The King County Groundwater Protection Program maintains a database of groundwater wells, water quality and water level sampling data. Users may search the database using Quick or Advanced Search OR use King County Groundwater iMap map set. The viewer provides a searchable map interface for locating groundwater well data.

This interactive mapping application provides access to water-related data for Texas. The viewer contains several GIS datasets relating to water resources, including TWDB groundwater data, brackish groundwater data, and data from the Submitted Driller's Reports Database. Contact Email: WDI-Support@twdb.texas.gov

SCDNR groundwater monitoring map with wells, well clusters, and well level data. Used in the online data viewer on the hydrology website.Well locations and cluster site polygons are generalized and approximate and are shown in a grid pattern for visualization. These are not precise well locations.

Groundwater is the water that soaks into the ground from rain and can be stored beneath the ground. Groundwater floods occur when the water stored beneath the ground rises above the land surface.It generally requires sustained rainfall over relatively longer duration than other forms of flooding, its location is discontinuous, and they can last for weeks or months. The increased frequency of groundwater flooding in Ireland in recent decades has highlighted the need to better understand, map and monitor groundwater flood events. In this context Geological Survey Ireland initiated theGWFlood projectin 2016 in order to address the deficit of data and fit-for-purpose flood maps. With the GWFlood project now complete, our work on groundwater flooding is now advancing through the newly establishedGWClimate projectwhich is developing flood forecast tools and evaluate the potential impacts of climate change to groundwater flooding (and groundwater drought).Installation of monitoring infrastructure commenced in October 2016. Over 60 exploratory monitoring stations were installed in counties Galway, Clare, Mayo, Roscommon, Longford and Westmeath. The installation of permanent monitoring stations began in summer 2017 and was completed in mid-2019. A subset of 18 sites representative of the spectrum of groundwater flooding conditions were established as permanent telemetered stations providing real-time information on water levels. Data from the telemetry network is available to the public through our Groundwater Level Data Viewer.

This app on the hydrology website allows views and downloads of groundwater data (daily water levels) from the SCDNR Hydrology Section's Groundwater Monitoring Network. A hydrograph can be viewed for each well. The period of record can be customized, and data can be download in CSV format.Data are updated approximately monthly.

The Texas Water Development Board (TWDB) Groundwater Database (GWDB) contains information on selected water wells, springs, oil/gas tests (that were originally intended to be or were converted to water wells), water levels, and water quality to gain representative information about aquifers in Texas to support water planning from a local to a more regional perspective. This is a scientific database, not a registry of every well drilled in the state.

Since 2002, NASA’s GRACE Satellite mission has allowed scientists of various disciplines to analyze and map the changes in Earth’s total water storage on a global scale. Although the raw data is available to the public, the process of viewing, manipulating, and analyzing the GRACE data can be tedious and difficult for those without strong technological backgrounds in programming or other related fields. The GRACE web app helps bridge the technical gap for decision makers by providing a user interface to visualize (in both map and time series format), not only the data collected from the GRACE mission, but the individual components of water storage as well. Using the GLDAS Land Surface model, the application allows the user to isolate and identify the changes in surface water and groundwater storage that makeup the total water storage quantities measured by the raw GRACE data. The application also includes the capability to upload a custom shapefile in order to perform a regional analysis of these changes allowing decision makers to aggregate and analyze the change in groundwater, surface water, and total water storage within their own personal regions of interest.

This viewer features data related to groundwater resources, wells, standards, and protection. See the following links for more information about OWRB groundwater-related programs:Groundwater Monitoring and Assessment Program (GMAP)Groundwater Monitoring Sites and DataWell Record Search ProgramWater Quality StandardsAdditional information on groundwater wells:USGS Groundwater Data for OklahomaOklahoma Mesonet websiteThe data in this map is available for download at https://www.owrb.ok.gov/data.

The USGS compiles online access to water-resources data collected at approximately 1.5 million sites in all 50 States, the District of Columbia, Puerto Rico, the Virgin Islands, Guam, American Samoa and the Commonwealth of the Northern Mariana Islands.

