- r , A SUMMARY OF THE GROUND-WATER RESOURCES AND GEOHYDROLOGY OF GRAND COUNTY, UTAH by Chris Eisinger and Mike Lowe Utah Geological Survey Cover photograph is the mouth of the Dirty Devil River at Lake Powell. Photo credit: Paul Link Cover design by Sharon Hamre Circular 99 May 1999 UTAH GEOLOGICAL SURVEY ....0, 9,9 a division of ~UTAH GEOLOGICAL SURVEY o Utah Department of Natural Resources STATE OF UTAH Michaela' Leavitt, Governor DEPARTMENT OF NATURAL RESOURCES Kathleen Clarke, Executive Director UTAH GEOLOGICAL SURVEY M. Lee Allison, Director UGS Board Member Representing C. William Berge (Chairman) ........................................................................................................... Mineral Industry D. Cary Smith .................................................................................................................................. Mineral Industry Craig Nelson .................................................................................................................................. Civil Engineering E.H. Deedee O'Brien ........................................................................................................................ Public-at-Large Robert Robison ............................................................................................................................... Mineral Industry Charles Semborski .......................................................................................................................... Mineral Industry Richard R. Kennedy ................................................................................................. Economics-Business/Scientific David Terry, Director, Trust Lands Administration ...................................................................... Ex officio member UTAH GEOLOGICAL SURVEY The UTAH GEOLOGICAL SURVEY is organized into five geologic programs with Administration, Editorial, and Computer Resources providing necessary support to the programs. The ECONOMIC GEOLOGY PROGRAM undertakes studies to identify coal, geothermal, uranium, hydrocarbon, and industrial and metallic resources; initiates detailed studies of these resources including mining dis­ trict and field studies; develops computerized resource data bases, to answer state, federal, and industry requests for information; and encourages the prudent development of Utah's geologic resources. The APPLIED GEOLOGY PROGRAM responds to requests from local and state governmental entities for engineering-geologic investigations; and identifies, documents, and interprets Utah's geologic hazards. The GEOLOGIC MAPPING PROGRAM maps the bedrock and surficial geology of the state at a regional scale by county and at a more detailed scale by quadrangle. The GEOLOGIC EXTENSION SERVICE answers inquiries from the public and provides information about Utah's geology in a non-technical format. The ENVIRONMENTAL SCIENCES PROGRAM maintains and publish­ es records of Utah's fossil resources, provides paleontological and archeological recovery services to state and local governments, con­ ducts studies of environmental change to aid resource management, and evaluates the quantity and quality of Utah's ground-water resources. The UOS Library is open to the public and contains many reference works on Utah geology and many unpublished documents on aspects of Utah geology by UOS staff and others. The UOS has several computer data bases with information on mineral and energy resources, geologic hazards, stratigraphic sections, and bibliographic references. Most files may be viewed by using the UOS Library. The UOS also manages a sample library which contains core, cuttings, and soil samples from mineral and petroleum drill holes and engineer­ ing geology investigations. Samples may be viewed at the Sample Library or requested as a loan for outside study. The UOS publishes the results of its investigations in the form of maps, reports, and compilations of data that are accessible to the public. For information on UOS publications, contact the Natural Resources Map/Bookstore, 1594 W. North Temple, Salt Lake City, Utah 84116, (80l) 537-3320 or 1-888-UTAH MAP. E-mail: [email protected] and visit our web site at http://www.ugs.state.ut.us. UGS Editorial StafT J. Stringfellow .................................................................................................................................................... Editor Vicky Clarke, Sharon Hamre ............................................................................................................... Graphic Artists Patricia H. Speranza, James W. Parker, Lori Douglas ........................................................................... Cartographers The Utah Department of Natural Resources receives federal aid and prohibits discrimination on the basis of race, color, sex, age, national origin, or disability. For information or complaints regarding discrimination, contact Executive Director, Utah Department of Natural Resources, 1594 West North Temple #3710, Box 145610, Salt Lake City, UT 84116-5610 or Equal Employment Opportunity Commission, 1801 L Street, NW, Washington DC 20507. Q Printed on recycled paper 2/99 TABLE OF CONTENTS ABSTRACT ......................................................................................... 1 INTRODUCTION .................................................................................... 1 SEITING ........................................................................................... 1 CHARACTERISTICS OF MAJOR AQUIFERS ............................................................ 2 Fractured Rock Aquifers ........................................................................ 2 Lower Paleozoic Aquifer. .. 8 Cutler Aquifer '" . .. 8 Wingate Aquifer ....................................................................... 8 Navajo Aquifer ........................................................................ 9 Entrada Aquifer . .. 10 Morrison Aquifer . .. 10 Dakota Aquifer ....................................................................... 10 Wasatch Aquifer ...................................................................... 11 Parachute Creek Aquifer . .. 11 Unconsolidated Aquifers ....................................................................... 11 RECHARGE ....................................................................................... 12 GROUND-WATERFLOWDIRECTION ................................................................ 13 DISCHARGE ....................................................................................... 13 WATER QUALITY .................................................................................. 14 Fractured-Rock Aquifers . .. 15 Lower Paleozoic Aquifer . .. 15 Cutler Aquifer ....................................................................... , 15 Wingate Aquifer ...................................................................... 15 Navajo Aquifer ....................................................................... 16 Entrada Aquifer . .. 16 Morrison Aquifer. .. 16 Dakota Aquifer ....................................................................... 17 Wasatch Aquifer ...................................................................... 17 Parachute Creek Aquifer . .. 17 Unconsolidated Aquifers ....................................................................... 17 SUMMARy ........................................................................................ 18 REFERENCES ..................................................................................... 18 FIGURES Figure 1. Grand County, Utah location map ................................................................ 2 Figure 2. General direction of water movement in the upper ground-water system (from Blanchard, 1990) . .. 13 Figure 3. Estimated ground-water inflow rate to the Colorado and Green Rivers (from Rush and others, 1982) .......... 14 Plate 1. Areal extent of the Lower Paleozoic aquifer. 21 Plate 2. Areal extent of the Cutler aquifer . .. 22 Plate 3. Areal extent of the Navajo and Wingate aquifers ..................................................... 23 Plate 4. Areal extent of the Entrada aquifer . 24 Plate 5. Areal extent of the Morrison aquifer ............................................................... 25 Plate 6. Areal extent of the Dakota aquifer ................................................................ 26 Plate 7. Areal extent of the Parachute Creek and Wasatch aquifers ............................................. 27 Plate 8. Areal extent of the potential unconsolidated aquifers . 28 TABLES Table 1. Characteristics of the major geologic units and their hydrologic characteristics and significance, Grand County (adapted from tables by Sumsion, 1971; Schlotthauer and others, 1981; Blanchard, 1990; Gloyn and others, 1995; and Gwynn, 1995; stratigraphic thicknesses after Hintze, 1988) .................................... 3 Table 2. Drinking-water and ground-water protection regulations in Utah (Snyder, 1996a) .......................... 15 A SUMMARY OF THE GROUND-WATER RESOURCES AND GEOHYDROLOGY OF GRAND COUNTY by Chris Eisinger and Mike Lowe Utah Geological Survey ABSTRACT that are not presently available, but can be useful for evaluating ground-water resources, including: In Grand County, ground water has been (1) structure contour maps showing the depth to withdrawn primarily from two types of aquifers: aquifers, (2) isopach maps showing the thickness fractured rock and unconsolidated deposits.