Regional Groundwater Availability Studies
Regional groundwater availability studies enable information about groundwater to be integrated and consistent, so that this resource can be analyzed and understood on an aquifer–wide scale. These studies provide decision–makers with a better understanding of the status and trends in the Nation's groundwater availability.
Regional Groundwater Availability Studies
Ongoing water availability studies
- California Coastal Basins
- Coastal Lowlands Aquifer System
- Colorado Plateaus
- Northwest Volcanic Aquifer System
- Hawaii Volcanic-Rock Aquifers
- Ozark Plateaus Aquifer System
- Floridan Aquifer System
- Pennsylvanian and Mississippian Aquifer System of the Appalachian Plateaus
- Williston and Powder River Basins
- Glacial Aquifer System
- Northern Atlantic Coastal Plain Aquifer System
- High Plains Aquifer
- Columbia Plateau Regional Aquifer System
- Mississippi Embayment Regional Aquifer Study
- Great Basin Carbonate and Alluvial Aquifer System
- Central Valley Aquifer
- North and South Carolina Atlantic Coastal Plain Aquifer System
- Denver Basin Aquifer
- Middle Rio Grande Basin Study
- Great Lakes Basin Pilot Study -- Lake Michigan Basin
- Southwest Alluvial Basins Project -- Groundwater Methods Development
Ongoing water availability studies
Transboundary Aquifer Assessment Program
The Transboundary Aquifer Assessment Program (TAAP) encompasses aquifers in the region along the United States-Mexico border. Groundwater-flow models and hydrogeological assessments in this region often end at political boundaries, but the aquifers of interest are transboundary in extent. Lack of data limits the ability to accurately model and assess aquifer characteristics and to enable management strategies to most effectively utilize groundwater resources.
The overarching goal of TAAP is to produce scientific products for priority transboundary aquifers that—(A) are of broad public interest; (B) establish and strengthen relationships with Mexican counterparts; and (C) provide the scientific information needed by water managers and natural-resource agencies on both sides of the United States-Mexico border to effectively accomplish their missions. The current priority aquifers named in federal legislation are the Hueco Bolson underlying Texas and Chihuahua, the Mesilla/Conejos-Médanos aquifer underlying New Mexico and Chihuahua, and the San Pedro and Santa Cruz aquifers underlying Arizona and Sonora.
- Visit the Transboundary Aquifer Assessment Program website for more information
Mississippi Alluvial Plain Aquifers
Aquifers underlying the Mississippi Alluvial Plain help sustain a vibrant agricultural region that is experiencing conflicts and concerns over groundwater availability. The Mississippi River Valley alluvial aquifer is the primary source for supply of irrigation from groundwater. Lack of regionally consistent monitoring efforts, focused groundwater modeling on the alluvial aquifer, and sub-regional hydrogeologic characterization have resulted in a limited capability to quantify the conjunctive use of groundwater and surface water in the region. The Mississippi Alluvial Plain Aquifers study is designed to improve previous simulations of groundwater flow and provide a more accurate management tool for water resource sustainability.
- Visit the Mississippi Alluvial Plain (MAP) Regional Water Availability Study website for more information
Completed Studies
California Coastal Basins
This study seeks to quantify the water budget in the California Coastal Basin Aquifers (CCBs). The proposed study will assess the available groundwater resources of the CCBs in the context of all available water supplies and their integrated use. The CCBs vary greatly in their water availability, their predominant water uses (agricultural, urban, or environmental), how availability and uses have changed over time, and how water supplies may change due to climate change. In this study, all of these aspects will be explored. Owing to the complex dynamics of the CCBs and the need to manage water supplies conjunctively, the study will evaluate the effects of variability in water supply and demand.
The main objective of this study will be to develop regional water budgets and associated tools to quantify historical and current conditions, and forecast future water budgets. Forecasting system response for the physically disjointed CCBs will be done using an overarching supply-and-demand framework. Extrapolation will be done from existing models that represent system dynamics by the use of “metamodels”. In addition, these metamodels will be used to develop web-based tools to enable stakeholders to utilize the these models to better understand the dynamics of their basins and evaluate potential management actions for addressing current and forecasted groundwater issues. This proposed study comes at a landmark time in California’s groundwater history, making these tools very valuable to water managers.
- Visit the California Coastal Basins regional groundwater availability study website for more information
Coastal Lowlands Aquifer System
Almost 2.4 billion gallons per day were withdrawn from aquifers along the Gulf of Mexico known as the Coastal Lowlands Aquifer System (CLAS) by the year 2000. The withdrawals were primarily for public supplies (43 percent), irrigation (39 percent), and self-supplied industries (18 percent). Heavy withdrawals from the aquifer system in some areas have resulted in water-level declines, saltwater encroachment, and land subsidence.
The CLAS study is designed to assess groundwater availability for the aquifers proximal to the Gulf of Mexico from the Texas-Mexico border through the panhandle of Florida. This assessment builds on decades of information and previous numerical models of groundwater throughout the area. The past and current information will be assimilated to develop a regional model covering an area of about 140,000 square miles. The model may be used to evaluate water level decline, land-surface subsidence, and groundwater storage changes through potential future scenarios based on anthropogenic and climatic changes to hydrologic components of the system. The CLAS study begins in late 2016 and is expected to culminate in 2021 with tools and publications for groundwater availability and resource management.
