New Mexico Geological Society Annual Spring Meeting — Abstracts

The Madera Formation forms a carbonate aquifer of regional significance for ground-water development in the Sandia Mountains east of Albuquerque, New Mexico. Characterization of carbonate aquifers is problematic due to the localized nature of ground-water flow in fractured limestone. Spring hydrographs and aquifer test data indicate that ground water in the Madera aquifer moves as combined diffuse flow and fracture flow. Aquifer test drawdown data fit a double-porosity model, and show that ground water is primarily transmitted through large fractures, but the majority of aquifer storage is attributable to the limestone matrix. Fracture transmissivity ranges from 170 to 200 m²/d. Total storativity, for both fractures and matrix, is 0.20 to 0.25. The fractures transmitting the bulk of spring discharge are associated with faults in the Madera Formation. Spring hydro graphs from fault-controlled springs near the Village of Placitas may provide a potentially valuable source of data on Madera aquifer hydraulic properties, including effective porosity, transmissivity, storage, water budgets, and recharge. Hydrograph separation and recession curve analysis yield preliminary estimates of dynamic storage and recharge for three Placitas Village springs. Further work is required before the full potential of spring hydrograph data can be utilized as a regional aquifer characterization tool in the Madera Formation.