This web map was created for use in its respective dashboard, in support of California's Groundwater Live.The web map includes data for current groundwater levels statewide.For inquiries, please email calgw@water.ca.gov.

The map graphic image at https://www.sciencebase.gov/catalog/file/get/63140561d34e36012efa2b7f?name=arsenic_map.png illustrates arsenic values, in micrograms per liter, for groundwater samples from about 31,000 wells and springs in 49 states compiled by the United States Geological Survey (USGS). The map graphic illustrates an updated version of figure 1 from Ryker (2001). Cited Reference: Ryker, S.J., Nov. 2001, Mapping arsenic in groundwater-- A real need, but a hard problem: Geotimes Newsmagazine of the Earth Sciences, v. 46 no. 11, p. 34-36 at http://www.agiweb.org/geotimes/nov01/feature_Asmap.html. An excel tabular data file, a txt file, along with a GIS shape file of arsenic concentrations (20,043 samples collected by the USGS) for a subset of the sites shown on the map. Samples were collected between 1973 and 2001 and are provided for download.

This dataset is available for use for non-commercial purposes only on request as AfA248 dataset Groundwater Vulnerability Maps (2017). For commercial use please contact the British Geological Survey.

The Groundwater Vulnerability Maps show the vulnerability of groundwater to a pollutant discharged at ground level based on the hydrological, geological, hydrogeological and soil properties within a single square kilometre. The 2017 publication has updated the groundwater vulnerability maps to reflect improvements in data mapping, modelling capability and understanding of the factors affecting vulnerability Two map products are available: • The combined groundwater vulnerability map. This product is designed for technical specialists due to the complex nature of the legend which displays groundwater vulnerability (High, Medium, Low), the type of aquifer (bedrock and/or superficial) and aquifer designation status (Principal, Secondary, Unproductive). These maps require that the user is able to understand the vulnerability assessment and interpret the individual components of the legend.

• The simplified groundwater vulnerability map. This was developed for non-specialists who need to know the overall risk to groundwater but do not have extensive hydrogeological knowledge or the time to interpret the underlying data. The map has five risk categories (High, Medium-High, Medium, Medium-Low and Low) based on the likelihood of a pollutant reaching the groundwater (i.e. the vulnerability), the types of aquifer present and the potential impact (i.e. the aquifer designation status). The two maps also identify areas where solution features that enable rapid movement of a pollutant may be present (identified as stippled areas) and areas where additional local information affecting vulnerability is held by the Environment Agency (identified as dashed areas). Attribution statement: © Environment Agency copyright and/or database right 2017. All rights reserved.Derived from 1:50k scale BGS Digital Data under Licence 2011/057 British Geological Survey. © NERC.

This data release contains data used to develop models and maps that estimate the occurrence of lithium in groundwater used as drinking water throughout the conterminous United States. An extreme gradient boosting model was developed to estimate the most probable lithium concentration category (≤4, >4 to ≤10, >10 to ≤30 or >30 µg/L). The model uses lithium concentration data from wells located throughout the conterminous United States and predictor variables that are available as geospatial data. The model is included in this data release in the zipped folder named Model_Archive and was used to produce maps that are also included in this data release. The model input data (predictor variables) that were used to make the maps are within a zipped folder (Map_Input_Data.zip) that contains 20 tif-raster files, one for each model predictor variable. The map probability estimates that are outputs from the model are in a zipped folder (Map_Output_Data.zip) that contains 10 tif-raster files, two model estimate maps for each of the lithium concentration categories and the category with the highest probability for public supply well depths and domestic supply well depths.

Groundwater Elevation Change Maps summarize the change in groundwater level measurements over time, collected from wells in the northern Sacramento Valley by the Department of Water Resources (DWR) Northern Region Office (NRO) and monitoring cooperators. Northern Sacramento Valley groundwater levels are measured seasonally, during the annual water year, as part of our ongoing data collection program. Many of the wells have over 30 years of monitoring history, with the longest active monitoring well dating back to 1921. Groundwater level data provides valuable information regarding seasonal fluctuations and long-term changes in groundwater level trends over time. The groundwater level data presented in these figures includes the Sacramento Valley and Redding groundwater basin portions of Shasta, Tehama, Butte, Colusa, Glenn, and Sutter counties and are organized by year, season, well depth, and period of change.