- Visit the Coastal Lowlands Aquifer System study website for more information
Colorado Plateaus
The Colorado Plateaus aquifer system study is designed to quantify the status of groundwater as an integrated resource with surface water. Surface-water resources that originate in this region are over-allocated and serve 35 million people, 4.5 million acres of farmland, and are used to generate 12 billion kilowatt hours of electricity in the southwest U.S. Recent studies have found that nearly half of surface-water resources in this region are supplied directly from groundwater discharge. Prior studies in the Colorado Plateau have mainly examined groundwater and surface water as separate systems, and there has yet to be regional synthesis of groundwater availability in regional and locally-important aquifers that contribute to surface water. As a result, the potential changes to integrated groundwater and surface-water availability from human and natural water use and variable climate are uncertain.
- Visit the Colorado Plateaus aquifer system study website for more information
Northwest Volcanic Aquifer System
The Northwest Volcanic Aquifer Study will quantify groundwater resources and geothermal energy potential in much of eastern Oregon, northeastern California, southwestern Idaho, and northernmost Nevada.
This study area lies within a broadly-defined Northwest Volcanic Province that has been dominated by volcanic eruptions that have shaped the landscape over the past approximately 17 million years. Previous geothermal research in the region has identified high geothermal heat flow that may be used to generate large amounts of electricity. Groundwater is the major source of year-round dependable water supply in the study area, and water is a necessary component of geothermal energy development. Because flowing groundwater moves heat beneath the earth's surface, interpretation of geothermal heat flow patterns are greatly improved when groundwater flow patterns are taken into account
The Northwest Volcanic Aquifer Study will:
- develop a regional geologic/hydrogeologic framework;
- assess available groundwater resources and estimate post-1980 distributed natural groundwater recharge; and
- characterize the geothermal potential in the study area.
The Northwest Volcanic Aquifer Study is a joint project of the USGS Groundwater Resources Program and the USGS Geothermal Resource Investigations Project.
- Visit the Northwest Volcanic Aquifer Study website for more information
Hawaii Volcanic-Rock Aquifers
The volcanic-rock aquifers in Hawaii supply water to 1.36 million residents, diverse industries, and a large component of the U.S. military in the Pacific. The aquifers of individual Hawaiian Islands are isolated by sea water and have limited capacity. Fresh groundwater resources in Hawaii are therefore particularly vulnerable to impacts from human activity and climate change.
The Hawaii Volcanic-Rock Aquifer Study will provide an updated assessment of groundwater availability in Hawaii; assess the current condition of Hawaii volcanic-rock aquifers and show how groundwater resources have changed as a result of natural and human stresses; provide a tool to assess responses to future stresses; and evaluate the adequacy of the current data network for assessing groundwater resources in the future.
The study plan includes defining the hydrogeologic framework, quantifying components of the groundwater budget, and developing conceptual models of groundwater flow for Kauai, Oahu, Maui and the Big Island. Additionally, the plan includes construction of three separate whole-island numerical groundwater models for Kauai, Oahu, and Maui. The models together with input from the groundwater budget will be used to assess changes in groundwater availability in Hawaii.
Ozark Plateaus Aquifer System
The Ozark Plateaus aquifer system underlies parts of southern Missouri, southeastern Kansas, northwestern Arkansas, and northeastern Oklahoma. Building on previous USGS Ozark Regional Aquifer System Analysis (RASA) work, the Ozark Plateaus Aquifer System regional groundwater availability study will:
- quantify current groundwater resources,
- evaluate how these resources have changed over time, and
- provide the tools needed to simulate system response to future human and environmental stresses, including climate change.
The study will also provide information about changes in system-wide groundwater storage over time. The results of the study will be available for use by federal, state and local agencies to inform the evaluation and design of existing and new groundwater monitoring networks and other water-resource management decisions.
Learn more about this study:
- Read the report: Groundwater Availability in the Ozark Plateaus Aquifer System
- Visit the Ozark Plateaus study website for a complete bibliography and more information.
- Vew a video from the study: Groundwater, A Source To Streams in the Ozark Plateaus [YouTube]
Floridian Aquifer System
The Floridan Aquifer System covers approximately 100,000 square miles in the southeastern United States in Florida and portions of Georgia, Alabama, Mississippi, and South Carolina. The overall objective for the current study is to assess the availability of water in the Floridan Aquifer System. Achieving this objective includes quantifying the groundwater resource by creating water budgets both spatially and temporally as well as evaluating the groundwater resource changes over time. Additionally, tools will be provided to assess the future impacts of humans and environmental changes (such as climate) on the Floridan Aquifer System and aid in designing groundwater monitoring networks. Note: This study was restarted in late fiscal year 2013 after a short hiatus.C
Learn more about the outcomes of this study:
- Visit the Floridan study website for a complete bibliography and to learn more.
- Read the study summary report: Revised Hydrogeologic Framework of the Floridan Aquifer System in Florida and Parts of Georgia, Alabama, and South Carolina (PP 1807)
Pennsylvanian and Mississippian Aquifer System of the Appalachian Plateaus
Pennsylvanian- and Mississippian-age aquifers occupy approximately 86,000 square miles in the Appalachian Plateaus region of Pennsylvania, Ohio, Maryland, Virginia, West Virginia, Kentucky, Tennessee, Georgia, and Alabama. Groundwater in this aquifer system is essential for domestic supplies, energy resource development, and healthy aquatic ecosystems.
