Bill Eldridge
Hydrologist for the Dakota Water Science Center
Bill Eldridge is a hydrologist at the Dakota Water Science Center. He received a Bachelor and Master degrees in Geological Engineering from the South Dakota School of Mines and Technology. He also has a Bachelor degree in Chemistry from the U.S. Air Force Academy. Since joining the USGS in 2013, Bill studies Black Hills hydrology and groundwater modeling.
Science and Products
Simulation of Groundwater Flow in the Madison and Minnelusa Aquifers, Black Hills Area
Project Period: 2011-2018Cooperator: National Park Service, Black Hills National Forest, City of Rapid City, West Dakota Water Development DistrictProject Chief: Bill Eldridge
Electrical resistivity tomography (ERT) data collected near Summerset, South Dakota, between July 28 and August 5, 2025 Electrical resistivity tomography (ERT) data collected near Summerset, South Dakota, between July 28 and August 5, 2025
The U.S. Geological Survey, in cooperation with the City of Summerset, South Dakota, performed electrical resistivity tomography (ERT) surveys between July 28 and August 5, 2025. ERT data were collected using an Advanced Geosciences Incorporated SuperSting with 2 passive cables with 14 electrodes per cable. In total, ERT data were collected along 13 transects using 2 passive cables and...
MODFLOW–6 model of the Shell Valley aquifer, Belcourt, North Dakota, 1980-2022 MODFLOW–6 model of the Shell Valley aquifer, Belcourt, North Dakota, 1980-2022
A MODFLOW-6 groundwater flow model of the Shell Valley aquifer near the Turtle Mountain Band of the Chippewa Indians land area representation in northern North Dakota was constructed to improve the understanding and management of the water-supply resources. The model area included sub-watersheds containing the extent of the Shell Valley aquifer approximately between the towns of St. John...
Datasets used in constructing hydrologic budgets for six bedrock aquifers in the Black Hills area of South Dakota and Wyoming, 1931–2022 Datasets used in constructing hydrologic budgets for six bedrock aquifers in the Black Hills area of South Dakota and Wyoming, 1931–2022
Population growth and recurring droughts in the Black Hills region of western South Dakota and eastern Wyoming raised concerns regarding water resources and its future availability. Drought conditions in the late 1980s and the early 2000s stressed local water systems relying heavily on surface water as the population of the region was increasing. In response to water-availability...
Geospatial dataset of hydrologic characteristics of the Big Sioux aquifer near Sioux Falls, South Dakota Geospatial dataset of hydrologic characteristics of the Big Sioux aquifer near Sioux Falls, South Dakota
The city of Sioux Falls, in southeastern South Dakota, is the largest city in South Dakota. The U.S. Geological Survey (USGS), in cooperation with the city of Sioux Falls, completed a groundwater-flow model to use for improving the understanding of groundwater-flow processes, estimating hydrogeologic properties, and analyzing groundwater and surface-water interactions for the Big Sioux...
Three-Dimensional Delineation of the Pierre Shale Bedrock from Electrical Resistivity Surveys Conducted in Two Areas of Interest Within and Near Ellsworth Air Force Base, South Dakota, 2022 Three-Dimensional Delineation of the Pierre Shale Bedrock from Electrical Resistivity Surveys Conducted in Two Areas of Interest Within and Near Ellsworth Air Force Base, South Dakota, 2022
In 2022, the USGS, in cooperation with the U.S. Air Force Civil Engineer Center (USAF/CEC), performed geophysical surveys at two areas of interest within and near Ellsworth Air Force Base (EAFB) to delineate the Cretaceous Pierre Shale bedrock. Electrical resistivity tomography (ERT) data were collected in two grid patterns using the dipole-dipole array within and near EAFB and site...
Electrical resistivity tomography, electromagnetic induction, and ultraviolet optical scanning tool data collected at Malmstrom Air Force Base, Great Falls, Montana, August 28–August 31, 2023 Electrical resistivity tomography, electromagnetic induction, and ultraviolet optical scanning tool data collected at Malmstrom Air Force Base, Great Falls, Montana, August 28–August 31, 2023
The U.S. Geological Survey (USGS), in cooperation with the U.S. Air Force Civil Engineer Center (USAF/CEC), conducted a pilot study at Malmstrom Air Force Base (MAFB) to evaluate the utility of two non-invasive geophysical techniques for detecting hydrocarbons in subsurface materials. Electrical resistivity tomography (ERT) and electromagnetic induction (EMI) surveys were completed...
