Bedrock Aquifers in the Lower Dirty Devil River Basin Area, Utah, with Special Emphasis on the Navaho Sandstone (TP-68)

By: J. W. Hood and T. W. Danielson

The lower Dirty Devil River basin area in southeastern Utah has an area of about 4,300 square miles and ranges in altitude from about 3,700 to more than 11,000 feet above mean sea level. Precipitation, the main source of water in the area, ranges from slightly less than 6 inches per year in the lowlands to more than 30 inches per year in the Henry Mountains and along the western boundary. Rocks that crop out in or underlie the area range from the Precambrian to the Holocene in age. The thickness of the composite section of sedimentary rocks ranges from about 7,300 feet to about 23,000 feet. The Entrada, Navajo, Wingate, and Coconino Sandstones and rocks of Mississippian age are considered major aquifers because of their large aerial extent or thickness or their known locally large yields to wells. The chemical quality of the water in these aquifers ranges from fresh to briny. The permeability of the aquifers in the area is affected by folding, faulting, and igneous intrusion. These geologic processes have locally enhanced ground-water circulation by fracturing or impeded circulation by offsetting permeable beds or sealing some zones with rocks of lower permeability.

The principal objectives of this study were to determine (1) well yields of the bedrock formations, (2) the capability of formations to yield over the long term and (3) effects of withdrawal from wells on the surface-water supply in the Colorado River basin. Implicit in these objectives is a general definition of the hydrologic system in the project area.

Other Information:
Published: 1981
Pages: 143 p.
Plates: 2 pl.
Location: Emery County, Garfield County, Sevier County, and Wayne County
Media Type: Paper Publication