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Ground-water resources of the Hueco Bolson, northeast of El Paso, Texas
| Content Provider | Semantic Scholar |
|---|---|
| Author | Knowles, Doyle Blewer Kennedy, Richard A. |
| Copyright Year | 1958 |
| Abstract | The Hueco Bolson is in the extreme western part of Texas and southcentral New Mexico, covering parts of El Paso County, Tex., and Dona Ana ood Otero Counties, N. Mex. Wells tapping the bolson deposits furnish the major part of the water supply for the city of El Paso, Ciudad Ju~rez, Fort Bliss, Biggs Air Force Base, and private industries . in the area. The progressively increasing demand for water made it obvious that a comprehensive investigation of the quantity and quality of water in storage in the entire Hueco Bolson would be essential for the proper planning of future water supplies. A test-drilling program was started in 1953, jointly sponsored by the city of El Paso, the United States Army, the United States Air Force, and the Texas Board of Water Engineers. The drilling was supervised by the United States Geological Survey. Thirty-three deep test wells were drilled, comprising a total footage of 32,456 feet. Water samples for chemical analysis were obtained by means of drill-stem tests at most of the wells, an electric log was made 'after each test well was completed, water-level measurements were made in each well, and pumping tests were made at several selected wells. In addition to the test-drilling program, all avail able information was collected for existing wells in the area, and chemical analyses were made of water samples collected from many of the wells. The Hueco Bolson is an intermontane lowland sparsely covered with low vegetation. The bolson is traversed by the Rio Grande valley, the portion of which south of El Paso, known locally as the Lower Valley, is reached by an abrupt drop of 200 to 300 feet from the bolson surface, which is known locally as the Mesa. No welldeveloped drainage channels are on the Mesa, and the precipitation on it either infiltrates or is lost by evapotranspiration. The average annual evaporation from a U. S. Weather Bureau class A evaporation pan, based on a 4-year period, is 108.15 inches, whereas the average annual precipitation, based on a 75-year record, is 8.65 inches. The bedrock that underlies the bolson deposits amd makes up the surrounding mountains is relatively impermeable and will not supply large quantities of water to wells. The Franklin and Organ Mountains, which form part of the western boundary of the Hueco Bolson, consist largely of granitic and porphyritic rocks that ยท were the source beds for much of the bolson deposits. The latter consist of lenticular layers of clay, sand, and gravel, which cannot be correlated for long distances. The sands and gravels are thickest and coarsest near the Franklin and Organ Mountains and become progressively thinner and finer gnrlned toward the east. The maximum known thickness of the bolson deposits is 4,920 feet. Caliche lying nearly everywhere beneath the surface of the bolson affords a rather effective barrier to recharge from above. The caliche beds are partly or completely missing beneath depressions in the bolson, however, and recharge takes place when water collects in the depressions during periods of heavy rainfall. Contours of water levels in the Hueco Bolson show that the principal area of recharge is along the east edge of the Franklin and Organ Mountains, where the runoff from the mountains infiltrates into the coarse gravel of alluvial fans. The water in the bolson deposits in the Mesa is unconfined 1;1nd almost everywhere is of good quality. The bolson |
| File Format | PDF HTM / HTML |
| DOI | 10.3133/wsp1426 |
| Alternate Webpage(s) | https://pubs.usgs.gov/wsp/1426/report.pdf |
| Alternate Webpage(s) | https://doi.org/10.3133/wsp1426 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
