California's Groundwater Live Supporting Data

California’s Groundwater Live provides the most relevant and recent groundwater information at the click of a button. The webpage also includes a series of interactive dashboards which allow users to interact and customize what groundwater data they would like to view. Users can filter the data by address, county, groundwater basin, well depth and even time period to see unique data summaries. California’s Groundwater Live has been developed for a variety of users including groundwater managers, governmental agencies, well owners, non-governmental organizations, water policy makers and members of the public interested in groundwater.

This map shows the percentile statistics for groundwater monitoring wells in California comparing their most recent elevation level to historical levels at that well. The map shows percentile statistics for all wells measured in 2023 and 2024 to date. This map was last updated on October 11, 2024.

This data cover the period of Water Year 2023 which began on October 1, 2022 and ended on September 30, 2023.

Link to introductory video about California's Groundwater Live. From video description: "Welcome to California’s Groundwater Live, DWR’s newest tool to access groundwater information. From seeing the latest groundwater information at the click of a button to creating customized data summaries with one of the interactive dashboards, California’s Groundwater Live gives you the power to explore groundwater conditions in California."

Points representing monitoring wells in DWR's groundwater elevation database which have a groundwater elevation measurement reported in the last 18 months. Information on the most recent measurement is included. This information is based on the DWR Periodic Groundwater Levels dataset that contains seasonal and long-term groundwater level measurements collected by the Department of Water Resources and cooperating agencies in groundwater basins statewide. It also includes data collected through the Sustainable Groundwater Management Act (SGMA) Portal’s Monitoring Network Module (MNM), and the CASGEM (California Statewide Groundwater Elevation Monitoring) Program. Monitoring at active sites is typically done manually twice per year to capture the peak high and low values in groundwater elevations. However, the dataset also includes measurements recorded more frequently, monthly, weekly, or daily. The complete DWR Periodic Groundwater Levels dataset is available at https://data.cnra.ca.gov/dataset/periodic-groundwater-level-measurements. This service is under development as part of of ongoing enhancements to CalGW Live. Once the format is finalized, the service will be hosted at https://gis.water.ca.gov/arcgis/rest/services/. DWR makes no warranties or guarantees — either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data.

The DWR Groundwater Level Percentile Statistics are based on the USGS Groundwater Watch concept of comparing the most recent groundwater level measurement to historical measurements for the same month. For a well to be ranked, the most recent measurement must have occurred within the last 18 months, and measurements from at least 10 years must exist for that month. These statistics are derived from the DWR Periodic Groundwater Levels dataset that contains seasonal and long-term groundwater level measurements collected by the Department of Water Resources and cooperating agencies in groundwater basins statewide. It also includes data collected through the Sustainable Groundwater Management Act (SGMA) Portal’s Monitoring Network Module (MNM), and the CASGEM (California Statewide Groundwater Elevation Monitoring) Program. Most measurements are taken manually twice per year to capture the peak high and low values in groundwater elevations. However, the dataset also includes measurements recorded more frequently, monthly, weekly, or daily. The complete DWR Periodic Groundwater Levels dataset is available at https://data.cnra.ca.gov/dataset/periodic-groundwater-level-measurements. This service is under development as part of of ongoing enhancements to CalGW Live. Once the format is finalized, the service will be hosted at https://gis.water.ca.gov/arcgis/rest/services/. DWR makes no warranties or guarantees — either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data.

Seasonal groundwater level reports provide information from selected water level measurements and are intended to portray the change in seasonal groundwater levels over specific time intervals. Each point shows the calculated difference between the measured groundwater levels from the selected time periods. The change in groundwater level is plotted on the map only if a measurement exists in both time periods at a well. These change values are derived from the DWR Periodic Groundwater Levels dataset that contains seasonal and long-term groundwater level measurements collected by the Department of Water Resources and cooperating agencies in groundwater basins statewide. It also includes data collected through the Sustainable Groundwater Management Act (SGMA) Portal’s Monitoring Network Module (MNM), and the CASGEM (California Statewide Groundwater Elevation Monitoring) Program. Most measurements are taken manually twice per year to capture the peak high and low values in groundwater elevations. However, the dataset also includes measurements recorded more frequently, monthly, weekly, or daily. The complete DWR Periodic Groundwater Levels dataset is available at https://data.cnra.ca.gov/dataset/periodic-groundwater-level-measurements. This service is under development in support of ongoing enhancements to CalGW Live. Once the format is finalized, the service will be hosted at https://gis.water.ca.gov/arcgis/rest/services/. DWR makes no warranties or guarantees — either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data.

