A Long Time Coming
The dam took three years to build, but was more than 60 years in the making. During that time, more than 30 major floods were recorded, and flood control for many farmers was a life-long dream. The Associated Improvement Clubs of South King County was formed in 1926 to tackle the problem, but they later called in the U.S. Army Corps of Engineers for assistance.
After years of studies, the Corps chose Eagle Gorge for the location of a reservoir dam and Congress declared it a federal project in 1950. Construction began in 1959, at a cost of $40.5 million. A flood later that year wiped out a cofferdam, but completion of the project in 1962 was achieved a few months ahead of schedule.
An early proponent of the dam was Howard A. Hanson, Seattle attorney and early twentieth century State Legislator. Hanson promoted the regional benefits of the dam, raising $2 million from the State and King County. Hanson died in 1957, and a year later the dam, originally called Eagle Gorge Dam, was renamed Howard A. Hanson Dam by an Act of Congress.
Big Party by a Dam Site
The flood that wiped out the cofferdam at the construction site in 1959 was so bad that in the valley the water level reached the second story of some homes. In 1961, rising waters again threatened the community, but Christmas brought a gift when the almost-complete dam stopped its first flood on December 25 by holding back enough water to avert disaster.
Valley residents were so pleased, that many of them wanted to see the dam that would change their lives. When dedication day rolled around, a 44-coach “Casey Jones” special train filled with 1,500 passengers brought 1,500 visitors to Eagle Gorge. Others rode cars or Army buses to the dam site. This would be their only chance to see the structure, as it was located within the Tacoma City Watershed, usually off limits.
In the morning, the weather was drizzly with a flag-whipping breeze, but by the time the train arrived, the sun was out and the air was clear. More people arrived, and by 10:30 a.m. thousands of people spread across the dam. The Highland High School band began to play.
Shortly after 11:00 a.m., John Cartano, president of the Seattle Chamber of Commerce, got the program underway. An invocation was read by Seth G. Eastvold, president of Pacific Lutheran University. Cartano then introduced the mayors and visiting dignitaries from Auburn, Kent, and Renton. Other speakers included Lieutenant General Walter K. Wilson, chief of the Army Corps of Engineers, and Frank Matthias, superintendent of heavy construction for the prime contractor, Kaiser-Raymond International.
Senator Warren Magnuson (1905-1989) was the keynote speaker. He noted that by stopping the Christmas Day flood, the dam had already, “done something to repay the energy and effort that went into it.” Estimates were that another flood a month earlier had been averted that would have covered 2000 acres in the valley.
Magnuson also cited benefits such as pollution control, aid to fisheries, and more land for industry. “The economy down below in the Green River Valley is changing, and urbanization is going to reach this area quickly.” History has proven him right, probably more than he realized.
Signs of the Future
Two plaques were presented at the ceremony. The first was by Judson C. Colburn, past secretary of the Associated Improvement Clubs of South King County. This plaque cited the efforts by civic and community organizations on behalf of the project. The second plaque, which was installed by Senator Magnuson, bore the name Howard A Hanson Dam, along with the dam’s vital statistics.
The crest of the dam is 235 above the riverbed. Its total length, including spillway and abutments is 675 feet. Its thickness at the base is 960 feet, while at the top it is only 23 feet wide. The containment reservoir is 7 miles long, and holds 130,753,000 cubic meters of water.
The ceremonies ended at 11:59 a.m. A cheer went up from the crowd, many of whom would never have to suffer through another major flood for the rest of their lives. Those with picnic baskets headed for the hillsides for a pleasant lunch, after which they boarded the train or their cars back to a valley that would soon be changed forever.