The United States is home to some of the world’s most impressive feats of engineering, and its dams are no exception. These massive structures not only protect against floods and generate hydroelectric power but also create vast reservoirs that store mind-boggling amounts of water. In this comprehensive article, we take a look at the 20 largest dams in the USA, ranked by their maximum storage capacity. From the iconic Hoover Dam to the lesser-known Painted Rock Dam, each of these engineering marvels tells a unique story of human ingenuity and our complex relationship with water resources.
Read on below or watch our video on the 20 largest dams in the USA.
Map of Largest Dams in the US
Before we plunge into the details of each dam, let’s take a quick look at our colossal contenders and their maximum storage capacities. Here is the list of the 20 largest dams in the US:
- Hoover Dam: 30,237,000 acre-feet (37,296,735 ML)
- Glen Canyon Dam: 29,875,000 acre-feet (36,850,215 ML)
- Grand Coulee Dam: 9,562,000 acre-feet (11,794,536 ML)
- Herbert Hoover Dike: 8,519,000 acre-feet (10,508,016 ML)
- Kentucky Dam: 7,535,400 acre-feet (9,294,765 ML)
- Sam Rayburn Dam: 6,520,000 acre-feet (8,042,290 ML)
- Wright Patman Dam: 6,505,000 acre-feet (8,023,787 ML)
- Bull Shoals Dam: 5,408,000 acre-feet (6,670,660 ML)
- Harry S. Truman Dam: 5,202,000 acre-feet (6,416,563 ML)
- Denison Dam: 5,194,163 acre-feet (6,406,896 ML)
- Amistad Dam: 5,128,000 acre-feet (6,325,285 ML)
- Toledo Bend Dam: 5,097,500 acre-feet (6,287,664 ML)
- Painted Rock Dam: 4,831,500 acre-feet (5,959,559 ML)
- Shasta Dam: 4,661,860 acre-feet (5,750,311 ML)
- Flaming Gorge Dam: 4,003,100 acre-feet (4,937,744 ML)
- Eufaula Dam: 3,825,400 acre-feet (4,718,554 ML)
- J. Strom Thurmond Dam: 3,820,000 acre-feet (4,711,894 ML)
- Blakely Mountain Dam: 3,760,700 acre-feet (4,638,748 ML)
- Hungry Horse Dam: 3,588,000 acre-feet (4,425,726 ML)
- Oroville Dam: 3,540,000 acre-feet (4,366,519 ML)
Now, let’s embark on a journey across the United States to explore these engineering marvels in detail, uncovering their histories, purposes, and the vital roles they play in American infrastructure.
1. Hoover Dam: The Iconic Giant
Hoover Dam stands as a testament to American engineering prowess and Depression-era determination. Straddling the border between Nevada and Arizona, this concrete colossus has been holding back the mighty Colorado River since 1935.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 30,237,000 acre-feet | 37,296,735 ML |
| Dam Height | 730 feet | 223 m |
| Dam Length | 1,244 feet | 379 m |
| Structural Volume | 3,250,000 cubic yards | 2,484,804 cubic meters |
| Primary Purpose | Hydroelectric | Hydroelectric |
| Year Completed | 1935 | 1935 |
Hoover Dam’s primary purpose is hydroelectric power generation, but it also serves crucial roles in irrigation and water supply. The dam’s construction was a monumental undertaking, employing thousands during the Great Depression and forever changing the landscape of the American Southwest.
Its reservoir, Lake Mead, is the largest man-made lake in the United States by volume when at full capacity. However, recent years have seen declining water levels due to prolonged drought, highlighting the complex challenges of water management in the region.
2. Glen Canyon Dam: The Desert Oasis Maker
Just upstream from the Hoover Dam, Glen Canyon Dam creates Lake Powell, a massive reservoir that has transformed the desert landscape of southern Utah and northern Arizona.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 29,875,000 acre-feet | 36,850,215 ML |
| Dam Height | 710 feet | 216 m |
| Dam Length | 1,565 feet | 477 m |
| Structural Volume | 4,901,000 cubic yards | 3,747,084 cubic meters |
| Primary Purpose | Hydroelectric | Hydroelectric |
| Year Completed | 1963 | 1963 |
Completed in 1963, Glen Canyon Dam serves multiple purposes, including hydroelectric power generation, irrigation, and recreation. The creation of Lake Powell has been both celebrated for its recreational opportunities and criticized for its environmental impact on the Colorado River ecosystem.
