NAWQA High Plains Regional Groundwater Study Completed
As part of the National Water Quality Assessment Program (NAWQA), the USGS has evaluated ground-water quality in the High Plains aquifer system. Beginning in 1999 and continuing for a period of 6 years, the High Plains Regional Groundwater Study intensively investigated the quality of groundwater resources within the study area. Water quality impairment coupled with water-level declines focus concern on the continued sustainability of this Nationally important groundwater resource.
USGS Circular 1337 contains the major findings of a 1999–2004 assessment of water quality in the High Plains aquifer.
The High Plains aquifer system
- underlies 175,000 square miles in parts of eight States (CO, KS, NE, NM, OK, SD, TX, and WY).
- approximately 27 percent of the irrigated land in the United States
- about 30 percent of the groundwater used for irrigation in the U.S. is pumped from the High Plains aquifer. Irrigation withdrawals in 2000 were 17 billion gallons per day. In 2000, 1.9 million people were supplied by groundwater from the High Plains aquifer with total public-supply withdrawals of 315 million gallons per day.
The quality of water in the High Plains aquifer generally is suitable for irrigation use but, in many places, the water does not meet U.S. Environmental Protection Agency drinking-water standards with respect to several dissolved constituents (dissolved solids/salinity, fluoride, chloride, and sulfate). Only sparsely scattered water-quality data are available for pesticides, volatile organic compounds, and trace metals in the High Plains aquifer system. Nutrient data are available, to a varying degree, across the aquifer.
Study Area Setting
The High Plains aquifer system underlies 174,000 square miles in parts of eight States. The aquifer is a water-table aquifer that is composed mainly of sand and gravel with some silt and clay deposits.
The Ogallala Formation, which underlies about 80 percent of the High Plains, is the principle geologic unit forming the aquifer. The maximum saturated thickness of the High Plains aquifer is about 1,000 feet, and the average saturated thickness of the aquifer is about 200 feet.
The Ogallala Formation was deposited by braided streams flowing eastward from the ancestral Rocky Mountains that deposited random (heterogeneous) sequences of gravel, sand, silt, and clay. Groundwater generally flows from west to east and discharges naturally to streams and springs, and by evapotranspiration in areas where the water table is near land surface. Pumping from more than 165,000 wells is another important mechanism of ground-water discharge.
Precipitation is the principle source of recharge to the aquifer. Estimates of recharge rates range from 0.024 inches per year in parts of Texas to 6 inches per year in areas of dune sand in Kansas and Nebraska.
Several major river systems cross the High Plains aquifer from west to east. These river systems include the Platte, Republican, Arkansas, Cimarron, and Canadian Rivers. The alluvial-aquifer system associated with each river is also an important local water resource.
The High Plains aquifer is in hydraulic connection (water can move from the High Plains aquifer to the alluvial sediments associated with the rivers and visa versa) with the major river systems crossing the aquifer.
During low-flow periods, water in the rivers is almost entirely derived from ground-water discharge. Land use within the Study Unit primarily is agriculture and rangeland.
Regional variability of water-level changes in the High Plains aquifer results from large regional differences in climate, soils, land use, and ground-water withdrawals for irrigation. Substantial pumping of the High Plains aquifer for irrigation since the 1940's has resulted in water-level declines of nearly 150 feet in some parts of the aquifer.
Study Summary
USGS Circular 1337 contains the major findings of a 1999–2004 assessment of water quality in the High Plains aquifer.
Below are other science projects associated with this project.
National Water-Quality Assessment (NAWQA)
NAWQA Upper Colorado River Basin Study
NAWQA South Platte River Basin Study
Datasets from maps of water-level changes in the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming, predevelopment (about 1950) to 2015
High Plains Aquifer Groundwater Network
The High Plains Regional Groundwater Level Monitoring Network contains water levels and well information from selected wells measured annually by the USGS and numerous Federal, State, and local water-resources agencies.
Water-level changes in the High Plains aquifer, Republican River Basin in Colorado, Kansas, and Nebraska, 2002 to 2015
Below are publications associated with this project.