The Groundwater Conservation Districts (GCD) interactive online map allows users to view GCD boundaries within the State of Texas. This web map application displays the Texas Commission on Environmental Quality (TCEQ) Priority Groundwater Management Area (PGMA), an area designated and delineated by the TCEQ that is experiencing or is expected to experience, within the immediately following 50-year period, critical groundwater problems including shortages of surface water or groundwater, land subsidence resulting from groundwater withdrawal, and contamination of groundwater supplies. Contact Email: gpat@tceq.texas.gov

Los Angeles Public Works has developed a groundwater well web viewer to provide the public with current and historical groundwater depth information throughout Los Angeles County.Purpose:To provide active wells information to the public.Supplemental Information:1. The State of California Department of Water Resources (DWR) developed the California Statewide Groundwater Elevation Monitoring (CASGEM) Program to make groundwater monitoring information available to the public through collaboration between local monitoring parties and DWR to collect groundwater elevation information statewide. The data have been compiled in the CASGEM Online System and made available to the public via the Internet with a GIS map interface. As a result, all interested parties can use the data to evaluate and monitor groundwater conditions in California.The CASGEM Online System will allow you to:• View lists of local agencies, counties and associations who have volunteered to serve as CASGEM Monitoring Entities providing groundwater data statewide• View CASGEM Monitoring Plans and Groundwater Management Plans (via hyperlink)• Search and view groundwater elevation data in tabular format• View hydrographs that show groundwater elevations for wells• Search and view groundwater monitoring well information• View mapped locations of CASGEM wells, monitoring area boundaries, and other geographic information• Measure distances between wells and size of monitoring areas and basins• Download well information, groundwater data, hydrographs and maps• Download summary reports on wells, groundwater elevations, Monitoring Entities and basin information.2. The State of California Department of Conservation developed the Division of Oil, Gas & Geothermal Resources Well Finder, which is a web viewer that allows the public to access information on oil, gas, and geothermal wells throughout the State.

This app displays groundwater data for selected aquifers. It provides information on well locations and metadata, which includes details such as well depth, the aquifer associated with each well, and the well's elevation. The app also features time series data for each well, displaying the measured water depths over a period of time. Additionally, it offers maps of interpolated groundwater levels, which can be viewed on a statewide basis or can be subset by specific aquifers.

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

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 collected AEM data in all of California’s high- and medium-priority groundwater basins, where data collection is feasible. Data were collected in a coarsely spaced grid, with a line spacing of approximately 2-miles by 8-miles. AEM data collection started in 2021 and was completed in 2023. Additional information about the project can be found on the Statewide AEM Survey website. See the publication below for an overview of the project and a preliminary analysis of the AEM data.

California’s Statewide Airborne Electromagnetic Surveys and Preliminary Hydrogeologic Interpretations

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:

• 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.

• AEM 3D Viewer (Beta) (computer only)

• AEM Profile Viewer

• SGMA Data Viewer (Basin Characterization tab)

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

• Texture Interpretation (Coarse Fraction) Depth Slices and Shallow Subsurface Average Maps

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

• SkyTEM Instrument Comparison for Airborne EM

2018-2020 AEM Pilot Studies

Three AEM 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.

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.

This dataset contains files and materials in support of the California's Groundwater Live website. California's Groundwater Live is a user-friendly platform that allows users to view and interact with the latest information on groundwater in California. California's Groundwater Live website can be found at: https://sgma.water.ca.gov/CalGWLive/.

DWR has a long history of studying and characterizing California’s groundwater aquifers as a part of California’s Groundwater (Bulletin 118). California's Groundwater Basin Characterization Program provides the latest data and information about California’s groundwater basins to help local communities better understand their aquifer systems and support local and statewide groundwater management.

Under the Basin Characterization Program, new and existing data (AEM, lithology logs, geophysical logs, etc.) are integrated to create continuous maps and three-dimensional models. To support this effort, new data analysis tools have been developed to create texture models, hydrostratigraphic models, and aquifer flow parameters. Data collection efforts have been expanded to include advanced geologic, hydrogeologic, and geophysical data collection and data digitization and quality control efforts will continue. To continue to support data access and data equity, the Basin Characterization Program has developed new online, GIS-based, visualization tools to serve as a central hub for accessing and exploring groundwater related data in California.

Additional information can be found on the Basin Characterization Program webpage.