The dam’s construction sparked significant controversy and helped galvanize the environmental movement in the 1960s. Today, it continues to play a crucial role in water management for the southwestern United States, despite ongoing debates about its long-term sustainability.
3. Grand Coulee Dam: The Powerhouse of the Pacific Northwest
Grand Coulee Dam, located on the Columbia River in Washington state, is a true giant among dams. It’s not only one of the largest concrete structures in the world but also the largest hydroelectric power producer in the United States.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 9,562,000 acre-feet | 11,794,536 ML |
| Dam Height | 550 feet | 168 m |
| Dam Length | 5,673 feet | 1,729 m |
| Structural Volume | 11,975,520 cubic yards | 9,155,944 cubic meters |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1941 | 1941 |
Completed in 1941, Grand Coulee Dam was a cornerstone of President Franklin D. Roosevelt’s New Deal program. While its primary purpose is listed as flood risk reduction, it’s renowned for its massive hydroelectric capacity, which played a crucial role in the industrial development of the Pacific Northwest.
The dam also provides irrigation water to over 670,000 acres of farmland in the Columbia Basin Project, transforming once-arid land into productive agricultural areas. Its reservoir, Lake Roosevelt, offers extensive recreational opportunities and has significantly altered the region’s ecosystem.
4. Herbert Hoover Dike: Florida’s Hurricane Shield
Unlike the massive concrete structures we’ve seen so far, the Herbert Hoover Dike is an earthen embankment dam surrounding Lake Okeechobee in Florida. It’s a critical piece of infrastructure for flood control in the region.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 8,519,000 acre-feet | 10,508,016 ML |
| Dam Height | 35 feet | 11 m |
| Dam Length | 739,200 feet | 225,308 m |
| Structural Volume | 54,700,000 cubic yards | 41,821,159 cubic meters |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1965 | 1965 |
The Herbert Hoover Dike was built in response to devastating hurricanes in the 1920s that caused Lake Okeechobee to overflow, resulting in thousands of deaths. Today, it plays a crucial role in protecting surrounding communities from flooding and regulating water levels for agriculture and urban use.
However, the dike has faced ongoing maintenance challenges, and a major rehabilitation project has been underway to address structural concerns and improve its long-term safety and effectiveness.
5. Kentucky Dam: Taming the Tennessee River
Kentucky Dam, the final dam on the Tennessee River, creates Kentucky Lake, the largest man-made lake east of the Mississippi River.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 7,535,400 acre-feet | 9,294,765 ML |
| Dam Height | 206 feet | 63 m |
| Dam Length | 8,422 feet | 2,567 m |
| Structural Volume | 6,938,100 cubic yards | 5,304,559 cubic meters |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1944 | 1944 |
Completed in 1944, Kentucky Dam is a key component of the Tennessee Valley Authority’s (TVA) system for flood control, navigation, and power generation. Its primary purpose is flood risk reduction, but it also serves important roles in navigation, recreation, and hydroelectric power production.
The dam has played a significant role in the economic development of western Kentucky and Tennessee, providing flood protection, affordable electricity, and recreational opportunities that have boosted tourism in the region.
6. Sam Rayburn Dam: Texas-Sized Water Management
Sam Rayburn Dam, located on the Angelina River in eastern Texas, creates Sam Rayburn Reservoir, the largest lake entirely within the borders of Texas.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 6,520,000 acre-feet | 8,042,290 ML |
| Dam Height | 120 feet | 37 m |
| Dam Length | 12,400 feet | 3,780 m |
| Structural Volume | 6,000,000 cubic yards | 4,587,330 cubic meters |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1965 | 1965 |
Completed in 1965, Sam Rayburn Dam serves multiple purposes, including flood risk reduction, hydroelectric power generation, and recreation. The reservoir it creates has become a popular destination for fishing, boating, and other water activities, contributing significantly to the local economy.
The dam also plays a crucial role in water supply for the region, helping to manage water resources in an area that can experience both drought and flooding.
7. Wright Patman Dam: Sulphur River’s Gatekeeper
Wright Patman Dam, formerly known as Texarkana Dam, is located on the Sulphur River in northeastern Texas.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 6,505,000 acre-feet | 8,023,787 ML |
| Dam Height | 106 feet | 32 m |
| Dam Length | 18,640 feet | 5,681 m |
| Structural Volume | 7,370,000 cubic yards | 5,634,770 cubic meters |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1954 | 1954 |
Completed in 1954, Wright Patman Dam’s primary purpose is flood risk reduction, but it also serves important roles in recreation, fish and wildlife conservation, and water supply. The reservoir it creates, Lake Wright Patman, has become an important resource for the surrounding communities.
