Five massive turbines powered by water flowing through tunnels connected to nearby Lake Sakakawea spin an equal amount of huge generators that produce electricity. Hyrdoelectric power generated in North Dakota supplies clean, reliable electricity to customers across a wide area of the U.S.

“The country has become so dependent on having their electricity all the time, twenty-four seven,” said Todd Lindquist, U.S. Army Corps of Engineers Garrison Dam project manager. “The reliability has become a much bigger focus in recent years than it has been in the past just because a short outage can have significant impacts.”

Dale Evenson is the manager of the Garrison Dam Power Plant. He understands the importance of power produced at the North Dakota hydroelectric facility.

“Power from the Garrison Power Plant is tied to the grid which is marketed by the Western Power Administration,” said Evenson. “The grid is fairly large. Western Area Power and the Southwest Power Pool is what we are a part of now. It’s pretty much down the central portion of the U.S.”

Kim Fundingsland/MDN This photograph shows the Garrison Dam spillway as it was nearing completion of construction. The spillway was completed in 1956. Note the workers at the left center of the photograph.

The five hydroelectric turbines that drive the power plant generators are capable of creating about 575,000 megawatts of electricity. It is a significant amount of power. About 200 megawatts is what is generally needed for a city of 150,000 people.

“The amount of power we can produce is largely determined by the elevation of Lake Sakakawea and the volume of water we have to release,” said Lindquist. “When we do have available water we utilize it as much as possible to generate hydropower.”

Hydropower is one of eight authorized purposes of the Garrison Project, not the only purpose. Sometimes a balancing act is required for the Corps of Engineers to meet all of the authorized purposes, but hydroelectric power remains a key factor as the demand for “green” energy continues to grow.

“Hydropower is a green source of energy,” says Lindquist. “It’s very reliable. We have a lot more flexibility than other types of facilities because we can start and stop quickly.”

It takes just a few minutes to open the gates to the tunnels that funnel water to the power generating turbines. That means electricity can begin flowing almost as soon as the need arises. A new switchyard that came on line in recent years has further boosted the reliability of electricity produced at Garrison Dam, giving the facility modern, state of the art control systems.

“What impresses me the most at this facility is the reliability and consistency of the power that we produce and the minimal numbers of failure and breakdowns,” said Lindquist.

According to Evenson about 21 people work at the power plant, making it a very efficient operation for the volume of power produced. Profit from the sale of electricity generated at the plant, which approaches $40 million per year, goes directly into the nation’s treasury.

Workers began grading the embankment that later became Garrison Dam in 1947. The power plant and electrical switchyard were completed in 1956, the year the first hydropower was produced at Garrison Dam.

One of the most impressive structures associated with the power plant is the intake structure situated on the Lake Sakakawea side of Garrison Dam, just above the power plant. It is there that water enters five 24-foot diameter tunnels traveling underneath the dam to the five turbines in the power plant. The huge tunnels are 1,466 feet in length.

The intake has the unique distinction of being the tallest building in North Dakota. The state capitol building in Bismarck, known as the “Skyscraper on the Prairie,” is 21 stories tall and just inches short of 242 feet. The Garrison Dam intake structure, although much of it lies under water, is 249 feet high.