When water users within a basin are in dispute over legal rights to the water, a court can issue a ruling known as an adjudication. Adjudications can cover an entire basin, a portion of a basin, or a group of basins and all non-basin locations between. The court decree will define the area of adjudication. The court typically appoints a watermaster to administer the court's decree.
In basins or areas where a lawsuit is brought to adjudicate, the groundwater rights of all the overliers and appropriators are determined by the court.
The court also decides:
- Who the water rights owners are.
- How much groundwater those rights owners can extract.
- How the groundwater area will be managed. Often, a watermaster is emplaced by the court to manage the ownership of rights and water use.
At the time of SGMA's passage, 27 groundwater areas, located mostly in Southern California, were treated as adjudicated by SGMA. Since passage of SGMA, two areas submitted court decrees adjudicating water rights. SGMA established a process for adjudicated basin watermasters, or local agencies, to report information according to .
DWR is required to post notice and form answers related to comprehension adjudication that are submitted by plaintiffs to those actions (see Code of Civil Procedure Section 836(m)). DWR has received the following:
- Borrego Water District v. All Persons Who Claim a Right to Extract Groundwater in the Borrego Valley Groundwater Subbasin, etc., et al.
- Santa Barbara Channelkeeper v. SWRCB, et al. (Received: 12/10/2019)
- Los Posas Basin v. Fox Canyon Adjudication (Received: 11/13/2018)
SGMA required the adjudications specified in Section 10720.8 to submit to DWR by April 1, 2016, a copy of their governing final judgment, or other judicial order or decree, and any amendments entered before April 1, 2016.
- Two additional adjudications entered after April 1, 2016, have submitted their final judgements to DWR.
- A watermaster, or local agency is required to submit a copy of any amendments to final judgements to DWR within 90 days of entry by a court.
- By April 1, of each year, the watermaster or local agency submits to DWR a report containing the following information to the extent available for the portion of the basin subject to the adjudication:
A. Groundwater elevation data unless otherwise submitted pursuant to Section 10932. (DWR's CASGEM Program)
B. Annual aggregated data identifying groundwater extraction for the preceding water year.
C. Surface water supply used for or available for use for groundwater recharge or in-lieu use.
D. Total water use.
E. Change in groundwater storage.
F. The annual report submitted to the court.
Watermasters or local agencies submit SGMA information for Adjudicated Areas through the Adjudicated Area Annual Reporting System.