Lake Travis is the largest in the Highland Lakes chain and is essentially a reservoir designed to contain floodwaters in the Lower Colorado River basin in order to help prevent destruction downstream, particularly along the shores of Lake Austin. Much of our drinking water comes from Lake Travis. The dam is an impressive structure and was built across a deep canyon at Marshall Ford, a long-time river crossing and settlement.
The lake is about 65 miles long and over 100′ deep in places. It is a very popular boating and recreational lake, particularly with its close proximity to Austin and the surrounding communities.
Mansfield Dam and Lake Travis are the only structures in the Highland Lakes chain specifically designed to contain floodwaters in the lower Colorado River basin. The lake can store as much as 260 billion gallons of floodwaters, helping to prevent destruction downstream.
When the elevation of the lake exceeds 681 feet above mean sea level (msl), LCRA begins floodgate releases under the direction of the U.S. Army Corps of Engineers. The amount and duration of the releases will vary, depending upon the weather and flood conditions above and below the dam.
LCRA and the U.S. Bureau of Reclamation built the dam from 1937 to 1941. Its completion was accelerated after a severe flood in July 1938. After the flood, LCRA raised the height of the dam to add storage capacity for flood control.
The dam was built across a deep canyon at Marshall Ford, a long-time river crossing and settlement. The Corps of Engineers still refers to the structure as Marshall Ford Dam. It was renamed in 1941 for U.S. Rep. J.J. Mansfield, who assisted in the project’s development.
For information about parks on Lake Travis, see map of parks and preserves.
Elevation when full: 681 feet above mean sea level (msl)
Historic high: 710.4 feet above msl on Dec. 25, 1991
Historic low: 614.2 feet above msl on Aug. 14, 1951
Normal operating range: at or below 681 feet above msl
The Lower Colorado River Authority was created in 1934 by the Texas Legislature as a conservation and reclamation district with no taxing authority and operates solely on utility revenues and fees generated from supplying energy, water, and community services. LCRA supplies low-cost electricity for Central Texas, manages water supplies and floods in the lower Colorado River basin, develops water and wastewater utilities, provides public parks, and supports community and economic development including managing the Highland Lakes. Goals include providing low-cost utility services and to help ensure the protection and constructive use of the area’s natural resources. The Highland Lakes chain consists of 7 lakes starting at Lake Buchanan and culminating in Lady Bird Johnson Lake in Austin.