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 Survey Area Map for groundwater subbasins within a Survey Area: https://data.cnra.ca.gov/dataset/aem/resource/a6286b07-5597-49e6-9cac-6a3a98b904df + 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 + Survey Area 8: Seaside, Monterey, 180/400 (partially surveyed Summer 2021), Eastside (partially surveyed Summer 2021), Langley, Pajaro, Santa Cruz Mid-County, Santa Margarita, San Benito, and Llagas (partial). + Survey Area 9: Basin Characterization Pilot Study 1 - Madera and Kings. + Survey Area 10: San Antonio Creek Valley, Arroyo Grande, Santa Maria, San Luis Obispo, Los Osos Area, Warden Creek, Chorro Valley (limited), Morro Valley (limited) + Survey Area 11: Indian Wells Valley, Rose Valley, Owens Valley, Fish Slough, Indio, Mission Creek, West Salton Sea (limited), East Salton Sea (limited), Ocotillo-Clark Valley (limited), Imperial Valley (limited),Chocolate Valley (limited), Borrego Springs, and San Jacinto # 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 (for coarse fraction) + Interpreted AEM Data Uncertainty Analysis ### Supporting Datasets + Flown Survey Lines + Digitized Lithology Logs + Digitized Geophysical Logs #AEM Data Viewers DWR has developed AEM Data Viewers to provides a quick and easy way to visualize the AEM electrical resistivity data and the AEM data interpretations (as texture) 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 Data Viewers can be accessed by direct link, below, or from the Data Viewer Landing Page: https://data.cnra.ca.gov/dataset/aem/resource/29c4478d-fc34-44ab-a373-7d484afa38e8 AEM 3D Viewer (Beta) (computer only): https://dwr.maps.arcgis.com/apps/instant/3dviewer/index.html?appid=f781b14f42ab45e5b72f32cf07af899c AEM Profile Viewer: https://dwr.maps.arcgis.com/apps/instant/attachmentviewer/index.html?appid=65f0aa6db8124aeda54e1f33c5dfe66c #AEM Depth Slice and Shallow Subsurface Average Maps As a part of DWR’s upcoming Basin Characterization Program, DWR will be publishing a series of maps and tools to support advanced data analyses. The first of these maps have now been published and provide analyses of the Statewide AEM Survey data to support the identification of potential recharge areas. The maps are located on the SGMA Data Viewer (under the Hydrogeologic Conceptual Model tab) and show the AEM electrical resistivity and AEM-derived texture data as the following: + Shallow Subsurface Average: Maps showing the average electrical resistivity and AEM-derived texture in the shallow subsurface (the top approximately 50 feet below ground surface). These maps support identification of potential recharge areas, where the top 50 feet is dominated by high resistivity or coarse-grained materials. + Depth Slices: Depth slice automations showing changes in electrical resistivity and AEM-derived texture with depth. These maps aid in delineating the geometry of large-scale features (for example, incised valley fills). Shapefiles for the formatted AEM electrical resistivity data and AEM derived texture data as depth slices and the shallow subsurface average can be downloaded here: Electrical Resistivity Depth Slices and Shallow Subsurface Average Maps: https://data.cnra.ca.gov/dataset/aem/resource/7d115ac3-d7b8-47fa-ab8b-a078b2525bbe Texture Interpretation (Coarse Fraction) Depth Slices and Shallow Subsurface Average Maps: https://data.cnra.ca.gov/dataset/aem/resource/0952506a-1ad8-4c04-9372-ded45148e6a6 SGMA Data Viewer (Hydrogeologic Conceptual Model tab) - Depth Slices and Shallow Subsurface Average Maps: https://sgma.water.ca.gov/webgis/?appid=SGMADataViewer#hcm #Technical Memos Technical memos are developed by DWR's consultant team (Ramboll Consulting) to describe research related to AEM survey planning or data collection. Research described in the technical memos may also be formally published in a journal publication. + AEM Test Flights to Evaluate the Bias Signal Caused by Vineyard Trellises Containing Metal: https://data.cnra.ca.gov/dataset/aem/resource/42e5798e-c633-4a7a-8398-fc96c2afaced + SkyTEM Instrument Comparison for Airborne EM:https://data.cnra.ca.gov/dataset/aem/resource/d38f1284-71f3-45e3-9af5-676ebe22f61b #2018-2020 AEM Pilot Studies Three pilot studies were conducted in California from 2018-2020 to support the development of the Statewide AEM Survey Project. The AEM Pilot Studies were conducted in the Sacramento Valley in Colusa and Butte county groundwater basins, the Salinas Valley in Paso Robles groundwater basin, and in the Indian Wells Valley groundwater basin. All pilot study reports and data are available on the California Natural Resources Agency Open Data Portal: https://data.cnra.ca.gov/dataset/aem-pilot-studies. #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 files
| Data title and description | Access data | File details | Last updated |
|---|---|---|---|
