This raster data set represents water-level change in the High Plains aquifer of the United States from 2005 to 2009, in feet. The High Plains aquifer underlies 112.6 million acres (176,000 square miles) in parts of eight States: Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. The aquifer's saturated thickness ranges from near zero to about 1,200 feet (Weeks and Gutentag, 1981). Water-level declines occurred in parts of the High Plains aquifer soon after the onset of substantial increases in irrigation with groundwater (about 1950) (Luckey and others, 1981; Gutentag and others, 1984). This data set was generated in ESRI ArcInfo Workstation Version 9.3, which is a geographic information system (GIS), using water-level-change data from wells measured in 2005 and 2009 and from some additional wells in New Mexico, which were measured in 2006, 2007, and 2008. For this data set, areas of no substantial change were designated as areas where water-level change was between a rise of 1 foot and a decline of 1 foot; the raster was set to zero in the areas of no substantial change. REFERENCES CITED -- Gutentag, E.D., Heimes, F.J., Krothe, N.C., Luckey, R.R., and Weeks, J.B., 1984, Geohydrology of the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Professional Paper 1400-B, 63 p. Luckey, R.R., Gutentag, E.D., and Weeks, J.B., 1981, Water-level and saturated-thickness changes, predevelopment to 1980, in the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Hydrologic Investigations Atlas HA-652, 2 sheets, scale 1:2,500,000. Weeks, J.B., and Gutentag, E.D., 1981, Bedrock geology, altitude of base, and 1980 saturated thickness of the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Hydrologic Investigations Atlas HA-648, 2 sheets, scale 1:2,500,000.

This raster data set represents water-level change in the High Plains aquifer of the United States from 1995 to 2000, in feet. The High Plains aquifer underlies 112.6 million acres (176,000 square miles) in parts of eight States: Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. The aquifer's saturated thickness ranges from near zero to about 1,200 feet (Weeks and Gutentag, 1981). Water-level declines occurred in parts of the High Plains aquifer soon after the onset of substantial irrigation with groundwater (about 1950) (Luckey and others, 1981; Gutentag and others, 1984). This data set was generated in a geographic information system from water-level-change data from wells measured in 1995 and 2000 and from some additional wells in New Mexico, which were measured in 1996, 1997, 2001, and 2002. For this data set, areas of no substantial change were designated as areas where water-level change was between a rise of 1 foot and a decline of 1 foot; the raster was set to zero in the areas of no substantial change. REFERENCES CITED -- Gutentag, E.D., Heimes, F.J., Krothe, N.C., Luckey, R.R., and Weeks, J.B., 1984, Geohydrology of the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Professional Paper 1400-B, 63 p. Luckey, R.R., Gutentag, E.D., and Weeks, J.B., 1981, Water-level and saturated-thickness changes, predevelopment to 1980, in the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Hydrologic Investigations Atlas HA-652, 2 sheets, scale 1:2,500,000. Weeks, J.B., and Gutentag, E.D., 1981, Bedrock geology, altitude of base, and 1980 saturated thickness of the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Hydrologic Investigations Atlas HA-648, 2 sheets, scale 1:2,500,000.

This raster data set represents water-level change in the High Plains aquifer of the United States from 1980 to 1995, in feet. The High Plains aquifer underlies 112.6 million acres (176,000 square miles) in parts of eight States: Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. The aquifer's saturated thickness ranges from near zero to about 1,200 feet (Weeks and Gutentag, 1981). Water-level declines occurred in parts of the High Plains aquifer soon after the onset of substantial irrigation with groundwater (about 1950) (Luckey and others, 1981; Gutentag and others, 1984). This data set was generated in ESRI ArcInfo Workstation Version 9.3, which is a geographic information system (GIS), using water-level-change data from wells measured in 1980 and 1995 and from some additional wells in New Mexico, which were measured in 1996 and 1997. For this data set, areas of no substantial change were designated as areas where water-level change was between a rise of 3 feet and and decline of 3 feet; the raster was set to zero in the areas of no substantial change. REFERENCES CITED -- Gutentag, E.D., Heimes, F.J., Krothe, N.C., Luckey, R.R., and Weeks, J.B., 1984, Geohydrology of the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Professional Paper 1400-B, 63 p. Luckey, R.R., Gutentag, E.D., and Weeks, J.B., 1981, Water-level and saturated-thickness changes, predevelopment to 1980, in the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Hydrologic Investigations Atlas HA-652, 2 sheets, scale 1:2,500,000. Weeks, J.B., and Gutentag, E.D., 1981, Bedrock geology, altitude of base, and 1980 saturated thickness of the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Hydrologic Investigations Atlas HA-648, 2 sheets, scale 1:2,500,000.