Maps of elevation of top of Pierre Shale and surficial deposit thickness with hydraulic properties from borehole geophysics and aquifers tests within and near Ellsworth Air Force Base, South Dakota, 2020–21 Maps of elevation of top of Pierre Shale and surficial deposit thickness with hydraulic properties from borehole geophysics and aquifers tests within and near Ellsworth Air Force Base, South Dakota, 2020–21
The U.S. Geological Survey, in cooperation with the U.S. Air Force Civil Engineer Center, collected borehole geophysical data and completed simple aquifer tests to estimate the thickness and hydraulic properties of surficial deposits. The purpose of data collection was to create generalized contour maps of Pierre Shale elevation and surficial deposit thickness within and near Ellsworth...
Stratigraphic units of shallow unconsolidated deposits in Deadwood, South Dakota, delineated by real-time kinematic surveys Stratigraphic units of shallow unconsolidated deposits in Deadwood, South Dakota, delineated by real-time kinematic surveys
The City of Deadwood, South Dakota, has been working on a new archeological investigation in preparation for economic growth and expansion within the city limits, through the Deadwood Historic Preservation Office. During the excavation process, buried artifacts and historical features from the late 1800s have been uncovered. The stratigraphy of shallow unconsolidated deposits in the city...
Filter Total Items: 13
Hydrologic budgets and water availability of six bedrock aquifers in the Black Hills area, South Dakota and Wyoming, 1931–2022 Hydrologic budgets and water availability of six bedrock aquifers in the Black Hills area, South Dakota and Wyoming, 1931–2022
Population growth and recurring droughts in the Black Hills region raised interest in water resources and future availability. The Black Hills hydrology study (BHHS) was initiated in the early 1990s to address questions regarding water resources. Since completion of the BHHS in the early 2000s, the population of the Black Hills region increased by about 39 percent, which has renewed...
Authors
Colton J. Medler, Todd M. Anderson, William G. Eldridge
Borehole analysis, single-well aquifer testing, and water quality for the Burnpit well, Mount Rushmore National Memorial, South Dakota Borehole analysis, single-well aquifer testing, and water quality for the Burnpit well, Mount Rushmore National Memorial, South Dakota
Mount Rushmore National Memorial (hereafter referred to as “the memorial”), in western South Dakota, is maintained by the National Park Service (NPS) and includes 1,278 acres of land in the east-central part of the Black Hills. An ongoing challenge for NPS managers at the memorial is providing water from sustainable and reliable sources for operations, staff, and the increasing number of...
Authors
William G. Eldridge, Galen K. Hoogestraat, Steven E. Rice
Spring types and contributing aquifers from water-chemistry and multivariate statistical analyses for seeps and springs in Theodore Roosevelt National Park, North Dakota, 2018 Spring types and contributing aquifers from water-chemistry and multivariate statistical analyses for seeps and springs in Theodore Roosevelt National Park, North Dakota, 2018
Water resources in Theodore Roosevelt National Park, North Dakota, support wildlife, visitors, and staff, and play a vital role in supporting the native ecology of the park. The U.S. Geological Survey, in cooperation with the National Park Service, completed field work in 2018 for a study to address concerns about water availability and possible sources of groundwater contamination for...
Authors
Colton J. Medler, William G. Eldridge
Hydrogeology and groundwater flow in alluvial deposits, north Summerset, South Dakota Hydrogeology and groundwater flow in alluvial deposits, north Summerset, South Dakota
The city of Summerset is a growing community in west South Dakota. The Sun Valley Estates subdivision in the north part of the city was developed on unconsolidated deposits surrounded by steep terrain. During years with greater than normal precipitation, particularly in 2019, groundwater levels increased in the unconsolidated deposits and caused damage to stormwater systems, sewer...
Authors
William G. Eldridge, Todd M. Anderson
Inventory and analysis of groundwater resources: Theodore Roosevelt National Park, North Dakota Inventory and analysis of groundwater resources: Theodore Roosevelt National Park, North Dakota
Industrial and commercial developments in western North Dakota potentially could affect the sources of water that contribute to wells, spring flow, and seeps within Theodore Roosevelt National Park. Without basic water resources data, accurately predicting the effects of water withdrawals and water quality concerns related to industrial and commercial developments near the park would be
Authors
William G. Eldridge, Colton J. Medler
Groundwater-flow model and analysis of groundwater and surface-water interactions for the Big Sioux aquifer, Sioux Falls, South Dakota Groundwater-flow model and analysis of groundwater and surface-water interactions for the Big Sioux aquifer, Sioux Falls, South Dakota
The city of Sioux Falls, in southeastern South Dakota, is the largest city in South Dakota. The U.S. Geological Survey (USGS), in cooperation with the city of Sioux Falls, completed a groundwater-flow model to use for improving the understanding of groundwater-flow processes, estimating hydrogeologic properties, and analyzing groundwater and surface-water interactions for the Big Sioux...
