Cal. Wat. Code § 1005.2
Cessation of or reduction in the extraction of ground water, to permit the replenishment of such ground water by the use of water from an alternate nontributary source, is hereby declared to be a reasonable beneficial use of the ground water to the extent and in the amount that water from such alternate source is applied to beneficial use, not exceeding, however, the amount of such reduction. No lapse, reduction or loss of any right in ground water, shall occur under such conditions. Any such user of water from an alternate source who seeks the benefit of this Section 1005.2 with respect to the use of such water occurring prior to the effective date of this section, shall file with the board, within ninety (90) days from said effective date, a statement of the amounts of reduction in the extraction of ground water as the result of water from said alternate source having been so applied to reasonable beneficial use prior to said effective date to permit the replenishment of such ground water and said amounts shall be segregated and shown for each water year (November 1st to October 31st) during which such use occurred prior to the effective date of this section. Any such user of water from an alternate source who seeks the benefit of this Section 1005.2 with respect to the use of such water occurring subsequent to the effective date of this section, shall file with the board, on or before December 31st of each calendar year, a statement of the amount of reduction in the extraction of ground water as the result of water from said alternate source having been so applied to reasonable beneficial use during the next preceding water year (November 1st to October 31st) to permit the replenishment of such ground water. Such user cannot claim the benefit of this section for any water year for which such statement is not so filed.
The provisions of this section apply only as to the cessation of, or reduction in, the extraction of ground water within that area in this state defined by the exterior boundaries of the Counties of San Luis Obispo, Santa Barbara, Ventura, Los Angeles, Orange, San Diego, Imperial, Riverside, and San Bernardino.
The term "nontributary source" as used in this section shall be deemed to include water imported from another watershed or water conserved and saved in the watershed by a water conservation plan or works without which such water of the same watershed would have wasted, or would not have reached the underground source of supply of the owner relying upon this section.
Ca. Water Code § 1005.2