Electrical Resistivity Depth Slices and Shallow Subsurface Average Maps This zipped shapefile provides maps showing electrical resistivity (ohm-meters) depth slices and shallow subsurface average derived from the Statewide Airborne Electromagnetic (AEM) Survey data available at https://data.cnra.ca.gov/dataset/aem. The AEM data for a depth slice are displayed using a local polynomial interpolation on a 1 kilometer line buffered around the flown flight line. The depth slice intervals were defined by the AEM data inversion geometry and were not resampled. The shallow subsurface average map represents the average over the 0-17 meter depth interval. The interpolation defined as the depth weighted average electrical resistivity value over the defined interval. | Download | ZIP | 08/11/23 |
Survey Area 1 - Salinas Valley Data Report Appendices Appendices for the Salinas Valley Data Report. File updated on 5/31/2022. | Download | ZIP | 08/11/23 |
Survey Area 1 - Cuyama Valley Data Report Appendices Appendices for the Cuyama Valley Data Report. File updated on 5/31/2022. | Download | ZIP | 08/11/23 |
Survey Area 1 - Flown Survey Lines Flown flight lines for Survey Area 1. Flight lines can also be viewed online using the AEM Flight Line Map (https://data.cnra.ca.gov/dataset/aem/resource/8a020073-20e4-4feb-9271-fe8f76c99a85). | Download | SHP | 08/11/23 |
Survey Area 1 - Salinas Valley AEM Data - PROVISIONAL AEM data package containing provisional AEM data acquisition parameters, raw and inverted AEM data, and AEM profile and depth slice images. File updated on 4/26/2022. | Download | ZIP | 08/11/23 |
Survey Area 1 - Cuyama AEM Data - PROVISIONAL AEM data package containing provisional AEM data acquisition parameters, raw and inverted AEM data, and AEM profile and depth slice images. File updated on 4/26/2022. | Download | ZIP | 08/11/23 |
Survey Area 1 - Supporting Data - PROVISIONAL Package of compiled data used to support the AEM data interpretation, including digitized well completion reports, geophysical logs, water quality and water levels. File updated on 7/22/2022. | Download | ZIP | 08/11/23 |
Survey Area 1 - Esri Scene Layer Package - Resistivity This file contains the electrical resistivity data where each point represents the vertical center and the average resistivity value for a depth interval. Resistivity data were obtained from 04_XYZ_Ascii\02_Sharp MLM\*_inv.xyz files and displayed as a Point Cloud. The Esri Scene Layer Package (SLPK) files can be opened in the ArcPro within a Local Scene. | Download | ZIP | 08/11/23 |
Survey Area 2 - Data Report Appendices - Western Basins (Scott River Valley, Shasta Valley, Butte Valley) Appendices to the Data Report for the western groundwater basins within Survey Area 2 - Scott River Valley, Shasta Valley, and Butte Valley. File updated on 10/19/2022. | Download | ZIP | 08/11/23 |
Survey Area 2 - Data Report Appendices - Eastern Basins (Tulelake, Big Valley, Fall River Valley) Appendices to the Data Report for the eastern groundwater basins within Survey Area 2 - Tulelake, Big Valley, and Fall River Valley. File updated on 10/19/2022. | Download | ZIP | 08/11/23 |
Survey Area 2 - Flown Survey Lines Flown flight lines for Survey Area 2. Flight lines can also be viewed online using the AEM Flight Line Map (https://data.cnra.ca.gov/dataset/aem/resource/8a020073-20e4-4feb-9271-fe8f76c99a85). | Download | SHP | 08/11/23 |
Survey Area 2 - AEM Data – PROVISIONAL AEM data package containing a provisional AEM data acquisition parameters, raw, inverted, and interpreted AEM data. Survey Area 2 covers the following groundwater basins: Scott River Valley, Shasta Valley, Butte Valley, Tulelake, and Big Valley (Lassen/Modoc counties). File updated on 10/11/2022. | Download | ZIP | 08/11/23 |
Survey Area 2 - Supporting Data - PROVISIONAL Data package of compiled data used to support the AEM data interpretation, including digitized well completion reports, geophysical logs, water quality and water levels. File updated on 10/18/2022. | Download | ZIP | 08/11/23 |
Survey Area 2 - Esri Scene Layer Package - Resistivity This file contains the electrical resistivity data where each point represents the vertical center and the average resistivity value for a depth interval. Resistivity data were obtained from 04_XYZ_Ascii\02_Sharp MLM*_inv.xyz files and displayed as a Point Cloud. The Esri Scene Layer Package (SLPK) files can be opened in the ArcPro within a Local Scene. | Download | ZIP | 08/11/23 |
Survey Area 3 - Data Report Appendices - Big Valley (Lake County), Ukiah Valley, Santa Rosa Plain, Petaluma Valley, and Sonoma Valley Appendices to Data Report for Survey Area 3 (Big Valley (Lake County), Ukiah Valley, Santa Rosa Plain, Petaluma Valley, and Sonoma Valley). File updated on 2/10/2023. | Download | ZIP | 08/11/23 |
Survey Area 3 - Flown Survey Lines Flown flight lines for Survey Area 3. Flight lines can also be viewed online using the AEM Flight Line Map (https://data.cnra.ca.gov/dataset/aem/resource/8a020073-20e4-4feb-9271-fe8f76c99a85). | Download | SHP | 08/11/23 |
Survey Area 3 - AEM Data - PROVISIONAL AEM data package containing AEM data acquisition parameters, raw, inverted, and interpreted AEM data. Survey Area 3 covers the following groundwater basins: Big Valley (Lake County), Ukiah Valley, Santa Rosa Plain, Petaluma Valley, Sonoma Valley. File updated on 7/17/2023. | Download | ZIP | 08/11/23 |
Survey Area 3 - Supporting Data - Provisional Data package of compiled data used to support the AEM data interpretation, including digitized well completion reports, geophysical logs, water quality and water levels. File updated on 9/13/2022. | Download | ZIP | 08/11/23 |