The USGS Appalachian Plateau Groundwater Availability Study will provide fundamental regional understanding of groundwater flow and availability in this Pennsylvanian- and Mississippian-age aquifer system. The Phase I activities of the regional study will:
- develop a basin-wide hydrogeologic framework,
- construct a regional hydrologic budget, and
- assess conceptual models of groundwater flow at multiple scales.
A better understanding of groundwater availability in the Plateaus plays a central role in sustained economic development of the region. This study will provide important data that can be used by USGS and other federal, state, and local scientists, water-resource managers, and policy makers to assess drinking-water resources, aquatic ecosystems, and energy resource development in the region.
- Visit the Pennsylvanian and Mississippian Aquifer study website for a complete bibliography and more information
Williston and Powder River Basins
The development of two nationally important energy-producing areas, the Williston structural basin (containing the Bakken Formation) and Powder River structural basin, provide a critical opportunity to study the water-energy nexus within a groundwater context. Large amounts of water are needed for energy development in these basins. The hydraulically connected aquifers in the regional Lower Teritary and Upper Cretaceous aquifer system are the shallowest, most accessible, and in some cases, the only potable aquifers within the Northern Great Plains.
The purpose of the Williston and Powder River Basins Groundwater Availability Study is to quantify current groundwater resources in this aquifer system, evaluate how these resources have changed over time, and provide tools to better understand system response to future anthropogenic demands and environmental stress.
Learn more about this study:
- Read the report: Groundwater availability of the Williston Basin | Fact sheet summary
- Visit the Williston and Powder River Basins study website for a complete bibliography and more information
- Get aquifer system geospatial data from the Williston and Powder River Basins study
Glacial Aquifer System
The glacial aquifer system is present in parts of 25 states. The glacial aquifer system contains the glacial sand and gravel principal aquifer, which is the largest water source for public supply and self-supplied industrial for any principal aquifer; it also is an important source for irrigation supply.
The Glacial Aquifer System Groundwater Availability Study will quantify current groundwater resources in the glacial aquifer system, evaluate how these resources have changed over time, and provide tools to better understand system response to future anthropogenic demands and environmental condition. The study is part of the Department of Interior WaterSMART initiative and will provide important information and analysis to stakeholders and decisionmakers in the study area.
Learn more about this study:
Northern Atlantic Coastal Plain Aquifer System
The objectives of the Northern Atlantic Coastal Plain Groundwater Availability study are three fold: 1) quantify the current groundwater resources of one of the Nation's priority aquifer systems; 2) evaluate how this resource has changed over time; and 3) provide the tools needed to forecast how this aquifer system may respond to future human and environmental stresses. The focus of the Northern Atlantic Coastal Plain Groundwater Availability study is on improving fundamental knowledge of the water budget of this aquifer system, including the flows, storage, and use by humans and the environment. An improved quantitative understanding of the aquifer system's water budget not only provides key information about water quantity, but also is essential for assessments of water quality and ecosystem health.
Learn more about this study:
- Report: Hydrogeology and Hydrologic Conditions of the Northern Atlantic Coastal Plain Aquifer System from Long Island, New York, to North Carolina
- Fact Sheet: Assessing groundwater availability in the Northern Atlantic Coastal Plain aquifer system
- Read the final report: Assessment of groundwater availability in the Northern Atlantic Coastal Plain aquifer system From Long Island, New York, to North Carolina
High Plains Aquifer
The High Plains groundwater availability study quantified current groundwater resources, evaluated changes in those resources over time, and provided tools to forecast how those resources respond to stresses from future human and environmental uses. The improved quantitative understanding of the basin's water balance provided by this USGS study not only provides key information about water quantity but also is a fundamental basis for many analyses of water quality and ecosystem health.
Learn more about the outcomes of this study:
- Read an overview of the study: Assessing groundwater availability in the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming (Fact Sheet 2010–3008)
- Watch a video [Youtube] about how the USGS uses 3D modeling to show how groundwater levels change over time in the High Plains aquifer.
- Visit the High Plains study website for a complete bibliography and to learn more.
- Get aquifer system geospatial data from the High Plains study
Columbia Plateau Regional Aquifer System
The Columbia Plateau Regional Aquifer System (CPRAS) covers over 50,000 square miles of eastern Oregon and Washington and western Idaho. The USGS conducted a study of the Columbia Plateau Regional Aquifer System to characterize the hydrologic status of the system, identify trends in groundwater storage and use, and quantify groundwater availability.
Learn more about the outcomes of this study:
- Watch a video about how the USGS uses 3D modeling to investigate groundwater in the Columbia Plateau Aquifer System.
- Explore the interactive 3D hydrogeologic model of the Columbia Plateau Regional Aquifer System.
- Visit the Columbia Plateau study website for a complete bibliography and to learn more.
