Wat. Code, § 5101

(a) Each person who, after December 31, 1965, diverts water shall file with the board a statement of their diversion and use, as provided in subdivision (b), except that a statement is not required to be filed if the diversion is any of the following:

(1) From a spring that does not flow off the property on which it is located and from which the person’s aggregate diversions do not exceed 25 acre-feet in any year.

(2) Covered by a registration for small domestic use, small irrigation use, or livestock stockpond use, or permit or license to appropriate water on file with the board.

(3) Included in a notice filed pursuant to Part 5 (commencing with Section 4999).

(4) Regulated by a watermaster appointed by the department and included in annual reports filed with a court or the board by the watermaster, which reports identify the persons who have diverted water and describe the general purposes and the place, the use, and the quantity of water that has been diverted from each source.

(5) Included in annual reports filed with a court or the board by a watermaster appointed by a court or pursuant to statute to administer a final judgment determining rights to water, which reports identify the persons who have diverted water and give the general place of use and the quantity of water that has been diverted from each source.

(6) For use in compliance with Article 2.5 (commencing with Section 1226) or Article 2.7 (commencing with Section 1228) of Chapter 1 of Part 2.

(7) A diversion that occurs before January 1, 2009, if any of the following applies:

(A) The diversion is from a spring that does not flow off the property on which it is located, and the person’s aggregate diversions do not exceed 25 acre-feet in any year.

(B) The diversion is covered by an application to appropriate water on file with the board.

(C) The diversion is reported by the department in its hydrologic data bulletins.

(D) The diversion is included in the consumptive use data for the Delta lowlands published by the department in its hydrologic data bulletins.

(b) (1) For diversions after December 31, 1965, and before January 1, 2021, the statement shall be filed before July 1 of the year after the diversion.

(2) For diversions after December 31, 2020, and before October 1, 2021, the statement shall be filed before April 1, 2022.

(3) For diversions after September 30, 2021, the statement shall include diversions during the one-year period from October 1 of each year through September 30, inclusive, of the following year, and shall be filed before February 1 of the year after that one-year period.