Survey Area 3 - Esri Scene Layer Package - Resistivity This file contains the electrical resistivity data where each point represents the vertical center and the average resistivity value for a depth interval. Resistivity data were obtained from 04_XYZ_Ascii\02_Sharp MLM*_inv.xyz files and displayed as a Point Cloud. The Esri Scene Layer Package (SLPK) files can be opened in the ArcPro within a Local Scene. | Download | ZIP | 08/11/23 |
Survey Area 4 - Data Report Appendices - Kern County & White Wolf Appendices to the Data Report for Survey Area 4 (Kern County and White Wolf groundwater subbasins. File updated on 2/22/2023. | Download | ZIP | 08/11/23 |
Survey Area 4 - Data Report Appendices - Kaweah, Tulare Lake, & Kaweah Appendices to the Data Report for Survey Area 4 (Kaweah, Tulare Lake & Kaweah groundwater subbasins). File updated on 2/22/2023. | Download | ZIP | 08/11/23 |
Survey Area 4 - Flown Survey Lines Provisional flown flight lines for Survey Area 4 (Tulare Lake, Kaweah, Tule, Kern County, and White Wolf groundwater subbasins). Flight lines can also be viewed online using the AEM Flight Line Map (https://data.cnra.ca.gov/dataset/aem/resource/8a020073-20e4-4feb-9271-fe8f76c99a85). | Download | SHP | 08/11/23 |
Survey Area 4 - AEM Data - PROVISIONAL AEM data package containing AEM data acquisition parameters, raw, minimally processed, inverted, and interpreted AEM data. Survey Area 4 covers the following groundwater subbasins: Tulare Lake, Kaweah, Tule, Kern County, and White Wolf. File updated 3/9/2023. | Download | ZIP | 08/11/23 |
Survey Area 4 - AEM Data (2) - PROVISIONAL AEM data package containing AEM Aarhus Workbench Project files. Survey Area 4 covers the following groundwater subbasins: Tulare Lake, Kaweah, Tule, Kern County, and White Wolf. File updated 11/13/2023. | Download | ZIP | 11/15/23 |
Survey Area 4 - Supporting Data - PROVISIONAL Data package of compiled and digitized well completion reports, geophysical logs, water quality and water levels used to support the AEM data interpretation. Data file uploaded on 10/17/2022. | Download | ZIP | 08/11/23 |
Survey Area 4 - Esri Scene Layer Package - Resistivity This file contains the electrical resistivity data where each point represents the vertical center and the average resistivity value for a depth interval. Resistivity data were obtained from 04_XYZ_Ascii\02_Sharp MLM*_inv.xyz files and displayed as a Point Cloud. The Esri Scene Layer Package (SLPK) files can be opened in the ArcPro within a Local Scene. | Download | ZIP | 08/11/23 |
Survey Area 5 - Data Report Appendices - Kings, Madera, and Chowchilla Appendices to the Data Report for Survey Area 5 (Kings, Madera, and Chowchilla groundwater subbasins). File updated on 4/25/2023. | Download | ZIP | 08/11/23 |
Survey Area 5 - Data Report Appendices - Merced, Turlock, and Modesto Appendices to the Data Report for Survey Area 5 (Merced, Turlock, and Modesto groundwater subbasins). File updated on 2/8/2024. | Download | ZIP | 02/14/24 |
Survey Area 5 - Data Report Appendices - Westlands, Pleasant Valley, and Delta-Mendota Appendices to the Data Report for Survey Area 5 (Westlands, Pleasant Valley, and Delta-Mendota groundwater subbasins). File updated on 4/25/2023. | Download | ZIP | 08/11/23 |
Survey Area 5 - Flown Survey Lines Flown flight lines for Survey Area 5 (Pleasant Valley, Westside, Kings, Madera, Chowchilla, Merced, Turlock, Modesto, and Delta-Mendota groundwater subbasins). Flight lines can also be viewed online using the AEM Flight Line Map (https://data.cnra.ca.gov/dataset/aem/resource/8a020073-20e4-4feb-9271-fe8f76c99a85). | Download | SHP | 08/11/23 |
Survey Area 5 - AEM Data – PROVISIONAL AEM data package containing AEM data acquisition parameters, raw, minimally processed, inverted, and interpreted AEM data. Survey Area 5 covers the following groundwater subbasins: Pleasant Valley, Westside, Kings, Madera, Chowchilla, Merced, Turlock, Modesto, Delta-Mendota. File updated 4/18/2023. | Download | ZIP | 08/11/23 |
Survey Area 5 - AEM Data (2) - PROVISIONAL AEM data package containing AEM Aarhus Workbench Project processed data files. Survey Area 5 covers the following groundwater subbasins: Pleasant Valley, Westside, Kings, Madera, Chowchilla, Merced, Turlock, Modesto, Delta-Mendota. File updated 11/13/2023. | Download | ZIP | 11/15/23 |
Survey Area 5 - Supporting Data Package of compiled data used to support the AEM data interpretation, including digitized well completion reports, geophysical logs, water quality and water levels. File updated on 12/6/2022. | Download | ZIP | 08/11/23 |
Survey Area 5 - Esri Scene Layer Package - Resistivity This file contains the electrical resistivity data where each point represents the vertical center and the average resistivity value for a depth interval. Resistivity data were obtained from 04_XYZ_Ascii\02_Sharp MLM*_inv.xyz files and displayed as a Point Cloud. The Esri Scene Layer Package (SLPK) files can be opened in the ArcPro within a Local Scene. | Download | ZIP | 08/11/23 |
