State, Local Water Agencies Achieve Major Milestone in Efforts to Ensure Groundwater Sustainability Statewide


A groundwater well by an irrigation canal in Maxwell, California. Photo taken November 29, 2023.

A groundwater well by an irrigation canal in Maxwell, California. Photo taken November 29, 2023.

Under SGMA, groundwater basins covering 98 percent of the state’s groundwater use are actively managed by local agencies

Sacramento, Calif.The Department of Water Resources (DWR) marked a major milestone in long-term water supply management efforts today with the completion of the review process of groundwater sustainability plans for high and medium priority groundwater basins in the state. The plans were prepared and submitted at the local level for the first time, ensuring that communities near these precious resources have a significant role in ensuring their sustainability.

California’s groundwater basins, which collectively make up a massive underground reservoir, provide a critical water supply for 15.4 million people, especially during dry years when surface water supplies are lacking. As California adapts to a hotter, drier future, these groundwater supplies will become a more vital resource for local water agencies and agriculture.

In 2014, the state legislature passed the Sustainable Groundwater Management Act (SGMA), establishing a statewide framework to help protect groundwater resources over time. For each high and medium priority basin, local groundwater sustainability agencies are tasked with preparing and implementing groundwater sustainability plans to help ensure current and long-term water supply resiliency for the communities, households, industries, and environmental habitats that are dependent upon them.

Among other issues, the groundwater sustainability plans address overdraft, which is when the average annual amount of groundwater extraction exceeds the long-term average annual supply of water to the basin. Negative effects of overdraft can include seawater intrusion, land subsidence, groundwater depletion, and chronic lowering of groundwater levels. Some basins are at risk of critical overdraft, meaning that the continuation of present water management practices will likely result in significant adverse overdraft-related environmental, social, or economic impacts.

“It is remarkable that now, for the first time under SGMA, groundwater basins that make up 98 percent of the state’s groundwater use are being actively managed by local agencies with locally developed groundwater sustainability plans that have undergone initial review, said Paul Gosselin, Deputy Director of DWR’s Sustainable Groundwater Management Office. “Since 2014, local agencies, with state support, have met every ambitious milestone required by SGMA, and with today’s announcement, DWR has met the required deadline to review and issue determinations for all initial groundwater sustainability plans. The work does not stop here and DWR will continue to partner with local agencies to build a more sustainable water future for all Californians.”

In the final round of reviews for 17 plans released today, DWR has approved ten plans, and deemed seven plans incomplete.

DWR has approved plans for the following basins:

  • Anderson
  • Enterprise
  • San Antonio Creek Valley
  • Santa Clara River Valley East
  • Santa Ynez River Valley
  • Solano
  • Temescal
  • Tracy
  • Upper San Luis Rey Valley
  • Yucaipa

DWR has deemed the following basin plans incomplete:

  • Butte Valley
  • Fillmore
  • Modesto
  • Pleasant Valley (Basin No. 5-022.10)
  • Piru
  • Tulelake
  • Turlock

For those basins that have been deemed incomplete, groundwater sustainability agencies have 180 days to revise and resubmit their plans. Upon evaluation of resubmitted plans, DWR will determine that the basin is either approved or inadequate. An inadequate determination will initiate consultation with the State Water Resources Control Board for possible State intervention.

Under SGMA, DWR’s role is to provide regulatory oversight to ensure groundwater agencies and their plans are on track to reach the local sustainability goals, and to provide assistance to local agencies to help them meet their goals. DWR provides planning, technical, and financial assistance and an extensive suite of data and tools to all groundwater sustainability agencies, supporting local agencies and communities in this long-term effort to sustainably manage their groundwater basins. DWR has provided nearly $500 million in Sustainable Groundwater Management grant funding for SGMA planning and implementation.

Prior to the passage of SGMA, surface water and groundwater resources were managed separately. It is now recognized that the two resources are connected and must be managed together to ensure a long-term reliable water supply. California is expected to lose 10% of its water supply by 2040; Governor Newsom’s Water Supply Strategy calls on the state and local agencies to expand groundwater storage as a key strategy to address the water supply challenges of our warming climate.

It is important to acknowledge the accomplishments of the local agencies and communities that have been at the forefront of getting the work done to sustainably manage groundwater in California. These are just a few of the accomplishments to date under SGMA:

  • All of the high and medium priority groundwater basins required to comply with SGMA met the 2017 deadline to have the basins covered by one or more new local groundwater sustainability agencies. This required local agencies, that in most cases had not previously worked together, to agree on the structure of a new public agency with new authorities and responsibilities to manage and oversee local groundwater resources. DWR’s Facilitation Support Services were utilized in several basins to help with this process.
  • By January 2020, the newly formed groundwater sustainability agencies in the critically overdrafted basins met the deadline to complete and submit the first-ever groundwater sustainability plans to DWR for evaluation.
  • By January 2022, the groundwater sustainability agencies in the remaining high and medium priority groundwater basins met the plan submission deadline.
  • DWR has provided determinations for all of the basins required to submit plans by January 31, 2022.
  • The groundwater sustainability agencies are implementing planned projects, including groundwater recharge projects, and other management actions within their basins that will help create a resilient and sustainable water supply for California.

SGMA is a long-term solution for groundwater sustainability and local agencies are hard at work in an ongoing effort to progress towards their sustainability goals, including implementing projects and management actions, collecting data, providing community outreach, and submitting updates to DWR through annual report submittals by April 1 each year.                                                        

For more information:



Mary Fahey, Public Affairs, Department of Water Resources
916-820-8083 |