Hydrogeothermal Studies in New Mexico and Implications for Ground-Water Resources

Abstract

Subsurface temperatures and heat-flow data provide valuable information on both regional and local ground-water flow patterns. In the San Juan Basin of northwestern New Mexico and southwestern Colorado, heat-flow data are used to estimate basin-scale horizontal flow and predict hydraulic conductivities much higher than values measured in pumping tests or laboratory studies. Along the central Rio Grande rift in the Albuquerque Basin, hot water at depth may be present at a number of locations; however, the hydrogeology is such that warm springs are absent. In south-central New Mexico, along the southern Rio Grande rift, a number of warm springs result from tectonic activity and erosion exposing aquifers which allow deeply-circulating ground water to come near surface. In the Roswell Basin of southeastern New Mexico, recharge to the Pecos River deep aquifer is predicted from depths of ~1,000–1,500 m; in addition a ground-water divide appears present near the Mescalero ridge. On the Llano Estacado downward ground-water movement from the surface is suggested to depths of ~1,000–1,500 m. Along the Rio Grande at Bosque del Apache and Canutillo, and along the Pecos River at Artesia, there appear to be dual-flow systems with river water moving downward to depths of ~50–100 m, while upward flow of ground water occurs from much greater depths. This implies separation of the ground-water systems at these locales, an important ramification regarding the recharge of different zones. The deep pumping at Canutillo appears to have exceeded the natural recharge, and this may well be the case at other locales where pumping depths are below river recharge. Shallow pumping at Canutillo appears to have caused a much greater recharge from the river than was the prepumping case.