A view of the tunnel looking back on stationing from 394-00. The first stage of construction was completed between 1968-1971, and is comprised of a main aqueduct, a 3.78 mile tunnel through the River Mountains, eight pumping plants, and 31.4 miles of pipeline. This stage has a peaking capacity of 26.7 million cubic feet of potable water per day. The second stage enlarged the first stage system by expanding some of the existing facilities. New features included five pumping plants, the second barrel to the main aqueduct, and about 30 miles of pipeline and laterals with surge tanks, regulating tanks, and other delivery facilities. In conjunction with this stage, the State of Nevada enlarged and modified the Alfred Merritt Smith water treatment facilities to accommodate additional water supplies. The River Mountains Tunnel was constructed to full capacity in the first stage, and the Saddle Island intake facilities were oversized to accommodate both stages. The aqueduct system has a peaking capability of 53.4 million cubic feet of water per day. The River Mountains Tunnel was constructed during the first stage to accommodate second stage expansion. It is 3.78 miles long and was excavated through the River Mountains, which lie between Las Vegas Valley and Lake Mead. The concrete-lined tunnel has an inside diameter of 121.5 inches, and a maximum capacity of 608 cfs. The SNWA also constructed a larger tunnel, parallel to the River Mountains Tunnel for further expansion. The River Mountains Tunnel is used to convey raw water from Lake Mead to the River Mountains Water Treatment Facility that SNWA constructed near Henderson, NV. The River Mountains Facility, which began delivering treated water in October 2002, treats up to 300 million gallons of water per day, and was designed so it can expand to meet Southern Nevada's needs. In the future, the River Mountains facility will be able to treat up to 600 million gallons of water a day. This facility provides additional reliability and capacity to Southern Nevada's municipal water treatment and distribution capabilities.