WALLA WALLA , Wash. – The U.S. Army Corps of Engineers completed federal navigation channel dredging at Ice Harbor Lock and Dam yesterday, Jan. 14. Ice Harbor lock operations have returned to normal and dredging equipment has been removed, including water quality monitoring buoys, and relocated upstream to work areas in the Snake and Clearwater rivers at Lewiston-Clarkston.
The Corps’ dredging contractor, American Construction Company, completed dredging of about 2,000 cubic yards of material at the downstream lock approach of Ice Harbor Dam. Dredging began Monday morning, Jan. 12. American Construction Company has also been dredging with a second dredge at the confluence of the Snake and Clearwater rivers since Monday. A third dredge has also been deployed to the confluence area.
River mariners are urged to be cautious around dredging vessels and equipment, and travel at slowest safe speed to minimize wake production. Proceed with caution after passing arrangements have been made with dredges. The dredging vessels can be contacted on VHF-FM Channel 13 or 16.
The Corps issued a notice to the navigation industry about Ice Harbor’s return to normal operations. The Corps previously issued a notice to the navigation industry announcing the presence of dredging vessels and equipment in the lower Snake River between Jan. 8 and Feb. 28.
As previously announced:
Dredging vessels and equipment will be moving between dredging locations and the dredged material placement site (River Mile 116 near Knoxway Canyon) during January and February. Dredging is likely to involve 24-hour-a-day operation.
The contractor places water quality monitoring buoys both downstream and upstream of various dredging locations in the confluence area. Monitoring buoys measure water turbidity levels.
Maintenance dredging last occurred in the lower Snake River navigation channel in the winter of 2005-2006. Sediment accumulation has since encroached on certain areas of the federal navigation channel and related port berthing areas.
For information about the Corps’ Programmatic Sediment Management Plan, see the Walla Walla District website at http://www.nww.usace.army.mil/Missions/Projects/ProgrammaticSedimentManagementPlan.aspx.
Release no. 15-005