- Get aquifer system geospatial data from the Columbia Plateau study
Mississippi Embayment Regional Aquifer Study
A groundwater flow model of the northern Mississippi embayment was developed to aid in answering questions about groundwater availability in a study area covering portions of seven states (Arkansas, Louisiana, Mississippi, Tennessee, Alabama, Missouri, and Kentucky).
Learn more about the outcomes of this study:
- Read the study summary report: The Mississippi Embayment Regional Aquifer Study (MERAS): Documentation of a groundwater-flow model constructed to assess water availability in the Mississippi Embayment (SIR 2009-5172)
- Visit the Mississippi Embayment study website for a complete bibliography and to learn more.
- Get aquifer system geospatial data from the Mississippi Embayment study
Great Basin Carbonate and Alluvial Aquifer System
The Great Basin Carbonate and Alluvial Aquifer System Water Availability Study quantified current groundwater resources, evaluated how those resources have changed over time, and developed tools to assess system responses to stresses from future human uses and climate variability.
Learn more about the outcomes of this study:
- Visit the Great Basin study website for a complete bibliography
- Read the study summary report: Conceptual Model of the Great Basin Carbonate and Alluvial Aquifer System (SIR 2010-5193)
- Get aquifer system geospatial data from the Great Basin study
Central Valley Aquifer
For more than 50 years, California's Central Valley has been one of the most productive agricultural regions in the world. Large increases in population have resulted in greater competition for water within the Central Valley and statewide. The USGS assessed the groundwater availability of the Central Valley and quantified the groundwater resources using a variety of tools. The ultimate benefit of this assessment will be a better understanding of how the system responds to current and future human and environmental stresses that will prove useful to water managers in their decision making process related to this valuable resource.
Learn more about the outcomes of this study:
- Read an overview of the study: California's Central Valley groundwater study (Fact Sheet 2009-3057)
- Listen to a podcast about California's vast Central Valley groundwater system and the USGS study findings.
- Read the study summary report: Groundwater availability of the Central Valley Aquifer, California (Professional Paper 1766)
- Visit the Central Valley study website
- Get aquifer system geospatial data from the Central Valley study
North and South Carolina Atlantic Coastal Plain Aquifer System
Increased groundwater withdrawals related to population growth and drought of the last few years have emphasized the need for more accurate, detailed information describing the groundwater resources in the Coastal Plain in North and South Carolina. In January 2004, the U.S. Geological Survey began a study to combine and update the Regional Aquifer System Analysis (RASA) models of North and South Carolina in order to improve the understanding of groundwater availability in the North and South Carolina Atlantic Coastal Plain aquifer system.
Learn more about the outcomes of this study:
- Read the study summary report: Groundwater Availability in the Atlantic Coastal Plain of North and South Carolina (Professional Paper 1773)
- Visit the North and South Carolina Atlantic Coastal Plain study website for a complete bibliography and to learn more.
Denver Basin Aquifers
The Denver groundwater basin is an important and non-renewable source of water for municipal, industrial, and domestic uses in the Denver and Colorado Springs metropolitan areas. The USGS conducted a groundwater availability of the Denver Groundwater Basin to enhance our understanding of regional groundwater flow and aquifer storage, to evaluate current conditions, and to predict future conditions.
Learn more about the outcomes of this study:
- Visit the Denver Basin study website for a complete bibliography and to learn more.
- Read the study summary report: Groundwater Availability of the Denver Basin Aquifer System, Colorado (USGS Professional Paper 1770)
Middle Rio Grande Basin Study - Initial Proof of Concept Study
The Santa Fe Group aquifer system in Central New Mexico is the main source of municipal water for the region. The USGS Middle Rio Grande Basin Study was a 6-year effort (1995-2001) to improve the understanding of the hydrology, geology, and land-surface characteristics of the Middle Rio Grande Basin in order to provide the scientific information needed for water-resources management. This initial proof of concept study was conducted prior to the development of the strategy outlined in Circular 1323 and served as as a precursor to current GWRP regional groundwater availability studies.
Learn more about the outcomes of this study:
- Read an overview of the study: Ground-water resources of the Middle Rio Grande Basin (Fact Sheet 088-02) (PDF)
- Read the study summary report: Ground-water resources of the Middle Rio Grande Basin, New Mexico (Circular 1222)
- Visit the Middle Rio Grande Basin study website for a complete bibliography and to learn more.
Great Lakes Basin Pilot Study - Lake Michigan Basin
In 2005, USGS embarked on a pilot study of water availability in the Great Lakes Basin. The pilot study focused on understanding the dynamics of the water resources in the basin in terms of the flows and yields of both groundwater and surface water and demonstrated the importance of water-use data in quantifying water availability.
Learn more about the outcomes of this study:
- Read the study summary report: Water Availability and Use Pilot: A Multiscale Assessment in the U.S. Great Lakes Basin (Professional Paper 1778)
- Visit the Great Lakes Basin Pilot Study website for a complete bibliography and to learn more.
Southwest Alluvial Basins Project - Groundwater Methods Development
As groundwater is increasingly developed in the Lower Colorado River Basin, information on effects are needed for assessment of water availability. From 2006 to 2009, this project made assessments of groundwater availability and conditions in the Lower Colorado River Basin. A special emphasis was placed on development of methods of assessment and display of groundwater conditions that might be extended to other regions of the country.
