Grand Coulee Dam facts for kids
Quick facts for kids Grand Coulee Dam |
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| Country | United States |
| Location | Grant / Okanogan counties, Washington |
| Purpose | Power, regulation, irrigation |
| Status | Operational |
| Construction began | July 16, 1933 |
| Opening date | June 1, 1942 |
| Construction cost | Original dam: $163 million 1943 Third powerplant: $730 million 1973 |
| Operator(s) | Bureau of Reclamation |
| Dam and spillways | |
| Type of dam | Concrete gravity |
| Impounds | Columbia River |
| Height | 550 ft (168 m) |
| Length | 5,223 feet (1,592 m) |
| Width (crest) | 30 ft (9 m) |
| Width (base) | 500 ft (152 m) |
| Dam volume | 11,975,520 cu yd (9,155,942 m3) |
| Spillway type | Service, drum gate |
| Spillway capacity | 1,000,000 cu ft/s (28,317 m3/s) |
| Reservoir | |
| Creates |
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| Total capacity | 9,562,000 acre⋅ft (12 km3) |
| Active capacity | 5,185,400 acre⋅ft (6 km3) |
| Catchment area | 74,100 sq mi (191,918 km2) |
| Surface area | 125 sq mi (324 km2) |
| Power station | |
| Commission date | 1941–1950 (Left/Right) 1975–1980 (Third) 1973–1984 (PS) |
| Type | Conventional, pumped-storage |
| Hydraulic head | 380 ft (116 m) |
| Turbines | 33: 27 × Francis turbines 6 × pump-generators |
| Installed capacity | 6,809 MW 7,079 MW (max) |
| Capacity factor | 36% |
| Annual generation | 20.24 TWh |
| Website http://www.usbr.gov/pn/grandcoulee/ |
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The Grand Coulee Dam is a huge concrete dam on the Columbia River in Washington, USA. It was built to create hydroelectric power (electricity from water) and to provide water for farms. Construction started in 1933 and finished in 1942.
When it was first built, the Grand Coulee Dam had two powerhouses. Later, a third powerhouse was added in 1974. This made Grand Coulee the largest power station in the United States. It can produce 6,809 MW of electricity.
Building the dam was a big debate in the 1920s. Some people wanted to water the dry Grand Coulee area using a canal. Others wanted a tall dam that could pump water to farms. The dam supporters won in 1933.
At first, the plan was for a "low dam" about 290 feet (88 m) tall. This dam would make electricity but not help with irrigation. However, after President Franklin Delano Roosevelt visited the site in 1934, he supported a "high dam" design. This taller dam, at 550 ft (168 m) high, would make enough electricity to pump water for farming.
Congress approved the high dam in 1935, and it was finished in 1942. The first water flowed over the dam's spillway on June 1 of that year.
The dam's power helped industries in the Northwest United States during World War II. Later, from 1967 to 1974, the third powerhouse was built. This was due to a growing need for energy and agreements with Canada about river flows.
Today, the dam has four power stations that can produce 6,809 MW of electricity. It is a key part of the Columbia Basin Project. The dam's reservoir provides water to irrigate about 671,000 acres (2,700 km2) of farmland.
The reservoir behind the dam is called Franklin Delano Roosevelt Lake. It is named after the president who supported the dam. Building the reservoir meant that over 3,000 people had to move. This included Native American families whose lands were flooded.
The Grand Coulee Dam does not have a way for fish to pass through it. This means salmon cannot reach their old spawning grounds upstream. Other dams downstream, like Wells Dam, have special fish ladders to help salmon migrate.
Contents
Why the Dam Was Built
Early Ideas for Irrigation
The Grand Coulee is an old riverbed on the Columbia Plateau. It was formed by glaciers and huge floods long ago. People first thought about using the Columbia River to water the Grand Coulee in 1892. A man named Laughlin McLean suggested building a 1,000 ft (305 m) dam. This dam would make water flow back into the Grand Coulee. However, such a large dam would flood land in Canada, which was against treaties.
After the Bureau of Reclamation was created, it looked into pumping water from the Columbia River. This water would be used to irrigate parts of central Washington. But in 1914, voters in Washington rejected a plan to raise money for irrigation.