The dam has played a crucial role in managing flood risks in the Sulphur River basin, protecting downstream areas from potentially devastating floods while providing a stable water supply for the region.
8. Bull Shoals Dam: Ozark Mountains’ Hydroelectric Hub
Bull Shoals Dam, located on the White River in northern Arkansas, creates Bull Shoals Lake, a major recreational destination in the Ozark Mountains.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 5,408,000 acre-feet | 6,670,660 ML |
| Dam Height | 256 feet | 78 m |
| Dam Length | 2,256 feet | 688 m |
| Structural Volume | 2,100,000 cubic yards | 1,605,566 cubic meters |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1951 | 1951 |
Completed in 1951, Bull Shoals Dam serves multiple purposes, including flood risk reduction, hydroelectric power generation, and recreation. The dam has played a significant role in transforming the economy of the region, shifting it from primarily agricultural to one with a strong tourism component.
The cold water released from the dam has also created a world-class trout fishery in the White River below the dam, further boosting the area’s recreational appeal.
9. Harry S. Truman Dam: Missouri’s Multi-Purpose Marvel
Harry S. Truman Dam, located on the Osage River in west-central Missouri, is a key component of flood control and power generation in the region.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 5,202,000 acre-feet | 6,416,563 ML |
| Dam Height | 98 feet | 30 m |
| Dam Length | 5,000 feet | 1,524 m |
| Structural Volume | 7,411,000 cubic yards | 5,666,117 cubic meters |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1978 | 1978 |
Completed in 1978, Harry S. Truman Dam is one of the newer dams on our list. Its primary purpose is flood risk reduction, but it also serves important roles in hydroelectric power generation, recreation, and fish and wildlife conservation.
The dam’s design incorporates a unique “wet dam” concept, where water can flow through the dam’s structure, allowing for more efficient power generation and better control of downstream water temperatures.
10. Denison Dam: Red River’s Mighty Barrier
Denison Dam, straddling the Texas-Oklahoma border on the Red River, creates Lake Texoma, one of the largest reservoirs in the United States.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 5,194,163 acre-feet | 6,406,896 ML |
| Dam Height | 165 feet | 50 m |
| Dam Length | 17,200 feet | 5,243 m |
| Structural Volume | 18,800,000 cubic yards | 14,373,634 cubic meters |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1944 | 1944 |
Completed in 1944, Denison Dam plays a crucial role in flood control for the Red River basin. It also generates hydroelectric power and provides water for irrigation and municipal use. Lake Texoma, created by the dam, has become a major recreational destination, known for its excellent fishing and boating opportunities.
The dam’s construction was a significant engineering achievement of its time, requiring the relocation of entire towns and the creation of new infrastructure to support the massive project.
11. Amistad Dam: International Cooperation on the Rio Grande
Amistad Dam, located on the Rio Grande River between Texas and Mexico, is a joint project between the United States and Mexico.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 5,128,000 acre-feet | 6,325,285 ML |
| Dam Height | 254 feet | 77 m |
| Dam Length | 32,022 feet | 9,760 m |
| Structural Volume | 17,055,000 cubic yards | 13,039,486 |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1969 | 1969 |
Completed in 1969, Amistad Dam is a symbol of international cooperation between the United States and Mexico. Its name, “Amistad,” means “friendship” in Spanish, reflecting the collaborative nature of the project. The dam serves multiple purposes, including flood control, irrigation, recreation, and hydroelectric power generation.
Amistad Reservoir, created by the dam, is a popular destination for fishing and boating enthusiasts from both countries. The dam’s binational management serves as a model for shared water resource management across international borders.
12. Toledo Bend Dam: A Powerhouse on the Sabine
Toledo Bend Dam, straddling the border between Texas and Louisiana on the Sabine River, creates the massive Toledo Bend Reservoir.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 5,097,500 acre-feet | 6,287,664 ML |
| Dam Height | 112 feet | 34 m |
| Dam Length | 10,350 feet | 3,155 m |
| Structural Volume | 4,700,000 cubic yards | 3,593,409 cubic meters |
| Primary Purpose | Hydroelectric | Hydroelectric |
| Year Completed | 1966 | 1966 |
Completed in 1966, Toledo Bend Dam is unique in that it was built primarily for hydroelectric power generation rather than flood control. However, it also serves important roles in recreation, water supply, and navigation.