Groundwater levels at selected wells were analyzed using the Mann-Kendall non-parametric test to determine whether a statistically significant trend (declining trend, no trend, or increasing trends in groundwater levels) was present during the specified time period. The data used came only from wells that have at least 10 years of data within the last 21 years. If a statistically significant trend was observed, the Theil-Sen method was used to calculate the estimated slope of the trend line to quantify the decline or increase. These trends are derived from the DWR Periodic Groundwater Levels dataset that contains seasonal and long-term groundwater level measurements collected by the Department of Water Resources and cooperating agencies in groundwater basins statewide. It also includes data collected through the Sustainable Groundwater Management Act (SGMA) Portal’s Monitoring Network Module (MNM), and the CASGEM (California Statewide Groundwater Elevation Monitoring) Program. Most measurements are taken manually twice per year to capture the peak high and low values in groundwater elevations. However, the dataset also includes measurements recorded more frequently, monthly, weekly, or daily. The complete DWR Periodic Groundwater Levels dataset is available at https://data.cnra.ca.gov/dataset/periodic-groundwater-level-measurements This service is under development as part of ongoing enhancements to CalGW Live. Once the format is finalized, the service will be hosted at https://gis.water.ca.gov/arcgis/rest/services/. DWR makes no warranties or guarantees — either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data.

Information for domestic and irrigation wells are based on DWR’s Online System for Well Completion Reports (OSWCR). Well uses that are specified on well completion reports have been grouped into domestic wells, irrigation wells (See attribute 'B118WellUse'). The complete Well Completion Report Dataset is available at https://data.cnra.ca.gov/dataset/well-completion-reports. This service is under development as part of of ongoing enhancements to CalGW Live. Once the format is finalized, the service will be hosted at https://gis.water.ca.gov/arcgis/rest/services/. DWR makes no warranties or guarantees — either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data.

CalGW Live information for public supply wells is based on data from the State Water Resource Control’s Division of Drinking Water. This layer was last updated in May 2023.

Statistics on reported dry wells are based on the Household Water Supply Shortage Reporting System Data. The Household Water Supply Shortage Reporting System is available online at at https://mydrywatersupply.water.ca.gov/report/. This service is under development as part of of ongoing enhancements to CalGW Live. Once the format is finalized, the service will be hosted at https://gis.water.ca.gov/arcgis/rest/services/. DWR makes no warranties or guarantees — either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data.

Continuous Global Positioning System (CGPS) Stations record horizontal and vertical ground surface displacement over time. SOPAC/CSRC (https://sopac-csrc.ucsd.edu/) maintains a network of CGPS stations and provides public access to their data. SOPAC Stations in net format: ftp://garner.ucsd.edu/pub/timeseries/measures/ats/inputFiles/sopac_itrf2005.net SOPAC Timeseries Data in tar format (note: the following link is for 1/30/2021. You can replace “20210130” in the url with the desired date): ftp://garner.ucsd.edu/pub/timeseries/measures/ats/WesternNorthAmerica/WNAM_Clean_TrendNeuTimeSeries_sopac_20210130.tar This service is under development as part of of ongoing enhancements to CalGW Live. Once the format is finalized, the service will be hosted at https://gis.water.ca.gov/arcgis/rest/services/. DWR makes no warranties or guarantees — either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data.

Annual subsidence rate layer to be used in CalGW Live Storymap subsidence dashboard. This feature layer contains data for multiple years, and spatial data gaps have been filled for the purpose of statewide summaries. The layer has to be filtered by water year (WY). The TRE ALTAMIRA InSAR subsidence dataset is available at https://data.cnra.ca.gov/dataset/tre-altamira-insar-subsidence. This service is under development as part of of ongoing enhancements to CalGW Live. Once the format is finalized, the service will be hosted at https://gis.water.ca.gov/arcgis/rest/services/. DWR makes no warranties or guarantees — either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data.

DWR, in coordination with the State Water Resources Control Board, has developed an interactive dashboard, called the [Dry Domestic Well Susceptibility within Groundwater Basins Dashboard](https://storymaps.arcgis.com/stories/f2b252d15a0d4e49887ba94ac17cc4bb#ref-n-aoS5Sy) (Dry Well Susceptibility Dashboard), to identify areas within groundwater basins throughout the State that may be prone to water supply shortages due to domestic drinking water wells going dry. The dashboard identifies the density of "susceptible” domestic wells per square mile based on recent groundwater level measurements and modeled future depth to water. If the modeled future depth to water falls below the dry well depth of a domestic well, the well is labelled susceptible. The Dry Well Susceptibility Dashboard is housed on the California’s Groundwater Live web-based platform which contains the latest information and data on groundwater conditions across the State. The State, local agencies, and well owners can use this dashboard to anticipate where wells may be susceptible to inform drought preparedness decision-making and resource allocation. __If you are currently experiencing a dry domestic well, you can report that to DWR’s [Dry Well Reporting System](www.mydrywell.ca.gov) which will connect you with available local assistance.__ The query for domestic wells was based on DWR’s Online System for Well Completion Reports (OSWCR). Well uses that are specified on well completion reports have been grouped into domestic wells (See attribute 'B118WellUse'). The complete Well Completion Report Dataset is available at https://data.cnra.ca.gov/dataset/well-completion-reports. The complete DWR Periodic Groundwater Levels dataset is available at https://data.cnra.ca.gov/dataset/periodic-groundwater-level-measurements. This service is under development as part of ongoing enhancements to CalGW Live. Once the format is finalized, the service will be hosted at https://gis.water.ca.gov/arcgis/rest/services/. _DWR makes no warranties or guarantees — either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data._ _This dashboard and the underlying analysis provide a density map of domestic wells that are susceptible to going dry if recent groundwater trends continue. The map can be used to evaluate the relative density distribution within groundwater basins. However, the map should not be used to estimate the absolute number of domestic wells that are susceptible to going dry for any area or groundwater level scenario. While the applied groundwater level scenario is based on best available datasets, the scenario is hypothetical, and is chosen to resolve regional differences in the density of domestic wells that are susceptible to going dry. Available groundwater level data are interpolated and projected to domestic wells locations. To achieve near statewide coverage for this analysis, groundwater level measurements are projected up to 10 miles in areas where no local monitoring exists. Filling these groundwater level data gaps with new monitoring stations will improve the reliability of the Dry Well Susceptibility Analysis. The applied model for the depth at which a domestic well is susceptible to going dry is simplified and uncalibrated and is not intended to represent any specific well failure mode. Future calibration of this model, and consideration of well construction details will improve the reliability of the Dry Well Susceptibility Analysis._