The "Dam College" and Two Ideas
In 1917, a lawyer named William M. Clapp suggested damming the Columbia River right below the Grand Coulee. He thought a concrete dam could flood the plateau, just like ice did centuries ago. Clapp teamed up with James O'Sullivan, another lawyer, and Rufus Woods, a newspaper publisher. They were called the "Dam College." Woods used his newspaper, The Wenatchee World, to promote the Grand Coulee Dam.
By 1918, the idea of the dam became popular. People who wanted to reclaim land in Central Washington split into two groups:
- The "pumpers" wanted a dam with pumps to lift water from the river into the Grand Coulee. From there, canals would water farms.
- The "ditchers" wanted to bring water from the Pend Oreille River in northeast Washington using a canal. This water would flow by gravity to irrigate farms.
Many local people, like Woods, O'Sullivan, and Clapp, were pumpers. But powerful business people in Spokane, connected to the Washington Water and Power Company (WWPC), were ditchers. The pumpers argued that electricity from the dam could help pay for it. They also said the ditchers wanted to control all the electric power.
Challenges and Support for the Dam
The ditchers tried to stop the dam. In 1921, WWPC got a permit to build a dam at Kettle Falls. This dam would have blocked the Grand Coulee Dam's reservoir. WWPC also spread rumors that the Grand Coulee site was not strong enough for a dam. But later studies proved this wrong.
In July 1923, President Warren G. Harding visited Washington and supported irrigation. But he died a month later. The next president, Calvin Coolidge, was not very interested in such projects. The Bureau of Reclamation focused on the Hoover Dam instead.
In 1925, Congress asked the U.S. Army Corps of Engineers to study the Columbia River. Major John Butler's report in 1932 suggested building the Grand Coulee Dam and nine others. It said that selling electricity from the dam could pay for its construction. The Bureau of Reclamation supported this idea.
Some people still argued that the Northwest didn't need more electricity, and there were already too many crops. But the head of Reclamation, Elwood Mead, wanted the dam built no matter what. When President Franklin D. Roosevelt took office in 1933, he supported the dam. He liked its potential for irrigation and power. However, he was worried about the high cost of $450 million. So, he first supported a "low dam" of 290 ft (88 m).
Roosevelt provided $63 million in federal money, and Washington State added $377,000. In 1933, Washington's governor, Clarence Martin, created the Columbia Basin Commission to oversee the project. The Bureau of Reclamation was chosen to manage the construction.
Building the Grand Coulee Dam
Starting with the Low Dam
On July 16, 1933, about 3,000 people watched the first stake being driven at the low dam site. Digging for the foundation began soon after. The low dam was designed so it could be made taller later. It would help with floods, irrigation, and electricity, but on a smaller scale.
Workers and engineers faced many challenges. It was hard to find companies big enough to take on the different parts of the dam's construction. This made companies join together. Native American graves had to be moved, and temporary fish ladders were built. Landslides were also a problem, and new concrete had to be protected from freezing.
To dig out the dam's foundation, workers had to remove 22 million cubic yards (17 million m³) of dirt and rock. They built a conveyor belt nearly 2 mi (3.2 km) long to move the dirt. To make the foundation strong, workers drilled deep holes into the granite and filled cracks with grout. Sometimes, excavated areas would collapse. To stop this, pipes were put into the ground and chilled with cold liquid, freezing the earth so work could continue.
The main contract for the dam was given to MWAK, a group of three companies: Silas Mason Co., Walsh Construction Co., and Atkinson-Kier Company. Their bid was $29,339,301, which was much lower than other bids.
Building Cofferdams
Two large cofferdams were built to create dry areas for construction. These dams were parallel to the river. By the end of 1935, about 1,200 workers finished the west and east cofferdams. The west cofferdam was 2,000 ft (610 m) long and 50 ft (15 m) thick. These cofferdams allowed workers to build parts of the dam while the river still flowed through the middle.
In August 1936, after the west foundation was done, parts of the west cofferdam were removed. This let water flow through the new dam foundation. By December 1936, the entire Columbia River was redirected over the foundations. People came in large numbers to see the riverbed in early 1937.
