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Grand Coulee Dam

Columbia River, Washington

location of Grand Coulee Dam

The Grand Coulee Dam stands across the Columbia River about 90 miles northwest of Spokane, Washington. It is near the head of the Grand Coulee, a steep-walled chasm where the Columbia once flowed. The dam is the chief engineering feature of the Columbia Basin Project, which includes four other dams, three storage lakes, and 2,300 miles of irrigation canals. It was designed and built by the U.S. Bureau of Reclamation. Groundbreaking ceremonies took place on July 16, 1933. The first of the dam's primary generators went on line in October 1941. Construction officially ended one month later, nine years after it began.

Behind the dam is Franklin D. Roosevelt Lake, a 151-mile-long reservoir.

overhead view of Grand Coulee Dam

Facts and Figures

4,173 feet (1,272 meters) long

500 feet (152 meters) thick at the base

30 feet wide at the crest

550 feet (168 meters) high, about the height of a 46-story building

Spillway width is 1,650 feet

The dam contains 10,585,000 cubic yards (8,092,810 cubic meters) of concrete. This is enough concrete to build a two-lane highway from New York City to Seattle. If this concrete were placed on a city block, it would tower more than 2 times as high as the Empire State Building.

The base of the dam is almost four times as large as the Great Pyramid of Cheops.

Grand Coulee is the third largest producer of electricity in the world.

There are over 8 miles of corridors throughout the inside of the dam.


Grand Coulee Dam Area Chamber of Commerce
The Online Encyclopedia of Washington State History

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The Robinson Library >> Dams

This page was last updated on September 28, 2018.