Survey Area 6 - Data Report Appendices - Cosumnes, Tracy, Eastern San Joaquin, East Contra Costa, and Livermore Valley Appendices to the Data Report for Survey Area 6 (Cosumnes, Tracy, Eastern San Joaquin, East Contra Costa, and Livermore Valley groundwater subbasins). File updated on 5/24/2023. | Download | ZIP | 08/11/23 |
Survey Area 6 - Data Report Appendices (part 1) - Solano, South American, North American, Yolo, Sutter, South Yuba, and North Yuba Appendices Part 1 to the Data Report for Survey Area 6 (Solano, South American, North American, Yolo, Sutter, South Yuba, and North Yuba groundwater subbasins). File updated on 5/26/2023. | Download | ZIP | 08/11/23 |
Survey Area 6 - Data Report Appendices (Part 2) - Solano, South American, North American, Yolo, Sutter, South Yuba, and North Yuba Appendices Part 2 to the Data Report for Survey Area 6 (Solano, South American, North American, Yolo, Sutter, South Yuba, and North Yuba groundwater subbasins). File updated on 5/26/2023. | Download | ZIP | 08/11/23 |
Survey Area 6 - Flown Survey Lines - PROVISIONAL Provisional flown flight lines for Survey Area 6 (Cosumnes, Tracy, Eastern San Joaquin, East Contra Costa, Solano, Livermore, South American, North American, Yolo, Sutter, South Yuba, and North Yuba groundwater subbasins). Flight lines can also be viewed online using the AEM Flight Line Map (https://data.cnra.ca.gov/dataset/aem/resource/8a020073-20e4-4feb-9271-fe8f76c99a85). | Download | SHP | 08/11/23 |
Survey Area 6 - AEM Data – PROVISIONAL AEM data package containing a provisional AEM data acquisition parameters, raw, inverted, and interpreted AEM data. Survey Area 6 covers the following groundwater subbasins: Cosumnes, Tracy, Eastern San Joaquin, East Contra Costa, Solano, Livermore, South American, North American, Yolo, Sutter, South Yuba, and North Yuba. File updated on 5/23/2023. | Download | ZIP | 08/11/23 |
Survey Area 6 - Supporting Data - PROVISIONAL Data package of compiled data used to support the AEM data interpretation, including digitized well completion reports, geophysical logs, water quality and water levels. File updated on 1/25/2023. | Download | ZIP | 08/11/23 |
Survey Area 6 - Esri Scene Layer Package - Resistivity This file contains the electrical resistivity data where each point represents the vertical center and the average resistivity value for a depth interval. Resistivity data were obtained from 04_XYZ_Ascii\02_Sharp MLM*_inv.xyz files and displayed as a Point Cloud. The Esri Scene Layer Package (SLPK) files can be opened in the ArcPro within a Local Scene. | Download | ZIP | 08/11/23 |
Survey Area 7 - Data Report Appendices (North Sacramento Valley - Colusa, Butte, Wyandotte Creek, Vina, Los Molinos, Corning, Red Bluff, Antelope and Bend groundwater subbasins ) Appendices to the Data Report for Survey Area 7 (North Sacramento Valley - Colusa, Butte, Wyandotte Creek, Vina, Los Molinos, Corning, Red Bluff, Antelope and Bend groundwater subbasins). File updated on 6/30/2023. | Download | ZIP | 08/11/23 |
Survey Area 7 - Data Report Appendices (Redding Area) Appendices to the Data Report for Survey Area 7 (Redding Area - South Battle Creek, Bowman, Anderson, Enterprise, and Millville groundwater subbasins). File updated on 6/30/2023. | Download | ZIP | 08/11/23 |
Survey Area 7 - Data Report Appendices - Sierra Valley Appendices to the Data Report for Survey Area 7 (Sierra Valley groundwater subbasin). File updated on 8/7/2023. | Download | ZIP | 08/11/23 |
Survey Area 7 - Data Report Appendices - Eel River Valley Appendices to the Data Report for Survey Area 7 (Eel River Valley Groundwater Basin). File updated on 9/20/2023. | Download | ZIP | 12/01/24 |
Survey Area 7 - Flown Survey Lines - PROVISIONAL Provisional flown flight lines for 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 groundwater subbasins). Flight lines can also be viewed online using the AEM Flight Line Map (https://data.cnra.ca.gov/dataset/aem/resource/8a020073-20e4-4feb-9271-fe8f76c99a85). | Download | SHP | 08/11/23 |
Survey Area 7 - Raw AEM Data Raw AEM data and auxiliary data for Survey Area 7. | Download | ZIP | 08/11/23 |
Survey Area 7 - AEM Data - PROVISIONAL AEM data package containing a provisional AEM data acquisition parameters, raw, inverted, and interpreted AEM data for Sacramento Valley and Sierra Valley groundwater basins only. Eel River Valley AEM data to be added when available. Survey Area 7 covers the following groundwater subbasins: Colusa, Butte, Wyandotte Creek, Vina, Los Molinos, Corning, Red Bluff, Antelope, Bowman, Bend, Millville, South Battle Creek, Anderson, Enterprise, Eel River, Sierra Valley. File updated on 8/7/2023. | Download | ZIP | 08/11/23 |
Survey Area 7 - Supporting Data Package of compiled data used to support the AEM data interpretation, including digitized well completion reports, geophysical logs, water quality and water levels. File updated on 5/5/2023. | Download | ZIP | 08/11/23 |
Survey Area 7 - Esri Scene Layer Package - Resistivity This file contains the electrical resistivity data where each point represents the vertical center and the average resistivity value for a depth interval. Resistivity data were obtained from 04_XYZ_Ascii\02_Sharp MLM*_inv.xyz files and displayed as a Point Cloud. The Esri Scene Layer Package (SLPK) files can be opened in the ArcPro within a Local Scene. | Download | ZIP | 08/11/23 |
