Mansfield Dam and Lake Travis

Lake can store up to 256 billion gallons of floodwaters

water_mansfield.jpgMansfield 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 256 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 1942. After a severe flood in July 1938, LCRA raised the height of the dam to add storage capacity for floodwaters.

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 recreation areas.

Top 10 highest levels for Lake Travis

​Rank​Date​Height (msl)
​1​Dec. 25, 1991
​710.44
​2​May 18, 1957
​707.38
​3​June 25, 1997
​705.11
​4​Feb. 9, 1992
​704.68
​5​July 6, 2007​701.51
​6​Nov. 25, 2004
​696.70
​7​July 7, 2002
​693.50
​8​June 14, 1987
​693.48
​9​Oct. 7, 1959
​692.58
​10​April 18, 1977​692.42


Msl = mean sea level; height is feet above msl.



Lake Travis
Lowest lake elevations during major droughts

​Drought
​Min. Lake Level*
(msl)
​Date
​1940's-'50s
(Drought of Record)
​614.18​Aug. 14, 1951
​1963-64​615.02​Nov. 8, 1963
​1983-84​636.58​Oct. 7, 1984
​1999-2000​640.24​Oct. 15, 2000
​2005-06​643.55​Dec. 13, 2006
​2007-09​629.83​Oct. 4, 2009
​Current Drought​618.64​Sept. 20, 2013

*Based on daily readings at 8 a.m.

msl = mean sea level; height is feet above msl.

The lower Colorado River basin is currently in a severe drought. Check the Historical Lake Levels for monthly averages or the Daily River Report for current lake levels.

​FYI: Mansfield Dam


Location: Travis County, 318 river miles from the Gulf of Mexico
When built: 1937 to 1942
Dam dimensions: 278 feet high, 7,089.39 feet long
Primary purposes: Flood management, water storage, hydroelectric power
Generating capacity: 108 megawatts
Water supply storage capacity: 369.8 billion gallons
Spillway elevation: 714 feet above msl
Top of dam: 750 feet above msl Floodgates: 24
Total discharge capacity: More than 133,400 cubic feet per second (cfs):

  • 24 floodgates @ more than 5,250 cfs each

 

  • 2 turbines @ 2,500 cfs each

 

  • 1 turbine @ 2,400 cfs


Original name: Marshall Ford Dam

DETAILS ON LAKE TRAVIS


Lake area: 19,297 acres
Elevation when full: 681 feet above mean sea level (msl)
Volume when full: 1,134,956 acre-feet
Historic high: 710.44 feet above msl on Dec. 25, 1991
Historic low: 614.18 feet above msl on Aug. 14, 1951
Target operating range: at or below 681 feet above msl
100-year flood level at dam: 722 feet above msl