DWR's Groundwater Program Key to Long-Term Water Resilience


From left, Arnold Lamon, field supervisor, Cascade Drilling, LP, Bryce Russell, engineering geologist, California Department of Water Resources, and Bill Brewster, senior engineering geologist, California Department of Water Resources, discuss the installation a multicompletion monitoring well in Zamora, California, for the Sustainable Groundwater Management Program of the California Department of Water Resources. Zamora is a city in Yolo County. Photo taken September 28, 2018.

DWR staff and contractors discuss the installation a multicompletion monitoring well in Zamora, California, for the Sustainable Groundwater Management Program.

California’s new water year started on October 1 and with continued warm and dry weather in the long-range forecasts, the State is preparing for a fourth dry year. The Department of Water Resources (DWR) is continuing to address drought and planning for a hotter, drier future by spearheading the use of innovative technology, working in partnership with other agencies, and supporting communities at the local level.

Eighty-five percent of Californians depend on groundwater for some portion of their water needs every day, and during drought groundwater acts as a buffer, supplying up to 60% of the state’s water supply especially during extremely dry conditions. While the water beneath our feet is unseen and often overlooked, sustainable management of this resource is critical for long-term water supply reliability. That is why groundwater management is a key part of the Governor’s strategy to secure the future of California’s water supply.   DWR’s Statewide Groundwater Management Program is at the forefront of innovation, collaboration, and science-based excellence to ensure a reliable groundwater future for California.

Since the enactment of the Sustainable Groundwater Management Act (SGMA) in 2014, DWR’s Groundwater Management Program has made considerable advancements in collecting, reporting, and disseminating vital groundwater data, and providing support to local agencies through technical expertise, data and tools, assistance and engagement, and grant funding.

As Water Year 2022 (WY 2022) came to a close, DWR released the 2022 Groundwater Conditions Update which provides a look back at groundwater conditions during the last water year informed by DWR’s groundwater data and tools. The Update provides information about current and historical drought and effects on groundwater as well as data and maps that show changes over the last year in groundwater levels, land subsidence, well infrastructure and dry well reporting. Some key findings include:

  • Californians continue to rely heavily on groundwater during drought.
  • Statewide groundwater levels have been in general decline for the past 20 years which is associated with trends in reduced snowpack and precipitation.
  • Increased reliance on groundwater during drought periods has resulted in continued lowering of groundwater levels in several parts of the state.
  • The frequency of statewide land subsidence monitoring and reporting increased in 2022 and shows that land subsidence continued to occur during the July 2021 to July 2022 period. This can be expected during critically dry years when more people turn to groundwater pumping.
  • The number of dry wells reported to DWR during WY 2022 was similar to the number reported in WY 2021, both critically dry water years. Dry well reports are notably less during wet years.
  • DWR awarded more than $480 million to date in drought relief assistance to small and urban communities to address water supply challenges.

DWR produces the Groundwater Conditions Update annually in October to summarize the past water year to help state and local agencies make management decisions informed by the latest conditions. DWR also produces a more robust annual Groundwater Conditions Report in March which includes more up-to-date data that is not yet available at the end of each water year. These annual reports support DWR’s comprehensive California’s Groundwater (Bulletin 118) publication which is updated every five years. This suite of reports is critical in providing knowledge and understanding about our groundwater system that is necessary for state and local agencies to plan and implement management actions that will help to ensure long-term resiliency of the state’s water supply. The next Annual Groundwater Conditions Report will be published in March 2023.


Map of California depicting the one-year groundwater level change from Spring 2021 to Spring 2022.
Map of California depicting the one-year groundwater level change from Spring 2021 to Spring 2022.


As weather patterns have become more variable and extreme from the effects of climate change, we recognize that groundwater will continue to be relied upon, especially during dry periods,” said Paul Gosselin, Deputy Director of DWR’s Sustainable Groundwater Management Office. “The success of state and local groundwater management efforts, including near-term drought actions and long-term implementation of SGMA, depends on the availability of the best existing data and information to guide projects and actions.”

In the short seven years since SGMA went into effect, the state and DWR’s Groundwater Management Program have accelerated investments in the people, projects, and programs that are critical to long-term statewide groundwater resiliency.