Survey Area 8 - Data Report Appendices Appendices to Data Report for Survey Area 8. File updated on 10/24/2023. | Download | ZIP | 10/25/23 |
Survey Area 8 - Flown Survey Lines Flown flight lines as GIS Shapefile for Survey Area 8. Flight lines can also be viewed online using the AEM Flight Line Map (https://data.cnra.ca.gov/dataset/aem/resource/8a020073-20e4-4feb-9271-fe8f76c99a85). | Download | SHP | 08/11/23 |
Survey Area 8 - Raw AEM Data Raw AEM data and auxiliary data for Survey Area 8. | Download | ZIP | 08/11/23 |
Survey Area 8 - AEM Data - PROVISIONAL AEM data package containing a provisional AEM data acquisition parameters, raw, inverted, and interpreted AEM data. Survey Area 8 cover Seaside, Monterey, 180/400 (partially surveyed Summer 2021), Eastside (partially surveyed Summer 2021), Langley, Pajaro, Santa Cruz Mid-County, Santa Margarita, San Benito, and Llagas (partial) groundwater subbasins. File updated on 10/20/2023. | Download | ZIP | 10/25/23 |
Survey Area 8 - Supporting Data Package of compiled data used to support the AEM data interpretation, including digitized well completion reports, geophysical logs, water quality and water levels. File updated on 8/7/2023. | Download | ZIP | 08/11/23 |
Survey Area 9 - Data Report Appendices Appendices to Data Report for Survey Area 9 (Basin Characterization Pilot Study 1) - Madera and Kings subbasins. File updated on 2/28/2024. | Download | ZIP | 03/06/24 |
Survey Area 9 - Raw AEM Data Raw AEM data and auxiliary data for Survey Area 9 (Basin Characterization Pilot Study 1). File updated 10/9/2023. | Download | ZIP | 10/11/23 |
Survey Area 9 - AEM Data (limited) - PROVISIONAL AEM data package containing provisional AEM data acquisition parameters, raw, inverted AEM data (electrical resistivity values versus depth), and AEM data interpretations. Survey Area 9 covers the Basin Characterization Pilot Study 1 area within portions of Madera and Kings groundwater subbasins. File updated on 2/29/2024. | Download | ZIP | 03/06/24 |
Survey Area 9 - Supporting Data Survey Area 9 (Basin Characterization Pilot Study 1) package of compiled data used to support the AEM data interpretation, including digitized well completion reports, geophysical logs, water quality and water levels. File updated on 10/9/2023. | Download | ZIP | 10/11/23 |
Survey Area 10 - Raw AEM Data Raw AEM data and auxiliary data for Survey Area 10. | Download | ZIP | 02/21/24 |
Survey Area 10 - AEM Data - PROVISIONAL AEM data package containing provisional inverted AEM data (electrical resistivity values versus depth) and AEM data interpretations. Survey Area 10 covers the following groundwater subbasins: San Antonio Creek Valley, Arroyo Grande, Santa Maria, San Luis Obispo, Los Osos Area, Warden Creek, Chorro Valley (limited), and Morro Valley (limited). File updated on 11/1/2024. | Download | ZIP | 11/02/24 |
Survey Area 10 - Supporting Data - PROVISIONAL Package of compiled data used to support the AEM data interpretation, including digitized well completion reports, geophysical logs, water quality and water levels. File updated on 1/16/2024. | Download | ZIP | 01/17/24 |
Survey Area 11 - Raw AEM Data Raw AEM data and auxiliary data for Survey Area 11. | Download | ZIP | 02/21/24 |
Survey Area 11 - AEM Data - PROVISIONAL AEM data package containing provisional inverted AEM data (electrical resistivity values versus depth) and AEM data interpretations. Survey Area 11 covers the following groundwater subbasins: Indian Wells Valley, Rose Valley, Owens Valley, Fish Slough, Indio, Mission Creek, West Salton Sea (limited), East Salton Sea (limited), Ocotillo-Clark Valley (limited), Imperial Valley (limited),Chocolate Valley (limited), Borrego Springs, and San Jacinto File updated on 8/21/2024. | Download | ZIP | 08/22/24 |
Survey Area 11 - Supporting Data - PROVISIONAL Package of compiled data used to support the AEM data interpretation, including digitized well completion reports, geophysical logs, water quality and water levels. File updated on 8/5/2024. | Download | ZIP | 08/06/24 |
Supporting files
| Data title and description | Access data | File details | Last updated |
|---|---|---|---|
Read Me - DWR Disclaimer DWR's dataset and Data Report use disclaimer. | Download | PDF | 08/11/23 |
Survey Area Map Map showing Survey Areas | Download | AGOL | 08/10/24 |
AEM Flight Line Map Map showing the AEM survey flight lines where data have been collected to date. | Download | 08/11/23 | |