This project consists of 11 files: 1) a zipped folder with a geodatabase containing seven raster files and two shapefiles, 2) a zipped folder containing the same layers found in the geodatabase, but as standalone files, 3) 9 .xml files containing the metadata for the spatial datasets in the zipped folders. These datasets were generated in ArcPro 3.0.3. (ESRI). Six raster files (drainaged, geology, nlcd, precipitation, slope, solitexture) present spatially distributed information, ranked according to the relative importance of each class for groundwater recharge. The scale used for these datasets is 1-9, where low scale values are assigned to datasets with low relative importance for groundwater recharge, while high scale values are assigned to datasets with high relative importance for groundwater recharge. The seventh raster file contains the groundwater recharge potential map for the Anchor River Watershed. This map was calculated using the six raster datasets mentioned previously. Here, the values assigned represent Very Low to Very High groundwater recharge potential (scale 1 - 5, 1 being Very Low and 5 being Very High). Finally, the two shapefiles represent the groundwater wells and the polygons used for model validation. This data is part of the manuscript titled: Mapping Groundwater Recharge Potential in High Latitude Landscapes using Public Data, Remote Sensing, and Analytic Hierarchy Process, published in the journal remote sensing.

Groundwater in the arid Mountain Home area is vital to agricultural, municipal, industrial and other water users who are concerned about declining groundwater levels. The U.S. Geological Survey, in cooperation with the Idaho Department of Water Resources (IDWR), developed a hydrogeologic framework to provide a conceptual understanding of groundwater resources in the Mountain Home area. As part of the hydrogeologic framework, water-table contour and groundwater-level change maps were produced to describe the occurrence, movement, and change in groundwater. Water-table contours for spring 2023 (March 20 to 24, 2023) and autumn 2023 (November 1 to 7, 2023) were created for the regional aquifer and perched groundwater zone in the Mountain Home area. The well numbers and station names for sites used to create the water-table contours and groundwater-level change and groundwater storage change rasters are provided in this data release. The location, depth to water, and groundwater altit ...

The aquifer risk map is being developed to fulfill requirements of SB-200 and is intended to help prioritize areas where domestic wells and state small water systems may be accessing groundwater that does not meet primary drinking water standards (maximum contaminant level or MCL). In accordance with SB-200, the risk map is to be made available to the public and is to be updated annually starting January 1, 2021. The Fund Expenditure Plan states the risk map will be used by Water Boards staff to help prioritize areas for available SAFER funding.

This layer contains summarized water quality risk per census block group, square mile section, and well point. The overall census block group water quality risk is based on five risk factors (1. the count of chemicals with a long-term average (20 year) or recent result (within 2 years) above the MCL, 2. the count of chemicals with a long-term average (20 year) or recent result (within 2 years) within 80% of the MCL, 3. the average magnitude or results above the MCL, 4. the percent area with chemicals above the MCL, and 5. the percent area with chemicals within 80% of the MCL). The specific chemicals that contribute to these risk factors are listed as well. Higher values for each individual risk factor contribute to a higher overall score. The scores are converted to percentiles to normalize the results. Higher percentiles indicate higher water quality risk. The water quality data is based on depth-filtered, de-clustered water quality results from public and domestic supply wells, collected following a similar methodology as the Domestic Well Needs Assessment White Paper. The methodology used to calculate the risk percentiles is outlined in the Aquifer Risk Map Methodology. To provide comments or feedback on this map, please email SAFER@waterboards.ca.gov or Emily.Houlihan@Waterboards.ca.gov.Methodology for the draft aquifer risk map available for download.

The map of the vulnerability of the groundwater of the Flemish Region can be defined as a map of the degree of risk of contamination of the groundwater in the upper water layer by substances that penetrate into the ground from the bottom, taking only static parameters into account. This map can later serve as a basis for a more detailed map, which can also include dynamic and hydrochemical factors. However, where the upper recoverable aquifer is naturally salinized (< 1500 ppm), this is indicated. An aquifer is considered to be the saturated zone of a formation which has a thickness and extension sufficient to extract water from it in an economically viable manner. A flow rate of at least 4 m³ per hour has been assumed for the card. In practice, this sometimes leads to misunderstandings: the map gives an idea of ​​the first economically interesting water layer, which in many cases does not correspond to the layer that is first approached during excavation work, for example. The second important point is that the maps are made for contaminants that penetrate into the soil from the bottom, taking into account only static factors. i.e. they mainly reflect the danger of the flow-through, especially in a vertical direction, of pollutants carried by seeping water, or of polluting liquids from the surface into the saturated zone through the soil and the unsaturated zone. Factors such as the nature and extent of the contamination, its spread by the flow of the contaminated water under the prevailing hydrogeological conditions, as well as the interaction between the pollutant and the formation are thus not taken into account. In practical terms, the extent and nature of the aquifers and overburdens, together with their hydraulic parameters, in particular the nature and value of the permeability, are taken as starting points. The map is based on three factors. the aquifer, the overburden and the unsaturated zone. These are divided into a number of classes, each with a specific index, after which the final vulnerability scale is drawn up on the basis of combinations of the various indices. A map of the three factors is also available separately: >>>The naturally salinized zones This layer shows the zones where the groundwater in the first aquifer is naturally salinized.

