11 Largest Hydroelectric Dams in USA

If we asked you to name some of the largest hydroelectric dams in USA, would you be able to recall more than one or two? Hopefully, you should have a few dams in mind. Why? Here are some of the reasons.

How many hydroelectric dams are there in the US? Let’s just say there’s more than you can imagine. There are 2,198 active plants, which makes this country the world leader when it comes to the biggest number of hydroelectric dams in the world. If you’re wondering how the number of US dams stands globally, i.e., how many hydroelectric dams there are in the world,  it would be the best to look at the map made by Washington Post.

Size matters, and that’s a fact. Otherwise, why would you be spending your time here reading about some of the largest dams in the world? Unfortunately, the largest hydroelectric dam in the world isn’t  a part of our list. It’s located in China. More or less everyone had heard of the Three Gorges Dam when it took over the #1 spot of the largest hydroelectric dam so far in Brazil and Paraguay. Nevertheless, that doesn’t make it the most powerful dam in the world. Due to the river’s capacity over the year (read: drought and precipitation), these distant dams surprisingly produce almost the same amount of power. By the way, we discussed the hydropower matter further in 8 Countries that Produce the Most Hydroelectric Power in the World. But let’s go back to the USA.

We’ve already covered top hydropower producing states and what state produces the most hydroelectric power in our article on Top 15 Hydropower Producing States in America. That could also be the answer to what states use the hydroelectric power the most. How much hydroelectric power is used in the US? The most precise answer would be: not enough since it’s constantly trying to increase it. The USA is in the fourth place in the world based on hydroelectric power generation, right after China, Brazil, and Canada. On average, America generates 300,000 terawatts per hour every year. One terawatt equals 1 billion kilowatts, so you get the maths. However, the country is always in its never-ending quest for new renewable resources.

Harnessing this nature’s element is one of the oldest ways to generate power, and we feel obliged to say a word or two about the positives and negatives of hydroelectric power. There is a whole list of reasons why there are so many attempts to make use of other resources. Firstly, building a dam is extremely pricey, and it doesn’t always pay off, even when we are talking about huge constructions because even the biggest dams are eventually dependent on water and weather conditions. Hence, they’re not absolutely reliable. In addition, the animal and fish habitats are changed or endangered. We all remember the stories about Australia and its rapidly growing rabbit population. Well, similar scenarios occur when it comes to dam building. The natural cycle is disrupted, and the changes are usually detrimental to the living environment. That includes people, too. As International Rivers informs us, usually the first to be evicted are indigenous people. Unfortunately, a high number of victims due to dams bursting is nothing new. For instance, China kept hidden for years the Henan disaster in 1975 in which 80,000 to 230,000 were killed.

But let’s mention a few benefits, too. Firstly, the trapped water can be used as an irrigation system. The pollution is minimal compared to power plants using coal, for instance. Also, the technology used is highly reliable.

Now would be the right time to explain how we found out what the largest hydroelectric dams are in the US. Tata&Howard and WorldAtlas were our trustworthy sources on this quest (we also used USGS for some interesting facts above). The tricky part about establishing the biggest dam in the United States is actually defining the “biggest” part. What makes a hydroelectric dam the largest? Is it the one that is the longest (the Cochiti Dam is 29,040 feet (5.5 miles) long), or maybe the tallest (the Oroville Dam is 770 feet tall)? Since it is hydroelectric dams we are talking about, we decided to focus on the ones with the largest reservoirs. After all, a dam must have gigantic dimensions if it is to stand and support such amount of water.

We have already told you which is the largest hydroelectric dam in the world, but these 11 largest hydroelectric dams in USA are just as amazing. Go ahead and read about their capacity, reservoirs, locations and some other interesting facts. The capacity is given in acre-feet.

11. Toledo Bend Dam

Capacity: 4,477,000

Reservoir: Toledo Bend Lake

State: Lousiana/Texas

Toledo Bend Lake is the ninth largest human-created lake in the US, and as you can see, it spreads over two countries. The energy produced annually is around 205 million kilowatt-hours. In addition to the power and water, there are plenty of water activities here to be entertained. The Toledo Bend Dam was finally completed in 1969, and it cost $70 million.