AEM Data Viewers ##Overview of Tools The AEM 3D Viewer and AEM Profile Viewer are innovative tools that allows GSAs and stakeholders to view AEM datasets online. The GIS-based tools allow datasets can be viewed in a three-dimensional space and allows the user to interact with the data by zooming in and viewing the data from various angles. The tools can be accessed on a computer or mobile phone and does not require data to be downloaded or the use of specialized software. ###AEM Electrical Resistivity AEM electrical resistivity data shows the distribution of electrical resistivity values within the aquifer, where electrical resistivity describes a material's ability to resist an electric current. Generally, materials with higher electrical resistivity values correspond to coarse-grain dominated materials, like sands and gravels. Generally, materials with lower electrical resistivity values correspond to fine-grain dominated materials, like silts and clays, or materials saturated with fluids that have a high concentration of total dissolved solids, like brine or seawater. ###AEM Texture Data AEM electrical resistivity data are interpreted for sediment texture, described as coarse fraction. The interpretation is supported by incorporating existing lithology and geophysical logging data into the transform. (AEM Texture Data to be added to the AEM 3D Viewer soon!) ##AEM 3D Viewer (Beta) The AEM 3D Viewer shows AEM electrical resistivity values displayed as voxels. The voxel space can be navigated using the navigation widgets. Depth and profile slices can be created using the slice widget. The map insert in the right pane shows the average electrical resistivity values in the shallow subsurface (0-17 m). Zoom into the map to show survey line segments and locations of high-quality lithology and geophysical logs. Click on the survey line segments to show pop-ups of segment profile images. Click on the profile image in the popup to open the profile in a new window. Link to full screen AEM 3D Viewer (computer only): https://dwr.maps.arcgis.com/apps/instant/3dviewer/index.html?appid=f781b14f42ab45e5b72f32cf07af899c ##AEM Profile Viewer The AEM Profile Viewer allows the user to click on profile line segments and show the electrical resistivity profile images in the panel on the right. The Map Insert shows the average electrical resistivity values in the shallow subsurface (0-17 m), the location of survey line segments, and locations of high-quality lithology and geophysical logs. Click on the survey line segments to show the profile images. Link to full screen AEM Profile Viewer: https://dwr.maps.arcgis.com/apps/instant/attachmentviewer/index.html?appid=65f0aa6db8124aeda54e1f33c5dfe66c ##Limitations <ul> <li>Data are provisional. Data Viewers are under development. <li>AEM Data Interpretation Disclaimer: The AEM Data Viewer shows lithology interpretations based on available existing supporting data and are designed for informational purposes only. These resources are not intended for regulatory purposes as part of the Sustainable Groundwater Management Act. The Department of Water Resources makes no warranties, representations or guarantees, either expressed or implied, as to the accuracy, completeness, correctness, or timeliness of the information that is presented in the lithology transform and lithology interpretations provided in this report, nor accepts or assumes any liability arising from use of this report or underlying data. </ul> | Download | BIN | 12/01/24 |
Supporting Data Map #Supporting Data An important part of the AEM data processing, inversion, and interpretation is the integration of existing supporting data. Supporting data utilized in the Statewide AEM Survey Project include well lithology, geophysical (electrical resistivity) logs, water level measurements, and water quality measurements. Data were compiled from groundwater sustainability agencies, counties, the Online System for Well Completion Reports (OSWCR), the California Geologic Energy Management (CalGEM) Well Finder, the Groundwater Ambient Monitoring and Assessment (GAMA), the California Statewide Groundwater Elevation Monitoring (CASGEM), and the United States Geologic Survey. Additional geophysical logs were purchased from a private company. Data compiled were screened to select high quality wells (described in the sections below). High quality wells were digitized and are provided in the Survey Area’s Supporting Data zip file, linked below: <ul> <li>Survey Area 1: https://data.cnra.ca.gov/dataset/aem/resource/1f5509ec-6d57-4da4-8e7a-660d4c94efcd <li>Survey Area 2: https://data.cnra.ca.gov/dataset/aem/resource/1f2275fb-e001-45b9-9749-3d3a216ab7ef <li>Survey Area 3: https://data.cnra.ca.gov/dataset/aem/resource/8d405643-cb7f-4c3d-9333-736eeeb6ffd4 <li>Survey Area 4: https://data.cnra.ca.gov/dataset/aem/resource/eb09227e-32c7-4e11-94f5-359c9b202734 <li>Survey Area 5: https://data.cnra.ca.gov/dataset/aem/resource/366d53c0-6387-42d3-a39f-68aed6291853 <li>Survey Area 6: https://data.cnra.ca.gov/dataset/aem/resource/e40fa03b-f62d-443d-a290-672405c0a3a4 <li>Survey Area 7: https://data.cnra.ca.gov/dataset/aem/resource/ac9ed1fe-1487-4d31-a88b-361a8d584706 <li>Survey Area 8: https://data.cnra.ca.gov/dataset/aem/resource/8c59ee43-1ad0-4860-9746-a4815330aed6 <li>Survey Area 9: https://data.cnra.ca.gov/dataset/aem/resource/1e4bd143-63ec-4c5c-80ed-5dcf07ad1234 <li>Survey Area 10: https://data.cnra.ca.gov/dataset/aem/resource/cfd1b037-cc3d-45d3-a519-38f4a5c37a0d <li>Survey Area 11: https://data.cnra.ca.gov/dataset/aem/resource/262026e3-7a58-4e7b-ab77-4cba5b0ad7cf </ul> ##Well Lithology and Geophysical Logs ###High Quality Well lithology and geophysical logs located in the vicinity of the Survey Area were compiled with the objective of obtaining two high-quality logs in each of the