The map shows the location of the six hydrogeological regions in Canada and the location of observation wells. The terrain composition is also shown on the map, which includes crystalline rocks, mixed crystalline rocks, folded sedimentary rocks and flat lying sedimentary rocks. The southern limit of continuous permafrost zone and the limit of the discontinuous permafrost zone appear on the map. Canada has been divided into six hydrogeological regions on the basis of similarities of geology, climate, and topography. These six hydrogeological regions are (1) the Appalachians, covering the area of New Brunswick, Prince Edward Island, Nova Scotia, Newfoundland, and the Gaspé and Eastern Townships of Quebec; (2) the St. Lawrence Lowlands, covering Anticosti Island, the extreme southern area of Quebec, and the southern part of Ontario; (3) the Canadian Shield, lying north of the St. Lawrence Lowlands and extending northward to a line joining the north end of Lake Winnipeg to Anticosti Island; (4) the Interior Plains, lying approximately south of the southern limit of discontinuous permafrost and consisting largely of the southern prairie regions of the provinces of Manitoba, Saskatchewan, and Alberta; (5) the Cordilleran Region, the mountainous part of western Canada within British Columbia; and (6) the Northern Region, approximately covering the area north of the southern limit of discontinuous permafrost. To monitor the groundwater flow systems and fluctuations in these hydrogeological regions a series of groundwater observation wells and piezometers have been established in various parts of Canada, as is shown on the map. The groundwater observation well map indicates the extent of provincial observation well and piezometer networks in Canada. Because of scale limitations, the symbols on the map may indicate more than one well. These wells and piezometers have been established in the southern part of Canada to monitor groundwater fluctuations and may also be used to monitor groundwater quality. Since this region of Canada has the largest population density, groundwater is of more immediate interest here. In the areas of discontinuous and continuous permafrost little has been done at present to monitor groundwater conditions, although this is changing as mineral exploration looks north for new reserves.

Groundwater potentiometric-surface contours for spring 2022 (April 4 to 8, 2022) and autumn 2022 (October 30 to November 4, 2022) were created for the alluvial aquifer in Big Lost River Valley. The well numbers and station names used to create the potentiometric-surface contours and groundwater-level change maps are provided in this data release. The location, depth to water, and potentiometric-surface altitude for these wells can be accessed on USGS National Water Information System (NWIS) or Idaho Department of Water Resources (IDWR) groundwater portal. The interpreted 20-foot contours of the potentiometric-surface are also provided in this data release. The contours are referenced to the North American Vertical Datum of 1988 (NAVD 88). The potentiometric-surface contours are divided into three water-bearing units - shallow, intermediate, and deep - based on well depth, potentiometric-surface altitude, and hydrogeologic unit. The intermediate and deep units were only identified in the southern portion of the valley near Arco, Idaho. The potentiometric-surface contours ranged from 4,900 to 6,660 feet above NAVD 88. The groundwater-level change at well sites from spring to autumn 2022, spring to autumn 1968, spring 1968 to spring 2022, spring 1991 to spring 2022, and spring 1968 to spring 1991 were calculated and are provided in a shapefile.

