California's Groundwater Live Supporting Data

California’s Groundwater Live website 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, hydrologic region, and data-specifics 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. Available dashboards include: Groundwater Level Information * Current Groundwater Levels (depth to water) * Current Groundwater Level Conditions (percentiles) * Seasonal Groundwater Level Changes (1, 3, 5, 10-Years) * 20-Year Groundwater Level Trends Well Information * Domestic Wells * Irrigation Wells * Public Supply Wells * Reported Dry Wells * Dry Domestic Well Susceptibility within Groundwater Basins Subsidence Information * InSAR Land Subsidence and Continuous GPS Stations Sustainable Groundwater Management Act (SGMA) Reporting Information * Groundwater Sustainability Plans and Alternatives * Reported Change in Groundwater Storage * Reported Groundwater Recharge * Reported Groundwater Extractions * Groundwater Sustainability Plan Groundwater Level Monitoring Network

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 2025 and 2026 to date. This map was last updated on July 15, 2026. The data shown on the map is available in the Current Groundwater Level Statistics GIS Feature Service: https://data.cnra.ca.gov/dataset/calgw-live/resource/979ef98a-5ef6-4af5-9a98-85bb7d5b9c36 An interactive version of the map is available through the Current Groundwater Level Conditions Dashboard: https://storymaps.arcgis.com/stories/b3886b33b49c4fa8adf2ae8bdd8f16c3#ref-n-uWnp7G

This data covers the period of Water Year 2025 which began on October 1, 2024 and ended on September 30, 2025. Vertical displacement estimates are derived from Interferometric Synthetic Aperture Radar (InSAR) data that are collected by the European Space Agency (ESA) Sentinel-1A satellite and processed by TRE ALTAMIRA Inc. (TRE), under contract with the California Department of Water Resources (DWR) as part of DWR’s SGMA technical assistance to provide important SGMA-relevant data to GSAs for GSP development and implementation. The TRE ALTAMIRA InSAR Subsidence Dataset is available at https://data.cnra.ca.gov/dataset/tre-altamira-insar-subsidence The data is also available in the interactive InSAR Land Subsidence and Continuous GPS Station Dashboard: https://storymaps.arcgis.com/stories/41574a6d980b4e5d8d4ed7b90f9698d2#ref-n-v3v7cy

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. The field LAST_GSE_GWE represents the depth to groundwater and is calculated by subtracting the groundwater elevation (LAST_GWE) from the ground surface elevation (LAST_WLM_GSE). The Depth to Groundwater is then categorized into five bins for symbolization on the Current Groundwater Levels Dashboard. Those bins and their labels are: 0 ft through 25 ft (denoted as "25" in the attribute table), greater than 25 ft through 100 ft ("100"), greater than 100 ft through 200 ft ("200"), greater than 200 ft through 500 ft ("500"), and greater than 500 ft ("9999"). The Current Groundwater Levels Dashboard is available at https://storymaps.arcgis.com/stories/b3886b33b49c4fa8adf2ae8bdd8f16c3#ref-n-EWjEqA 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. This dataset is maintained primarily in the DWR Enterprise Water Management database. 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. Groundwater level percentile class information is determined by comparing a single measurement to all other measurements collected in the same month at that well. The “percentile class” is a statistical determination that describes the percentage of all measurements that are below a specific measurement. If 90 percent of measurements are below (deeper) than a given measurement, then it is in the 90th percentile and if only 10 percent of measurements are below, then that measurement is in the 10th percentile. An average measurement is the 50th percentile. The Fall 2022 and Spring 2024 measurement is classified into one of eight percentile categories, or statistical bins, based on all measurements for that well. These categories are: Lowest on Record, lowest 10% (Much Below Normal), 10-25% (Below Normal), 25-50% (Normal), 50-75% (Normal), 75-90% (Above Normal), highest 90% (Much Above Normal), and Highest on Record. The Groundwater Level Percentile Statistics are used for the Current Groundwater Level Conditions Dashboard, available at https://storymaps.arcgis.com/stories/b3886b33b49c4fa8adf2ae8bdd8f16c3#ref-n-uWnp7G 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. Data from the Periodic Groundwater Levels dataset is queried and categorized into seasons for each year, where "Spring" includes measurements occurring January through May, and "Fall" includes measurements occurring September through November. Measurements are excluded if they had quality codes indicating active pumping or flowing conditions, oil or foreign substances, or other quality issues. Of the Spring measurements for each well, the maximum groundwater level is taken to represent the seasonal high groundwater level. For Fall, the minimum groundwater level measurement for each well is taken to represent the seasonal low groundwater level. For Spring, the differences between the recent Spring maximum and the past Spring maximums (1, 3, 5, or 10 years ago) are shown in the WSE_CHANGE field. For Fall, the difference between the recent Fall minimum and the past Fall minimums are shown in the WSE_CHANGE field. The data is then classified into five categories in the WSE_CHANGE_CATEGORY field: decrease more than 25ft, decrease 5-25ft, no significant change (-5ft and +5ft), increase 5 25ft, increase more than 25ft. 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. To ensure sufficient data quality and temporal coverage, each well included in the analysis must meet minimum data requirements: at least 10 unique years of spring measurements, and those spring measurements must span at least 15 years within the 20-year period. When more than one spring measurement was available for a year, the highest (shallowest) water level was selected to represent that year. If a statistically significant trend was observed, the Thiel-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. 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. 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 November 2024.

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. 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. 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. _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._