DWR Airborne Electromagnetic (AEM) Surveys Data

Statewide AEM Surveys Project Overview

The Department of Water Resources’ (DWR’s) Statewide Airborne Electromagnetic (AEM) Surveys Project is funded through California’s Proposition 68 and the General Fund. The goal of the project is to improve the understanding of groundwater aquifer structure to support the state and local goal of sustainable groundwater management and the implementation of the Sustainable Groundwater Management Act (SGMA).

During an AEM survey, a helicopter tows electronic equipment that sends signals into the ground which bounce back. The data collected are used to create continuous images showing the distribution of electrical resistivity values of the subsurface materials that can be interpreted for lithologic properties. The resulting information will provide a standardized, statewide dataset that improves the understanding of large-scale aquifer structures and supports the development or refinement of hydrogeologic conceptual models and can help identify areas for recharging groundwater.

DWR is collecting AEM data in all of California’s high- and medium-priority groundwater basins, where data collection is feasible. Data are collected in a coarsely spaced grid, with a line spacing of approximately 2-miles by 8-miles. AEM data collection started in 2021 and will continue over the next several years. Visit the AEM Survey Schedule Webpage to get up-to-date information on the survey schedule: https://gis.water.ca.gov/app/AEM-schedule.

Additional information about the Statewide AEM Surveys can be found at the project website: https://water.ca.gov/Programs/SGMA/AEM

Survey Areas

AEM data are being collected in groups of groundwater basins, defined as a Survey Area. See the Survey Area Map in the Data and Resources Section below to see the basins in each Survey Area.

  • Survey Area 1: 180/400 Foot Aquifer (partial), East Side (partial), Upper Valley, Forebay Aquifer, Paso Robles, Atascadero (limited), Adelaida (limited), Cuyama Valley.
  • Survey Area 2: Scott River Valley, Shasta Valley, Butte Valley, Tulelake, Fall River Valley (limited), Big Valley (Modoc/Lassen County).
  • Survey Area 3: Big Valley (Lake County), Ukiah Valley, Santa Rosa Plain, Petaluma Valley, Sonoma Valley.
  • Survey Area 4: White Wolf, Kern County, Tulare Lake, Tule, Kaweah.
  • Survey Area 5: Pleasant Valley, Westside, Kings, Madera, Chowchilla, Merced, Turlock, Modesto, Delta-Mendota
  • Survey Area 6: Cosumnes, Tracy, Eastern San Joaquin, East Contra Costa, Solano, Livermore, South American, North American, Yolo, Sutter, South Yuba, North Yuba
  • Survey Area 7: Colusa, Butte, Wyandotte Creek, Vina, Los Molinos, Corning, Red Bluff, Antelope, Bowman, Bend, Millville, South Battle Creek, Anderson, Enterprise, Eel River, Sierra Valley

Data Reports

Data reports detail the AEM data collection, processing, inversion, interpretation, and uncertainty analyses methods and procedures. Data reports also describe additional datasets used to support the AEM surveys, including digitized lithology and geophysical logs. Multiple data reports may be provided for a single Survey Area, depending on the Survey Area coverage.

Data Availability and Types

All data collected as a part of the Statewide AEM Surveys will be made publicly available, by survey area, approximately six to twelve months after individual surveys are complete (depending on survey area size). Datasets that will be publicly available include:

AEM Datasets

  • Raw AEM Data
  • Processed AEM Data
  • Inverted AEM Data
  • Inverted AEM Data Uncertainty Analysis
  • Interpreted AEM Data
  • Interpreted AEM Data Uncertainty Analysis

Supporting Datasets

  • Flown Survey Lines
  • Digitized Lithology Logs
  • Digitized Geophysical Logs

AEM Data Viewer

The AEM Data Viewer provides a quick and easy way to visualize the inverted resistivity data in a three-dimensional space. The most recent data available are shown, which my be the provisional data for some areas that are not yet finalized. The AEM Data Viewer is under development.

Provisional Statement

Data Reports and datasets labeled as provisional may be incomplete and are subject to revision until they have been thoroughly reviewed and received final approval. Provisional data and reports may be inaccurate and subsequent review may result in revisions to the data and reports. Data users are cautioned to consider carefully the provisional nature of the information before using it for decisions that concern personal or public safety or the conduct of business that involves substantial monetary or operational consequences.

