Mansfield Dam, owned by LCRA, creates Lake Travis.

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.

Dam dimensions: 278 feet high, 7,089.39 feet long, 213 feet thick at the base, 30 feet thick at the top
Lake area: 18,622 acres
Primary purposes: flood management, water storage, hydroelectric power
Generating capacity: 102 megawatts
Water supply storage capacity: 380 billion gallons
Floodgates: 24
Total discharge capacity:

• 121,080 cubic feet per second (cfs)
• 24 floodgates @ 4,770 cfs each
• 3 turbines @ 2,200 cfs each