What is a groundwater basin?

A groundwater basin is an area underlain by permeable materials (such as sand and gravel) that is capable of storing and providing a significant supply of groundwater to wells. The California Department of Water Resources’ Bulletin 118 identifies the groundwater basin in our region as the “Delta-Mendota Subbasin”. The Delta-Mendota Subbasin is a long, relatively narrow groundwater basin on the west side of the San Joaquin Valley that covers portions of six counties: Sacramento, San Joaquin, Stanislaus, Merced, Madera and Fresno. For more information about groundwater basins, visit the California Department of Water Resources’ website at www.water.ca.gov/Programs/Groundwater-Management/Bulletin-118.

What does a Groundwater Sustainability Agency do?

A key part of the Sustainable Groundwater Management Act (SGMA) is maintaining local control over groundwater resources. Locally-formed Groundwater Sustainability Agencies (GSA) are responsible for complying with the requirements of SGMA and overseeing the sustainable management of our region’s groundwater resources. SGMA requires GSAs to prepare Groundwater Sustainability Plans, implement actions to bring the subbasin into sustainability, and engage local stakeholders in the SGMA process.

SGMA grants the following authorities to all GSAs to aid in the implementation of GSPs:
• Adopt rules, regulations, ordinances, and resolutions to implement SGMA
• Monitor compliance and enforcement
• Require registration of groundwater wells
• Require appropriate measurement devices and reporting of extractions
• Investigate, appropriate and acquire surface water rights, groundwater and groundwater rights into the GSA
• Acquire or augment local water supplies to enhance the sustainability of the groundwater basin
• Propose and collect fees
• Adopt and fund a GSP according to existing laws

The GSAs in the Delta-Mendota Subbasin may choose to use some, all, or none of these authorities.

What is the Sustainable Groundwater Management Act (SGMA)?

The Sustainable Groundwater Management Act is a California State law passed in 2014. SGMA’s goal is to ensure the long-term sustainable management of the State’s groundwater resources. SGMA requires agencies throughout California to meet certain requirements. These include:
• Forming Groundwater Sustainability Agencies (GSA)
• Developing Groundwater Sustainability Plans (GSP)
• Achieving sustainable groundwater levels within 20 years

What is a Groundwater Sustainability Agency?

A Groundwater Sustainability Agency (GSA) is one or more local public agencies that implement the provisions of the Sustainable Groundwater Management Act. To be eligible to serve as a GSA, an agency must be a local public agency that has water supply, water management, or land use management responsibilities with the groundwater basin. In the Delta-Mendota Subbasin, this includes cities, counties, public water agencies, irrigation districts, and a resource conservation district. Some GSAs in the Delta-Mendota Subbasin only include a single agency. Other GSAs include multiple agencies.

Why was the Sustainable Groundwater Management Act established?

Over the years, California water managers, individual well owners, and communities that rely on groundwater have observed a rapid decline of water levels in some groundwater basins. Groundwater quality has also declined in some communities. These problems were worsened by the historic drought experienced in California from 2012 to 2017. The Sustainable Groundwater Management Act was passed to provide local agencies with new authorities and tools to sustainably manage their region’s groundwater resources.

What is a GSP?

A Groundwater Sustainability Plan (GSP) is a plan developed by a Groundwater Sustainability Agency (GSA) under the Sustainable Groundwater Management Act. A GSP must outline how the GSA will implement, manage, and measure specific actions to sustainably manage the groundwater levels in the groundwater basin. The GSPs for the Delta-Mendota Subbasin must be submitted to the California Department of Water resources no later than January 31, 2020. The GSAs will then be required implement the actions outlined in the GSP.

How can I participate in the Groundwater Sustainability Plan development process?

Six Groundwater Sustainability Plans (GSP) covering the Delta-Mendota Subbasin are currently being developed. All six GSPs will be submitted to the California Department of Water Resources together. However, they are currently being developed at different rates. Each GSP will be adopted at a public meeting. Prior to adoption, the Groundwater Sustainability Agencies (GSA) will hold public comment periods to receive input on the GSPs. The GSAs will also conduct public outreach throughout the GSP development process. Ask to be added to your local GSA’s contact list to receive email updates on their GSP and notices about GSP workshops, public meetings, and opportunities for public comment.