Cal. Water Code § 72111

In a district containing lands situated in more than one county, the auditor of each affected county shall immediately after equalization and not later than the 15th day of August of each year, prepare and deliver to the secretary of the district, or such other officer thereof as may be designated by the board, a certificate showing the assessed valuation of all property within the district lying within the county. Thereafter, the board shall make the certification and statement, and issue the directions, as required by Sections 72094 and 72095. After collection of taxes by the proper county officers at the rate specified, such officers shall pay the moneys received therefrom to the district.