Authors
Kyle W. Davis, William G. Eldridge, Joshua F. Valder, Kristen J. Valseth
Science and Products
Simulation of Groundwater Flow in the Madison and Minnelusa Aquifers, Black Hills Area
Project Period: 2011-2018Cooperator: National Park Service, Black Hills National Forest, City of Rapid City, West Dakota Water Development DistrictProject Chief: Bill Eldridge
Electrical resistivity tomography (ERT) data collected near Summerset, South Dakota, between July 28 and August 5, 2025 Electrical resistivity tomography (ERT) data collected near Summerset, South Dakota, between July 28 and August 5, 2025
The U.S. Geological Survey, in cooperation with the City of Summerset, South Dakota, performed electrical resistivity tomography (ERT) surveys between July 28 and August 5, 2025. ERT data were collected using an Advanced Geosciences Incorporated SuperSting with 2 passive cables with 14 electrodes per cable. In total, ERT data were collected along 13 transects using 2 passive cables and...
MODFLOW–6 model of the Shell Valley aquifer, Belcourt, North Dakota, 1980-2022 MODFLOW–6 model of the Shell Valley aquifer, Belcourt, North Dakota, 1980-2022
A MODFLOW-6 groundwater flow model of the Shell Valley aquifer near the Turtle Mountain Band of the Chippewa Indians land area representation in northern North Dakota was constructed to improve the understanding and management of the water-supply resources. The model area included sub-watersheds containing the extent of the Shell Valley aquifer approximately between the towns of St. John...
Datasets used in constructing hydrologic budgets for six bedrock aquifers in the Black Hills area of South Dakota and Wyoming, 1931–2022 Datasets used in constructing hydrologic budgets for six bedrock aquifers in the Black Hills area of South Dakota and Wyoming, 1931–2022
Population growth and recurring droughts in the Black Hills region of western South Dakota and eastern Wyoming raised concerns regarding water resources and its future availability. Drought conditions in the late 1980s and the early 2000s stressed local water systems relying heavily on surface water as the population of the region was increasing. In response to water-availability...
Geospatial dataset of hydrologic characteristics of the Big Sioux aquifer near Sioux Falls, South Dakota Geospatial dataset of hydrologic characteristics of the Big Sioux aquifer near Sioux Falls, South Dakota
The city of Sioux Falls, in southeastern South Dakota, is the largest city in South Dakota. The U.S. Geological Survey (USGS), in cooperation with the city of Sioux Falls, completed a groundwater-flow model to use for improving the understanding of groundwater-flow processes, estimating hydrogeologic properties, and analyzing groundwater and surface-water interactions for the Big Sioux...
Three-Dimensional Delineation of the Pierre Shale Bedrock from Electrical Resistivity Surveys Conducted in Two Areas of Interest Within and Near Ellsworth Air Force Base, South Dakota, 2022 Three-Dimensional Delineation of the Pierre Shale Bedrock from Electrical Resistivity Surveys Conducted in Two Areas of Interest Within and Near Ellsworth Air Force Base, South Dakota, 2022
In 2022, the USGS, in cooperation with the U.S. Air Force Civil Engineer Center (USAF/CEC), performed geophysical surveys at two areas of interest within and near Ellsworth Air Force Base (EAFB) to delineate the Cretaceous Pierre Shale bedrock. Electrical resistivity tomography (ERT) data were collected in two grid patterns using the dipole-dipole array within and near EAFB and site...
Electrical resistivity tomography, electromagnetic induction, and ultraviolet optical scanning tool data collected at Malmstrom Air Force Base, Great Falls, Montana, August 28–August 31, 2023 Electrical resistivity tomography, electromagnetic induction, and ultraviolet optical scanning tool data collected at Malmstrom Air Force Base, Great Falls, Montana, August 28–August 31, 2023
The U.S. Geological Survey (USGS), in cooperation with the U.S. Air Force Civil Engineer Center (USAF/CEC), conducted a pilot study at Malmstrom Air Force Base (MAFB) to evaluate the utility of two non-invasive geophysical techniques for detecting hydrocarbons in subsurface materials. Electrical resistivity tomography (ERT) and electromagnetic induction (EMI) surveys were completed...
Maps of elevation of top of Pierre Shale and surficial deposit thickness with hydraulic properties from borehole geophysics and aquifers tests within and near Ellsworth Air Force Base, South Dakota, 2020–21 Maps of elevation of top of Pierre Shale and surficial deposit thickness with hydraulic properties from borehole geophysics and aquifers tests within and near Ellsworth Air Force Base, South Dakota, 2020–21
The U.S. Geological Survey, in cooperation with the U.S. Air Force Civil Engineer Center, collected borehole geophysical data and completed simple aquifer tests to estimate the thickness and hydraulic properties of surficial deposits. The purpose of data collection was to create generalized contour maps of Pierre Shale elevation and surficial deposit thickness within and near Ellsworth...