Water Quality in the High Plains Aquifer, Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming, 1999-2004
Water Quality in the High Plains Aquifer, Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming, 1999-2004
Hydrogeology, Chemical Characteristics, and Transport Processes in the Zone of Contribution of a Public-Supply Well in York, Nebraska
Assessing the vulnerability of public-supply wells to contamination—High Plains Aquifer near York, Nebraska
Susceptibility to enhanced chemical migration from depression-focused preferential flow, High Plains aquifer
Water-Quality Assessment of the High Plains Aquifer, 1999-2004
Hydrogeologic Setting and Ground-Water Flow in the Leetown Area, West Virginia
Vertical gradients in water chemistry and age in the Northern High Plains Aquifer, Nebraska, 2003
Ground-Water Quality of the Northern High Plains Aquifer, 1997, 2002-04
Nitrous oxide fluxes from cultivated areas and rangeland: U.S. High Plains
Climate variability controls on unsaturated water and chemical movement, High Plains aquifer, USA
Vulnerability of recently recharged ground water in the High Plains aquifer to nitrate contamination
Storage and transit time of chemicals in thick unsaturated zones under rangeland and irrigated cropland, High Plains, United States
- Overview
As part of the National Water Quality Assessment Program (NAWQA), the USGS has evaluated ground-water quality in the High Plains aquifer system. Beginning in 1999 and continuing for a period of 6 years, the High Plains Regional Groundwater Study intensively investigated the quality of groundwater resources within the study area. Water quality impairment coupled with water-level declines focus concern on the continued sustainability of this Nationally important groundwater resource.
USGS Circular 1337 contains the major findings of a 1999–2004 assessment of water quality in the High Plains aquifer.
The High Plains aquifer system
- underlies 175,000 square miles in parts of eight States (CO, KS, NE, NM, OK, SD, TX, and WY).
- approximately 27 percent of the irrigated land in the United States
- about 30 percent of the groundwater used for irrigation in the U.S. is pumped from the High Plains aquifer. Irrigation withdrawals in 2000 were 17 billion gallons per day. In 2000, 1.9 million people were supplied by groundwater from the High Plains aquifer with total public-supply withdrawals of 315 million gallons per day.
The quality of water in the High Plains aquifer generally is suitable for irrigation use but, in many places, the water does not meet U.S. Environmental Protection Agency drinking-water standards with respect to several dissolved constituents (dissolved solids/salinity, fluoride, chloride, and sulfate). Only sparsely scattered water-quality data are available for pesticides, volatile organic compounds, and trace metals in the High Plains aquifer system. Nutrient data are available, to a varying degree, across the aquifer.
Study Area Setting
The High Plains aquifer system underlies 174,000 square miles in parts of eight States. The aquifer is a water-table aquifer that is composed mainly of sand and gravel with some silt and clay deposits.
The Ogallala Formation, which underlies about 80 percent of the High Plains, is the principle geologic unit forming the aquifer. The maximum saturated thickness of the High Plains aquifer is about 1,000 feet, and the average saturated thickness of the aquifer is about 200 feet.
The Ogallala Formation was deposited by braided streams flowing eastward from the ancestral Rocky Mountains that deposited random (heterogeneous) sequences of gravel, sand, silt, and clay. Groundwater generally flows from west to east and discharges naturally to streams and springs, and by evapotranspiration in areas where the water table is near land surface. Pumping from more than 165,000 wells is another important mechanism of ground-water discharge.
Precipitation is the principle source of recharge to the aquifer. Estimates of recharge rates range from 0.024 inches per year in parts of Texas to 6 inches per year in areas of dune sand in Kansas and Nebraska.
Several major river systems cross the High Plains aquifer from west to east. These river systems include the Platte, Republican, Arkansas, Cimarron, and Canadian Rivers. The alluvial-aquifer system associated with each river is also an important local water resource.
The High Plains aquifer is in hydraulic connection (water can move from the High Plains aquifer to the alluvial sediments associated with the rivers and visa versa) with the major river systems crossing the aquifer.
During low-flow periods, water in the rivers is almost entirely derived from ground-water discharge. Land use within the Study Unit primarily is agriculture and rangeland.
Regional variability of water-level changes in the High Plains aquifer results from large regional differences in climate, soils, land use, and ground-water withdrawals for irrigation. Substantial pumping of the High Plains aquifer for irrigation since the 1940's has resulted in water-level declines of nearly 150 feet in some parts of the aquifer.
Study Summary
USGS Circular 1337 contains the major findings of a 1999–2004 assessment of water quality in the High Plains aquifer.