This is the 2022 version of the Aquifer Risk Map. The 2021 version of the Aquifer Risk Map is available here.This aquifer risk map is developed to fulfill requirements of SB-200 and is intended to help prioritize areas where domestic wells and state small water systems may be accessing raw source groundwater that does not meet primary drinking water standards (maximum contaminant level or MCL). In accordance with SB-200, the risk map is to be made available to the public and is to be updated annually starting January 1, 2021. The Fund Expenditure Plan states the risk map will be used by Water Boards staff to help prioritize areas for available SAFER funding. This is the final 2022 map based upon feedback received from the 2021 map. A summary of methodology updates to the 2022 map can be found here.This map displays raw source groundwater quality risk per square mile section. The water quality data is based on depth-filtered, declustered water quality results from public and domestic supply wells. The process used to create this map is described in the 2022 Aquifer Risk Map Methodology document. Data processing scripts are available on GitHub. Download/export links are provided in this app under the Data Download widget.This draft version was last updated December 1, 2021. Water quality risk: This layer contains summarized water quality risk per square mile section and well point. The section water quality risk is determined by analyzing the long-tern (20-year) section average and the maximum recent (within 5 years) result for all sampled contaminants. These values are compared to the MCL and sections with values above the MCL are “high risk”, sections with values within 80%-100% of the MCL are “medium risk” and sections with values below 80% of the MCL are “low risk”. The specific contaminants above or close to the MCL are listed as well. The water quality data is based on depth-filtered, de-clustered water quality results from public and domestic supply wells.Individual contaminants: This layer shows de-clustered water quality data for arsenic, nitrate, 1,2,3-trichloropropane, uranium, and hexavalent chromium per square mile section. Domestic Well Density: This layer shows the count of domestic well records per square mile. The domestic well density per square mile is based on well completion report data from the Department of Water Resources Online System for Well Completion Reports, with records drilled prior to 1970 removed and records of “destruction” removed.State Small Water Systems: This layer displays point locations for state small water systems based on location data from the Division of Drinking Water.Public Water System Boundaries: This layer displays the approximate service boundaries for public water systems based on location data from the Division of Drinking Water.Reference layers: This layer contains several reference boundaries, including boundaries of CV-SALTS basins with their priority status, Groundwater Sustainability Agency boundaries, census block group boundaries, county boundaries, and groundwater unit boundaries. ArcGIS Web Application

Map Direct focus to show Groundwater Contamination. Please refer to https://floridadep.gov/water for more information. Originally created 03/01/2007, and moved to Map Direct Lite on 06/24/2015. Please contact GIS.Librarian@floridadep.gov for more information.

Estimating groundwater recharge rates is vitally important to understanding and managing groundwater. Numerous studies have used collated recharge datasets to understand and project regional or global-scale recharge rates. However, a key challenge stems from the inherent variability in recharge estimation methods utilised across these collations. Recharge estimation methods each carry distinct assumptions, address different recharge components, and operate over varied temporal scales. To address these challenges, this study uses a comprehensive dataset of over 200,000 groundwater chloride measurements to estimate groundwater recharge rates using the chloride mass balance (CMB) method throughout Australia. Recharge rates were produced stochastically using the groundwater chloride dataset and supplemented by gridded chloride deposition, runoff, and precipitation datasets within a Python framework. After QA/QC and data filtering, the resulting recharge rates and 17 spatial datasets are integrated into a random forest regression algorithm, generating a high-resolution (0.05°) model of recharge rates across Australia. This study presents a robust and automated approach to estimate recharge using the CMB method, offering a unified model based on a single estimation method. The resulting datasets, the Python script for recharge rate calculation, and the spatial recharge models collectively provide valuable insights for water resources management across the vast and dry Australian continent and similar approaches can be applied globally. If you use the datasets, gridded map output files, or Python scripts, we would appreciate it if you could cite the associated publication in Hydrology and Earth System Sciences here: https://hess.copernicus.org/articles/28/1771/2024/. For any further information, please do not hesitate to contact Stephen Lee on stephen.lee@cdu.edu.au.

The geographical information service platform for water conservancy provides the location map of groundwater water quality monitoring stations.

Spatial coverage index compiled by East View Geospatial of set "Yemen 1:500,000 Groundwater Resources Map". Source data from MOM (publisher). Type: Geoscientific - Energy Resources. Scale: 1:500,000. Region: Middle East.

Groundwater levels of important aquifers as a specialist layer of the digital hydrogeological map 1:100,000. It is recommended to display them together with the separate specialist layers for groundwater levels and bases for constructing the groundwater levels. Zoom limitation min. 1:200,000 to max. 1:50,000. Groundwater levels are lines of the same height of a groundwater surface or groundwater pressure area. The dHK100 was created in the period from 2000 to 2015 (planning region 14 Munich to 2019) according to planning regions. The basis for the creation of the groundwater balance is the knowledge of groundwater levels in boreholes, wells, groundwater measuring points and springs as well as in surface waters, which are interpolated to lines of the same height taking into account hydrogeological and hydraulic conditions. Inaccuracies in the construction of the groundwater levels result in particular from the uneven distribution of the exploration points. A systematic update of the dHK100 does not take place. Due to the planning region-wise processing over longer periods of time, geometric and attributive inconsistencies can occur along the planning region borders between the groundwater levels that meet there. These are due to different basic data from which the groundwater levels are derived. Geometries and legend units are designed for the overview scale 1:100 000 (1 cm on a map corresponds to 1 km in nature) and i. i.e. R. strongly generalized. The dHK100 or HK100 is intended as a basis for large-scale observations. It does not replace detailed investigations and assessments by a specialist office when planning local projects. The scale-related statement accuracy does not change due to the scale-independent visualization options of digital maps. For further interpretations that combine or overlay the map series with other spatial datasets, it should be noted that an overlay of spatial data with very different resolutions or different target scales or different types of attribution can lead to implausible results or results that are difficult to interpret.

