The project was authorized by the Flood Control Act of 1946.
Construction of Lucky Peak Dam began in 1949. It was dedicated June 23, 1955.
The project includes the dam, Lucky Peak Lake, federally owned lands managed by the U.S. Army Corps of Engineers (USACE), and operational and recreational facilities. The project provides flood risk management, fish and wildlife habitat, irrigation and recreation. Since 1961, more than $2.37 billion in potential flood damages have been prevented.
Lucky Peak Dam
The dam is a rolled earthfill dam about 250 feet above the streambed and 2,340 feet long at the crest. The spillway, located on the left abutment, has a 600 foot long, free-overflow concrete ogee crest. The outlet works, located in the left abutment, consist of a 23-foot diameter tunnel with six slide gates and one hollow jet valve. There are two 10-foot by 23-foot Broome-type emergency gates located in the intake tower.
Upstream of Lucky Peak Dam is a storage reservoir, Lucky Peak Lake. At normal full pool - elevation 3,055 feet above mean sea level (MSL) - the lake is 12 miles long, has 45 miles of shoreline, and 3,019 acres of surface area. The reservoir provides a total storage capacity of 264,400 acre-feet. Flood risk management and irrigation storage is jointly coordinated between USACE and the Bureau of Reclamation, which operates two upstream dams, Arrowrock Dam (opened in 1915) and Anderson Ranch Dam (opened in 1950). Together, this three-dam system stores approximately 1,000,000 acre-feet when full.
The Federal Power Act of 1920 authorized the use of federal lands by non-federal entities to construct hydropower facilities. The Federal Energy Regulatory Commission issued a license to the Boise-Kuna Irrigation District to construct a 100-megawatt facility in June, 1980. After reconstruction of the primary outlet and construction a new secondary outlet, the plant went online in 1988. The power purchaser, Seattle City Light, operates and maintains the facility.
There are 4,288 acres of public lands surrounding Lucky Peak Lake. These include lands that are federally owned and managed by USACE, as well as easement lands to which USACE has specific rights to flood.
There are 4,079 acres of USACE-managed lands that are used for public recreation, wildlife habitat and operations purposes. Lucky Peak Lake bisects Idaho Fish and Game’s Boise River Wildlife Management Area, a major winter range in the state for deer and elk. The Idaho State Parks operates Lucky Peak State Park Units at three locations on Lucky Peak Lake. Ada County Parks and Waterways provides over 500 public-use floating dock sections. USACE recreation facilities at Lucky Peak Lake consist of seven park areas, four boat launch ramps, and 80 dispersed recreation sites accessible only by boat. The fiscal year 2020 public visitation to all areas was approximately 950,000 visits.
10 full-time Walla Walla District employees work at Lucky Peak Dam and Lake. They serve as park rangers, natural resource specialists, administrative staff and maintenance workers. Temporary employees augment the staff during high-visitation months. Together, they manage the safe and continuous operation of the dam and its facilities. The staff also manages a volunteer program to help operate park areas and make improvements to Lucky Peak Lake’s numerous public recreation facilities.