Flaming Gorge Dam facts for kids

Quick facts for kids Flaming Gorge Dam
Location	Daggett County, Utah
Coordinates	40°54′52″N 109°25′17″W / 40.91444°N 109.42139°W / 40.91444; -109.42139
Construction began	1958
Opening date	1964
Owner(s)	U.S. Bureau of Reclamation
Dam and spillways
Type of dam	Concrete thin arch
Impounds	Green River
Height	502 ft (153 m)
Length	1,285 ft (392 m)
Elevation at crest	6,047 ft (1,843 m)
Spillways	Gated concrete tunnel
Spillway capacity	28,800 cu ft/s (820 m3/s)
Reservoir
Creates	Flaming Gorge Reservoir
Total capacity	3,788,700 acre⋅ft (4.6733 km3)
Catchment area	15,000 sq mi (39,000 km2)
Surface area	42,020 acres (17,000 ha)
Normal elevation	6,040 ft (1,840 m)
Power station
Hydraulic head	400 ft (120 m)
Turbines	3x Francis
Installed capacity	151.95 MW
Capacity factor	25.9%
Annual generation	344,369,058 KWh

The Flaming Gorge Dam is a huge concrete dam in northern Utah, United States. It was built on the Green River, which is a big branch of the Colorado River. This dam creates the Flaming Gorge Reservoir.

The reservoir stretches about 91 miles (146 km) into southern Wyoming. It covers four deep canyons of the Green River. The dam is a key part of the Colorado River Storage Project. This project helps store and share water from the upper Colorado River area.

The dam gets its name from a nearby canyon. Explorer John Wesley Powell named it in 1869. The U.S. Bureau of Reclamation built the dam between 1958 and 1964. It stands 502 feet (153 meters) tall and is 1,285 feet (392 meters) long.

The reservoir can hold over 3.7 million acre-feet (4.6 cubic kilometers) of water. This is about twice the amount of water that flows through the upper Green River in a year. The dam helps store water for people downstream. It also makes a lot of hydroelectricity (power from water). Plus, it's the main way to control floods on the Green River.

The dam and reservoir have changed the Green River. They block fish from moving and affect many native animals. Water from the dam is usually cold and clear. The river's natural flow was warm and silty. This change has also affected the river's environment. However, the cold water has created a great "Blue Ribbon Trout Fishery" for about 28 miles (45 km) of the Green River. The Flaming Gorge Reservoir is also famous for fishing in Utah and Wyoming.

The Dam's Story and Where It Is

The Flaming Gorge Dam is actually in a place called Red Canyon. This canyon is in northeastern Utah. It's a steep canyon with fast-moving water. The canyon that gave the dam its name, Flaming Gorge, is about 20 miles (32 km) upstream. It is now covered by the reservoir.

Red Canyon was the best spot for the dam. It was the narrowest and deepest of the four canyons there. John Wesley Powell named Flaming Gorge in 1869. He saw the "brilliant, flaming red of its rocks" when the sun shined on them.

Why the Dam Was Built: The Colorado River Project

Flaming Gorge Dam is one of six dams in the Colorado River Storage Project (CRSP). This huge project built many reservoirs in the upper Colorado River Basin. The Bureau of Reclamation built them from the 1950s to the 1970s.

The project was needed because of agreements made in the early 1900s. These agreements divided the Colorado River's water among seven U.S. states and two Mexican areas. The 1922 Colorado River Compact set aside water for the Upper Basin states (Wyoming, Colorado, Utah, New Mexico). It also set aside an equal amount for the Lower Basin states (Arizona, Nevada, California).

The river's flow changes a lot each year. In dry years, the Upper Basin couldn't send enough water to the Lower Basin. In wet years, a lot of water was wasted because there was no way to store it. So, dams were needed to store water.

