Dams in Washington - Dams of the World

Introduction

Washington State, known for its lush landscapes and abundant water resources, is home to an impressive network of dams that play a crucial role in the region’s infrastructure, economy, and environment. These engineering marvels serve multiple purposes, from generating clean hydroelectric power to controlling floods and supporting irrigation. In this article, we’ll explore the diverse world of Washington State dams, their impact, and their significance to the Pacific Northwest.

Jump to the list of dams in Washington State.

Overview of Dams in Washington State

Washington State boasts an extensive system of dams, with 71 major structures listed in our data. These dams vary greatly in size, type, and purpose, reflecting the diverse needs and geography of the state. The dams are spread across various counties, including Grant, Okanogan, Lewis, and Pierce, among others.

The largest dam in Washington State by reservoir capacity is the Grand Coulee Dam, with an impressive 9,562,000 acre-feet of storage. This colossal structure on the Columbia River stands as a testament to the state’s commitment to harnessing its water resources for multiple benefits.

Also read: The Mighty Dams on the Columbia River: An Engineering Marvel

Interesting Stats About Dams in Washington State

Highest dam: The highest dam in Washington is Grand Coulee Dam, with a height of 550 feet (168 meters).
Largest dam by storage capacity: The dam with the largest storage capacity is also Grand Coulee Dam, with a capacity of 9,562,000 acre-feet.
Oldest dam: The oldest dam in this dataset is Morse Lake Overflow Dike, completed in 1904.
Number of dams: There are 71 dams listed in this dataset.
Most common primary purpose: The most common primary purpose for dams in Washington is Hydroelectric, followed by Flood Risk Reduction and Irrigation.
Longest dam: The longest dam is O’Sullivan Dam, with a length of 19,000 feet (5,791 meters).
Largest surface area: The dam creating the largest surface area is Grand Coulee Dam, with 82,300 acres (33,306 hectares).
Most recent dam: The most recently completed dam in this dataset is Cowlitz Falls Dam, finished in 1994.
Largest drainage area: The dam with the largest drainage area is Grand Coulee Dam, with a drainage area of 74,100 square miles (191,918 square kilometers).
Highest maximum discharge: The dam with the highest maximum discharge is Wanapum Dam, with a capacity of 1,400,000 cubic feet per second (39,644 cubic meters per second).

These statistics provide a good overview of the scale, purpose, and characteristics of dams in Washington state.

Notable Dams in Washington

Grand Coulee Dam

The Grand Coulee Dam is not only the largest in Washington but also one of the largest concrete structures in the world. Completed in 1941, this 550-foot-tall concrete gravity dam serves multiple purposes, including flood risk reduction, irrigation, and hydroelectric power generation. With a length of 5,673 feet, it’s a true engineering marvel that has shaped the landscape and economy of central Washington.

Ross Dam

Another significant structure is the Ross Dam on the Skagit River. At 540 feet tall, it’s one of the highest dams in the state. Built in 1949, Ross Dam is primarily used for hydroelectric power generation but also contributes to flood control, recreation, and fish and wildlife conservation. Its reservoir, Ross Lake, is a popular destination for outdoor enthusiasts.

Mossyrock Dam

The Mossyrock Dam on the Cowlitz River stands out for its impressive height of 606 feet, making it the tallest dam in Washington State. Completed in 1968, this arch dam serves multiple purposes, including hydroelectric power generation, recreation, and flood control. Its reservoir, Riffe Lake, is a significant water body in southwest Washington.

Types of Dams and Their Purposes

Washington’s dams come in various types, each suited to specific geological conditions and purposes. The most common types include:

Earth Dams: These are the most numerous, with examples like the North Dam and Dry Falls Dam. They are often used for irrigation and flood control.
Concrete Dams: Including gravity and arch types, these robust structures like the Grand Coulee and Ross dams are ideal for hydroelectric power generation.
Rockfill Dams: Less common but still present, as seen in the Wanapum Dam, which combines rockfill with concrete construction.

The purposes of these dams are equally diverse:

Hydroelectric Power: Many large dams, including Grand Coulee, Ross, and Mossyrock, have this as their primary purpose.
Flood Risk Reduction: A critical function for dams like the Osullivan Dam.
Irrigation: Essential for agriculture, especially in the drier eastern parts of the state.
Recreation: Many reservoirs, such as those created by the Boundary Dam and Box Canyon Dam, offer recreational opportunities.
Water Supply: Dams like the Tolt River – South Fork Dam provide crucial water resources for urban areas.

Environmental and Economic Impact

Washington State dams have a significant impact on both the environment and the economy. On the environmental front, these structures have altered river ecosystems, affecting fish migration patterns, particularly for salmon. However, many dams now incorporate fish ladders and other measures to mitigate these effects.

Economically, the dams have been transformative. The hydroelectric power generated by Washington’s dams provides clean, renewable energy to millions of homes and businesses across the Pacific Northwest. The Grand Coulee Dam alone can generate up to 6,809 megawatts of electricity, making it a cornerstone of the region’s power grid.

The irrigation provided by these dams has turned vast areas of arid land into productive agricultural regions, contributing significantly to Washington’s economy. Additionally, the flood control function of many dams has protected communities and valuable agricultural land from devastating floods.

Conclusion

Washington State’s dams are more than just concrete and steel structures; they are the lifeblood of the region’s water resource management, power generation, and agricultural productivity. From the towering Grand Coulee Dam to the numerous smaller structures dotting the landscape, these engineering marvels continue to shape the state’s economy, environment, and way of life.

As we look to the future, the management and maintenance of these crucial infrastructures will remain a priority. Balancing the benefits of hydroelectric power and water resource management with environmental concerns will be an ongoing challenge. However, with careful stewardship and continued innovation, Washington’s dams will undoubtedly continue to play a vital role in powering the Pacific Northwest for generations to come.

List of Dams in Washington