The Aquifer Risk Map Web Tool contains all archived maps, including this 2023 Aquifer Risk Map.The Aquifer Risk Map is developed to fulfill requirements of SB-200 (Monning, 2019) and is intended to help prioritize areas where domestic wells and state small water systems may be accessing groundwater that does not meet primary drinking water standards (maximum contaminant level or MCL). In accordance with SB-200, the map is made available to the public and updated annually starting January 1, 2021. This web map is part of the 2023 Aquifer Risk Map. The Fund Expenditure Plan states the risk map will be used by Water Boards staff to help prioritize areas for available SAFER funding.

This web map includes the following layers:Water Quality Risk: water quality risk estimates per square mile section for all contaminants with an MCL. Water quality risk is listed as “high” (average or recent concentration in section is above MCL for one or more contaminants), “medium” (average or recent concentration in section is between 80% - 100% of MCL for one or more contaminants), “low” (average or recent concentration in section is less than 80% of MCL for all measured contaminants) or “unknown” (no water quality data available in section).Individual Contaminant Risk: water quality risk estimates for nitrate, arsenic, 1,2,3-trichloropropane, hexavalent chromium, and uranium per square mile section.State Small Water Systems (DDW): state small water systems (5-14 connections) location from the Division of Drinking Water joined with water quality risk section estimates from the 2023 Aquifer Risk Map.Domestic Well Records (OSWCR): the approximate count and location of domestic well completion reports submitted to the Department of Water Resources. This is used as a proxy to identify domestic well locations.Public Water System Boundaries (DDW): the approximate boundaries of public drinking water systems, from the Division of Drinking Water. For reference only.Census Areas: Census block groups and census tract boundaries containing demographic information from the 2021 American Community Survey (B19013 Median Household Income and B03002 race/ethnicity) joined with summarized water quality risk estimates from the 2023 Aquifer Risk Map (count of high risk domestic wells and state small water systems per census area).Reference Boundaries: Various geographic boundaries including counties, basins, GSA’s, CV-SALTS basin prioritization status, Disadvantaged Community (DAC) status, and legislative boundaries. For reference only.CalEnviroScreen 4.0: CalEnviroScreen scores from OEHHA. For reference only.Groundwater Level Percentiles (DWR): Groundwater depth in various monitoring wells compared to the historic average at that well. For reference only.

The water quality risk is based on depth-filtered, de-clustered water quality results from public and domestic supply wells. The methodology used to determine water quality risk is outlined here. For more information about the SAFER program, please email SAFER@waterboards.ca.gov. For technical questions or feedback on the map please email GAMA@waterboards.ca.gov.

This part of the data release contains the water-level measurement data compiled and synthesized from various sources. This compilation includes two tables that contain all the water-level measurements that were considered in the development of the groundwater-level altitude maps (Input_VisGWDB), and a table of median-water-level data that were used to develop the groundwater-level altitude maps (MedianWaterLevelData). Also included in this part of the data release is a geologic unit code look-up table which defines the geologic units that wells are reported to be screened in for wells with water-level measurements. These digital data accompany Houston, N.A., Thomas, J.V., Foster, L.K., Pedraza, D.E., and Welborn, T.L., 2020, Hydrogeologic framework, groundwater-level altitudes, groundwater-level changes, and groundwater-storage changes in selected alluvial basins in the upper Rio Grande focus area study, Colorado, New Mexico, and Texas, U.S. and Chihuahua, Mexico, 1980 to 2015

The Global Groundwater Information System (GGIS) is an interactive, web-based portal to groundwater-related information and knowledge. The GGIS consists of several modules structured around various themes. Each module has its own map-based viewer with underlying database to allow storing and visualizing geospatial data in a systematic way. Data sets include global data on transboundary aquifers, global groundwater data by aquifer, and country disaggregation, global groundwater stress (based on GRACE data), global groundwater quality data. There is also specific regional/national data focusing on the following aquifers: Dinaric Karst (Balkans), Ramotswa and Stampriet aquifers (Southern Africa), Esquipulas-Ocotepeque-Citala (Central Amerca), Pretashkent Aquifer (Central Asia). It also provides access to SADC Groundwater Information Portal, and groundwater on Small Island States