Learn more about the outcomes of this study:
Regional groundwater availability studies enable information about groundwater to be integrated and consistent, so that this resource can be analyzed and understood on an aquifer–wide scale. These studies provide decision–makers with a better understanding of the status and trends in the Nation's groundwater availability.
Regional Groundwater Availability Studies
Ongoing water availability studies
- California Coastal Basins
- Coastal Lowlands Aquifer System
- Colorado Plateaus
- Northwest Volcanic Aquifer System
- Hawaii Volcanic-Rock Aquifers
- Ozark Plateaus Aquifer System
- Floridan Aquifer System
- Pennsylvanian and Mississippian Aquifer System of the Appalachian Plateaus
- Williston and Powder River Basins
- Glacial Aquifer System
- Northern Atlantic Coastal Plain Aquifer System
- High Plains Aquifer
- Columbia Plateau Regional Aquifer System
- Mississippi Embayment Regional Aquifer Study
- Great Basin Carbonate and Alluvial Aquifer System
- Central Valley Aquifer
- North and South Carolina Atlantic Coastal Plain Aquifer System
- Denver Basin Aquifer
- Middle Rio Grande Basin Study
- Great Lakes Basin Pilot Study -- Lake Michigan Basin
- Southwest Alluvial Basins Project -- Groundwater Methods Development
Ongoing water availability studies
Transboundary Aquifer Assessment Program
The Transboundary Aquifer Assessment Program (TAAP) encompasses aquifers in the region along the United States-Mexico border. Groundwater-flow models and hydrogeological assessments in this region often end at political boundaries, but the aquifers of interest are transboundary in extent. Lack of data limits the ability to accurately model and assess aquifer characteristics and to enable management strategies to most effectively utilize groundwater resources.
The overarching goal of TAAP is to produce scientific products for priority transboundary aquifers that—(A) are of broad public interest; (B) establish and strengthen relationships with Mexican counterparts; and (C) provide the scientific information needed by water managers and natural-resource agencies on both sides of the United States-Mexico border to effectively accomplish their missions. The current priority aquifers named in federal legislation are the Hueco Bolson underlying Texas and Chihuahua, the Mesilla/Conejos-Médanos aquifer underlying New Mexico and Chihuahua, and the San Pedro and Santa Cruz aquifers underlying Arizona and Sonora.
- Visit the Transboundary Aquifer Assessment Program website for more information
Mississippi Alluvial Plain Aquifers
Aquifers underlying the Mississippi Alluvial Plain help sustain a vibrant agricultural region that is experiencing conflicts and concerns over groundwater availability. The Mississippi River Valley alluvial aquifer is the primary source for supply of irrigation from groundwater. Lack of regionally consistent monitoring efforts, focused groundwater modeling on the alluvial aquifer, and sub-regional hydrogeologic characterization have resulted in a limited capability to quantify the conjunctive use of groundwater and surface water in the region. The Mississippi Alluvial Plain Aquifers study is designed to improve previous simulations of groundwater flow and provide a more accurate management tool for water resource sustainability.
- Visit the Mississippi Alluvial Plain (MAP) Regional Water Availability Study website for more information
Completed Studies
California Coastal Basins
This study seeks to quantify the water budget in the California Coastal Basin Aquifers (CCBs). The proposed study will assess the available groundwater resources of the CCBs in the context of all available water supplies and their integrated use. The CCBs vary greatly in their water availability, their predominant water uses (agricultural, urban, or environmental), how availability and uses have changed over time, and how water supplies may change due to climate change. In this study, all of these aspects will be explored. Owing to the complex dynamics of the CCBs and the need to manage water supplies conjunctively, the study will evaluate the effects of variability in water supply and demand.
The main objective of this study will be to develop regional water budgets and associated tools to quantify historical and current conditions, and forecast future water budgets. Forecasting system response for the physically disjointed CCBs will be done using an overarching supply-and-demand framework. Extrapolation will be done from existing models that represent system dynamics by the use of “metamodels”. In addition, these metamodels will be used to develop web-based tools to enable stakeholders to utilize the these models to better understand the dynamics of their basins and evaluate potential management actions for addressing current and forecasted groundwater issues. This proposed study comes at a landmark time in California’s groundwater history, making these tools very valuable to water managers.
- Visit the California Coastal Basins regional groundwater availability study website for more information
Coastal Lowlands Aquifer System
Almost 2.4 billion gallons per day were withdrawn from aquifers along the Gulf of Mexico known as the Coastal Lowlands Aquifer System (CLAS) by the year 2000. The withdrawals were primarily for public supplies (43 percent), irrigation (39 percent), and self-supplied industries (18 percent). Heavy withdrawals from the aquifer system in some areas have resulted in water-level declines, saltwater encroachment, and land subsidence.
The CLAS study is designed to assess groundwater availability for the aquifers proximal to the Gulf of Mexico from the Texas-Mexico border through the panhandle of Florida. This assessment builds on decades of information and previous numerical models of groundwater throughout the area. The past and current information will be assimilated to develop a regional model covering an area of about 140,000 square miles. The model may be used to evaluate water level decline, land-surface subsidence, and groundwater storage changes through potential future scenarios based on anthropogenic and climatic changes to hydrologic components of the system. The CLAS study begins in late 2016 and is expected to culminate in 2021 with tools and publications for groundwater availability and resource management.