Changing the Design to a High Dam
On August 4, 1934, President Franklin D. Roosevelt visited the construction site. He was very impressed. He told workers, "I leave here today with the feeling that this work is well undertaken; that we are going ahead with a useful project, and we are going to see it through for the benefit of our country."
Soon after, Reclamation was allowed to build the high dam. This meant changing the design and making a new agreement with MWAK. In June 1935, MWAK and Six Companies, Inc. (who built the Hoover Dam) joined to form Consolidated Builders Inc. They agreed to build the high dam for an extra $7 million. The new design included a pumping plant for irrigation.
President Roosevelt saw the dam as part of his New Deal plan. It would create jobs and farming chances. He also wanted to keep electricity prices low by limiting private power companies. In August 1935, with Roosevelt's help, Congress approved funding for the upgraded high dam. This was a major step forward for the project.
Pouring Concrete and Finishing the Dam
On December 6, 1935, Governor Clarence Martin oversaw the first ceremonial concrete pour. Concrete was brought by train, mixed, and then placed into large forms by cranes. To cool the concrete and help it harden, about 2,000 mi (3,200 km) of pipes were placed inside the dam. Cold river water was pumped through these pipes. This cooled the concrete from 105 °F (41 °C) to 45 °F (7 °C). This cooling caused the dam to shrink about 8 inches (20 cm) in length. The gaps that formed were then filled with grout.
Before the dam, there was no bridge across this part of the Columbia River. This made it hard to move workers and materials. In January 1936, the Grand Coulee Bridge, a permanent highway bridge, opened. By March 1938, the lower dam was finished, and Consolidated Builders Inc. began building the high dam.
In December 1939, the west powerhouse was completed. About 5,500 workers were on site that year. Between 1940 and 1941, the dam's eleven floodgates were installed. In January 1941, the dam's first generator started working. On June 1, 1942, the reservoir was full, and water flowed over the spillway for the first time. The dam was officially completed on January 31, 1943.
Clearing the Reservoir Area
In 1933, Reclamation began buying land for the future reservoir, which would stretch 151 mi (243 km) upstream. This area, later called Lake Roosevelt, would flood 70,500 acres (285 km2) of land. Eleven towns, two railroads, and many roads, bridges, and power lines were in this zone. All these things had to be bought or moved, and 3,000 residents had to relocate.
Members of the Colville Confederated and Spokane tribes also had settlements in the reservoir zone. Their lands were acquired, and they were resettled. By 1942, all the land was bought for $10.5 million. This cost included moving farms, bridges, and roads.
In late 1938, the Works Progress Administration began clearing 54,000 acres (220 km2) of trees and plants. The cut timber was sold. The clearing work sped up in April 1941 because it was needed for national defense. The last tree was cut down on July 19, 1941, in a ceremony. Over 2,600 people worked on this project.
Workers and Their Homes
Workers building the dam earned about 80¢ an hour. The dam's payroll was one of the largest in the country. Most workers came from nearby counties. Women were allowed to work in the dorms and cookhouses. About 8,000 people worked on the project. Building conditions were dangerous, and 77 workers died.
To house the workers, new towns were built. The Bureau of Reclamation built Engineer's Town. MWAK built Mason City in 1934, which had a hospital, post office, and electricity. Mason City had 3,000 people, and houses rented for $32 a month. Other living areas, called Shack Town, did not have good access to electricity. The city of Grand Coulee also supported workers. In 1956, Mason City and Engineer's Town were combined to form the city of Coulee Dam.
Irrigation System
When World War II started, making electricity became more important than irrigation. In 1943, Congress approved the Columbia Basin Project. The Bureau of Reclamation began building irrigation facilities in 1948.
The North Dam and Dry Falls Dam were built near the Grand Coulee Dam. These dams created Banks Lake, which covers the northern 27 mi (43 km) of the Grand Coulee. Other dams, siphons, and canals were built to create a huge irrigation network. Irrigation began between 1951 and 1953. Six of the 12 pumps were installed, and Banks Lake was filled.
Expanding the Dam
The Third Powerplant
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After World War II, the demand for electricity grew. This led to interest in building another power plant at the Grand Coulee Dam. One challenge was that the Columbia River's flow changed a lot throughout the year. Historically, about 75% of the river's water flowed between April and September. During low flow times, only half of the dam's generators could run all year.
