Howard A. Hanson Dam | |
---|---|
![]() Howard A. Hanson Dam (rear) | |
Location | King County, Washington, USA |
Construction began | 1959 |
Opening date | 1961 |
Operator(s) | U.S. Army Corps of Engineers |
Dam and spillways | |
Impounds | Green River |
Height | 235 ft (72 m) |
Length | 675 ft (206 m) |
Width (crest) | 23 ft (7 m) |
Width (base) | 960 ft (292 m) |
Spillway type | Service, controlled |
Spillway capacity | 107,000 cubic feet per second (3,000 m3/s) |
Reservoir | |
Creates | Howard A. Hanson Reservoir/Pool |
Total capacity | 106,000 acre⋅ft (131,000,000 m3) |
Catchment area | 220 square miles (570 km2) |
Howard A. Hanson Dam is an earthen embankment dam on the Green River, 21 miles (34 km) east of Auburn, Washington. The dam was completed in 1961 and its primary purpose is flood control along with water supply for Tacoma, Washington.
After the dam's reservoir reached record levels in January 2009, the U.S. Army Corps of Engineers discovered seepage in the right abutment of the dam, leading to efforts to mitigate a potential flood.[1] Improved drainage works were completed in October 2011 and although studies are still underway, the dam was declared safe to maintain its maximum reservoir level.