- Visit the Coastal Lowlands Aquifer System study website for more information
Colorado Plateaus
The Colorado Plateaus aquifer system study is designed to quantify the status of groundwater as an integrated resource with surface water. Surface-water resources that originate in this region are over-allocated and serve 35 million people, 4.5 million acres of farmland, and are used to generate 12 billion kilowatt hours of electricity in the southwest U.S. Recent studies have found that nearly half of surface-water resources in this region are supplied directly from groundwater discharge. Prior studies in the Colorado Plateau have mainly examined groundwater and surface water as separate systems, and there has yet to be regional synthesis of groundwater availability in regional and locally-important aquifers that contribute to surface water. As a result, the potential changes to integrated groundwater and surface-water availability from human and natural water use and variable climate are uncertain.
- Visit the Colorado Plateaus aquifer system study website for more information
Northwest Volcanic Aquifer System
The Northwest Volcanic Aquifer Study will quantify groundwater resources and geothermal energy potential in much of eastern Oregon, northeastern California, southwestern Idaho, and northernmost Nevada.
This study area lies within a broadly-defined Northwest Volcanic Province that has been dominated by volcanic eruptions that have shaped the landscape over the past approximately 17 million years. Previous geothermal research in the region has identified high geothermal heat flow that may be used to generate large amounts of electricity. Groundwater is the major source of year-round dependable water supply in the study area, and water is a necessary component of geothermal energy development. Because flowing groundwater moves heat beneath the earth's surface, interpretation of geothermal heat flow patterns are greatly improved when groundwater flow patterns are taken into account
The Northwest Volcanic Aquifer Study will:
- develop a regional geologic/hydrogeologic framework;
- assess available groundwater resources and estimate post-1980 distributed natural groundwater recharge; and
- characterize the geothermal potential in the study area.
The Northwest Volcanic Aquifer Study is a joint project of the USGS Groundwater Resources Program and the USGS Geothermal Resource Investigations Project.
- Visit the Northwest Volcanic Aquifer Study website for more information
Hawaii Volcanic-Rock Aquifers
The volcanic-rock aquifers in Hawaii supply water to 1.36 million residents, diverse industries, and a large component of the U.S. military in the Pacific. The aquifers of individual Hawaiian Islands are isolated by sea water and have limited capacity. Fresh groundwater resources in Hawaii are therefore particularly vulnerable to impacts from human activity and climate change.
The Hawaii Volcanic-Rock Aquifer Study will provide an updated assessment of groundwater availability in Hawaii; assess the current condition of Hawaii volcanic-rock aquifers and show how groundwater resources have changed as a result of natural and human stresses; provide a tool to assess responses to future stresses; and evaluate the adequacy of the current data network for assessing groundwater resources in the future.
The study plan includes defining the hydrogeologic framework, quantifying components of the groundwater budget, and developing conceptual models of groundwater flow for Kauai, Oahu, Maui and the Big Island. Additionally, the plan includes construction of three separate whole-island numerical groundwater models for Kauai, Oahu, and Maui. The models together with input from the groundwater budget will be used to assess changes in groundwater availability in Hawaii.
Ozark Plateaus Aquifer System
The Ozark Plateaus aquifer system underlies parts of southern Missouri, southeastern Kansas, northwestern Arkansas, and northeastern Oklahoma. Building on previous USGS Ozark Regional Aquifer System Analysis (RASA) work, the Ozark Plateaus Aquifer System regional groundwater availability study will:
- quantify current groundwater resources,
- evaluate how these resources have changed over time, and
- provide the tools needed to simulate system response to future human and environmental stresses, including climate change.
The study will also provide information about changes in system-wide groundwater storage over time. The results of the study will be available for use by federal, state and local agencies to inform the evaluation and design of existing and new groundwater monitoring networks and other water-resource management decisions.
Learn more about this study:
- Read the report: Groundwater Availability in the Ozark Plateaus Aquifer System
- Visit the Ozark Plateaus study website for a complete bibliography and more information.
- Vew a video from the study: Groundwater, A Source To Streams in the Ozark Plateaus [YouTube]
Floridian Aquifer System
The Floridan Aquifer System covers approximately 100,000 square miles in the southeastern United States in Florida and portions of Georgia, Alabama, Mississippi, and South Carolina. The overall objective for the current study is to assess the availability of water in the Floridan Aquifer System. Achieving this objective includes quantifying the groundwater resource by creating water budgets both spatially and temporally as well as evaluating the groundwater resource changes over time. Additionally, tools will be provided to assess the future impacts of humans and environmental changes (such as climate) on the Floridan Aquifer System and aid in designing groundwater monitoring networks. Note: This study was restarted in late fiscal year 2013 after a short hiatus.C
Learn more about the outcomes of this study:
- Visit the Floridan study website for a complete bibliography and to learn more.
- Read the study summary report: Revised Hydrogeologic Framework of the Floridan Aquifer System in Florida and Parts of Georgia, Alabama, and South Carolina (PP 1807)
Pennsylvanian and Mississippian Aquifer System of the Appalachian Plateaus
Pennsylvanian- and Mississippian-age aquifers occupy approximately 86,000 square miles in the Appalachian Plateaus region of Pennsylvania, Ohio, Maryland, Virginia, West Virginia, Kentucky, Tennessee, Georgia, and Alabama. Groundwater in this aquifer system is essential for domestic supplies, energy resource development, and healthy aquatic ecosystems.
