Cederstrand, Joel R. Becker, Mark F. 1999 1.0 map Open-File Report OFR99-265 Reston, VA U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?ofr99-265 This digital data set consists of contours of predevelopment to 1980 water-level elevation changes for the High Plains aquifer in the central United States. The High Plains aquifer extends from south of 32 degrees to almost 44 degrees north latitude and from 96 degrees 30 minutes to 106 degrees west longitude. The outcrop area covers 174,000 square miles and is present in Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital data set was created by digitizing the contours for predevelopment to 1980 water-level elevation change from a 1:1,000,000-scale base map created by the U.S. Geological Survey High Plains Regional Aquifer-System Analysis (RASA) project (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.) The data are not intended for use at scales larger than 1:1,000,000. This data set was created to archive the original map produced by the High Plains RASA project and make available the data on those maps for use with geographic information systems. Introduction -- The information provided in the introduction is found in U.S. Geological Survey Professional Paper 1400-B (Gutentag and others, 1984). This data set consists of digital contours of predevelopment to 1980 water-level elevation changes for the High Plains aquifer in the United States. 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. Elevation refers to distance above sea level and sea level refers to the National Geodetic Vertical Datum of 1929 (NGVD29)-- a geodetic datum derived from a general adjustment of the first-order level nets of both the United States and Canada, formerly called Sea Level Datum of 1929. The High Plains aquifer is a regional water-table aquifer consisting mostly of near-surface sand and gravel deposits. The maximum saturated thickness of the aquifer in 1980 was about 1,000 feet and averaged 200 feet. Hydraulic conductivity and specific yield were highly variable because of the heterogeneity of the aquifer. 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 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 the erosional extent of the High Plains aquifer and hydrologic 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 hydraulically connected Tertiary and Quaternary rocks were used. Streams and physiographic provinces in eastern Nebraska were used as hydrologic boundaries of Quaternary deposits. This digital data set was created by digitizing the predevelopment to 1980 water-level elevation change contours from a 1:1,000,000-scale base map created by the High Plains RASA project (Gutentag and others, 1984). Reviews Applied to Data -- This electronic report was subjected to the same review standard that applies 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 -- Other 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. Notes -- Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. 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. 1980 Ground condition Complete None planned -105.92091073 -96.29377645 43.66316552 31.80397248 none aquifers ground water groundwater High Plains aquifer Ogallala Formation Ogallala aquifer aquifer boundary inlandWaters none High Plains Great Plains region western U.S. None. None Mark F. Becker U.S. Geological Survey Hydrologist mailing address

202 NW 66th St., Bldg. 7

Oklahoma City Oklahoma 73116 United States of America 1-888-275-8747 (405) 843-7712 mfbecker@usgs.gov none http://water.usgs.gov/GIS/browse/ofr99-265.gif A browse image of the data set of changes in water levels from predvelopment to 1980 for the High Plains aquifer. GIF None Public UNCLASSIFIED None Operating System-- UNIX, ARC/INFO Version 7.0.3, (Mon Mar 13 22:21:55 PST 1995) Polygon and chain-node topology present. This data set includes the contours for predevelopment to 1980 water-level elevation changes published by Gutentag and others (1984) in U.S. Geological Survey Professional Paper 1400-B. None. None. A mylar map of the contours for predevelopment to 1980 water-level elevation changes were digitized using ARC/INFO. 199707010000 -- 199708010000 The coverage had been incorrectly registered because the easternmost tics used in digitizing were one degree longitude east of the actual tics. The coverage was adjusted using the ARC/INFO TRANSFORM command. 199710231610 The coverage was projected from Lambert Conformal Conic projection with the 1927 North American Datum to an Albers Equal-Area projection with the 1983 North American Datum using ARC/INFO. The new 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 projection origin of 23 degrees north latitude. 199710231610 The coverage including features and attributes was checked and corrected, where necessary, using ARC/INFO. The MAJOR1, MINOR1, and DIFF arc attributes and MAJOR1, MINOR1, and RANGE polygon attributes were added and calculated. 199801281450 -- 199803091418 The coverage was projected from Albers Equal-Area projection to decimal degrees with the 1983 North American Datum using ARC/INFO. 199903231320 Vector Point 239 String 313 GT-polygon composed of chains 240 0.0012486445889 0.0012486445889 Decimal Degrees North American Datum of 1983 GRS1980 6378206.4 294.98 WLCHNGE.PAT Polygon attribute table of WLCHNGE ARC/INFO - Polygon attribute table of WLCHNGE ARC/INFO - n/a n/a AREA Area of polygon in square coverage units Computed Positive real numbers n/a n/a PERIMETER Perimeter of polygon in coverage units Computed Positive real numbers n/a n/a WLCHNGE# Internal feature number Computed Sequential unique positive integer n/a n/a WLCHNGE-ID User-assigned feature number User-defined Integer n/a n/a RANGE Range of change from predevelopment to 1980 water-levels in feet Gutentag and others, 1984 -150 to -125, -125 to -100, -100 to -75, -75 to -50, -50 to -25, -25 to -10, -10 to +10, +10 to +25, +25 to +50, -1 n/a n/a MAJOR1 Lower limit of range of change from predevelopment to 1980 water-levels in feet Gutentag and others, 1984 -150, -125, -100, -75, -50, -25, -10, -1, 10, 25 n/a n/a MINOR1 Upper limit of range of change from predevelopment to 1980 water-levels in feet Gutentag and others, 1984 -125, -100, -75, -50, -25, -10, -1, 10, 25, 50 n/a n/a WLCHNGE.AAT Arc attribute table ARC/INFO - Arc attribute table ARC/INFO - n/a n/a FNODE# Internal number of from-node Computed Sequential unique positive integer n/a n/a TNODE# Internal number of to-node Computed Sequential unique positive integer n/a n/a LPOLY# Internal number of poly to left of arc Computed Sequential unique positive integer n/a n/a RPOLY# Internal number of poly to right of arc Computed Sequential unique positive integer n/a n/a LENGTH Length of arc in coverage units Computed Positive real numbers n/a n/a WLCHNGE# Internal feature number Computed Sequential unique positive integer n/a n/a WLCHNGE-ID User-assigned feature number User-defined Integer n/a n/a DIFF Change in water-level elevation from predevelopment to 1980 in feet Gutentag and others, 1984 -150, -125, -100, -75, -50, -25, -10, 0, 10, 25, 50 n/a n/a MAJOR1 Change in water-level elevation from predevelopment to 1980 in feet Gutentag and others, 1984 -150, -125, -100, -75, -50, -25, -10, 0, 10, 25, 50 n/a n/a MINOR1 0 n/a 0 n/a n/a Each line has associated attributes of DIFF and MAJOR1 containing values of change for predevelopment to 1980 water levels expressed in feet. Each polygon has an associated attribute, RANGE, containing ranges of predevelopment to 1980 water-level changes in feet. For example, a polygon with a RANGE value of '-25 to -10', means the water-level has decreased between 25 and 10 feet from predevelopment to 1980. Polygons that contain a RANGE value of -1 represent aquifer outcrops where the change in water-levels is not known. MAJOR1 contains the lower RANGE limit and MINOR1 contains the upper RANGE limit. 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/ofr99-265.e00.gz Other DLG file format zipped 1 http://water.usgs.gov/GIS/dsdl/ofr99-265.dlg.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+ofr99-265 FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998