Public Land Survey System (PLSS) one-mile square sections that the flight lines cross. High-quality lithology logs were defined as having a verified location accuracy of less than 50 meters (164 feet) and having an average lithology description interval of less than 30 meters (98 feet). High-quality well lithology logs were digitized and tabulated by transcribing the original lithology descriptions and categorized into the free-form, the Unified Soils Classification System (USCS), and texture descriptions. High-quality geophysical logs were defined as being less than 40 years old and having an image quality that could be digitized. Digitized geophysical logs are provided as .las files. ###Low Quality Well lithology and geophysical logs that were not within a one-mile square PLSS section that the flight lines cross or did not meet the high-quality criteria, were categorized as low-quality. Low quality wells were not digitized and are shown to provide the locations where lithology and geophysical logs were considered. ##Limitations Data are provisional. Map is under development. ###Integration of Supporting Data into Existing Databases The Supporting Data Map was developed for the purposes of displaying data compiled as a part of the Statewide AEM Survey Project. Digitized or refined data will be imported back into their original existing databases, like OSWCR or CalGEM. | Download | 08/11/23 | |
Texture Interpretation (Coarse Fraction) Depth Slices and Shallow Subsurface Average Maps This shapefile represents texture data interpretations (as coarse fraction) provided as depth slices and the shallow subsurface averages derived from the Statewide Airborne Electromagnetic (AEM) Survey data available at https://data.cnra.ca.gov/dataset/aem. The Coarse Fraction data for a depth slice are displayed using a local polynomial interpolation on a 1 kilometer line buffered around the flown flight line. The depth slice intervals were defined by the Coarse Fraction data inversion geometry. The 1-15 meter depth interval was defined as the depth weighted average Coarse Fraction value over the defined interval. Coarse Fraction data for Survey Area 1 were averaged to match Survey Areas 2 through 7 data resolution. The accuracy of the depth slice values for Survey Area 1 are +/- 1 meter of the depth slice displayed. | Download | FILE GEODATABASE OR SHAPEFILE | 08/11/23 |
Survey Area 1 - Salinas Valley Data Report Data Report for the Salinas Valley portion of Survey Area 1. File updated on 5/31/2022. | Download | PDF | 08/11/23 |
Survey Area 1 - Salinas Valley Fact Sheet This two-page fact sheet provides a high level overview of the activities completed and data generated during the AEM survey. | Download | PDF | 08/11/23 |
Survey Area 1 - Cuyama Valley Data Report Data Report for the Cuyama Valley portion of Survey Area 1. File uploaded on 5/31/2022. | Download | PDF | 08/11/23 |
Survey Area 1 - Cuyama Fact Sheet This two-page fact sheet provides a high level overview of the activities completed and data generated during the AEM survey. | Download | PDF | 08/11/23 |
Survey Area 2 - Data Report - Western Basins (Scott River Valley, Shasta Valley, Butte Valley) Data Report for the western groundwater basins within Survey Area 2 - Scott River Valley, Shasta Valley, and Butte Valley. File updated on 10/19/2022. | Download | PDF | 08/11/23 |
Survey Area 2- Scott River, Shasta, & Butte Fact Sheet This two-page fact sheet provides a high level overview of the activities completed and data generated during the AEM survey. | Download | PDF | 08/11/23 |
Survey Area 2 - Data Report - Eastern Basins (Tulelake, Big Valley, Fall River Valley) Data Report for the eastern groundwater basins within Survey Area 2 - Tulelake, Big Valley (Lassen/Modoc counties), and Fall River Valley. File updated on 10/19/2022. | Download | PDF | 08/11/23 |
Survey Area 2 - Tulelake, Big Valley, & Fall River Valley Fact Sheet This two-page fact sheet provides a high level overview of the activities completed and data generated during the AEM survey. | Download | PDF | 08/11/23 |
Survey Area 3 - Data Report - Big Valley (Lake County), Ukiah Valley, Santa Rosa Plain, Petaluma Valley, and Sonoma Valley Data Report for Survey Area 3 (Big Valley (Lake County), Ukiah Valley, Santa Rosa Plain, Petaluma Valley, and Sonoma Valley). File updated on 2/10/2023. | Download | PDF | 08/11/23 |
Survey Area 4 - Data Report - Kern County & White Wolf Data Report for Survey Area 4 (Kern County and White Wolf groundwater subbasins). File updated on 3/3/2023 | Download | PDF | 08/11/23 |
Survey Area 4 - Data Report - Kaweah, Tulare Lake, & Tule Data Report for Survey Area 4 (Kaweah, Tulare Lake, and Tule groundwater subbasins). File updated on 3/3/2023 | Download | PDF | 08/11/23 |
Survey Area 5 - Data Report - Kings, Madera, and Chowchilla Data Report for Survey Area 5 (Kings, Madera, and Chowchilla groundwater subbasins). File updated on 4/24/2023. | Download | PDF | 08/11/23 |
Survey Area 5 - Data Report - Merced, Turlock, and Modesto Data Report for Survey Area 5 (Merced, Turlock, and Modesto groundwater subbasins). File updated on 4/24/2023. | Download | PDF | 08/11/23 |
