Wirtz Dam and Lake LBJ

Lake provides cooling water for nearby power plant

Once named Granite Shoals


Wirtz Dam, owned by LCRA, creates Lake ​LBJ.

Wirtz Dam was built from 1949 to 1951 primarily to provide additional hydroelectric power. It was built in tandem with Starcke Dam downstream. Lake LBJ provides cooling water for LCRA's Thomas C. Ferguson Power Plant along Horseshoe Bay.

The dam and lake originally were called Granite Shoals. The dam was renamed in 1952 for Alvin J. Wirtz who was instrumental in LCRA's creation and served as its first general counsel. The lake was renamed in 1965 for another advocate of LCRA, President Lyndon B. Johnson.

For information about parks on Lake LBJ, see map of parks and recreation areas.

​FYI: Wirtz Dam

Location: Llano and Burnet counties, 387 river miles from the Gulf of Mexico
When built: 1949 to 1951
Dam dimensions: 118.3 feet high, 5,491.4 feet long
Primary purpose: Hydroelectric power, cooling water for Thomas C. Ferguson Power Plant
Generating capacity: 60 megawatts
Top of dam: 838 feet above msl
Floodgates: 10
Discharge capacity: 317,400 cubic feet per second (cfs):

  • 10 floodgates @ 30,800 cfs each
  • 2 turbines @ 4,700 cfs each

Original name: Granite Shoals Dam​

Details on Lake LBJ

Lake area: 6,275 acres
Lake elevation when full: 825 feet above mean sea level (msl)
Volume when full: 133,216 acre-feet
Historic high: 836.2 feet above msl on Sept. 11, 1952
Historic low: 793.8 feet above msl on Nov. 16, 1970
Target operating range: 824.4 feet to 825 feet above msl
100-year flood level at dam: 828.1 feet above msl
Dimensions: 21.15 miles long and 10,800 feet at widest point
Original name: Lake Granite Shoals