To make a new power plant work, the river's flow needed to be controlled more. This would require water storage projects in Canada and a treaty. The Columbia River Treaty had been discussed since 1944 and was seen as the solution. Building the Third Powerplant was also influenced by competition with the Soviet Union, which had built larger power plants.
On September 16, 1964, the Columbia River Treaty was approved. Canada agreed to build the Duncan, Keenleyside, and Mica Dams upstream. The U.S. would build the Libby Dam in Montana. Soon after, the Third Powerplant was approved. President Lyndon Johnson signed the bill on June 14, 1966.
Between 1967 and 1974, the dam was expanded to add the Third Powerplant. This involved digging out a huge amount of dirt and rock. A new 1,725 ft (526 m) section of the dam was built. This made the original 4,300 ft (1,300 m) dam almost a mile long. The new powerhouse was designed to hold six of the largest generators available. To power them, six 40 ft (12 m) diameter penstocks (large pipes) were installed. The first new generator started in 1975, and the last one in 1980. Some of these units were later upgraded to be even more powerful.
Pump-Generating Plant
After power shortages in the 1960s, it was decided that the remaining six planned pumps should also be pump-generators. These machines can generate electricity when demand is high. They use water from the Banks Lake feeder canal, which is at a higher elevation.
By 1973, the Pump-Generating Plant was finished, and the first two generators were working. By January 1984, all six were operational. These six pump-generators added 314 MW to the dam's power capacity. In May 2009, the plant was renamed the John W. Keys III Pump-Generating Power Plant.
Upgrades and Maintenance
A major overhaul of the Third Powerplant began in March 2008. This project will continue for many years. It includes replacing old cables with new overhead lines and installing new transformers. Overhauls for the largest generators are planned to start in 2013 and finish by 2017.
How the Dam Works and Its Benefits
The dam's main purpose, irrigation, was put on hold when World War II started. The dam's powerhouses began producing electricity around the start of the war. This electricity was very important for the war effort. It powered aluminum factories, Boeing airplane factories, and shipyards. In 1943, its electricity was also used to make plutonium at the Hanford Site, which was part of the secret Manhattan Project.
Irrigation for Farms
Water is pumped from Lake Roosevelt up 280 ft (85 m) through 12-foot (3.7 m) diameter pipes. This water goes into a 1.6 mi (2.6 km) feeder canal. From there, it flows into Banks Lake. The plant's twelve pumps can move up to 1,605 cu ft/s (45 m3/s) of water to the lake.
Today, the Columbia Basin Project irrigates about 670,000 acres (2,700 km2) of land. It has the potential to irrigate 1.1 million acres. Over 60 different crops are grown in this area and sent all over the United States.
Generating Power
Grand Coulee Dam has four powerhouses with 33 hydroelectric generators.
- The original Left and Right Powerhouses have 18 main generators and 3 service generators. Their total capacity is 2,280 MW. The first generator started in 1941, and all 18 were working by 1950.
- The Third Power Plant has six main generators with a 4,215 MW capacity. Some of these can operate at a maximum of 690 MW each.
- The Pump-Generating Plant has six pump-generators with a 314 MW capacity. When they pump water into Banks Lake, they use 600 MW of electricity.
Each generator gets water from its own penstock (large pipe). The biggest penstocks are 40 ft (12 m) in diameter and can supply up to 35,000 cu ft/s (990 m3/s) of water. The dam's power facilities now have a total installed capacity of 6,809 MW, with a maximum of 7,079 MW. Grand Coulee Dam generates about 21 TWh of electricity each year.