Toledo Bend Reservoir has become renowned for its excellent fishing, particularly for largemouth bass. The project has significantly impacted the economy of the region, transforming it into a popular tourist destination while providing a reliable source of renewable energy.
13. Painted Rock Dam: Arizona’s Flood Guardian
Painted Rock Dam, located on the Gila River in southern Arizona, stands as a silent sentinel against devastating floods.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 4,831,500 acre-feet | 5,959,559 ML |
| Dam Height | 181 feet | 55 m |
| Dam Length | 4,780 feet | 1,457 m |
| Structural Volume | Not Available | Not Available |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1960 | 1960 |
Completed in 1960, Painted Rock Dam’s sole purpose is flood risk reduction. Unlike many of the other dams on this list, it does not generate power or provide water for irrigation. Instead, it stands ready to capture and control floodwaters from the Gila River, protecting downstream communities and agricultural lands.
The dam’s reservoir is usually dry, filling only during flood events. This unique characteristic has made the area around the dam an important habitat for desert wildlife and a popular spot for off-road vehicle enthusiasts when conditions permit.
14. Shasta Dam: California’s Water Bank
Shasta Dam, located on the Sacramento River in northern California, is a keystone of the Central Valley Project, one of the world’s largest water management systems.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 4,661,860 acre-feet | 5,750,311 ML |
| Dam Height | 602 feet | 183 m |
| Dam Length | 3,460 feet | 1,055 m |
| Structural Volume | 8,430,000 cubic yards | 6,445,199 cubic meters |
| Primary Purpose | Hydroelectric | Hydroelectric |
| Year Completed | 1945 | 1945 |
Completed in 1945, Shasta Dam serves multiple purposes, with hydroelectric power generation being its primary function. It also plays crucial roles in flood control, water supply for agriculture and urban use, and recreation.
Lake Shasta, created by the dam, is California’s largest reservoir and a critical component of the state’s water supply system. The dam’s construction dramatically altered the ecosystem of the Sacramento River, impacting salmon runs but also creating new opportunities for recreation and water-based tourism.
15. Flaming Gorge Dam: Green River’s Power Generator
Flaming Gorge Dam, located on the Green River in northeastern Utah, creates the stunning Flaming Gorge Reservoir.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 4,003,100 acre-feet | 4,937,744 ML |
| Dam Height | 502 feet | 153 m |
| Dam Length | 1,285 feet | 392 m |
| Structural Volume | 986,600 cubic yards | 754,310 cubic meters |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1963 | 1963 |
Completed in 1963, Flaming Gorge Dam’s primary purpose is flood risk reduction, but it also generates hydroelectric power and provides water for various uses. The dam and its reservoir have become major recreational attractions, known for their scenic beauty and excellent fishing.
The dam’s construction was controversial due to its environmental impact, flooding a scenic canyon and altering the river’s ecosystem. However, it has also created new recreational opportunities and plays a crucial role in water management for the Upper Colorado River Basin.
16. Eufaula Dam: Oklahoma’s Gentle Giant
Eufaula Dam, located on the Canadian River in eastern Oklahoma, creates Lake Eufaula, the largest lake entirely within Oklahoma’s borders.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 3,825,400 acre-feet | 4,718,554 ML |
| Dam Height | 114 feet | 35 m |
| Dam Length | 3,200 feet | 975 m |
| Structural Volume | 3,850,600 cubic yards | 2,943,995 cubic meters |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1964 | 1964 |
Completed in 1964, Eufaula Dam’s primary purpose is flood risk reduction, but it also serves important roles in hydroelectric power generation, water supply, and recreation. Lake Eufaula has become a major tourist attraction, known for its fishing, boating, and camping opportunities.
The dam has played a significant role in the economic development of eastern Oklahoma, providing flood protection, affordable electricity, and a boost to the local tourism industry.
17. J. Strom Thurmond Dam: Savannah River’s Workhorse
J. Strom Thurmond Dam, located on the Savannah River between Georgia and South Carolina, is a key component of the Savannah River Basin system.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 3,820,000 acre-feet | 4,711,894 ML |
| Dam Height | 124 feet | 38 m |
| Dam Length | 5,680 feet | 1,731 m |
| Structural Volume | 4,550,000 cubic yards | 3,478,725 cubic meters |
| Primary Purpose | Hydroelectric | Hydroelectric |
| Year Completed | 1954 | 1954 |
Completed in 1954, the J. Strom Thurmond Dam (formerly known as Clarks Hill Dam) was built primarily for hydroelectric power generation. However, it also serves crucial roles in flood control, recreation, and water supply.