DWR has a long history of collecting and analyzing groundwater data, providing reports and guidance, and offering the technical expertise needed to improve statewide groundwater management practices. These data and tools are important resources that are being utilized by state and federal agencies and local groundwater sustainability agencies (GSAs) to make informed groundwater management decisions. Today, GSAs have developed groundwater sustainability plans (GSP) in all the required basins under SGMA, to better manage 98% of the total groundwater pumped in the state, and SGMA is shifting now from the planning phase into the implementation phase, where data-driven projects and actions will be implemented. DWR’s groundwater data and tools are utilized by these local agencies in developing GSPs and designing and implementing projects.

Along with the programs and reports described above, DWR makes groundwater data available to the public through several online resources, listed below:

  • California’s Groundwater Live – This site is updated daily and presents the most up-to-date groundwater data received by DWR, including groundwater conditions, well infrastructure, reported dry wells and land subsidence.
  • InSAR subsidence surveys – DWR collects new data provided quarterly from satellite-based subsidence monitoring, illustrating changes to land surface elevation that can impact roads, canals, and other critical infrastructure.
  • SGMA Data Viewer – This is a technical mapping application for viewing and downloading SGMA-related datasets.
  • Airborne Electromagnetic (AEM) surveys - Data from AEM surveys is like a window into the underground aquifers where sand, gravel, and clay may be present, improving our understanding of aquifer structures and function.
  • AEM Data Viewer – This GIS-based tool displays AEM data in a three-dimensional space and allows the user to interact with the data.
  • SGMA Portal – Users can view and download information related to GSAs, GSPs, alternatives to GSPs, adjudicated areas, and basin boundary modifications, and public comments can be submitted to the Department through the Portal.
  • Water Data Library – Viewers can locate monitoring stations and retrieve data for groundwater levels and water quality.
  • Online System for Well Completion Reports (OSCWR) – OSCWR provides public access to well completion reports submitted to the state.
  • California Statewide Groundwater Elevation Monitoring (CASGEM) program - Senate Bill x7-6 passed by the legislature in 2009, established collaboration between local monitoring parties and DWR to collect statewide groundwater elevations and make the data available to the public, and this resulted in the CASGEM program. 
  • CNRA Open Data Open data is public data collected by the state through its routine business activities and published in a format that is easy to search, download and combine with other data sets from other sources.

DWR’s groundwater program also provides direct support to local agencies and communities on near-term dry well assistance and long-term groundwater management assistance through several programs, listed below, and we strive to make these programs easy to access.

  • Dry Well Reporting System – In response to drought, DWR developed and manages this system where Californians experiencing problems with their private, self-managed wells that are not served by a public water system can voluntarily report dry wells and be connected with entities providing local assistance for drought.
  • Dry Domestic Well Susceptibility Tool This interactive mapping tool identifies areas within groundwater basins throughout the state that may be prone to water supply shortages in drinking water wells so the State, local agencies, and well owners can anticipate where wells may go dry based on historical conditions.
  • Assistance and Engagement DWR is committed to providing guidance and support as GSAs and interested parties work together to implement SGMA and work toward achieving groundwater sustainability goals.
  • Regulatory Assistance for groundwater recharge projectsDWR is engaging multiple State and local agencies to implement streamlined water right permitting, and exercising executive order direction to expedite groundwater recharge projects and capture high flows when they occur.
  • Sustainable Groundwater Management Grant Program – DWR provides funding to GSAs and other responsible entities under SGMA to promote healthy and sustainable groundwater basins, to reduce and eliminate undesirable effects, and to promote projects that provide multiple benefits while also improving groundwater supply and quality.

There are also new emerging efforts on the horizon at DWR, including making annual groundwater use data reported by GSAs available to the public in an ongoing effort to improve timely data reporting. DWR is also partnering with the California Water Data Consortium and the State Water Board on development of a new water accounting platform.

The technical assistance, data, and information provided by DWR gives local agencies a higher level of understanding to enhance their groundwater management decision making, but we recognize that data gaps still exist, and that it takes partnerships and multiple agencies working together to manage groundwater and build resilience for the new hotter and drier future in California. DWR will continue to collaborate with our partners, invest in the latest data and tools, and support local management to ensure a healthy statewide groundwater supply for all Californians long into the future.