Geohydrology of the aquifer in the Santa Fe Group, northern West Mesa of the Mesilla Basin near Las Cruces, New Mexico

Because of the heterogeneity of the Santa Fe Group, New Mexico, the hydrologic characteristics of the aquifer vary substantially from place to place. Hydraulic conductivities of 12 and 30 feet per day were estimated from aquifer tests for two wells in the eastern one-half of the study area. Well yields in the western one-half of the study area generally are less than 5 gallons per minute. Some of the well yields in the eastern one-half of the study area are greater than 1,000 gallons per minute. Ground water flows southeastward across the western one-half of the study area at a gradient of about 50 feet per mile. Across the eastern one-half of the study area, ground water flows southeastward at a gradient of less than 5 feet per mile. Dissolved-solids concentrations in groundwater range from 906 to 1,470 milligrams per liter in the western one-half of the study area and from 378 to 556 milligrams per liter in the eastern one-half.