Flaming Gorge Dam


Flaming Gorge Dam is on the Green River in northeastern Utah about 32 miles downstream from the Utah-Wyoming border. The concrete thin-arch structure has a maximum height of 502 feet and a crest length of 1,285 feet, and contains 987,000 cubic yards of concrete. The top thickness is 27 feet, and the maximum base thickness is 131 feet.

Floodwaters are spilled through a 675-foot-long tunnel spillway extending through the left abutment. The concrete-lined tunnel has a maximum capacity of 28,800 cubic feet per second and reduces in size from 26.5 feet in diameter at the upstream portal to 18 feet in diameter at the downstream portal. The spillway intake structure is controlled by two 16.75- by 34-foot hydraulically operated fixed-wheel gates.

The outlet works consist of two 72-inch steel pipes through the dam, reducing to 66 inches at the toe of the dam and continuing downstream to a valve structure on the left riverbank where discharge is directed into the river channel. Each outlet is controlled by a 66-inch hydraulically operated ring-follower gate at the downstream toe of the dam and a 66-inch hydraulically operated hollow-jet valve at the valve structure. Discharge capacity at elevation 6,045.0 feet is 4,000 cubic feet per second.

The Flaming Gorge Reservoir has a total capacity of 3,788,900 acre-feet and an active capacity of 3,515,700 acre-feet. At normal water surface elevation, the reservoir has a surface area of 42,020 acres. Three 10-foot-diameter penstock pipes near the center of the dam convey water to the powerplant. The powerplant is at the downstream toe of the dam and houses three 51,000-kilowatt generators driven by three 50,000-horsepower Francis-type turbines.


Foundation: Steep-sided narrow canyon composed of siliceous sandstone and hard quartzites inter-bedded with softer shales, siltstones, and argillates.

RegionFacilities in Upper Colorado | Upper Colorado Home Page
ProjectColorado River Storage
Dam Type
ReservoirGflaming Gorge
WatercourseGreen River
Net Generation344,369,058 kWh
Original Construction1958-1964
Modified Construction1978, 1984
National ID NumberUT10121
Hydrologic Unit Code

Structural Height502 ft
Hydraulic Height (Normal Operating Depth at Dam)453 ft
Top Parapet (Elevation)
Spillway Crest Elevation
Crest Elevation6047 ft
Crest Length1285 ft
Crest Width27 ft
Base Width131 ft
Volume of Dam Construction Materials986,000 cu. yd
Streambed at Dam Axis5592.0 ft
Top of Exclusive Flood Control Pool (Elevation)
Top of Joint Use Pool (Elevation)
Top of Active Conservation Pool (Elevation)6040.0 ft
Top of Inactive Conservation Pool (Elevation)5871.0 ft
Top of Dead Storage Pool (Elevation)5740.0 ft

Hydraulics & Hydrology
Total Water Storage at Elevation3788700 acre-ft at 6040
Maximum Water Surface Elevation6045.0 ft
Normal Water Surface Elevation
Spillway Type
Auxiliary Spillway
Spillway Capacity at Elevation28,000 cfs at 6046.0 ft
Auxiliary Spillway Capacity at Elevation
Uncontrolled Spillway Capacity at Elevation
Outlet Works Capacity at Elevation4,000 cfs at 6045.0 ft
Diversion Capacity at Elevation
Drainage Area15000 sq mi
Hydrometeorological Report (HMR)
Probable Maximum Flood (PMF) Report

Contact Information
Organization Western Colorado Area Office
Address 445 W. Gunnison Ave., Suite 221 
City Grand Junction, CO 81501
Phone (Office) 970 248-0600
OrganizationFlaming Gorge Field Division
Address575 South Boulevard
CityDutch John, UT 84023
Phone (Office)435 885-3106

Last updated: Feb 20, 2009