BURBANK, Wash. – Operations officials with the U.S. Army Corps of Engineers’ Walla Walla District issued a public notice to navigators today advising them of an accumulation of sediment in the downstream navigation lock approach at Ice Harbor Lock and Dam, located at Snake River Mile 9.7 near Burbank, Wash.
A recent survey indicated a situation where there could be less than the standard 14-foot draft available to vessels if Lake Wallula, the reservoir immediately upstream of McNary Lock and Dam on the Columbia River, falls below 339 feet mean sea level (m.s.l.) in elevation. Lake Wallula’s target operating range varies between 335-340 feet m.s.l., as measured on the upstream side of McNary Dam. Lake Wallula pool elevation was approximately 339 feet m.s.l. at 2 p.m. today.
Pool conditions on Lake Wallula may vary because of seasonally low water inflows. Operators of vessels with drafts that exceed 12 feet are advised to use extreme caution when navigating through the downstream lock approach at Ice Harbor. Vessel operators can contact Corps staff at Ice Harbor Lock and Dam, 509-543-3231, for current pool elevations. Hourly reservoir reports can also be found online at
http://www.nwd-wc.usace.army.mil/nww/rreports.htm.
“We don’t see many recreational vessels with 12-foot-plus drafts using Ice Harbor’s lock, but we want to get the word out to everyone we can for safety’s sake,” said Natural Resources Manager Lanell Adams.
Commercial shippers and Coast Guard officials have been advised of the situation, and Corps staff will continue to monitor and provide updates. Operations officials are developing a plan to address the sediment buildup in the lock approach.
The Corps coordinates navigation maintenance with inland shippers and cruise lines to achieve minimal impact to the various industries that use the locks. Public Notices and other navigation lock information are available on the Walla Walla District website at http://www.nww.usace.army.mil/Missions/Navigation.aspx.
The Corps’ Walla Walla and Portland districts maintain about 350 miles of the federal navigation channel from Portland, Ore. to Lewiston, Idaho. The Columbia-Snake navigation system of eight dams on the Snake and Columbia rivers is vital to the economic health of the Pacific Northwest. The system accommodates the transportation of about 10 million tons of cargo annually. Ten million tons equals about 2,700 barges, 100,000 railcars or 350,000 semi-trucks.
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