| Location | Type | Quantity | Capacity (MW) | Total capacity (MW) |
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| Left Powerhouse | Francis turbine, service generator | 3 (LS1-LS3) | 10 | 30 |
| Francis turbine, main generator | 9 (G1-G9) | 125 | 1,125 | |
| Right Powerhouse | Francis turbine, main generator | 9 (G10-G18) | 125 | 1,125 |
| Third Power Plant | Francis turbine, main generator | 3 (G22-G24) | 805 | 2,415 |
| Francis turbine, main generator | 3 (G19-G21) | 600 (Max: 690 MW) | 1,800 | |
| Pump-Generating Plant | Pump-generator, peak generator | 4 (PG9-PG12) | 53.5 | 214 |
| Pump-generator, peak generator | 2 (PG7-PG8) | 50 | 100 | |
| Totals | 33 | 6,809 |
The Spillway
The Grand Coulee Dam's spillway is 1,650 feet (500 m) long. It's designed to let excess water flow over the dam. In May and June 1948, a record flood caused water to flow at 637,800-cubic-foot-per-second (18,060 m3/s). This flood damaged areas downstream and the dam's spillway. This event helped lead to the Columbia River Treaty, which aimed to control the river's flow better with dams in Canada.
Economic Success
The Bureau of Reclamation thought the dam would cost $168 million. It actually cost $163 million in 1943. Even with later additions and repairs, the dam became an economic success. The Third Powerplant, for example, brought in twice as much money as it cost to build. The Bureau expects that the money earned from selling power and irrigation water will pay off the construction cost by 2044.
Impact on Environment and People
The dam had a big impact on the local Native American tribes. Their traditional way of life depended on salmon and the natural environment. Because the dam has no fish ladder, it completely blocks fish migration. This removed over 1,100 mi (1,770 km) of natural spawning grounds for salmon.
This meant that salmon, like Chinook and Sockeye, could no longer reach the upper Columbia Basin. The "June hogs," very large salmon that weighed over 80 pounds, disappeared. The Spokane and other tribes could no longer hold their sacred salmon ceremonies after 1940.
The Grand Coulee Dam flooded over 21,000 acres (85 km2) of important land. Native Americans had lived and hunted there for thousands of years. Their settlements and burial sites had to be moved. The government worked with tribes to move human remains to new burial sites. Many artifacts were found, but the way they were collected damaged archaeological evidence.
The town of Inchelium, Washington, home to about 250 Colville Indians, was submerged and later moved. Kettle Falls, a main Native American fishing spot, was also flooded. The average catch of over 600,000 salmon per year was lost. In June 1940, the Confederated Tribes of the Colville Reservation held a "Ceremony of Tears" to mark the end of fishing at Kettle Falls.
The dam also affected animals like mule deer and pygmy rabbits, causing their populations to decrease. However, it also created new habitats like wetlands. The dam changed the traditional way of life for native people. The government later paid the Colville Indians about $53 million in the 1990s, plus annual payments. In 2019, a bill was passed to give more money to the Spokane Tribe.
To help with the lack of fish passage, three fisheries have been created above the dam. These fisheries release fish into the upper Columbia River. Half of these fish are for the displaced tribes. Also, one quarter of the reservoir is set aside for tribal hunting and boating.
Visiting the Dam
The Visitor Center, built in the late 1970s, has many historical photos, rock samples, and models of the dam and turbines. The building was designed by Marcel Breuer. Since May 1989, a laser light show is projected onto the dam's wall on summer evenings. The show includes images of battleships and the Statue of Liberty.
You can take tours of the Third Power Plant, which last about an hour. Visitors take a shuttle to see the generators and travel across the main dam. The headquarters of the Lake Roosevelt National Recreation Area is near the dam. The lake is a great place for fishing, swimming, canoeing, and boating.
  Grand Coulee Dam
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Woody Guthrie's Connection
Folk singer Woody Guthrie wrote some of his most famous songs while working near the dam in the 1940s. In 1941, Guthrie moved to Oregon for a job. He was asked to narrate a documentary for the Bonneville Power Administration about the Grand Coulee Dam. He was also asked to sing songs for the film.
The Department of the Interior hired him for one month to write songs about the Columbia River and the federal dams. Guthrie traveled around the Columbia River and the Pacific Northwest. He said he "couldn't believe it, it's a paradise," which inspired him. In one month, Guthrie wrote 26 songs. Three of his most famous are "Roll On, Columbia, Roll On", "Pastures of Plenty", and "Grand Coulee Dam". The songs that survived were released as Columbia River Songs. Guthrie was paid $266.66 for his work in 1941.
The film Columbia River was finished in 1949 and included Guthrie's music. The project had been delayed by World War II.
See also
In Spanish: Presa Grand Coulee para niños
