Conceptual model of the Bolson-fill aquifer, Soledad Canyon area, Dona Ana County, New Mexico
— Cheryl A. Naus

A conceptual model of the bolson-fill aquifer in the Soledad Canyon area was developed to synthesize existing information, to promote a better understanding of the flow system, and to provide a framework for development of a numerical ground-water-flow model. Hydraulic properties of the aquifer are expected to be highly variable because of the heterogeneity of bolson-fill sediments and tectonic activity. Water-transmitting properties of the bolson-fill deposits have been affected by debris flows, calcium carbonate cementation, and faulting. Mountain-front recharge was assumed to be the primary recharge mechanism in the study area. Mountain-front recharge rates estimated using empirical, regression, and chloride-balance methods probably represent a reasonable range of volumetric recharge rates in the Soledad Canyon area. Significant discharge from the bolson-fill aquifer is limited to Soledad Canyon production wells. Ground-water withdrawal from nearby Post Headquarters wells apparently has not affected ground-water storage in the Soledad Canyon area, and it appears unlikely that alluvial deposits that contain springs are hydraulically connected to the bolson-fill aquifer. Ground-water quality in the study area becomes poorer toward the center of the basin and with increasing depth, The freshwater part of the aquifer is estimated to be approximately 16 km wide and more than 610 m thick in the study area. The conceptual model developed for the Soledad Canyon area assumes a narrow transition zone between fresh and saline water that can be approximated by a stationary, sharp interface.