WHPacific investigated sources of water and designed a water supply system for Tyrone Copper Mine near Silver City, New Mexico. The project area is semiarid and most water resources were already committed. As part of the investigation, the groundwater potential of alluviums along Gila River was evaluated. WHPacific furnished geological supervision for drilling and testing of exploration and observation wells. The test found an excessive amount of bentonite in the sediments, preventing the required quantity of water for mining milling. The decision was made to supply the project by direct diversion of surface water from Gila River. The supply system consists of an off-channel dam and reservoir, 22 miles of 27- to 33inch pipeline, and three pumping plants to lift the water 1,500 feet above the diversion point.