The USGS Appalachian Plateau Groundwater Availability Study will provide fundamental regional understanding of groundwater flow and availability in this Pennsylvanian- and Mississippian-age aquifer system. The Phase I activities of the regional study will:
- develop a basin-wide hydrogeologic framework,
- construct a regional hydrologic budget, and
- assess conceptual models of groundwater flow at multiple scales.
A better understanding of groundwater availability in the Plateaus plays a central role in sustained economic development of the region. This study will provide important data that can be used by USGS and other federal, state, and local scientists, water-resource managers, and policy makers to assess drinking-water resources, aquatic ecosystems, and energy resource development in the region.
- Visit the Pennsylvanian and Mississippian Aquifer study website for a complete bibliography and more information
Williston and Powder River Basins
The development of two nationally important energy-producing areas, the Williston structural basin (containing the Bakken Formation) and Powder River structural basin, provide a critical opportunity to study the water-energy nexus within a groundwater context. Large amounts of water are needed for energy development in these basins. The hydraulically connected aquifers in the regional Lower Teritary and Upper Cretaceous aquifer system are the shallowest, most accessible, and in some cases, the only potable aquifers within the Northern Great Plains.
The purpose of the Williston and Powder River Basins Groundwater Availability Study is to quantify current groundwater resources in this aquifer system, evaluate how these resources have changed over time, and provide tools to better understand system response to future anthropogenic demands and environmental stress.
Learn more about this study:
- Read the report: Groundwater availability of the Williston Basin | Fact sheet summary
- Visit the Williston and Powder River Basins study website for a complete bibliography and more information
- Get aquifer system geospatial data from the Williston and Powder River Basins study
Glacial Aquifer System
The glacial aquifer system is present in parts of 25 states. The glacial aquifer system contains the glacial sand and gravel principal aquifer, which is the largest water source for public supply and self-supplied industrial for any principal aquifer; it also is an important source for irrigation supply.
The Glacial Aquifer System Groundwater Availability Study will quantify current groundwater resources in the glacial aquifer system, evaluate how these resources have changed over time, and provide tools to better understand system response to future anthropogenic demands and environmental condition. The study is part of the Department of Interior WaterSMART initiative and will provide important information and analysis to stakeholders and decisionmakers in the study area.
Learn more about this study:
Northern Atlantic Coastal Plain Aquifer System
The objectives of the Northern Atlantic Coastal Plain Groundwater Availability study are three fold: 1) quantify the current groundwater resources of one of the Nation's priority aquifer systems; 2) evaluate how this resource has changed over time; and 3) provide the tools needed to forecast how this aquifer system may respond to future human and environmental stresses. The focus of the Northern Atlantic Coastal Plain Groundwater Availability study is on improving fundamental knowledge of the water budget of this aquifer system, including the flows, storage, and use by humans and the environment. An improved quantitative understanding of the aquifer system's water budget not only provides key information about water quantity, but also is essential for assessments of water quality and ecosystem health.
Learn more about this study:
- Report: Hydrogeology and Hydrologic Conditions of the Northern Atlantic Coastal Plain Aquifer System from Long Island, New York, to North Carolina
- Fact Sheet: Assessing groundwater availability in the Northern Atlantic Coastal Plain aquifer system
- Read the final report: Assessment of groundwater availability in the Northern Atlantic Coastal Plain aquifer system From Long Island, New York, to North Carolina
High Plains Aquifer
The High Plains groundwater availability study quantified current groundwater resources, evaluated changes in those resources over time, and provided tools to forecast how those resources respond to stresses from future human and environmental uses. The improved quantitative understanding of the basin's water balance provided by this USGS study not only provides key information about water quantity but also is a fundamental basis for many analyses of water quality and ecosystem health.
Learn more about the outcomes of this study:
- Read an overview of the study: Assessing groundwater availability in the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming (Fact Sheet 2010–3008)
- Watch a video [Youtube] about how the USGS uses 3D modeling to show how groundwater levels change over time in the High Plains aquifer.
- Visit the High Plains study website for a complete bibliography and to learn more.
- Get aquifer system geospatial data from the High Plains study
Columbia Plateau Regional Aquifer System
The Columbia Plateau Regional Aquifer System (CPRAS) covers over 50,000 square miles of eastern Oregon and Washington and western Idaho. The USGS conducted a study of the Columbia Plateau Regional Aquifer System to characterize the hydrologic status of the system, identify trends in groundwater storage and use, and quantify groundwater availability.
Learn more about the outcomes of this study:
- Watch a video about how the USGS uses 3D modeling to investigate groundwater in the Columbia Plateau Aquifer System.
- Explore the interactive 3D hydrogeologic model of the Columbia Plateau Regional Aquifer System.
- Visit the Columbia Plateau study website for a complete bibliography and to learn more.
