Groundwater Management in El Paso, Texas


Book Description

Groundwater represents an important supply source for municipal and irrigation uses in Far West Texas. The City of El Paso receives about 50 percent of its municipal water supply from surface water and 50 percent from local groundwater. Groundwater pumping in El Paso is from the Hueco Bolson and the Mesilla Bolson. Historic groundwater pumping in the Texas portion of the Mesilla Bolson has not resulted in significant changes in groundwater levels or groundwater quality in existing wells. Historic pumping in the Hueco Bolson has resulted in lowered groundwater levels and brackish groundwater intrusion. The groundwater level declines have resulted in the intrusion of brackish groundwater into areas that historically pumped fresh groundwater. A 1979 assessment concluded that El Paso would deplete fresh groundwater in the Hueco Bolson by 2030 if groundwater pumping continued to increase. Partly as a result of the 1979 assessment, El Paso reduced its groundwater pumping from the Hueco Bolson by increasing surface water diversions from the Rio Grande, increasing conservation efforts, and increasing reclaimed water use. As a result, groundwater levels in many parts of the Hueco Bolson have stabilized. Brackish groundwater intrusion remains an issue, and is being addressed with a brackish groundwater desalination plant, currently under construction. The new wells and existing wells that will supply this desalination plant will also assist in the management of brackish groundwater intrusion by intercepting the brackish groundwater before it can flow towards existing fresh groundwater wells. The 2006 Far West Texas Regional Water Plan contemplates a groundwater transfer project to meet increasing demands in El Paso County beginning about 2030, mostly from the Dell City area in Hudspeth County, Texas. Groundwater management in the Dell City area is governed by a groundwater conservation district that has established limits on groundwater pumping based on existing and historic uses. Groundwater pumping for irrigation began in the Dell City area in 1948, and groundwater levels have been essentially stable for since the 1980s. Future planning for a groundwater transfer project will require a detailed understanding of the hydrogeology of the groundwater in the Dell City area.




Evaluation of Selected Resources in El Paso County, Texas


Book Description

The Texas Natural Resource Conservation Commission (TNRCC), working with the Texas Water Development Board (TWDB) and the Texas Parks and Wildlife Department (TPWD), is charged with identifying priority ground-water management areas (PGMAs) - areas in the State that are experiencing, or are expected to experience in the future, critical ground-water problems. The purpose of the PGMA program is to assist local and regional interests to address ground-water management issues; including quantity and quality of surface water and groundwater, contamination issues, and land subsidence. Senate Bill 1 (75th legislature, 1997) placed priority on the completion of pending PGMA studies that were called for by House Bill 2 (69th Legislature) in 1985. The TNRCC and TWDB identified El Paso County in west Texas for a PGMA study in 1990. The study was initiated in 1990 with TNRCC requesting a ground-water resource and availability study from TWDB. The TWDB completed the report Evaluation of Ground-water Resources in El Paso County, Texas (TWDB Report No. 324, Ashworth) in March of 1990.
















Ground-water, Surface-water, and Water-chemistry Data, Black Mesa Area, Northeastern Arizona, 1999


Book Description

The N aquifer is the major source of water in the 5,400-square-mile area of Black Mesa in northeastern Arizona. Availability of water is an important issue in this area because of continued industrial and municipal use, a growing population, and a precipitation of only about 6 to 12 inches per year. The monitoring program in Black Mesa has been operating since 1971 and is designed to determine the long-term effects of ground-water withdrawals from the N aquifer for industrial and municipal uses. The monitoring program includes measurements of (1) ground-water pumping, (2) ground-water levels, (3) spring discharge, (4) surface-water discharge, and (5) ground-water chemistry. In 1999, total ground-water withdrawals were 7,110 acre-feet, industrial use was 4,210 acre-feet, and municipal use was 2,900 acre-feet. From 1998 to 1999, total withdrawals increased by 0.7 percent, industrial use increased by 4 percent, and municipal use decreased by 4 percent. From 1998 to 1999, water levels declined in 11 of 15 wells in the unconfined part of the aquifer, and the median decline was 0.7 foot. Water levels declined in 14 of 16 wells in the confined part of the aquifer, and the median decline was 1.2 feet. From the prestress period (prior to 1965) to 1999, the median water-level decline in 31 wells was 10.6 feet. Median water-level changes were 0.0 foot for 15 wells in the unconfined part of the aquifer and -45.5 feet in 16 wells in the confined part. From 1998 to 1999, discharges were measured annually at four springs.