- Science
Below are other science projects associated with this project.
National Water-Quality Assessment (NAWQA)
Our surface water, groundwater, and aquatic ecosystems are priceless resources, used by people across the Nation for drinking, irrigation, industry, and recreation. The National Water-Quality Assessment (NAWQA) Project is a leading source of scientific data and knowledge for development of science-based policies and management strategies to improve and protect our water resources.NAWQA Upper Colorado River Basin Study
The USGS implemented the National Water-Quality Assessment (NAWQA) Program in 1991 to support national, regional, and local information needs and decisions related to water-quality management and policy. Shaped by and coordinated with ongoing efforts of other Federal, State, and local agencies, the NAWQA Program is designed to answer: What is the condition of our Nation’s streams and ground water...NAWQA South Platte River Basin Study
The South Platte River Basin study, conducted as part of the U.S. Geological Survey's National Water-Quality Assessment Program, combines information on water chemistry, physical characteristics, stream habitat, and aquatic life to provide science-based insights for current and emerging water issues in surface waters (streams, rivers, reservoirs) and groundwaters of the South Platte River Basin... - Data
Datasets from maps of water-level changes in the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming, predevelopment (about 1950) to 2015
Dataset of wells used to create map and raster of map of water-level changes in the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming, predevelopment (about 1950) to 2015 and 2013 to 2015.High Plains Aquifer Groundwater Network
The High Plains Regional Groundwater Level Monitoring Network contains water levels and well information from selected wells measured annually by the USGS and numerous Federal, State, and local water-resources agencies.
- Maps
Water-level changes in the High Plains aquifer, Republican River Basin in Colorado, Kansas, and Nebraska, 2002 to 2015
The High Plains aquifer underlies 111.8 million acres (about 175,000 square miles) in parts of eight States—Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. More than 95 percent of the water withdrawn from the High Plains aquifer is used for irrigation. Water-level declines began in parts of the High Plains aquifer soon after the beginning of substantial irrigati - Publications
Below are publications associated with this project.
Water Quality in the High Plains Aquifer, Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming, 1999-2004
This report contains the major findings of a 1999-2004 assessment of water quality in the High Plains aquifer. It is one of a series of reports by the National Water-Quality Assessment (NAWQA) Program that present major findings for principal and other aquifers and major river basins across the Nation. In these reports, water quality is discussed in terms of local, regional, State, and national isAuthorsJason J. Gurdak, Peter B. McMahon, Kevin Dennehy, Sharon L. QiFilter Total Items: 35Water Quality in the High Plains Aquifer, Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming, 1999-2004
This report contains the major findings of a 1999-2004 assessment of water quality in the High Plains aquifer. It is one of a series of reports by the National Water-Quality Assessment (NAWQA) Program that present major findings for principal and other aquifers and major river basins across the Nation. In these reports, water quality is discussed in terms of local, regional, State, and national isAuthorsJason J. Gurdak, Peter B. McMahon, Kevin Dennehy, Sharon L. QiHydrogeology, Chemical Characteristics, and Transport Processes in the Zone of Contribution of a Public-Supply Well in York, Nebraska
In 2001, the U.S. Geological Survey, as part of the National Water Quality Assessment (NAWQA) Program, initiated a topical study of Transport of Anthropogenic and Natural Contaminants (TANC) to PSW (public-supply wells). Local-scale and regional-scale TANC study areas were delineated within selected NAWQA study units for intensive study of processes effecting transport of contaminants to PSWs. ThiAuthorsMatthew K. Landon, Brian R. Clark, Peter B. McMahon, Virginia L. McGuire, Michael J. TurcoAssessing the vulnerability of public-supply wells to contamination—High Plains Aquifer near York, Nebraska
The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program found, in studies from 1991 to 2001, low levels of mixtures of contaminants in ground water near the water table in urban areas across the Nation. Although contaminants were detected less frequently in deeper ground water typically developed for public supply the proximity of contaminant mixtures to underlying public-waAuthorsMartha L. Jagucki, Matthew K. Landon, Brian R. Clark, Sandra M. EbertsSusceptibility to enhanced chemical migration from depression-focused preferential flow, High Plains aquifer
