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Groundwater Sustainability Agency

Current Status of Groundwater Sustainability Plan

The Final ECC GSP was adopted by the Board of Directors at the Special Board Meeting on November 17, 2021.

The Annual Report for the East Contra Costa Subbasin (ECC Subbasin) is prepared to support the adopted GSP submitted to DWR in January 2022.

This Annual Report includes data elements for the current reporting water year. The report is prepared on behalf of the ECC Working Group, and fulfills statutory and regulatory requirements included in the GSP. The Regulations require the GSA to submit an Annual Report to DWR by April 1st following the water year (October through September).

Sustainable Groundwater Management Act (SGMA)

Recognizing the importance of groundwater, and the consequences of overuse, a package of bills addressing the sustainable management of groundwater in California was approved in 2014. Collectively, these bills are the Sustainable Groundwater Management Act (SGMA).

Our Local Groundwater Basin is known as the East Contra Costa Subbasin

It stretches from Antioch and Bethel Island, through Oakley, Brentwood, Knightsen, down through Discovery Bay, to Clifton Court Forebay. Groundwater from the Subbasin is a vital component of our water supply, along with water from the San Joaquin and Sacramento Rivers that reaches us through the Delta. SGMA took effect on January 1, 2015, and requires all groundwater basins, designated as medium or high priority by the Department of Water Resources, to be sustainably managed by the year 2042. The Department of Water Resources designated the East Contra Costa Subbasin as medium priority based on several factors, including population, number of wells, irrigated area, and groundwater conditions.

Collaborative Groundwater Management Planning in the East Contra Costa Subbasin

To ensure long-term sustainability of the groundwater basin, the District formed a Groundwater Sustainability Agency (GSA). Our GSA collaborates closely with other water suppliers' GSAs in the Subbasin to maintain the Groundwater Sustainability Plan (GSP) in compliance with SGMA.

To learn more about the Sustainable Groundwater Management Planning for the East Contra Costa Subbasin, please see the dedicated website for it at