California Code, Water Code - WAT § 37203

(a) On or before December 31st of any year the board may by resolution elect to proceed under this part for the levy, collection, and enforcement of any or all assessments, and thereafter until termination of that election the provisions of this part shall apply to the levy, collection, and enforcement of those assessments.  The board by resolution may at any time on or before December 31st of any year terminate its election to proceed under this part, and thereafter the provisions of this part shall no longer apply to the levy, collection, and enforcement of those assessments.  On or before January 1st following the adoption of either of those resolutions, a certified copy thereof shall be filed with the auditor, assessor, tax collector and treasurer of each county within which a district is located and with the State Board of Equalization.  There shall also be filed with the county assessor and the State Board of Equalization a statement as required by Chapter 8 (commencing with Section 54900) of Part 1 of Division 2 of Title 5 of the Government Code.

(b) Notwithstanding subdivision (a), the board may, by resolution, elect at any time to proceed under this part only for the collection and enforcement of delinquent assessments, including standby and other charges, and thereafter until termination of that election this part shall apply to the collection and enforcement of the delinquent assessments.  A certified copy of the resolution shall be filed with the auditor, assessor, tax collector, and treasurer of each county within which the district is located and the assessments shall thereafter be included in all county tax statements.