Groundwater adjudication.

Hart's measure reshapes California's groundwater adjudication by creating an alternative pathway for claimants who extract only minor quantities of groundwater to be treated separately rather than exempted, beginning with a hearing to determine exemption versus separate treatment and establishing a registration and administration framework for those claims. It also anchors adjudication in Sustainable Groundwater Management Act planning by requiring court alignment with SGMA basins that have an approved groundwater sustainability plan and by directing the court to seek technical input from the relevant groundwater sustainability agencies where feasible.

Key mechanisms and details center on four interrelated changes. First, minor-quantity claimants may be processed separately through a defined procedure and orders, with a hearing scheduled after mailing requirements are satisfied. Second, initial disclosures are expanded for all parties, including a presumption of accuracy for claims of not more than 100 acre-feet per year and a requirement to disclose crop types and acres irrigated for agricultural use over the preceding ten years. Third, in basins with SGMA-adopted, DWR-approved groundwater sustainability plans, the court must request a technical report from the applicable groundwater sustainability agency to quantify and describe groundwater use by parties who have not appeared, with costs reimbursed and potential interim payments during the reporting period. Fourth, special masters may have expanded duties, including joint factfinding and assisting with technical/administrative tasks, with compensation and potential involvement of the State Water Resources Control Board or the Department of Water Resources in identifying candidates.

In broader context, the measure links adjudication procedures to SGMA governance by formalizing case-management considerations for SGMA basins and by elevating GSAs as technical sources of information whose reports may be used as evidence, subject to rebuttal. The changes alter evidentiary dynamics by introducing a presumption of accuracy for small-quantity claims, expanding agricultural reporting obligations, and establishing cost-sharing mechanisms for GSA-produced reports, all without creating an explicit new appropriation. Implementation would require courts to establish timelines and registration processes for separate-treatment claims, to integrate SGMA-based case management into adjudications, and to manage the administrative and financial arrangements associated with GSA reporting and intermediate payments.