Aquifer susceptibility to contamination is controlled in part by the inherent hydrogeologic properties of the vadose zone, which includes preferential-flow pathways. The purpose of this study was to investigate the importance of seasonal ponding near leaky irrigation wells as a mechanism for depression-focused preferential flow and enhanced chemical migration through the vadose zone of the High PlAuthorsJason J. Gurdak, Michelle Ann Walvoord, Peter B. McMahonWater-Quality Assessment of the High Plains Aquifer, 1999-2004
Water quality of the High Plains aquifer was assessed for the period 1999-2004 as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program. This effort represents the first systematic regional assessment of water quality in this nationally important aquifer. A stratified, nested group of studies was designed to assess linkages between the quality of water recharging tAuthorsPeter B. McMahon, Kevin F. Dennehy, Breton W. Bruce, Jason J. Gurdak, Sharon L. QiHydrogeologic Setting and Ground-Water Flow in the Leetown Area, West Virginia
The Leetown Science Center is a research facility operated by the U.S. Geological Survey that occupies approximately 455-acres near Kearneysville, Jefferson County, West Virginia. Aquatic and fish research conducted at the Center requires adequate supplies of high-quality, cold ground water. Three large springs and three production wells currently (in 2006) supply water to the Center. The recent cAuthorsMark D. Kozar, David J. Weary, Katherine S. Paybins, Herbert A. PierceVertical gradients in water chemistry and age in the Northern High Plains Aquifer, Nebraska, 2003
The northern High Plains aquifer is the primary source of water used for domestic, industrial, and irrigation purposes in parts of Colorado, Kansas, Nebraska, South Dakota, and Wyoming. Despite the aquifer’s importance to the regional economy, fundamental ground-water characteristics, such as vertical gradients in water chemistry and age, remain poorly defined. As part of the U.S. Geological SurveAuthorsP. B. McMahon, J.K. Böhlke, C. P. CarneyGround-Water Quality of the Northern High Plains Aquifer, 1997, 2002-04
An assessment of ground-water quality in the northern High Plains aquifer was completed during 1997 and 2002-04. Ground-water samples were collected at 192 low-capacity, primarily domestic wells in four major hydrogeologic units of the northern High Plains aquifer-Ogallala Formation, Eastern Nebraska, Sand Hills, and Platte River Valley. Each well was sampled once, and water samples were analyzedAuthorsJennifer S. Stanton, Sharon L. QiNitrous oxide fluxes from cultivated areas and rangeland: U.S. High Plains
Concentration profiles of N2O, a greenhouse gas, and the conservative trace gases SF6 and the chlorofluorocarbons CFC-11, CFC-12, CFC-113, and were measured periodically through thick vadose zones at nine sites in the U.S. High Plains. The CFC and SF6 measurements were used to calibrate a one-dimensional gas diffusion model, using the parameter identification program UCODE. The calibrated model waAuthorsEdwin P. Weeks, Peter B. McMahonClimate variability controls on unsaturated water and chemical movement, High Plains aquifer, USA
Responses in the vadose zone and groundwater to interannual, interdecadal, and multidecadal climate variability have important implications for groundwater resource sustainability, yet they are poorly documented and not well understood in most aquifers of the USA. This investigation systematically examines the role of interannual to multidecadal climate variability on groundwater levels, deep infiAuthorsJ.J. Gurdak, R. T. Hanson, P. B. McMahon, B. W. Bruce, J.E. McCray, G.D. Thyne, R.C. ReedyVulnerability of recently recharged ground water in the High Plains aquifer to nitrate contamination
Nitrate concentrations greater than background levels have been detected in ground water of the High Plains aquifer. Empirically based models and corresponding maps were developed that predict the vulnerability of the aquifer to nonpoint-source nitrate contamination. The models predict the probability of detecting nitrate concentrations larger than 4 milligrams per liter in ground water of the HigAuthorsJason J. Gurdak, Sharon L. QiStorage and transit time of chemicals in thick unsaturated zones under rangeland and irrigated cropland, High Plains, United States
In 2000-2002, three rangeland and six irrigated sites were instrumented to assess the storage and transit time of chemicals in thick (15 to 50 m) unsaturated zones (UZ) in the High Plains. These processes are likely to influence relations between land use and groundwater quality, yet they have not been documented systematically in the High Plains. Land use and climate were important controls on thAuthorsP. B. McMahon, K. F. Dennehy, B. W. Bruce, J.K. Böhlke, R. L. Michel, J.J. Gurdak, D.B. Hurlbut