History In The Making

Theodore Roosevelt Dam dedicated a century ago

The public is invited Saturday, March 19 to celebrate the 100th birthday of Theodore Roosevelt Dam by taking a walk across the crest of the dam as part of a free centennial event offered by Salt River Project, the Bureau of Reclamation and the U.S. Forest Service. See page 4B for more information about this historic event.

The public is invited Saturday, March 19 to celebrate the 100th birthday of Theodore Roosevelt Dam by taking a walk across the crest of the dam as part of a free centennial event offered by Salt River Project, the Bureau of Reclamation and the U.S. Forest Service. See page 4B for more information about this historic event.


March 18, 2011 is a milestone for me, Theodore Roosevelt Dam. It was on that day 100 years ago that former President Theodore Roosevelt stood on a platform on top of my roadway and said, “if there could be any monument which would appeal to any man, surely it is this.”


SRP photo

Theodore Roosevelt

And so it was that I, then the world’s largest masonry, thick arch dam, on March 18, 1911, officially became Roosevelt’s monument, or, simply, Roosevelt Dam (my name was changed to Theodore Roosevelt Dam by the U.S. Congress in 1959; I’ll explain later how that happened).

My location is on the Salt River a few 100 yards west of its confluence with Tonto Creek at the Tonto Basin, about 65 air miles northeast of Phoenix, Ariz. Then, and now, my job is to store and provide water and electricity primarily to the Salt River Valley, where Phoenix, the nation’s 5th largest city, is located.

The next important thing to know is that in the 1990s my appearance was radically changed. Instead of a masonry thick arch dam, I am now a concrete gravity arch dam. I also am thicker and higher.

At bedrock in the Salt River, my original width was 184 feet. From there, my height rose 280 feet and at the top my width narrowed to 16 feet. Safeguarded by a 4-foot high parapet wall, pedestrian and other traffic traveled my 723-foot length.

The dam was formed from stone cut from the dam’s spillways and cemented together in rows of giant steps on the downstream side. Italian-born stonemasons living in the United States did the cutting when the construction started.

In the 1980s, the organization that owns me, the U.S. Bureau of Reclamation, an agency of the U.S. Department of the Interior, decided to increase my thickness and height. The Salt River Project, the association that operates my reservoir and powerhouse, concurred.

The modification, completed in 1996, was done to toughen me against the possibility of an earthquake and to enlarge Roosevelt Lake to contain the biggest flood that might come down the Salt River and Tonto Creek. The enlargement also provided water storage for Salt River Valley cities.

Engineers were concerned that if I broke apart or were over topped by floods, uncontrolled water would threaten the stability of three downstream water storage/hydroelectric dams and would cause widespread damage through the Phoenix metropolitan area.

So today, as a concrete gravity arch dam, my appearance is nothing like my original look. On the downstream side, I am covered completely by concrete. On the upstream — or Roosevelt Lake side — my original appearance, a wall of rocks, comes into view when the reservoir’s elevation goes below 2,129 feet.


Courtesy of Rim Country Museum

A six-ton cornerstone was laid on Sept. 20, 1906, and construction of Roosevelt Dam commenced. The monument was dedicated by its namesake on March 18, 1911.

At bedrock now, my thickness is 196 feet and my height rises to 357 feet as I taper inwardly to a top width of 21.6 feet. My length at the top is 1,210 feet, but motor traffic does not pass over me any longer. Instead, vehicles travel on the Roosevelt Lake Bridge a short distance upstream. The bridge was dedicated in 1990.

The original lake could hold 1,336,734 acre-feet of water compared to 1,653,043 acre-feet now. One acre-foot equals 325,851 gallons of water and covers an acre of ground, 43,560 square feet, to a depth of one foot.

The capacity of the powerhouse in front of the dam on the south bank is 36,000 kilowatts. This is the same as before I was enlarged. The spillways’ water release capacity both before and after alternations was 150,000 cubic feet per second. One cubic foot is 7.48 gallons of water.

I regard as my birthday Sept. 20, 1906, the day a six-ton cornerstone was laid in the center of the channel on the upstream end of the dam excavation.

The bottom of the cornerstone sits 32 feet below the river’s normal bed. Like every rock in the dam, before being put in place it was washed with a high-pressure hose to remove all dirt so cement would adhere firmly.

Some people may consider my birthday to be March 14, 1903, the day the Interior Department announced the first five federal reclamation projects, including my construction. Others might cite Aug. 3, 1903, the day the U.S. Geological Survey, an Interior Department agency, approved an application by the Salt River Valley Water Users’ Association to build the dam. The association, incorporated Feb. 7, 1903, is one of two organizations forming today’s Salt River Project.

Association landowners were required to obtain shares in the organization by agreeing to obligate their land, up to a maximum of 160 acres, as assurance the federal government would be repaid for the construction. The $10.3 million debt was paid off in 1955.

Finally, about the change in my name, U.S. Sen. Barry Goldwater, R-Ariz., running for reelection in 1958, said that if voters sent him back to the Senate he would introduce legislation to change the name of the dam from Roosevelt Dam to Theodore Roosevelt Dam.

Goldwater said this would end confusion, particularly among younger people, who mistakenly believed the dam was named after President Franklin Delano Roosevelt and not Theodore Roosevelt. Franklin Roosevelt, a Democrat, was sworn into office for his first term March 4, 1933, and for a fourth term January 20, 1945. Theodore Roosevelt, Republican, became president Sept. 14, 1901, succeeding the assassinated William McKinley, and was reelected, starting his second term March 4, 1905.

Theodore Roosevelt was an obvious choice to be honored by his name being attached to me (also to the lake formed behind me and to the powerhouse) because he supported passage by the Congress of the Hansbrough-Newlands Act (the national reclamation bill) and signed it into law June 17, 1902. The law allowed for federal aid to irrigation on public and private lands.

About the author

Earl Zarbin of Phoenix, a reporter and editor for the Arizona Republic before retirement, is the author of “Roosevelt Dam: A History to 1911,” published in 1984, and five other Arizona history books.


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