This dataset depicts groundwater level (expressed as elevation in feet amsl) at selected monitoring locations (wells) , by season and year. Other information on the monitoring location is also included. Water level monitoring locations and measurements used are selected based on measurement date and well construction information, where available, and approximate groundwater levels in the unconfined to uppermost semi-confined aquifers. This dataset was created to assist state and local agencies in assessing the status of groundwater levels statewide for recent seasons/years and in relation to other periods. For more information on this service, please contact gis@water.ca.gov

These contours represent water level change in the shallow aquifer in Lahontan Valley from 1992 - 2012 based on depth-to-groundwater measurements made in 73 wells in 1992 and 2012, with limited measurements made in 2013. Measurements collected in 2013 were used to develop the contours only in limited cases where the measurement well was being pumped or was inaccessible in 2012. Water-level change in the shallow aquifer was determined by differencing measurements made in 1992 with current measurements. The difference values were used to interpolate a change surface and contours were developed from that surface.

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 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 2000 to 2005, 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. Water-level declines occurred in parts of the High Plains aquifer soon after the onset of substantial irrigation with groundwater (about 1950). 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 2000 and 2005 and from some additional wells in New Mexico, which were measured in 2001, 2002, 2006, and 2007. 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.

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 dataset consists of three sets of water-level measurements. The first set are the supplemental water-level measurements for 547 wells screened in the High Plains aquifer, not located in New Mexico, measured in predevelopment and at least once for 2015 through 2018, but not for 2019. These supplemental measurements were used to calculate historical water-level change values for predevelopment to 2015 to 2018 and approximate water-level change values from predevelopment to 2019 to substantiate the map of water-level changes, predevelopment (about 1950) to 2019 (figure 1 in https://doi.org/10.3133/sir20235143). The water-level measurements used to calculate historical water-level changes from predevelopment are (1) 218 wells measured in predevelopment and in 2018, but not measured in 2019, which are used to calculate water-level change, predevelopment to 2018, (2) 152 wells measured in predevelopment and in 2017, but not measured in 2018 or 2019, which are used to calculate water-level change, predevelopment to 2017, (3) 117 wells measured in predevelopment and in 2016, but not measured in 2017, 2018, or 2019, which are used to calculate water-level change, predevelopment to 2016, and (4) 60 wells measured in predevelopment and in 2015, but not measured in 2016, 2017, 2018, or 2019, which are used to calculate water-level change, predevelopment to 2015. The second and third sets of water-level measurements were used to approximate water-level change, predevelopment to 2019, but did not have predevelopment water-level measurements. The second set included 292 wells, which were located in areas where water level declines from predevelopment to 1980 were 50 feet or more (Luckey and others, 1981; Cederstrand and Becker, 1999) and were measured in 1980 and in 2019, but not measured in the predevelopment period. For these wells, approximate water-level changes, predevelopment to 2019, were calculated as the starting value of the polygon range (for example 50 ft for the polygon of declines from 50 to 75 ft) from the map of water-level change, predevelopment to 1980, plus measured water-level change from 1980 to 2019. The third set of water-level measurements used to calculate approximate water-level changes were from 1,213 wells that were measured on or before 6/15/1978 (termed post-development) and in 2019, but not in the predevelopment period. For these wells, approximate water-level changes, predevelopment to 2019, were calculated as the water level, 2019, minus water level, post-development.

This dataset depicts groundwater level (expressed as elevation) at selected monitoring locations (wells), by season and year. Other information on the monitoring location is also included. Water level monitoring locations and measurements used are selected based on measurement date and well construction information, where available, and approximate groundwater levels in the unconfined to uppermost semi-confined aquifers.

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 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 dataset consists of a raster of water-level changes for the High Plains aquifer, predevelopment (about 1950) to 2015. This digital dataset was created using water-level measurements from 3,092 wells measured in both the predevelopment period (about 1950) and in 2015, the latest available static water level measured in 2011 to 2014 from 72 wells in New Mexico and Wyoming, and using other published information on water-level change in areas with few water-level measurements. The map was reviewed for consistency with the relevant data at a scale of 1:1,000,000.