DWR's Evaluation of Groundwater Resources

Maps and Models

DWR is undertaking local, regional, and statewide investigations to evaluate California's groundwater resources and develop state-stewarded maps and models. New and existing data have been combined and integrated using the analysis tools described below to develop maps and models that describe grain size, the hydrostratigraphic properties, and hydrogeologic conceptual properties of California’s aquifers. These maps and models help groundwater managers understand how groundwater is stored and moves within the aquifer. The models will be state-stewarded, meaning that they will be regularly updated, as new data becomes available, to ensure that up-to-date information is used for groundwater management activities. The first iterations of the following maps and models will be published as they are developed:

• Texture Models
• Hydrostratigraphic Models
• Aquifer Recharge Potential Maps
• Extent of Important Aquifer Units
• Depth to Basement
• Depth to Freshwater

Click on the link below for each local, regional, or statewide investigation to find the following datasets.

Local Investigations

• Madera & North Kings: AEM data collection, lithology log digitization, texture model development, aquifer recharge potential mapping analysis.
• Pajaro: AEM and tTEM data collection
• Western San Joaquin Valley: AEM data collection, lithology and geophysical log data digitization, texture model development.
• Prospect Island: AEM data collection, FloaTEM data collection test.

Regional Investigations

• Sacramento Valley: AEM data collection, texture model development, aquifer recharge potential mapping analysis.
• Four County Area of San Joaquin Valley (Madera, Fresno, Kings, and Tulare)
• San Joaquin Valley

Statewide Investigations

• Statewide AEM Surveys: AEM data collection, geophysical and lithology log data digitization.

Data Collection & Compilation

As a part of the Basin Characterization Program, advanced geologic, hydrogeologic, and geophysical data will be collected to improve our understanding of groundwater basins. Data collected under Basin Characterization are collected at a local, regional, or statewide scale depending on the scope of the study. Advanced data collection methods include:

• Airborne electromagnetics (AEM)
• All-terrain vehicle towed electromagnetics (tTEM)
• Watercraft towed electromagnetics (FloaTEM)
• Geophysical borehole logging

Digitized Existing Lithology and Geophysical Logs

Lithology and geophysical logging data have been digitized to support the Statewide AEM Survey Project and will continue to be digitized to support Basin Characterization efforts. All digitized lithology logs with Well Completion Report IDs will be imported back into the OSWCR database. Digitized lithology and geophysical logging can be found under the following resource:

• Digitized Lithology and Geophysical Logs.

Analysis Tools and Process Documents

To develop the state-stewarded maps and models outlined above, new tools and process documents have been created to integrate and analyze a wide range of data, including geologic, geophysical, and hydrogeologic information. By combining and assessing various datasets, these tools help create a more complete picture of California's groundwater basins. All tools, along with guidance documents, are made publicly available for local groundwater managers to use to support development of maps and models at a local scale. All tools and guidance will be updated as revisions to tools and process documents are made.

Data Analysis Tools

• Data2Texture: Data2Texture is an advanced spatial data interpolation tool for estimating the distribution of sediment textures from airborne electromagnetic data and lithology logs to create a 3D texture model

• Data2HSM - Smart Interpretation: Data2HSM via Smart Interpretation (SI) is a semi-automatic Python tool for delineating continuous hydrogeologic surfaces from airborne electromagnetic data products.

• Data2HSM - Gaussian Mixture Model: The Data2HSM via Gaussian Mixture Model tool ingests the AEM data and groups the data into a user-specified number of clusters that are interpreted as stratigraphic units in the hydrostratigraphic model (HSM)

• Data2HSM - Geological Pseudolabel Deep Neural Network: The GeoPDNN (Geological Pseudolabel Deep Neural Network) is a semi-supervised machine learning tool that integrates lithologic well logs and AEM data into plausible stratigraphic surfaces.

• Texture2Par V2: Texture2Par V2 is a groundwater model pre-processor and parameterization utility developed to work with the IWFM and MODFLOW families of hydrologic simulation code.

Process Documents

• Aquifer Recharge Potential Mapping: The Aquifer Recharge Potential (ARP) Mapping Process Document provides a framework for identifying locations that have relatively higher potential for managed aquifer recharge.

Data Visualization

Data access equity is a priority for the Basin Characterization Program. To ensure data access equity, the Basin Characterization Program has developed applications and tools to allow data to be visualized without needing access to expensive data visualization software. This list below provides links and descriptions for the Basin Characterization's suite of data viewers.