Survey Area 5 - Data Report - Westlands, Pleasant Valley, and Delta-Mendota Data Report for Survey Area 5 (Westlands, Pleasant Valley, and Delta-Mendota groundwater subbasins). File updated on 4/24/2023. | Download | PDF | 08/11/23 |
Survey Area 6 - Data Report - Cosumnes, Tracy, Eastern San Joaquin, East Contra Costa, and Livermore Valley Data Report for Survey Area 6 (Cosumnes, Tracy, Eastern San Joaquin, East Contra Costa, and Livermore Valley groundwater subbasins). File updated on 5/24/2023. | Download | PDF | 08/11/23 |
Survey Area 6 - Data Report - Solano, South American, North American, Yolo, Sutter, South Yuba, and North Yuba Data Report for Survey Area 6 (Solano, South American, North American, Yolo, Sutter, South Yuba, and North Yuba groundwater subbasins). File updated on 5/24/2023. | Download | PDF | 08/11/23 |
Survey Area 7 - Data Report - North Sacramento Valley Data Report for Survey Area 7 (North Sacramento Valley - Colusa, Butte, Wyandotte Creek, Vina, Los Molinos, Corning, Red Bluff, Antelope and Bend groundwater subbasins ). File updated on 6/30/2023 | Download | PDF | 08/11/23 |
Survey Area 7 - Data Report - Redding Area Data Report for Survey Area 7 (Redding Area - South Battle Creek, Bowman, Anderson, Enterprise, and Millville groundwater subbasins). File updated on 6/30/2023. | Download | PDF | 08/11/23 |
Survey Area 7 - Data Report - Sierra Valley Data Report for Survey Area 7 (Sierra Valley groundwater subbasin). File updated on 10/19/2023 | Download | PDF | 10/25/23 |
Survey Area 7 - Data Report - Eel River Valley Data Report for Survey Area 7 (Eel River Valley Groundwater Basin). File updated on 9/20/2023 | Download | PDF | 09/27/23 |
Survey Area 8 - Data Report Data Report for Survey Area 8. Survey Area 8 cover Seaside, Monterey, 180/400 (partially surveyed Summer 2021), Eastside (partially surveyed Summer 2021), Langley, Pajaro, Santa Cruz Mid-County, Santa Margarita, San Benito, and Llagas (partial) groundwater subbasins. File updated on 10/20/2023. | Download | PDF | 10/25/23 |
Survey Area 9 - Data Report Data Report for Survey Area 9 (Basin Characterization Pilot Study 1) - Madera and Kings subbasins. File updated on 2/28/2024. | Download | PDF | 03/06/24 |
Survey Area 9 - Flown Survey Lines Flown flight lines for Survey Area 9 (Basin Characterization Pilot Study 1). Flight lines can also be viewed online using the AEM Flight Line Map (https://data.cnra.ca.gov/dataset/aem/resource/8a020073-20e4-4feb-9271-fe8f76c99a85). File updated 10/10/2023. | Download | FILE GEODATABASE OR SHAPEFILE | 10/18/23 |
Survey Area 10 - Flown Survey Lines Flown flight lines for Survey Area 10. Flight lines can also be viewed online using the AEM Flight Line Map (https://data.cnra.ca.gov/dataset/aem/resource/8a020073-20e4-4feb-9271-fe8f76c99a85). File updated 3/22/2024. | Download | FILE GEODATABASE OR SHAPEFILE | 03/27/24 |
Survey Area 11 - Flown Survey Lines Flown flight lines for Survey Area 11. Flight lines can also be viewed online using the AEM Flight Line Map (https://data.cnra.ca.gov/dataset/aem/resource/8a020073-20e4-4feb-9271-fe8f76c99a85). File updated 3/22/2024. | Download | FILE GEODATABASE OR SHAPEFILE | 03/27/24 |
Survey Area 11 - Data Report - Eastern Sierras Data Report for Survey Area 11 (Eastern Sierras - Indian Wells Valley, Rose Valley, Owens Valley, and Fish Slough groundwater subbasins). File updated on 9/13/2024 | Download | PDF | 09/14/24 |
Survey Area 11 - Data Report Appendices - Eastern Sierras Appendices to Data Report for Survey Area 11 (Eastern Sierras - Indian Wells Valley, Rose Valley, Owens Valley, and Fish Slough groundwater subbasins). File updated on 9/20/2024. | Download | 09/21/24 | |
Survey Area 11 - Data Report - Salton Sea Area Data Report for Survey Area 11 (Salton Sea Area: Coachella-Indio, Coachella-Mission Creek, West Salton Sea (limited), East Salton Sea (limited), Ocotillo-Clark Valley (limited), Imperial Valley (limited),Chocolate Valley (limited), Borrego Springs, and San Jacinto groundwater subbasins). File updated on 9/20/2024 | Download | PDF | 09/21/24 |
Survey Area 11 - Data Report Appendices - Salton Sea Area Appendices to Data Report for Survey Area 11 (Salton Sea Area: Coachella-Indio, Coachella-Mission Creek, West Salton Sea (limited), East Salton Sea (limited), Ocotillo-Clark Valley (limited), Imperial Valley (limited),Chocolate Valley (limited), Borrego Springs, and San Jacinto groundwater subbasins). File updated on 9/20/2024. | Download | 09/21/24 | |
Technical Memo - AEM Test Flights to Evaluate the Bias Signal Caused by Vineyard Trellises Containing Metal Title: AEM Test Flights to Evaluate the Bias Signal Caused by Vineyard Trellises Containing Metal. Authors: Ian Gottschalk, Max Halkaer, Timothy Parker, Paul Thorn Contact Authors: Ian Gottschalk, Ramboll U.S., igottschalk@rambol.com CNRA Posting Date: 2/20/2024 | Download | PDF | 02/21/24 |
Technical Memo - SkyTEM Instrument Comparison for Airborne EM Title: SkyTEM Instrument Comparison for Airborne EM Authors: Ian Gottschalk, Frederik Christensen, Mikkel Toftdahl, Jeppe Frost Scherning, and Paul Thorn Contact Author: Ian Gottschalk, Water Resources, Ramboll U.S. igottschalk@ramboll.com CNRA Posting Date: 2/28/2024 | Download | PDF | 03/06/24 |