Data and Resources

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identifier a9c7ef72-2a79-4fa7-8c34-04fd6756067c
issued 2021-12-21T15:14:41.303134
modified 2022-07-25T21:45:37.480067
publisher California Department of Water Resources
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  • AmeriGEOSS
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Tags
  • aem
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  • amerigeo
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  • ckan
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  • geophysics
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isopen False
license_id notspecified
license_title License not specified
maintainer Ben Brezing
maintainer_email benjamin.brezing@water.ca.gov
metadata_created 2025-11-20T07:27:53.240346
metadata_modified 2025-11-20T07:27:53.240350
notes #Statewide AEM Surveys Project Overview The Department of Water Resources’ (DWR’s) Statewide Airborne Electromagnetic (AEM) Surveys Project is funded through California’s Proposition 68 and the General Fund. The goal of the project is to improve the understanding of groundwater aquifer structure to support the state and local goal of sustainable groundwater management and the implementation of the Sustainable Groundwater Management Act (SGMA). During an AEM survey, a helicopter tows electronic equipment that sends signals into the ground which bounce back. The data collected are used to create continuous images showing the distribution of electrical resistivity values of the subsurface materials that can be interpreted for lithologic properties. The resulting information will provide a standardized, statewide dataset that improves the understanding of large-scale aquifer structures and supports the development or refinement of hydrogeologic conceptual models and can help identify areas for recharging groundwater. DWR is collecting AEM data in all of California’s high- and medium-priority groundwater basins, where data collection is feasible. Data are collected in a coarsely spaced grid, with a line spacing of approximately 2-miles by 8-miles. AEM data collection started in 2021 and will continue over the next several years. Visit the AEM Survey Schedule Webpage to get up-to-date information on the survey schedule: https://gis.water.ca.gov/app/AEM-schedule. Additional information about the Statewide AEM Surveys can be found at the project website: https://water.ca.gov/Programs/SGMA/AEM # Survey Areas AEM data are being collected in groups of groundwater basins, defined as a Survey Area. See the Survey Area Map in the Data and Resources Section below to see the basins in each Survey Area. + Survey Area 1: 180/400 Foot Aquifer (partial), East Side (partial), Upper Valley, Forebay Aquifer, Paso Robles, Atascadero (limited), Adelaida (limited), Cuyama Valley. + Survey Area 2: Scott River Valley, Shasta Valley, Butte Valley, Tulelake, Fall River Valley (limited), Big Valley (Modoc/Lassen County). + Survey Area 3: Big Valley (Lake County), Ukiah Valley, Santa Rosa Plain, Petaluma Valley, Sonoma Valley. + Survey Area 4: White Wolf, Kern County, Tulare Lake, Tule, Kaweah. + Survey Area 5: Pleasant Valley, Westside, Kings, Madera, Chowchilla, Merced, Turlock, Modesto, Delta-Mendota + Survey Area 6: Cosumnes, Tracy, Eastern San Joaquin, East Contra Costa, Solano, Livermore, South American, North American, Yolo, Sutter, South Yuba, North Yuba + Survey Area 7: Colusa, Butte, Wyandotte Creek, Vina, Los Molinos, Corning, Red Bluff, Antelope, Bowman, Bend, Millville, South Battle Creek, Anderson, Enterprise, Eel River, Sierra Valley # Data Reports Data reports detail the AEM data collection, processing, inversion, interpretation, and uncertainty analyses methods and procedures. Data reports also describe additional datasets used to support the AEM surveys, including digitized lithology and geophysical logs. Multiple data reports may be provided for a single Survey Area, depending on the Survey Area coverage. # Data Availability and Types All data collected as a part of the Statewide AEM Surveys will be made publicly available, by survey area, approximately six to twelve months after individual surveys are complete (depending on survey area size). Datasets that will be publicly available include: ### AEM Datasets + Raw AEM Data + Processed AEM Data + Inverted AEM Data + Inverted AEM Data Uncertainty Analysis + Interpreted AEM Data + Interpreted AEM Data Uncertainty Analysis ### Supporting Datasets + Flown Survey Lines + Digitized Lithology Logs + Digitized Geophysical Logs #AEM Data Viewer The AEM Data Viewer provides a quick and easy way to visualize the inverted resistivity data in a three-dimensional space. The most recent data available are shown, which my be the provisional data for some areas that are not yet finalized. The AEM Data Viewer is under development. #Provisional Statement Data Reports and datasets labeled as *provisional* may be incomplete and are subject to revision until they have been thoroughly reviewed and received final approval. *Provisional* data and reports may be inaccurate and subsequent review may result in revisions to the data and reports. Data users are cautioned to consider carefully the provisional nature of the information before using it for decisions that concern personal or public safety or the conduct of business that involves substantial monetary or operational consequences.
num_resources 25
num_tags 12
title DWR Airborne Electromagnetic (AEM) Surveys Data