Groundwater adjudication: burden of proof.

Assembly Member Hart's groundwater adjudication legislation establishes new evidentiary standards for legal challenges to groundwater sustainability agency decisions. The measure assigns the burden of proof to parties seeking judicial review of actions taken under groundwater sustainability plans adopted after January 30, 2020.

The bill modifies California's groundwater adjudication framework, which currently operates under the Sustainable Groundwater Management Act's requirements for high- and medium-priority basins. Under existing law, local agencies can form groundwater sustainability agencies to manage these basins through adopted sustainability plans. The standard burden of proof rules in civil proceedings require each party to prove facts essential to their claims or defenses.

This legislation creates a specific exception for groundwater rights adjudication cases involving challenges to sustainability agency decisions. When parties contest actions taken pursuant to qualifying sustainability plans, they must now carry the burden of proving their claims in court rather than following traditional evidentiary standards. The provision applies only to plans adopted after January 30, 2020, maintaining existing proof requirements for earlier plans.