AB 1466: Groundwater adjudication.

Official summary

Legislative Counsel’s Digest (official, as of the latest version). Written by nonpartisan legislative staff; reproduced verbatim.

(1)Existing law establishes procedures for the comprehensive adjudication of groundwater rights in civil court. Under existing law, if the court finds that claims of right to extract or divert only minor quantities of water, as defined, would not have a material effect on the groundwater rights of other parties, the court may exempt those claimants from the proceedings, except as specified. Existing law further prescribes that a judgment in a comprehensive adjudication to determine rights to extract groundwater in a basin is not binding on, among others, claimants whose claims have been exempted.

This bill would authorize a court, in lieu of the exemption process described above, to treat persons with claims of right to extract or divert only minor quantities of water separately from other parties to the comprehensive adjudication. The bill would require the court to hold a hearing within a specified time to determine whether to exempt or treat those claimants separately and to establish a procedure to register and administer such claims.

(2)Existing law, in a comprehensive adjudication of groundwater rights in civil court, requires a party to serve on the other parties and the special master, if appointed, an initial disclosure that includes certain information within six months of the party’s appearance in a comprehensive adjudication, except as specified. Existing law requires that information to include a description of the general purpose for which the groundwater has been used and the area in which the groundwater has been used.

This bill would require the court to presume the accuracy of the facts asserted by a party in the initial disclosure described above if the party claims an annual extraction of not more than 100 acre-feet of water. The bill would provide that a party who challenges the facts asserted in an initial disclosure that qualifies for this presumption has the burden of proving the inaccuracy of those facts. The bill would, if the groundwater has been used for an agricultural use, require the initial disclosure to include information regarding the type of crops grown and the number of acres irrigated during the preceding 10 years.

(3)Existing law, the Sustainable Groundwater Management Act, requires all groundwater basins designated as high- or medium-priority basins by the Department of Water Resources to be managed under a groundwater sustainability plan or coordinated groundwater sustainability plans, except as specified. Existing law authorizes any local agency or combination of local agencies overlying a groundwater basin to decide to become a groundwater sustainability agency for that basin and imposes specified duties upon that agency or combination of agencies, as provided.

This bill would require the court to, in any adjudication in a basin where one or more groundwater sustainability agencies have adopted a groundwater sustainability plan that has been approved by the department, request that the groundwater sustainability agency provide a technical report, to the extent that the agency is able to do so at a reasonable effort and expense. The bill would require such a report to, at a minimum, quantify and describe the groundwater use of parties that have not otherwise appeared before the court, as provided. The bill would provide for the payment or reimbursement of costs related to the technical report, as provided. The bill would permit the court during the pendency of the report to award interim or partial payments to be made by the parties, upon a motion with proper notice, as specified, by a groundwater sustainability agency, and following a hearing. The bill would provide that the technical report shall be prima facie evidence of the physical facts found in the report, as provided.

Sponsors

Sponsors by party (alphabetical): Democratic 1

“Support” is shown only as formal sponsorship recorded by the legislature. Roll-call votes are available on the official bill page.

Recent official actions

1. October 11, 2025Chaptered by Secretary of State - Chapter 643, Statutes of 2025.
2. October 11, 2025Approved by the Governor.
3. September 23, 2025Enrolled and presented to the Governor at 4 p.m.
4. September 11, 2025Senate amendments concurred in. To Engrossing and Enrolling. (Ayes 69. Noes 1. Page 3331.).
5. September 10, 2025In Assembly. Concurrence in Senate amendments pending.
6. September 10, 2025Read third time. Passed. Ordered to the Assembly. (Ayes 35. Noes 5. Page 2823.).
7. September 8, 2025Read second time. Ordered to third reading.
8. September 4, 2025Read third time and amended. Ordered to second reading.
9. August 26, 2025Read second time. Ordered to third reading.
10. August 25, 2025From committee: Be ordered to second reading pursuant to Senate Rule 28.8.
11. August 13, 2025In committee: Hearing postponed by committee.
12. July 17, 2025Read second time and amended. Re-referred to Com. on APPR.