Twin Buttes Dam


Twin Buttes Dam is a 134-foot-high zoned earthfill structure with a crest of 30 feet and a crest length of over 8 miles. The embankment contains 21,465,854 cubic yards of material. An equalizing channel with a bottom width of 250 feet was excavated between the South Concho River and Spring Creek drainage areas. The outlet works for the dam, located near the left abutment, include an approach channel from the Middle Concho River, a concrete intake structure, 3-barreled concrete conduit with gate chambe and shaft, chute, and stilling basin. The spillway structure, also near the left abutment, is an uncontrolled ogee weir 200 feet in width. A concrete chute section, 320 feet long, extends from the crest to a stilling basin. Water from the stilling basins of both the spillway and outlet works discharges into a common channel.

Twin Buttes Reservoir has a total capacity of 640,580 acre-feet with a surface area of 23,508 acres. Active capacity of the reservoir is 632,210 acre-feet.

RegionFacilities in Great Plains | Great Plains Home Page
CountyTom Green
ProjectSan Angelo
Dam Type
ReservoirTwin Buttes
WatercourseSpring Creek
Original Construction1960-1963
Modified Construction
National ID NumberTX00022
Hydrologic Unit Code

Structural Height134.0 ft
Hydraulic Height (Normal Operating Depth at Dam)122.0 ft
Top Parapet (Elevation)
Spillway Crest Elevation1969.1 ft
Crest Elevation1991.0 ft
Crest Length42460.0 ft
Crest Width
Base Width
Volume of Dam Construction Materials
Streambed at Dam Axis
Top of Exclusive Flood Control Pool (Elevation)
Top of Joint Use Pool (Elevation)
Top of Active Conservation Pool (Elevation)1940.2 ft
Top of Inactive Conservation Pool (Elevation)1940.2 ft
Top of Dead Storage Pool (Elevation)1885.0 ft

Hydraulics & Hydrology
Total Water Storage at Elevation
Maximum Water Surface Elevation
Normal Water Surface Elevation1940.2 ft
Spillway Type
Auxiliary SpillwayNo
Spillway Capacity at Elevation
Auxiliary Spillway Capacity at Elevation
Uncontrolled Spillway Capacity at Elevation
Outlet Works Capacity at Elevation
Diversion Capacity at Elevation
Drainage Area
Hydrometeorological Report (HMR)
Probable Maximum Flood (PMF) Report

Contact Information
TitleArea Office Manager
OrganizationOklahoma-Texas Area Office
Address5316 HWY 290 W, Suite 510
CityAustin, TX 78735-8931
Phone (Office)512 899-4150
Phone (FAX)512 899-4179
OperatorNo value defined

Last updated: Jan 24, 2014