SGMA Data Viewer: Basin Characterization tab: Provides maps, depth slices, and profiles of Basin Characterization maps, models, and datasets, including the following:

• Aquifer Recharge Potential Maps
• Subsurface Texture Model Depth Slices
• Statewide AEM Survey Texture Depth Slices
• Lithology Log Location Maps
• Geophysical Logs Location Maps
• Statewide AEM Survey Profile Images

3D AEM Data Viewer: Displays the Statewide AEM Survey electrical resistivity and coarse fraction data, along with lithology logs, in a three-dimensional space.

California's Groundwater Subsurface Viewer: Provides a map view and profile view of the Statewide AEM Survey electrical resistivity and coarse fraction data, along with lithology logs. The map view dynamically shows the exact location of AEM data displayed.

Basin Characterization Exchange

The Basin Characterization

Groundwater age distributions and susceptibility to natural and anthropogenic contaminants were assessed for selected wells, streambed piezometers, and springs in southeastern Minnesota. The data provide information to understand how long it will take to observe groundwater quality improvements from best management practices implemented at land surface to reduce losses of nitrate (and other chemicals) from agricultural practices. Nineteen water samples were collected from ten wells, three streambed piezometers, and four springs between August 2020 and September 2022. Two of these samples are field replicate samples collected from a spring site and a well site. A child item contains historical data from 15 water samples from 10 wells between July 1996 to May 1997. Groundwater ages were estimated from dissolved gas (neon, argon, krypton, and xenon) and environmental tracer data (tritium, sulfur hexafluoride, chlorofluorocarbons, and tritiogenic helium-3) from field samples using the equations available in TracerLPM (an Excel® workbook for interpreting groundwater age distributions from environmental tracer data) and DGMETA (an Excel® workbook for dissolved gas modeling and environmental tracer analysis); groundwater age estimates are reported in Table_1_Age_Information.txt. DGMETA was used to compute the optimal water temperature, excess air, entrapped air, fractionation of gases, and excess nitrogen gas (mainly from denitrification) for the measured dissolved gases in a sample; condensed results are reported in Table_1_Age_Information.txt and these results are reported in detail in Table_2_Dissolved_Gases.txt. These values were then used to convert the raw measured concentrations of environmental tracers into a form appropriate for age dating analysis; these results are reported in Table_3_Computed_Tracer_Concentrations.txt. Calculated concentrations of environmental tracers that were used in groundwater age calculations are the dry air mixing ratio of sulfur hexafluoride or chlorofluorocarbons, and tritiogenic helium-3, which is the concentration of helium-3 from the decay of tritium. Table_4_Site_And_Background_Information.txt reports additional site information and field parameters. In addition to these four tables, two ancillary tables are included to provide more detailed information about the fields and the abbreviations used in tables 1-4. A readme file is provided that describes each table in more detail and processes to use the data in this data release to view age distributions in TracerLPM and to set up TracerLPM to run scenarios for other chemicals of interest.

A well is a hole dug into the ground usually for the purpose of taking water from the ground but also for monitoring groundwater. Most private wells are used for home and farm water supplies are in rural areas. Springs occur where groundwater comes out at the surface. A borehole is a hole drilled into the ground to gain access to groundwater. The hole is usually deep, narrow and round. This map shows the location of the dug wells, springs and boreholes in Ireland. Data was collected by GSI drilling or submitted to the GSI from Local Authorities and other state bodies, Private Well Grants, Drillers, Consultants, Group Water Schemes and Academia. The location accuracy is visually portrayed on the GSI webmapping viewer by the size of the circle displaying the record. It is NOT a comprehensive database and many wells and springs are not included in this database. You should not rely only on this database, and should undertake your own site study for wells in the area of interest if needed. This map is to the scale 1:100,000. This means it should be viewed at that scale. When printed at that scale 1cm on the map relates to a distance of 1km. It is a vector dataset. Vector data portray the world using points, lines, and polygons (areas). The data is shown as polygons. Each polygon holds information on the location of the borehole (X and Y coordinates), Well ID (well identifier), hole details, location details, yield, abstraction ,drilling details.