10. Shasta  Dam

Capacity: 4,552,000

Reservoir: Lake Shasta

State: California

Construction of the dam began in 1935, and it was completed in 1945. People living in the nearby were extremely grateful for job opportunities after the Great Depression, but today the area is one of the most popular vacation spots. The Shasta Dam is spreading across the Sacramento River, and its height is impressive – 602 feet, which makes it the eighth tallest dam in the States. As for the power, it has been upgraded recently to be 98% efficient.

9. Amistad Dam

Capacity: 5,658,600

Reservoir: Lake Amistad

State: Texas/ Mexico

Everything is big in Texas. Another enormous construction lies partly in the US, and partly in Mexico. This dam ranks 9th on our list of largest hydroelectric dams in USA. It is actually a joint venture of the two countries which took only five years to build. Naturally, it is managed by International Boundary and Water Commission, which is an international body formed by the Mexican and American governments.

8. Bull Shoals Dam

Capacity: 5,760,000

Reservoir: Bull Shoals Lake

State: Arkansas

The Bull Shoals Dam was finished in 1951, and at the time it was the 5th largest dam in the world. Its basic purpose was flood control, and now the lake is a tourist attraction.

7. Libby Dam

Capacity: 5,809,000

Reservoir: Lake Koocanusa

State: Montana

The Libby dam stands in the way of Lake Koocanusa, which actually stretches a little bit into British Columbia, Canada. Therefore, some of its power goes to the American next-door neighbor. The dam was completed in 1972, and it is 422 feet tall, which makes an impressive view.

6. Grand Coulee Dam

Capacity: 9,562,000

Reservoir: Lake Franklin

State: Washington

We are continuing our list of largest hydroelectric dams in USA with Grand Coulee Dam is 550 feet tall, which is almost one mile long and has a drum gate spillway. It’s got three power stations, and it is the largest power generator in the US.

5. Fort Peck Dam

Capacity: 15,400,000

Reservoir: Fort Peck Lake

State: Montana

The Fort Peck Dam ranks 5th on our list of largest hydroelectric dams in USA. It is managed by the Army Corps of Engineers. This is a hydraulic earth-fill dam, and its height is 250 feet. Interestingly, the dam is enlisted in the National Register of Historic Places, and it’s the largest hydraulically filled dam in the whole country. What is more, its structure volume makes it the second largest dam (the first is the Tarbela Dam in Pakistan).

4. Garrison Dam

Capacity: 18,500,000

Reservoir: Lake Sakakawea

State: North Dakota

The Garrison Dam cost some $300 million to make back in 1953. Apart from being one of the largest hydroelectric dams in USA, its position in the world isn’t so bad either. The Garrison Dam is the fifth largest earthen dam in the whole world.

3. Oahe Dam

Capacity: 19,300,000

Reservoir: Lake Oahe

State: South Dakota

What makes this dam important, apart from its grandeur? Firstly, this construction was officially dedicated to President John F. Kennedy. The second reason is the world’s first rock tunnel boring machine (TBM). This invention was first used on this dam. Actually, the dam was the reason for its creation, which later on had a huge impact on machines replacing humans in digging tunnels.

2. Glen Canyon Dam

Capacity: 27,000,000

Reservoir: Lake Powell

State: Arizona

The Glen Canyon Dam ranks second on the list of largest hydroelectric dams in USA. It is made out of over five million cubic yards of concrete. This arch-gravity dam is 710 feet tall. It’s not dedicated to a president, but to the First Lady – Lady Bird Johnson in 1966.

1. Hoover Dam

Capacity: 28,255,000

Reservoir: Lake Mead

State: Nevada

Admit it, when we asked you about the 11 largest hydroelectric dams in USA, this is the first one that popped into your mind. As you can see, it was for a good reason. Perhaps it’s not the largest one in the world, but it is definitely one of the most famous. Apparently, it was named after the President Herbert Hoover.

The Hoover Dam was being built between 1931 and 1936 by 21,000 workers, which cost the Bureau of Reclamation some $49 million. The dam impounds the Colorado River, thus creating Lake Mead. Also, it weighs 6,600,000 tons.