Choosing the Dam Site

Before the CRSP started in 1956, the Bureau of Reclamation looked for good places to build reservoirs. They checked the upper Colorado River and its branches. One early idea was the Echo Park Dam. This dam would have been built inside the Dinosaur National Monument.

The Sierra Club, an environmental group, fought against the Echo Park Dam. They used the media and courts to stop it. The Bureau of Reclamation decided not to build the Echo Park Dam. This was an early win for the environmentalism movement.

However, a dam was still needed on the Green River. So, they decided to build it about 50 miles (80 km) upstream. This new spot was near the bright red-rock canyon called Flaming Gorge. Many people think the Glen Canyon Dam was part of this deal. But the Bureau had always planned to build a dam at Glen Canyon anyway.

Besides holding back the Green River, Flaming Gorge Dam also carries U.S. Route 191 across the river.

Climate Around Flaming Gorge Dam

Building the Dam

Construction of Flaming Gorge Dam began soon after the CRSP was approved. President Dwight D. Eisenhower started it with a special blast. This first blast happened in Red Canyon.

Workers prepared the site and checked the geology. A town called Dutch John was built nearby by 1958. This town housed the workers. At its busiest, over 3,000 people lived in Dutch John.

Arch Dam Constructors won the main contract to build the dam. This was a group of several construction companies. Actual building at the dam site started in late 1958. They began by digging a tunnel to send the Green River around the dam area. This cleared the spot for construction.

Flaming Gorge Damsite on June 30, 1960

Construction work on Flaming Gorge Dam in 1962

River Diversion and Foundation Work

By April 1959, the diversion tunnel was finished. Its concrete lining was completed in August. Next, workers built two earthen dams called cofferdams. These were placed above and below the main dam site. On November 19, the river was sent through the tunnel. This allowed the dam site to be dry.

In September, they started digging the foundation for the dam. They also built the spillway entrance. All these early structures were done by early 1960. The lower cofferdam was finished in February. This let workers pump water out from between the two barriers.

They had to remove all the silt and sediment from the riverbed. This was done to reach solid rock for the foundations. This important step was finished in August 1960. Then, work on the main dam foundations could begin.

Building the Dam Wall

Flaming Gorge Dam was built using large concrete blocks. The first concrete for the power plant was poured on September 8. Building the main dam wall started ten days later. To make the concrete harden faster, cold water was pumped through metal tubes inside the dam.

Concrete pouring continued until November 15, 1962. On that day, workers finished the top of the dam. By the end of 1962, the river outlet works and spillway tunnel were also done. The diversion tunnel was closed, and water began to fill behind the dam.

The dam's power generators were installed by mid-August 1963. The first one started working on September 27. President John F. Kennedy pressed a switch to turn it on. The dam was officially opened by Lady Bird Johnson on August 17, 1964.

Dam Size and How It Works

Flaming Gorge Reservoir in Wyoming

Dam and Reservoir Details

The Flaming Gorge Dam is 502 feet (153 meters) tall from its base. It rises 448 feet (137 meters) above the Green River. The dam is 1,285 feet (392 meters) long at its top. Its base is 131 feet (40 meters) thick, and its top is 27 feet (8.2 meters) thick. The dam contains about 987,000 cubic yards (755,000 cubic meters) of concrete.

The reservoir first reached its highest level in August 1974. At that point, its surface covered 42,020 acres (170 square kilometers). It can hold 3,788,700 acre-feet (4.67 cubic kilometers) of water. Most of this water (3,515,700 acre-feet or 4.33 cubic kilometers) can be used for release and power. During floods, the reservoir can rise even higher. It can hold up to 4,003,100 acre-feet (4.94 cubic kilometers) and cover 43,820 acres (17,730 hectares).

Making Electricity: The Power Plant

The dam has a power plant at its base. It has three generators, each making 50,650 kilowatts of power. These are powered by three Francis turbines, each with 50,000 horsepower. In total, the Flaming Gorge Dam can make 151,950 kilowatts of electricity.