This software archive is superseded by Hydrologic Toolbox v1.1.0, available at the following citation: Barlow, P.M., McHugh, A.R., Kiang, J.E., Zhai, T., Hummel, P., Duda, P., and Hinz, S., 2024, U.S. Geological Survey Hydrologic Toolbox version 1.1.0 software archive: U.S. Geological Survey software release, https://doi.org/10.5066/P13VDNAK. The U.S. Geological Survey Hydrologic Toolbox is a Windows-based desktop software program that provides a graphical and mapping interface for analysis of hydrologic time-series data with a set of widely used and standardized computational methods. The software combines the analytical and statistical functionality provided in the U.S. Geological Survey (USGS) Groundwater (Barlow and others, 2014) and Surface-Water (Kiang and others, 2018) Toolboxes and provides several enhancements to these programs. The main analysis methods are the computation of hydrologic-frequency statistics such as the 7-day minimum flow that occurs on average only once every 10 years (7Q10); the computation of design flows, including biologically based flows; the computation of flow-duration curves and duration hydrographs; eight computer-programming methods for hydrograph separation of a streamflow time series, including the BFI (Base-flow index), HYSEP, PART, and SWAT Bflow methods and Eckhardt’s two-parameter digital-filtering method; and the RORA recession-curve displacement method and associated RECESS program to estimate groundwater-recharge values from streamflow data. Several of the statistical methods provided in the Hydrologic Toolbox are used primarily for computation of critical low-flow statistics. The Hydrologic Toolbox also facilitates retrieval of streamflow and groundwater-level time-series data from the USGS National Water Information System and outputs text reports that describe their analyses. The Hydrologic Toolbox supersedes and replaces the Groundwater and Surface-Water Toolboxes. The Hydrologic Toolbox was developed by use of the DotSpatial geographic information system (GIS) programming library, which is part of the MapWindow project (MapWindow, 2021). DotSpatial is a nonproprietary, open-source program written for the .NET framework that includes a spatial data viewer and GIS capabilities. This software archive is designed to document different versions of the Hydrologic Toolbox. Details about version changes are provided in the “Release.txt” file with this software release. Instructions for installing the software are provided in files “Installation_instructions.pdf” and “Installation_instructions.txt.” The “Installation_instructions.pdf” file includes screen captures of some of the installation steps, whereas the “Installation_instructions.txt” file does not. Each version of the Hydrologic Toolbox is provided in a separate .zip file. Citations: Barlow, P.M., Cunningham, W.L., Zhai, T., and Gray, M., 2014, U.S. Geological Survey groundwater toolbox, a graphical and mapping interface for analysis of hydrologic data (version 1.0)—User guide for estimation of base flow, runoff, and groundwater recharge from streamflow data: U.S. Geological Survey Techniques and Methods 3–B10, 27 p., https://doi.org/10.3133/tm3B10. Kiang, J.E., Flynn, K.M., Zhai, T., Hummel, P., and Granato, G., 2018, SWToolbox: A surface-water toolbox for statistical analysis of streamflow time series: U.S. Geological Survey Techniques and Methods, book 4, chap. A–11, 33 p., https://doi.org/10.3133/tm4A11. MapWindow, 2021, MapWindow software, accessed January 9, 2021, at https://www.mapwindow.org/#home.

The Division of Water Ground Water Database has approximately 407,000 water well records, and of those, approximately 147,000 have been field located and have x, y (UTM) coordinates. Approximately 39,000 were located based on address geocoding. The remaining records have no utms and cannot be easily utilized in a GIS format. The purpose of this dataset was to include those wells with UTM coordinates and to approximate the UTM coordinates for the others based on the most precise of county, or Township, Range, Section, quarter sections (TRS) locations available from office locating, which is effectively the centroid of the smallest known section or quarter sections; thus, increasing the amount of data available for display and analysis in a GIS format. This dataset is combination of the located water well records and the water well records for which an estimated location was able to be determined using the methods described below. This leaves less than 15,000 records with no UTM's associated with them. This dataset and associated table has selected fields from the main digital water well database that are typically needed for most research. This file is a digital geospatial point feature class of both located water well records (which include UTM coordinates) and unlocated water well records. The estimated locations used for the unlocated wells were based on the polygon centroid values for the smallest indicated county, section, quarter, quarter-quarter, or quarter-quarter-quarter section (as indicated in the database) for over 221,000 water well records and for about 39,000 water well records the UTM's were obtained from address geocoding using the owners address, a generally more accurate method (see process steps below).