April 11, 2002 GSA Release No. 02-23

Water Issues in West Texas

Communities in southwest Texas have grown substantially in recent years and the issue of whether there's enough water to sustain them has come to the fore. Geologists have been brought in to assess water conditions and several of them will be reporting preliminary results April 12 at a Water Resource Frontiers session at the Geological Society of America's South-Central Section Meeting in Alpine, Texas.

"This is the first real attempt to compile data and find out where water is, where it's coming from, and how we're going to manage it," session co-chair Diane Doser said. Doser is a geophysicist from the University of Texas at El Paso.

Ian C. Jones, a hydrologist for the Texas Water Development Board in Austin, Texas, will discuss differences in water recharge processes in two basins of the Cenozoic Pecos Alluvium aquifer which is an important source of irrigation water.

"The irony of the Cenozoic Pecos Alluvium aquifer is that the conditions most suitable for aquifer recharge are not conducive for crop cultivation and vice versa," Jones said. "The result is that demand for groundwater is greatest in areas with potentially less recharge."

Jeffrey Bennett, a geologist at John Shomaker & Associates in Albuquerque, will explore the complexities of understanding ground water recharge in the Trans-Pecos Region of Texas. While most researchers assume that the recharge for the area is one percent of the annual precipitation, Bennett has found that the recharge varies throughout the region from less than one percent to over five percent of the annual precipitation. The different watershed and hydrogeologic characteristics of the region account for the range of rates.

Areas of southwest Texas rely on the Rio Grande for drinking water. But a 10-year drought that has been lowering the flow rate and consequently the available water from the Rio Grande is a signal to communities that they need to understand the extent and limits of their own groundwater resources. Larger municipalities such as El Paso are depleting their nearby groundwater supplies and are now considering pumping water from property they've bought in outlying communities. The smaller communities in these areas, such as Culberson County, are feeling a need to understand their resources so they can protect and conserve them. Some folks are also feeling intimidated by the encroaching water needs of the larger municipalities.

Steve Finch, also from John Shomaker and Associates, recently completed the first comprehensive hydrogeologic assessment of Culberson County.

"The Culberson County Groundwater Conservation District is concerned about the sustainability of water supply and how importation of ground water may affect the community in a socioeconomic way," Finch said. Finch's work provides a better understanding of the recharge rates to the aquifers in the area and the extent of each aquifer in Culberson County and how the aquifers are connected with each other. The different composition of rocks in the county accounts for varying amounts of groundwater.

"Ground water yield to wells can be over 3,785 liters per minute (1,000 gallons per minute) in the basin fill deposits and Permian-age Capitan Reef, where permeability is fairly uniform," Finch wrote in his abstract. Later he added: "But ground water yield to wells and availability of ground water in storage can vary by several orders of magnitude in the volcanic rocks and in areas of fracture-controlled permeability."

Doser will present two water-related papers at the meeting. For the Geophysics and Remote Sensing session on April 11, she will introduce a new method she developed to discern shallow faults that could affect the quality and quantity of groundwater. Serendipitously, this technique can also be used to identify faults that may pose earthquake hazards or may serve as barriers to contaminant flow. For the Water Resource Frontiers session on April 12, she will discuss the intricacies of geophysical measuring of water salinity and saturation near the Rio Grande, west Texas.

— by Kara LeBeau, GSA Staff Writer

Contact information:

Ian C. Jones

Abstract: http://gsa.confex.com/gsa/2002SC/finalprogram/abstract_32895.htm

Water Resources Planning Division

Texas Water Development Board

P.O. Box 13231

Austin, TX 78711-3231

E-mail: ian.jones@twdb.state.tx.us

Phone: 512-936-0848

FAX: 512-936-0889

Jeffery B. Bennett

Abstract: http://gsa.confex.com/gsa/2002SC/finalprogram/abstract_33143.htm

John Shomaker & Associates, Inc

2703-D Broadbent Parkway, NE

Albuquerque, NM 87107 USA

E-mail: mycajah@mailpuppy.com

Phone: (505) 345-3407

FAX: (505) 345-9920

Steven T. Finch

Abstract: http://gsa.confex.com/gsa/2002SC/finalprogram/abstract_33138.htm

John Shomaker & Associates, Inc

2703-D Broadbent Parkway, NE

Albuquerque NM 87107 USA

E_mail: sfinch@shomaker.com

PHONE: (505)345-3407

FAX: (505) 345-9920

Diane Doser

Abstracts: http://gsa.confex.com/gsa/2002SC/finalprogram/abstract_33102.htm (April 11)

Abstracts: http://gsa.confex.com/gsa/2002SC/finalprogram/abstract_32914.htm (April 12)

Geological Sciences

University of Texas at El Paso

500 W. University

El Paso, TX 79968

E-mail: doser@geo.utep.edu

Phone: 915-747-5851

FAX: 915-747-5073

Session information and abstracts are available at:

http://gsa.confex.com/gsa/2002SC/finalprogram/session_1555.htm (morning presentations)

http://gsa.confex.com/gsa/2002SC/finalprogram/session_3018.htm (afternoon presentations)

Geological Society of America
South-Central Section Meeting
April 11-12, 2002
Sul Ross State University, Alpine, Texas

For information and assistance during the meeting, please see the media assistant at the GSA registration table or call 915-837-8326.

###

top