Tom Miller Dam is owned by the City of Austin. It is leased to and operated by the LCRA.
LCRA operates six hydroelectric dams on the Highland Lakes of central Texas. Wirtz Dam, at what used to be called Granite Shoals, backs uip water to create Lake LBJ. Five of the 6 LCRA dams were built for the primary purpose of making hydroelectric power. Although all LCRA dams can manage floodwaters, only Mansfield Dam, downstream at Lake Travis, was to hold back floodwaters.
From the LCRA website: (
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"LCRA dams form the Highland Lakes
Structures designed for flood management, water supply, hydroelectricity
LCRA operates six dams on the lower Colorado River in Central Texas: Buchanan, Inks, Wirtz, Starcke, Mansfield and Tom Miller. These dams form the six Highland Lakes: Buchanan, Inks, LBJ, Marble Falls, Travis and Austin.
Flood management
Each of the dams was built to manage floods, but Mansfield Dam, which forms Lake Travis, is the only one designed to hold back floodwaters.
. . .
Electricity
The dams in the Highland Lakes chain have hydroelectric generation stations that contribute to the Central Texas energy supply. Together, the hydroelectric plants at the dams can provide more than 295 megawatts of electricity per year.
Hydroelectricity was once the major source of power for LCRA's electric service area, but hydroelectric generation now is primarily a byproduct of other river operations. Water is moved through hydroelectric generation solely to create power at the request of the Electric Reliability Council of Texas during a power emergency.
From the Tom Miller Dam page: (
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Tom Miller Dam and Lake Austin
Dam built atop of two earlier structures destroyed by floods
Leased from the City of Austin
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 1912 to 1915. Massive floods destroyed the first dam and heavily damaged the second. The lake originally was called Lake McDonald.
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
Primary purposes: Hydroelectric power, water supply
Generating capacity: 17 megawatts
Top of dam: 519 feet above msl
Spillway elevation: 492.8 feet above msl
Floodgates: nine
Total discharge capacity: 107,700 cubic feet per second (cfs):
4 large floodgates @ 15,300 cfs each
5 small floodgates @ 8,600 cfs each
2 turbines @ 1,750 cfs each
Original name: Tom Miller Dam
Details on Lake Austin
Lake area: 1,830 acres
Elevation when full: 492.8 feet above mean sea level (msl)
Volume when full: 24,644 acre-feet
Historic high: 495.2 feet above msl on May 25, 1981
Historic low: 474.3 feet above msl on Feb. 17, 1963
Target operating range: 491.8 to 492.8 feet above msl
100-year flood level at dam: 493 feet above msl
Dimensions: 20.25 miles long, 1,300 feet at widest point
Original name: Lake McDonald