The Roswell Artesian Basin is located in the lower Pecos Valley of southeastern New Mexico, on the northern fringe of the Chihuahua Desert. Summers are long and hot and precipitation is sparse, averaging less than 15 inches/year. However, the Roswell Basin is also one of the most intensively farmed areas in the state, the principal crops being alfalfa, cotton, sorghum, chiles and pecans. The Basin derives virtually all of its irrigation water from groundwater stored in a shallow alluvial aquifer and an artesian aquifer formed principally in the San Andres limestone. The Roswell Artesian Basin has been described as a world-class example of a rechargeable artesian aquifer system.