Stratigraphic units of shallow unconsolidated deposits in Deadwood, South Dakota, delineated by real-time kinematic surveys Stratigraphic units of shallow unconsolidated deposits in Deadwood, South Dakota, delineated by real-time kinematic surveys
The City of Deadwood, South Dakota, has been working on a new archeological investigation in preparation for economic growth and expansion within the city limits, through the Deadwood Historic Preservation Office. During the excavation process, buried artifacts and historical features from the late 1800s have been uncovered. The stratigraphy of shallow unconsolidated deposits in the city...
Filter Total Items: 13
Hydrologic budgets and water availability of six bedrock aquifers in the Black Hills area, South Dakota and Wyoming, 1931–2022 Hydrologic budgets and water availability of six bedrock aquifers in the Black Hills area, South Dakota and Wyoming, 1931–2022
Population growth and recurring droughts in the Black Hills region raised interest in water resources and future availability. The Black Hills hydrology study (BHHS) was initiated in the early 1990s to address questions regarding water resources. Since completion of the BHHS in the early 2000s, the population of the Black Hills region increased by about 39 percent, which has renewed...
Authors
Colton J. Medler, Todd M. Anderson, William G. Eldridge
Borehole analysis, single-well aquifer testing, and water quality for the Burnpit well, Mount Rushmore National Memorial, South Dakota Borehole analysis, single-well aquifer testing, and water quality for the Burnpit well, Mount Rushmore National Memorial, South Dakota
Mount Rushmore National Memorial (hereafter referred to as “the memorial”), in western South Dakota, is maintained by the National Park Service (NPS) and includes 1,278 acres of land in the east-central part of the Black Hills. An ongoing challenge for NPS managers at the memorial is providing water from sustainable and reliable sources for operations, staff, and the increasing number of...
Authors
William G. Eldridge, Galen K. Hoogestraat, Steven E. Rice
Spring types and contributing aquifers from water-chemistry and multivariate statistical analyses for seeps and springs in Theodore Roosevelt National Park, North Dakota, 2018 Spring types and contributing aquifers from water-chemistry and multivariate statistical analyses for seeps and springs in Theodore Roosevelt National Park, North Dakota, 2018
Water resources in Theodore Roosevelt National Park, North Dakota, support wildlife, visitors, and staff, and play a vital role in supporting the native ecology of the park. The U.S. Geological Survey, in cooperation with the National Park Service, completed field work in 2018 for a study to address concerns about water availability and possible sources of groundwater contamination for...
Authors
Colton J. Medler, William G. Eldridge
Hydrogeology and groundwater flow in alluvial deposits, north Summerset, South Dakota Hydrogeology and groundwater flow in alluvial deposits, north Summerset, South Dakota
The city of Summerset is a growing community in west South Dakota. The Sun Valley Estates subdivision in the north part of the city was developed on unconsolidated deposits surrounded by steep terrain. During years with greater than normal precipitation, particularly in 2019, groundwater levels increased in the unconsolidated deposits and caused damage to stormwater systems, sewer...
Authors
William G. Eldridge, Todd M. Anderson
Inventory and analysis of groundwater resources: Theodore Roosevelt National Park, North Dakota Inventory and analysis of groundwater resources: Theodore Roosevelt National Park, North Dakota
Industrial and commercial developments in western North Dakota potentially could affect the sources of water that contribute to wells, spring flow, and seeps within Theodore Roosevelt National Park. Without basic water resources data, accurately predicting the effects of water withdrawals and water quality concerns related to industrial and commercial developments near the park would be
Authors
William G. Eldridge, Colton J. Medler
Groundwater-flow model and analysis of groundwater and surface-water interactions for the Big Sioux aquifer, Sioux Falls, South Dakota Groundwater-flow model and analysis of groundwater and surface-water interactions for the Big Sioux aquifer, Sioux Falls, South Dakota
The city of Sioux Falls, in southeastern South Dakota, is the largest city in South Dakota. The U.S. Geological Survey (USGS), in cooperation with the city of Sioux Falls, completed a groundwater-flow model to use for improving the understanding of groundwater-flow processes, estimating hydrogeologic properties, and analyzing groundwater and surface-water interactions for the Big Sioux...
Authors
Kyle W. Davis, William G. Eldridge, Joshua F. Valder, Kristen J. Valseth