This resource includes a brief fact sheet describing DWR's [Dry Domestic Well Susceptibility Analysis](https://data.cnra.ca.gov/dataset/calgw-live/resource/e0bf3d2b-ceca-41ca-876f-d3e378503583) and [Dry Well Reporting System](https://mydrywell.water.ca.gov). DWR, in coordination with the State Water Resources Control Board, has developed an interactive dashboard, called the Dry Domestic Well Susceptibility within Groundwater Basins Dashboard (Dry Well Susceptibility Dashboard), to identify areas within groundwater basins throughout the State that may be prone to water supply shortages due to domestic drinking water wells going dry. The dashboard identifies the density of "susceptible” domestic wells per square mile based on recent groundwater level measurements and modeled future depth to water. If the modeled future depth to water falls below the dry well depth of a domestic well, the well is labelled susceptible. The Dry Well Susceptibility Dashboard is housed on the California’s Groundwater Live web-based platform which contains the latest information and data on groundwater conditions across the State. The State, local agencies, and well owners can use this dashboard to anticipate where wells may be susceptible to inform drought preparedness decision-making and resource allocation.

DWR, in coordination with the State Water Resources Control Board, has developed an interactive dashboard, called the [Dry Domestic Well Susceptibility within Groundwater Basins Dashboard](https://storymaps.arcgis.com/stories/f2b252d15a0d4e49887ba94ac17cc4bb#ref-n-aoS5Sy) (Dry Well Susceptibility Dashboard), to identify areas within groundwater basins throughout the State that may be prone to water supply shortages due to domestic drinking water wells going dry. The dashboard identifies the density of "susceptible” domestic wells per square mile based on recent groundwater level measurements and modeled future depth to water. If the modeled future depth to water falls below the dry well depth of a domestic well, the well is labelled susceptible. The Dry Well Susceptibility Dashboard is housed on the California’s Groundwater Live web-based platform which contains the latest information and data on groundwater conditions across the State. The State, local agencies, and well owners can use this dashboard to anticipate where wells may be susceptible to inform drought preparedness decision-making and resource allocation. __If you are currently experiencing a dry domestic well, you can report that to DWR’s [Dry Well Reporting System](www.mydrywell.ca.gov) which will connect you with available local assistance.__ The query for domestic wells was based on DWR’s Online System for Well Completion Reports (OSWCR). Well uses that are specified on well completion reports have been grouped into domestic wells (See attribute 'B118WellUse'). The complete Well Completion Report Dataset is available at https://data.cnra.ca.gov/dataset/well-completion-reports. The complete DWR Periodic Groundwater Levels dataset is available at https://data.cnra.ca.gov/dataset/periodic-groundwater-level-measurements. This service is under development as part of ongoing enhancements to CalGW Live. Once the format is finalized, the service will be hosted at https://gis.water.ca.gov/arcgis/rest/services/. _DWR makes no warranties or guarantees — either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data._ _This dashboard and the underlying analysis provide a density map of domestic wells that are susceptible to going dry if recent groundwater trends continue. The map can be used to evaluate the relative density distribution within groundwater basins. However, the map should not be used to estimate the absolute number of domestic wells that are susceptible to going dry for any area or groundwater level scenario. While the applied groundwater level scenario is based on best available datasets, the scenario is hypothetical, and is chosen to resolve regional differences in the density of domestic wells that are susceptible to going dry. Available groundwater level data are interpolated and projected to domestic wells locations. To achieve near statewide coverage for this analysis, groundwater level measurements are projected up to 10 miles in areas where no local monitoring exists. Filling these groundwater level data gaps with new monitoring stations will improve the reliability of the Dry Well Susceptibility Analysis. The applied model for the depth at which a domestic well is susceptible to going dry is simplified and uncalibrated and is not intended to represent any specific well failure mode. Future calibration of this model, and consideration of well construction details will improve the reliability of the Dry Well Susceptibility Analysis._