Lake Travis is a reservoir on the Colorado River in central Texas in the United States. The reservoir was formed in 1942 by the construction of Mansfield Dam on the western edge of Austin, Texas by the Lower Colorado River Authority. Lake Travis has the largest storage capacity of the seven reservoirs known as the Highland Lakes, and stretches 65 miles (105 km) upriver from western Travis County in a highly serpentine course into southern Burnet County to Max Starcke Dam, southwest of the town of Marble Falls. The Pedernales River, a major tributary of the Colorado River, flows into the lake from the southwest in western Travis County. The lake is used for flood control, water supply, electrical power generation and recreation.
The other reservoirs on the Colorado River are Lake Buchanan, Inks Lake, Lake LBJ, Lake Marble Falls, Lake Austin, and Lady Bird Lake. Lake Travis is considered "full" (at maximum desired capacity) when the lake's water level is at 681 feet (208 m) above mean sea level (msl). Above 681 feet (208 m), flood control gates are opened under the direction of the U.S. Army Corps of Engineers. The historic high level on the lake was 710.4 feet (216.5 m) above msl on December 25, 1991. The historic low was 614.2 feet (187.2 m) above msl on August 14, 1951. The extreme drought of 2008-2009 brought the lake to its fourth lowest level at 626.09 feet (190.83 m) above msl in November 2009. The second lowest level was 615.02 feet (187.46 m) above msl on November 8, 1963. Due to the drought beginning in 2011, levels have gone as low as 618 feet, making it the third lowest level ever. The LCRA makes reports of lake levels available on the internet.