The reservoir created by the dam, J. Strom Thurmond Lake, is a popular destination for fishing, boating, and other water-based activities. The dam has played a significant role in the economic development of the region, providing affordable electricity and attracting tourism.
18. Blakely Mountain Dam: Ouachita River’s Hidden Gem
Blakely Mountain Dam, located on the Ouachita River in central Arkansas, creates Lake Ouachita, the largest lake entirely within Arkansas.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 3,760,700 acre-feet | 4,638,748 ML |
| Dam Height | 226 feet | 69 m |
| Dam Length | 1,100 feet | 335 m |
| Structural Volume | 4,215,000 cubic yards | 3,222,599 cubic meters |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1953 | 1953 |
Completed in 1953, Blakely Mountain Dam’s primary purpose is flood risk reduction, but it also generates hydroelectric power and provides water for various uses. Lake Ouachita, known for its clear waters and scenic beauty, has become a major recreation destination in the region.
The dam and its reservoir have played a significant role in the economic development of central Arkansas, providing flood protection, affordable electricity, and a boost to the local tourism industry.
19. Hungry Horse Dam: Montana’s Concrete Arch
Hungry Horse Dam, located on the South Fork Flathead River in northwestern Montana, is a key component of the Columbia River Basin system.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 3,588,000 acre-feet | 4,425,726 ML |
| Dam Height | 564 feet | 172 m |
| Dam Length | 2,115 feet | 645 m |
| Structural Volume | Not Available | Not Available |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1952 | 1952 |
Completed in 1952, Hungry Horse Dam’s primary purpose is flood risk reduction, but it also generates hydroelectric power and provides water for irrigation. The dam’s reservoir, Hungry Horse Reservoir, is known for its scenic beauty and recreational opportunities.
The dam plays a crucial role in regulating water flow in the Columbia River system, helping to manage flood risks and ensure a steady water supply for downstream users. Its construction significantly altered the local ecosystem but also created new habitats for certain species.
20. Oroville Dam: California’s Tallest Dam
Oroville Dam, located on the Feather River in northern California, is the tallest dam in the United States and a critical component of the California State Water Project.
| Statistic | Imperial | Metric |
|---|---|---|
| Maximum Storage | 3,540,000 acre-feet | 4,366,519 ML |
| Dam Height | 770 feet | 235 m |
| Dam Length | 6,920 feet | 2,109 m |
| Structural Volume | 80,000,000 cubic yards | 61,164,400 cubic meters |
| Primary Purpose | Flood Risk Reduction | Flood Risk Reduction |
| Year Completed | 1968 | 1968 |
Completed in 1968, Oroville Dam’s primary purpose is flood risk reduction, but it also serves crucial roles in water supply, hydroelectric power generation, and recreation. Lake Oroville, created by the dam, is the second-largest reservoir in California and a key water source for the state.
The dam gained international attention in 2017 when damage to its main spillway led to the evacuation of more than 180,000 people living downstream. This incident highlighted the critical importance of dam safety and maintenance, leading to significant repairs and upgrades to the structure.
Conclusion: Monumental Achievements, Ongoing Challenges
As we’ve journeyed across the United States exploring these 20 colossal dams, we’ve seen how they’ve shaped the landscape, economy, and water management strategies of entire regions. From the iconic Hoover Dam to the lesser-known Painted Rock Dam, each structure tells a unique story of engineering prowess, environmental impact, and human ambition.
These dams stand as testaments to human ingenuity and our ability to harness natural resources for our benefit. They provide flood protection, generate clean hydroelectric power, create recreational opportunities, and ensure water supply for millions of people. However, they also remind us of the profound ways in which we’ve altered natural ecosystems and the ongoing challenges of balancing human needs with environmental conservation.
As we look to the future, the management and maintenance of these massive structures will be crucial. Climate change, aging infrastructure, and evolving environmental standards present new challenges that will require innovative solutions and continued investment.
The story of America’s largest dams is far from over. As we continue to grapple with issues of water scarcity, renewable energy, and environmental stewardship, these monumental structures will undoubtedly play a central role in shaping our relationship with water resources for generations to come.