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Grand Coulee Dam - Grand Coulee, WA
Posted by: Groundspeak Premium Member BK-Hunters
N 47° 57.618 W 118° 59.197
11T E 351697 N 5313796
Quick Description: The largest producer of hydroelectric power in the country, Grand Coulee Dam was the largest concrete structure in the world when built, containing 11,975,521 cubic yards of concrete. It remains the largest concrete structure in the country.
Location: Washington, United States
Date Posted: 5/27/2018 4:21:56 PM
Waymark Code: WMYC23
Published By: Groundspeak Premium Member QuesterMark
Views: 2

Long Description:
Grand Coulee Dam was declared a National Historic Civil Engineering Landmark by the American Society of Civil Engineers in 1998. A bronze plaque acknowledging this achievement is mounted on a wall of honour in the dam's visitor centre, amongst no less than four other plaques acknowledging the engineering achievements accomplished in the construction of the dam and its powerhouses.

Undoubtedly the largest single project of the Public Works Administration, construction of the Grand Coulee Dam began in 1933, not being completed until 1941, just in time to provide power for wartime industry of the Pacific Northwest. $63 million was allocated for the initial phase of construction, with the final cost coming to $163 million in 1943 dollars. However, repairs due to design flaws and to finish the power stations through the '40s and '50s added another $107 million, bringing the total cost to $270 million. The later addition of the Third Powerplant from 1967 to 1974 added another $460 million, bringing the final cost in 1973 to $730 million. Construction of the dam also cost the lives of 77 of the thousands of workmen employed on the project, with an additional four men killed during the construction of the Third Power Plant and Forebay Dam from 1967 to 1975.

Grand Coulee Dam remains the largest dam in the United States and one of the largest in the world. Initially conceived to provide irrigation, the dam quickly came to be seen as a three fold resource, providing not only water to irrigate more than 671,000 acres, but also providing flood control of the Columbia River and producing 21 billion kilowatt hours of electricity annually. With a generating capacity of 6,809 megawatts, far and away the most of any hydro facility in the country, the dam produces electricity for all or parts of eleven states. This mammoth structure stands 550 feet high and is 1.2 miles wide. Within the dam's three powerhouses are no less than 33 turbines and generators, the main generators varying in size from 150,000 horsepower to 1,053,900 horsepower.

Lake Roosevelt, impounded behind the dam, covers 82,300 acres, stretching 151 miles to the Canadian border, with a storage capacity of 9,562,000 acre feet of water. The lake provides recreational opportunities for a million people each year, with 35 campgrounds around the lake and several more boat launches.

Prior to the commencement of construction of the dam, the area was occupied only by sagebrush, sand and rocks. As thousands came to the area in the Depression looking for work towns were built, with four towns now surrounding the dam, Elmer City, the most northerly, Coulee Dam, just north of the dam, Grand Coulee, to the southwest, and Electric City further west.

Coordinates given are at the Grand Coulee Dam Visitor Center, an excellent viewing location.

The Grand Coulee Dam, a concrete gravity dam, is the largest concrete structure and hydroelectric facility in the United States.

The massive Grand Coulee Dam, on the Columbia River, is the largest concrete structure in the U.S., the largest hydroelectric facility in the U.S., and the sixth-largest hydroelectric facility in the world. It provides irrigation for up to 1.1 million acres of agricultural lands and the hydroelectric complex maintains a generating capacity of 6.8 million kilowatts. It also serves as the primary flood control for the Columbia River basin (with a capacity of 5.18 million acre-feet of water) and provides recreational opportunities on the 150-mile-long Franklin D. Roosevelt Lake. It is the uppermost of 11 dams that comprise the Columbia River Basin Project.

Grand Coulee Dam was critical to the war efforts during World War II, generating abundant electrical power that was crucial for aluminum production for war machinery.
From the ASCE Website

Grand Coulee Dam Statistics and Facts

How much electricity does produce annually?
Grand Coulee Dam is the largest hydropower producer in the United States, generating more than 21 billion kilowatt-hours of electricity each year. That's enough power to supply 2.3 million households with electricity for one year. Power from Grand Coulee Dam is supplied to eleven western states (WA, OR, ID, MT, WY, CO, CA, NV, NM, UT, AZ) and Canada.

How big is Grand Coulee Dam?
Grand Coulee Dam is one of the largest concrete structures in the world. It contains nearly 12 million cubic yards of concrete.

What could you build with 12 million cubic yards of concrete?
You could build a sidewalk four feet wide and four inches thick and wrap it twice around the equator (50,000 miles). You could build a highway from Seattle, Washington to Miami, Florida. You could build the Grand Coulee Dam, one of the modern wonders of the world.

What are the holes in the face of the dam?
Those little holes are 8.5 feet in diameter — you could fit a standard-size truck in one of them. They are used to discharge water through the dam when the elevation of the water in the lake is lower than the drum gates at the top of the spillway.

\ For more information call the visitor center at (509) 633-9265 or visit

Grand Coulee Dam Hoover Dam
Type Gravity Dam Gravity-Arch Dam
Operating Agency Bureau of Reclamation Bureau of Reclamation
Capacity 6,809 megawatts 2,078 megawatts
Location Washington State Nevada/Arizona
Dates of Construction 1933-1941 1967-1974
Third Powerplant
Height 550 feet 726 feet
Length 5,223 feet 1,244 feet
Concrete 11,975,521 cubic yards 3,250,000 cubic yards
Purposes and Benefits Purposes and benefits of both dams include flood control and river regulation, water storage and delivery (including irrigation), power generation, recreation, and fish and wildlife.

From a visitor centre brochure

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Grand Coulee Dam Visitor Center Highway 155 Coulee Dam, WA 99116 USA

Type of structure/site: Dam

Date of Construction: 1941

Engineer/Architect/Builder etc.: Bureau of Reclamation, U.S. Department of the Interior

Engineering Organization Listing: American Society of Civil Engineers

Primary Web Site: [Web Link]

Secondary Web Site: [Web Link]

Visit Instructions:
The listed coordinates for this waymark must be personally visited.

Please submit at least one ORIGINAL PHOTO of the structure, preferably one showing a different aspect, angle, season, etc. from the original waymark.

Give the DATE of your visit and any comments or additional information that will help other visitors enjoy this site.
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