The High Plains aquifer extends from about 32 degrees to almost 44 degrees north latitude and from about 96 degrees 30 minutes to 106 degrees west longitude. The aquifer underlies about 175,000 square miles in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital data set is comprised of water-level measurements from 7,698 wells measured in both 2015 and 2017, which were used to map water-level changes, 2015 to 2017. The map was reviewed for consistency with the relevant data at a scale of 1:1,000,000.

The High Plains aquifer extends from south of about 32 degrees to almost 44 degrees north latitude and from about 96 degrees 30 minutes to 106 degrees west longitude. The aquifer underlies about 175,000 square miles in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital data set is the water-level measurements from 7,526 wells measured in both 2013 and 2015, which was used to map water-level changes, 2013 to 2015. The map was reviewed for consistency with the relevant data at a scale of 1:1,000,000.

The High Plains aquifer extends from south of about 32 degrees to almost 44 degrees north latitude and from about 96 degrees 30 minutes to 106 degrees west longitude. The aquifer underlies about 175,000 square miles in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital data set contains the water-level measurements from 3,092 wells measured in both predevelopment (about 1950) and 2015 and from 72 wells, which are located in New Mexico and Wyoming and were measured in predevelopment and at least one time from 2011 to 2014. These water-level measurements were used to map water-level changes, predevelopment (about 1950) to 2015. The map was reviewed for consistency with the relevant data at a scale of 1:1,000,000.

The High Plains aquifer extends from approximately 32 to 44 degrees north latitude and from 96 degrees 30 minutes to 106 degrees west longitude. The aquifer underlies about 175,000 square miles in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital data set contains water-level measurements from wells screened in the High Plains aquifer and measured in both predevelopment (about 1950) and for 2017. There were 2,928 wells measured in both predevelopment (about 1950) and 2017 as well as 63 wells located in New Mexico, which were measured in predevelopment and at least once between 2013 and 2016. These water-level measurements were used to map water-level changes, predevelopment (about 1950) to 2017. The map was reviewed for consistency with the relevant data at a scale of 1:1,000,000.

The High Plains aquifer extends from south of about 32 degrees to almost 44 degrees north latitude and from about 96 degrees 30 minutes to 106 degrees west longitude. The aquifer underlies about 175,000 square miles in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital data set is the supplemental water-level measurements from 1,897 wells located in Colorado, Kansas, Nebraska, Oklahoma, South Dakota, or Texas and measured in various time periods, which were used to historical water-level change values for predevelopment to 2011 to 2014 and approximate water-level change values from predevelopment to 2015 to substantiate the map of water-level changes, predevelopment (about 1950) to 2015. The water-level measurements and the calculated historical water-level change values are (1) 219 wells measured in predevelopment and in 2014, but not measured in 2015, which are used to calculate water-level change, predevelopment to 2014, (2) 135 wells measured in predevelopment and in 2013, but not measured in 2014 or 2015, which are used to calculate water-level change, predevelopment to 2013, (3) 94 wells measured in predevelopment and in 2012, but not measured in 2013, 2014, or 2015, which are used to calculate water-level change, predevelopment to 2012, and (4) 57 wells measured in predevelopment and in 2011, but not measured in 2012, 2013, 2014, or 2015, which are used to calculate water-level change, predevelopment to 2011. One of two sets of water-level measurements used to calculate an approximate water-level-change values from predevelopment to 2015 are from 302 wells that are located in the areas where water level declines from predevelopment to 1980 (Luckey and others, 1981; Cederstrand and Becker, 1999) were 50 feet or more and were measured in 1980 and in 2015, but not measured in the predevelopment period. For these wells, approximate water-level change is calculate as the beginning contour interval from the map of water-level change, predevelopment to 1980 plus water-level change from 1980 to 2015. The second set of water-level measurements used to calculate approximate water-level change are from 1,090 wells that were measured on or before 6/15/1978 (termed post-development) and in 2015, but not in the predevelopment period. For these wells, approximate water-level change, predevelopment to 2015, is calculate as the water level, 2015, minus water level, post-development.

The High Plains aquifer extends from approximately 32 to 44 degrees north latitude and from 96 degrees 30 minutes to 106 degrees west longitude. The aquifer underlies about 175,000 square miles in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital dataset contains water-level measurements from wells screened in the High Plains aquifer and measured in both predevelopment (about 1950) and for 2019. There were 2,741 wells measured in both predevelopment (about 1950) and 2019 as well as 71 wells located in New Mexico, which were measured in predevelopment and at least once between 2015 and 2018. These water-level measurements were used to map water-level changes, predevelopment (about 1950) to 2019. The map was reviewed for consistency with the relevant data at a scale of 1:1,000,000.