collected, be deposited with the treasurer of the district.