Three large pipes, 10 feet (3 meters) wide, carry water to the power plant. The Bureau of Reclamation runs the power plant. The Western Area Power Administration sells the electricity. When first built in 1963, the power plant made 108,000 kilowatts. The generators were upgraded between 1990 and 1992 to their current power.

The power plant used to release water in a way that caused big changes in the river flow. There were high flows during the day and very low flows at night. In 1992, new rules were made to protect endangered fish. In 2006, the water release patterns were changed again. Now, the power plant releases water to copy the natural flow of the Green River before the dam was built. Also, water flow must always stay above 800 cubic feet per second (23 cubic meters per second).

Spillways for Flood Control

The dam's spillway is a 675-foot (206-meter) long tunnel. It goes through the left side of the dam. Two large gates at the tunnel entrance can let out up to 28,800 cubic feet per second (816 cubic meters per second) of floodwater. The tunnel is 26.5 feet (8.1 meters) wide at the start and 18 feet (5.5 meters) wide at the end.

The dam also has two other ways to release water. These are two 72-inch (1.8-meter) wide steel pipes through the dam. They can release 4,000 cubic feet per second (113 cubic meters per second). Because the reservoir can hold so much water, the spillway tunnel is not used often. It's mainly used in years with very high water, like 1983–84. When first built, the spillway had some damage from fast-moving water. An "aeration slot" was added in the mid-1980s to fix this problem.

Changes to the Environment

An aerial view of the Flaming Gorge Dam, by the U.S. Bureau of Reclamation.

Flaming Gorge Dam has greatly changed the Green River. It stops big floods and keeps low flows higher than they would be naturally. This is especially true above where the Green River meets the Yampa River. The loud roar of spring floods in places like the Canyon of Lodore is now much quieter.

The dam has caused more plants to grow along the riverbanks. These plants would not have grown naturally because floods used to wash them away. Fewer changes in water flow have also reduced places for amphibians to live. The dam traps the river's natural mud and sand. This has harmed many native fish. The cold, clear water released from the dam has also caused sandbars to disappear and banks to erode. This means important homes for four types of native fish have been lost.

In 2008, the Bureau of Reclamation studied how the dam affects the environment. This was to make sure the dam followed rules to protect endangered fish. The four native fish affected are the razorback sucker, Colorado pikeminnow, humpback chub, and bonytail chub.

However, the cold water has helped many introduced trout fish grow. About 28 miles (45 km) of the Green River below the dam is a "Blue Ribbon Trout Fishery." Further downstream, the water gets warmer, which is better for native fish. Also, Flaming Gorge Reservoir is "nationally known for the spectacular fishing." Its cool, clear water is perfect for growing large trout.

Plans for Moving Water

Since the early 2000s, the Colorado River system has faced problems due to a serious drought. The Front Range Urban Corridor in Colorado is growing fast. This area gets water from the Colorado River, even though it's not in the river basin. It's predicted that this area could run out of water in about 20 years if new water sources aren't found.

One idea to get more water is to build a 501-mile (806-km) pipeline. This pipeline would go from Flaming Gorge Reservoir to southeastern Wyoming and then to eastern Colorado. This project would cost about $9 billion. It would provide about 160,000 to 200,000 acre-feet (0.20 to 0.25 cubic kilometers) of new water each year. Even though eastern Colorado is lower than Flaming Gorge, the water would need to be pumped over the Rocky Mountains. This would use a lot of electricity.

This plan has caused big arguments over water rights. About 87% of Wyoming residents surveyed were against the project. Both the Federal Energy Regulatory Commission and U.S. Army Corps of Engineers have said no to permits for building this project.

The lower end of Flaming Gorge Reservoir is seen nearly full in July 2010. The Flaming Gorge Dam is seen to the left.

See also

• Blue Mesa Dam
• Dams in the Colorado River system
• List of reservoirs and dams in the United States
• List of the tallest dams in the United States
• Navajo Dam