Lewiston, Idaho – Water levels in the Lower Granite reservoir may fluctuate more than in recent years, now that dredging operations at the confluence of the Snake and Clearwater rivers have completed.
Before dredging cleared sediment from the confluence, the Lower Granite pool was kept at a minimum elevation of 736 feet, as measured by the confluence gage (LWSI). Now that dredging at the confluence is complete, the Lower Granite reservoir will be returning to its full operating range of 733 to 738 feet.
This increased range could lower water levels at the confluence three feet more than boaters and other river users have experienced in recent years.
The Walla Walla District advises the public to be aware of the danger associated with fluctuating river flows and elevations. Boaters should be aware of how lower water levels may affect nearby marinas.
More information about Lower Granite pool elevations and readings from the LWSI gage can be found here: https://www.nwd-wc.usace.army.mil/dd/nwdp/project_hourly/webexec/rep?r=lwg&ago=0. For more questions, contact us at 509-527-7020.
Release no. 23-013