Hueco Bolson Groundwater Model
1. Purpose and Objectives: The purpose of this project is to develop a simulation flow program for the El Paso Water Utilities. Also, a GIS of available data will be created so that both El Paso and Cd. Juárez can share information about the parameters, quality, supply, and all other pertinent information regarding the Hueco Bolson. The objective is to integrate the latest geo-hydrologic data and concepts in a simulation of the flow of fresh and saline water and aquifer compaction in the Hueco Bolson. The approach to the investigation will consist of:
2. Background: The Tularosa Basin and the Hueco Bolson together form one rift basin approximately 200 miles long in a north-south direction and 40 miles across at the widest point. The Tularosa Basin and the Hueco Bolson are separated by a minor topographic divide near the New Mexico-Texas State line. The Santa Fe Group of Tertiary and Quaternary age forms the principle aquifer in the Hueco Bolson and consists of the Fort Hancock Formation and the overlying Camp Rice Formation. Fresh ground water occurs in an irregularly shaped wedge bordering the Franklin and Organ Mountains overlying saline water in the Fort Hancock Formation and the overlying Camp Rice Formation. Ground water is kept fresh by mounting-front recharge estimated by Sayre and Livingston to occur at a rate of approximately 13 million gallons per day. This area of fresh water extends southward beyond the Franklin Mountains into the area beneath El Paso, TX, and Ciudad Juárez, Mexico. The lowering of water levels in an aquifer, by groundwater withdrawal or other means, can cause aquifer compaction in turn leading to land subsidence. In a water table aquifer such as the Hueco Bolson, the effects of groundwater withdrawal on aquifer compaction can be obscured or delayed.
3. Funding: Total tabulation of funding has yet to be determined.
4. Description: The increasing number of inhabitants in El Paso and Juárez pose a burden on the limited supply of fresh groundwater in the southern Hueco Bolson. Withdrawals have resulted in substantial water-table and plezometric head declines. Consequently, good-quality water supplies are becoming scarce. A related effect has been land subsidence resulting from compaction of the aquifer system. Saline water has intruded formerly freshwater bearing zones of the aquifer, either by lateral migration or up-coning. The quality of water from wells penetrating zones where intrusion has been significant has been degraded, necessitating abandonment of some wells. The City of El Paso requires an improved understanding of these effects so that the groundwater resource can be more effectively managed. Hence, the purpose of this study.
5. Status: To this date, there has been a proposal refinement, GIS coverage preparation, and literature review. The next stage aims to collect and compile data, and have preliminary ground-water flow modeling.
6. Partners: El Paso Water Utilities and USGS
7. U.S. Contacts: Dr. Ernest Rebuck, El Paso Water Utilities, (915) 594-5562, and Charles Heywood, USGS, (505) 262-5351, Fax: 262-5398, e-mail: cheywood@usgs.gov