Cal. Wat. Code § 47903
An election pursuant to Section 47902 is effective with respect to all assessments designated by the board to be collected pursuant to the provisions of this article and which were levied or called after February 1, next succeeding the date upon which the certified copy is filed. Thereafter, the assessments designated by the board shall be collected by the tax collectors of the county or counties in which the district is situated until the board, by resolution, elects otherwise. When the board elects otherwise, a certified copy of such resolution shall be filed with the auditor, assessor, tax collector and treasurer of each county within which the district is situated and it is effective, with respect to any assessments levied or called, after February 1, next succeeding the date upon which the certified copy is filed.
Ca. Water Code § 47903