Fischer, Brian C. McGuire, Virginia L. 1999 1.0 map Open-File Report USGS OFR 99-197 Lincoln, NE U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?ofr99-197_wlc80_95 This data set consists of digital water-level-change contours for the High Plains aquifer in the central United States, 1980 to 1995. The High Plains aquifer extends from south of 32 degrees to almost 44 degrees north latitude and from 96 degrees 30 minutes to 104 degrees west longitude. The aquifer underlies about 174,000 square miles in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital data set was created from 5,892 wells measured in both 1980 and 1995. The water-level-change contours were drawn manually on mylar. The contours were converted to a digital map at a scale of 1:1,250,000. The data should not be used at scales larger than 1:1,250,000. This data set was created to document the original map (McGuire, V.L. and Sharpe, J.B., 1997) produced by the High Plains Water-level Monitoring project and to make available the data on this map for use with geographic information systems. Introduction -- The information provided in this introduction is found in U.S. Geological Survey Professional Paper 1400-B (Gutentag and others, 1984). This data set consists of digital water-level-change contours for the High Plains aquifer in the United States, 1980 to 1995. The High Plains aquifer, which underlies about 174,000 square miles in parts of eight states, is the principal water source in one of the nation's major agricultural areas. In 1980, about 170,000 wells pumped water from the aquifer to irrigate about 13 million acres. The High Plains aquifer is a regional water-table aquifer consisting mostly of near-surface sand-and-gravel deposits. In 1980, the maximum saturated thickness of the aquifer was about 1,000 feet and averaged about 200 feet. Hydraulic conductivity and specific yield of the aquifer depend on sediment types, which vary significantly both horizontally and vertically. Hydraulic conductivity ranged from less than 25 to greater than 300 feet per day and averaged 60 feet per day. Specific yields ranged from less than 10 to 30 percent and averaged about 15 percent. The High Plains aquifer boundaries were determined by erosional extent of associated geologic units and by hydraulic and physiographic boundaries where the High Plains aquifer extends eastward from the Great Plains physiographic province (Fenneman, 1931). In most of the area, the erosional extent of the hydraulically connected Tertiary and Quaternary deposits were used as the aquifer boundary. In eastern Nebraska, streams and physiographic boundaries were used as the aquifer boundary. Reviews Applied to Data -- This electronic report was subjected to the same review standards that apply to all U.S. Geological Survey reports. Reviewers were asked to check the topological consistency, tolerances, attribute frequencies and statistics, projection, and geographic extent. Reviewers were given digital data sets for checking against the source maps to verify the linework and attributes. The reviewers checked the metadata files for completeness and accuracy. Related Spatial and Tabular Data Sets -- Predevelopment to 1980 water-level change digital data set 1980 to 1994 water-level change digital data set 1980 to 1996 water-level change digital data set 1980 to 1997 water-level change digital data set References Cited -- Fenneman, N.M., 1931, Physiography of western United States (1st ed.): New York, McGraw-Hill, 534 p. 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. McGuire, V.L., and Sharpe, J.B., 1997, Water-level changes in the High Plains aquifer, 1980 to 1995: U.S. Geological Survey Factsheet FS-068-97, 4 p. 1999 1995 Complete None Planned -106.016 -96.260 43.806 31.653 none aquifers ground water groundwater High Plains aquifer Ogallala Formation Ogallala aquifer water-level change inlandWaters none High Plains Great Plains region western U.S. none none Virginia L. McGuire U.S. Geological Survey Hydrologist mailing address

Room 406 Federal Bldg., 100 Centennial Mall North

Lincoln NE 68508 USA 1-888-275-8747 (402) 437-5139 Webmaster@ne20dnelnc.cr.usgs.gov http://water.usgs.gov/GIS/browse/ofr99-197_wlc80_95.gif A browse image of the water-level-change contours data set for the High Plains aquifer, 1980 to 1995. GIF McGuire, Virginia L. and Sharpe, Jennifer B. Public UNCLASSIFIED None dgux, R4.11MU04, AViiON UNIX ARC/INFO version 7.1.1 Polygon and chain-node topology present. This data set includes the water-level-change contours produced by McGuire and Sharpe(1997) in U.S. Geological Survey Factsheet FS-068-97. None 0.003 inches RMS error, in inches (digitized data in inches, on coversion to Albers Equal Area Conic meters) none A mylar map of the water-level-change contours, 1980 to 1995 was digitized using ARC/INFO. 1995 The coverage was projected to Albers Equal-Area projection with the 1927 North American Datum using ARC/INFO. The projection has standard parallels of 29 degrees 30 minutes and 45 degrees 30 minutes north latitude, a central meridian of 96 degrees west longitude, and a latitude of projection origin of 23 degrees north latitude. 1995 The coverage, including features and attributes, was checked and corrected where necessary using ARC/INFO. The RANGE polygon attribute was added and calculated. 1995 Vector GT-polygon composed of chains 714 Albers Conical Equal Area 29.5 45.5 -96 23 0.0 0.0 coordinate pair 0.461 meters 0.461 meters Meters North American Datum of 1927 Clarke 1866 6378206.4 294.98 WLC80_95.PAT Polygon attribute table ARC/INFO AREA Area of polygon in coverage units Computed Positive real numbers n/a n/a PERIMETER Perimeter of polygon in coverage units Computed Real positive numbers n/a n/a WLC80_95# Internal feature number Computed Sequential unique positive integer n/a n/a WLC80_95-ID User-assigned feature number User-defined Integer n/a n/a RANGE Polygon's water-level-change intervals in feet or polygon's identification of an area where the aquifer is not present, or polygon's identification of an area of little or no saturated thickness. n/a '< -40', '-40 to -20', '-20 to -10', '-10 to -5', '-5 to 5', '5 to 10', '10 to 20', '20 to 40', '> 40', 'island', 'dewatered' n/a n/a Each polygon is this data set has an associated attribute of RANGE containing ranges of water-level change expressed in feet or an identification of ISLAND, noting an area where the aquifer is not present or DEWATERED, noting an area of little or no saturated thickness. See overview. U.S. Geological Survey Ask USGS - Water Webserver Team mailing

445 National Center

Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://water.usgs.gov/user_feedback_form.html Although this data set has been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Export Full coverage zipped 1 http://water.usgs.gov/GIS/dsdl/ofr99-197_wlc80_95.e00.gz Other SDTS file format zipped 1 http://water.usgs.gov/GIS/dsdl/ofr99-197_wlc80_95.sdts.tgz Other SHAPE file format zipped 1 http://water.usgs.gov/GIS/dsdl/ofr99-197_wlc80_95.shp.tar.gz None. This dataset is provided by USGS as a public service. 20041108 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing

445 National Center

Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+ofr99-197_wlc80_95 FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998