BOISE, Idaho — The U.S. Army Corps of Engineers plans to increase flows through the City of Boise by 1,500 cubic feet per second (cfs) Monday, June 3, reaching approximately 5,000 cfs by noon. Boise River flows through town are approximately 3,500 cfs, as measured at the Glenwood Bridge gauge.
The increase in flows from Lucky Peak Dam and Lake is in response to increased inflows. The flow increase is necessary to help balance reservoir-refill goals with the continued risk of flooding, which can happen with rapidly melting snow and seasonal precipitation.
Currently, the Boise River reservoirs are at about 93% of capacity. As of June 2, the Boise River system of reservoirs has about 65,623 acre-feet of available storage space. A full supply of irrigation water is expected this summer.
Additional adjustments in water releases from Lucky Peak Dam and Lake may depending on weather conditions and resulting inflows. Flows also could vary depending on water diversions for irrigation use, as determined by Idaho Water District 63.
When river flows exceed 4,000 cfs at the Glenwood Bridge gauge, water is likely to begin seeping onto low spots on the Greenbelt path next to the river, especially near bridge underpasses. The Greenbelt serves as a flowage easement area, intentionally designed to provide space for higher flows occurring in the Boise River.
A flow rate of 7,000 cfs, or about 10 feet in water depth, at the Glenwood Bridge gauge, is considered flood-stage level on the Boise River. Officials advise the public to be aware of risks associated with flood season. The water is deep, cold and fast. Extreme caution should be used near the river banks.
Residents of flood-prone areas in and near the greater Boise area are encouraged to keep informed of changing river, stream, and weather conditions on the National Weather Service, Boise Office website. The site offers flow data, weather forecasts, and flood alerts. Follow flood-response instructions issued by your local emergency management agency, and tune-in to local radio and television news stations. Ada County residents can sign up for CodeRED emergency alerts, or download the CodeRED mobile app from your mobile device’s app store.