Water
 
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Leased from the City of Austin
Tom Miller Dam and Lake Austin
Dam built atop of two earlier structures destroyed by floods

 
Miller Dam

Tom Miller Dam is leased to LCRA by the City of Austin until December 2020. The dam, built to provide hydroelectricity and store water, creates Lake Austin.

Named for an Austin mayor, the dam was built from 1938 to 1940 atop the remains of two earlier structures, both called Austin Dam. The first was built from 1890 to 1893, and the other from 1909 to 1912. Massive floods destroyed both structures. The lake originally was called Lake McDonald.

For information on parks on the Highland Lakes, see map of parks and preserves.

FYI: TOM MILLER DAM

Location: Travis County, 298 river miles from the Gulf of Mexico
When built: 1938 to 1940
Dam dimensions: 100.5 feet high, 1,590 feet long, 155 feet thick at base, 22.8 feet thick at top.
Lake area: 1599 acres
Primary purposes: hydroelectric power, water supply
Generating capacity: 17.3 megawatts
Floodgates: nine
Total discharge capacity:

  • 110,000 cubic feet per second (cfs)
  • 4 floodgates @ 15,500 cfs each
  • 5 small floodgates @ 8,800 cfs each
  • 2 turbines @ 2,000 cfs each

Original name: Tom Miller Dam, Lake McDonald

DETAILS ON LAKE AUSTIN

Elevation when full: 492.8 feet above mean sea level (msl)
Volume when full: 21,725 acre-feet
Historic high: 495.2 feet above msl on May 25, 1981
Historic low: 474.3 feet above msl on Feb. 17, 1963
Normal operating range: 491.8 to 492.8 feet above msl
Spillway elevation: 492.8 feet above msl
100-year flood level at dam: 493 feet above msl
500-year flood level at dam: 503.25 feet above msl
Top of dam: 519 feet above msl
Dimensions: 20.25 miles long, 1,300 feet at widest point