By 1962, Ice Harbor Lock and Dam had been built and construction of the second lower Snake River dam, Lower Monumental, was being passed to the US Army Corps of Engineers Seattle District. The third dam in the queue was right on the heels of Lower Monumental, but construction could not begin until the details of its downstream neighbor were determined.
The construction of Lower Monumental Lock and Dam allowed for the development of an isolated region. Today, Lower Monumental allows convenient river crossing, as well as shoreline recreational opportunities. Boating is one of the primary activities enjoyed by visitors to the Lower Monumental Project. USACE parks along Lake West include six boat ramps, as well as multiple sites for picnicking and hiking. More than 6,900 acres of the project lands are open to public hunting.
Ice Harbor Lock and Dam boasts some of the most cutting-edge hydropower technology in the world. Two advanced technology turbines currently sit in the powerhouse, with a third one on the way. These new turbines were designed to improve fish passage and generate electricity more efficiently.
Today, McNary is an essential part of the river highway that was envisioned before the formation of the Walla Walla District. It sits as the midpoint, the last lock on the Columbia before the mouth of the Snake River. With its 14 generator units, McNary is also an incredible source of hydropower, capable of producing 980-megawatts or enough electricity to power about 686,000 homes.
Every year, snowmelt from the surrounding mountains flows into creeks and streams that join the Boise River. When flows reach 7,000 cubic feet per second or higher, the river is considered at flood stage.
In 1931, a torrent of brown water roared down Mill Creek, with water levels rising at a rate of one foot per hour. The water escaped the confines of the riverbanks and rushed through the City of Walla Walla, destroying homes, roads and bridges. Born in the wake of this disastrous event, the Mill Creek Project now stands to protect the city from floods like this.
The Walla Walla District constructs, operates, maintains, and secures multipurpose infrastructure to energize the economy, reduce flood risk, and serve as stewards of water resources for the Snake River Basin and the Nation.

News Releases

Wawawai Landing Boat Ramp Closed for Repair Work
Clarkston, Wash – The Lower Granite Natural Resource Management office has closed the boat ramp at Wawawai Landing until further notice to assess the ramp’s condition and perform needed repairs...
Dworshak celebrates the 50th anniversary by offering powerhouse tours
Ahsahka, Idaho – Don’t miss your chance to see the inner workings of Dworshak Dam and the Powerhouse. In honor of our 50th Anniversary, we will be offering powerhouse tours three times a day on...
23-032 Dworshak Dam releases to decrease to minimum flow this weekend
AHSAHKA, Idaho – Dworshak Dam is currently releasing 2,300 cubic feet per second (cfs). Flows will begin decreasing on the evening of Saturday, May 27 to be in the approximate range of 1,400-1,600...