It was early in the morning and a steam-powered paddleboat made its way up the lower Snake River, trimmed with colored flags. The date was June 19, 1975, and the mood was festive. The vessel was heading for Lower Granite Lock and Dam, whose pool had been raised just four months prior.
The U.S. Army Corps of Engineers Walla Walla District has started the installation process in Unit 1 for another adjustable blade turbine designed for improved fish passage. The Corps has been working diligently to decrease fish injury and improve survival rates through turbines designed for improved fish passage at Ice Harbor Lock and Dam.
In May 1948, floodwaters on the Columbia River overtopped the cofferdam where construction was underway on McNary Lock and Dam. This flood, one of the largest on record, was one of many documented in the region since the mid-1880s. The propensity for flooding in the Northwest sparked much discussion about regional flood control.
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.
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

23-048 Dworshak Dam releases to fluctuate between 2,400 and 5,000 cfs on Oct. 5 and 6 for testing
9/28/2023
AHSAHKA, Idaho – Operators of Dworshak Dam will increase flows from 1,700 to 2,400 cubic feet per second on the evening of Oct. 4 to help minimize stage changes during testing on the following days...
23-047 Lower Monumental Dam closes public dam crossing Oct. 5 to perform maintenance
9/26/2023
Kahlotus, Wash. – Officials at Lower Monumental Lock and Dam will be closing public dam crossings Oct. 5 to perform transformer maintenance...
23-046 Lower Monumental Dam closes public dam crossing Sept 11 through 28 to perform maintenance
9/8/2023
Kahlotus, Wash. – Officials at Lower Monumental Lock and Dam will be closing public dam crossings Sept. 11 through 28 to perform maintenance...