- Get aquifer system geospatial data from the Columbia Plateau study
Mississippi Embayment Regional Aquifer Study
A groundwater flow model of the northern Mississippi embayment was developed to aid in answering questions about groundwater availability in a study area covering portions of seven states (Arkansas, Louisiana, Mississippi, Tennessee, Alabama, Missouri, and Kentucky).
Learn more about the outcomes of this study:
- Read the study summary report: The Mississippi Embayment Regional Aquifer Study (MERAS): Documentation of a groundwater-flow model constructed to assess water availability in the Mississippi Embayment (SIR 2009-5172)
- Visit the Mississippi Embayment study website for a complete bibliography and to learn more.
- Get aquifer system geospatial data from the Mississippi Embayment study
Great Basin Carbonate and Alluvial Aquifer System
The Great Basin Carbonate and Alluvial Aquifer System Water Availability Study quantified current groundwater resources, evaluated how those resources have changed over time, and developed tools to assess system responses to stresses from future human uses and climate variability.
Learn more about the outcomes of this study:
- Visit the Great Basin study website for a complete bibliography
- Read the study summary report: Conceptual Model of the Great Basin Carbonate and Alluvial Aquifer System (SIR 2010-5193)
- Get aquifer system geospatial data from the Great Basin study
Central Valley Aquifer
For more than 50 years, California's Central Valley has been one of the most productive agricultural regions in the world. Large increases in population have resulted in greater competition for water within the Central Valley and statewide. The USGS assessed the groundwater availability of the Central Valley and quantified the groundwater resources using a variety of tools. The ultimate benefit of this assessment will be a better understanding of how the system responds to current and future human and environmental stresses that will prove useful to water managers in their decision making process related to this valuable resource.
Learn more about the outcomes of this study:
- Read an overview of the study: California's Central Valley groundwater study (Fact Sheet 2009-3057)
- Listen to a podcast about California's vast Central Valley groundwater system and the USGS study findings.
- Read the study summary report: Groundwater availability of the Central Valley Aquifer, California (Professional Paper 1766)
- Visit the Central Valley study website
- Get aquifer system geospatial data from the Central Valley study
North and South Carolina Atlantic Coastal Plain Aquifer System
Increased groundwater withdrawals related to population growth and drought of the last few years have emphasized the need for more accurate, detailed information describing the groundwater resources in the Coastal Plain in North and South Carolina. In January 2004, the U.S. Geological Survey began a study to combine and update the Regional Aquifer System Analysis (RASA) models of North and South Carolina in order to improve the understanding of groundwater availability in the North and South Carolina Atlantic Coastal Plain aquifer system.
Learn more about the outcomes of this study:
- Read the study summary report: Groundwater Availability in the Atlantic Coastal Plain of North and South Carolina (Professional Paper 1773)
- Visit the North and South Carolina Atlantic Coastal Plain study website for a complete bibliography and to learn more.
Denver Basin Aquifers
The Denver groundwater basin is an important and non-renewable source of water for municipal, industrial, and domestic uses in the Denver and Colorado Springs metropolitan areas. The USGS conducted a groundwater availability of the Denver Groundwater Basin to enhance our understanding of regional groundwater flow and aquifer storage, to evaluate current conditions, and to predict future conditions.
Learn more about the outcomes of this study:
- Visit the Denver Basin study website for a complete bibliography and to learn more.
- Read the study summary report: Groundwater Availability of the Denver Basin Aquifer System, Colorado (USGS Professional Paper 1770)
Middle Rio Grande Basin Study - Initial Proof of Concept Study
The Santa Fe Group aquifer system in Central New Mexico is the main source of municipal water for the region. The USGS Middle Rio Grande Basin Study was a 6-year effort (1995-2001) to improve the understanding of the hydrology, geology, and land-surface characteristics of the Middle Rio Grande Basin in order to provide the scientific information needed for water-resources management. This initial proof of concept study was conducted prior to the development of the strategy outlined in Circular 1323 and served as as a precursor to current GWRP regional groundwater availability studies.
Learn more about the outcomes of this study:
- Read an overview of the study: Ground-water resources of the Middle Rio Grande Basin (Fact Sheet 088-02) (PDF)
- Read the study summary report: Ground-water resources of the Middle Rio Grande Basin, New Mexico (Circular 1222)
- Visit the Middle Rio Grande Basin study website for a complete bibliography and to learn more.
Great Lakes Basin Pilot Study - Lake Michigan Basin
In 2005, USGS embarked on a pilot study of water availability in the Great Lakes Basin. The pilot study focused on understanding the dynamics of the water resources in the basin in terms of the flows and yields of both groundwater and surface water and demonstrated the importance of water-use data in quantifying water availability.
Learn more about the outcomes of this study:
- Read the study summary report: Water Availability and Use Pilot: A Multiscale Assessment in the U.S. Great Lakes Basin (Professional Paper 1778)
- Visit the Great Lakes Basin Pilot Study website for a complete bibliography and to learn more.
Southwest Alluvial Basins Project - Groundwater Methods Development
As groundwater is increasingly developed in the Lower Colorado River Basin, information on effects are needed for assessment of water availability. From 2006 to 2009, this project made assessments of groundwater availability and conditions in the Lower Colorado River Basin. A special emphasis was placed on development of methods of assessment and display of groundwater conditions that might be extended to other regions of the country.
Learn more about the outcomes of this study: