Debris damages Lower Granite upstream navigation lock gate; Service suspended for recreational boats; commercial vessels to lock through using bulkhead

Published June 20, 2011

POMEROY, Wash. – Lower Granite Dam’s navigation lock suspended service to recreational vessels this afternoon after a routine inspection of the upstream gate revealed the gate cables were damaged and needed to be replaced, according to operations officials with the U.S. Army Corps of Engineers Walla Walla District.

Lock service for commercial vessels will be suspended from 6:30 p.m. today until 6:30 p.m. tomorrow.  Commercial vessels will be allowed to lock past Lower Granite Dam daily between the hours of 6:30 pm. and 6:30 a.m. starting on June 21 until the repairs are completed.  Lockages will be conducted using a floating bulkhead to block the upstream side of the lock during operations.

Operations staff anticipates the lock will return to full service for both commercial and recreational vessels by 6:30 p.m. on Thursday, June 23.

Maintenance crews will be working 12-hour shifts to replace the cables. Spare cables are already on hand, load tested and ready to be installed, according to Rob Lustig, maintenance chief at Lower Granite Lock and Dam. 

Because of high spring flows throughout the Snake River Basin, an unusually large amount of floating wood – ranging in size from small twigs to telephone pole-sized logs – has been swept from the shoreline into the rivers and streams. This floating debris has caused damage to the Kevlar material gate cables, requiring immediate replacement, according to maintenance staff at the dam.

Vehicle crossings at the dam have not been impacted by the navigation lock repair.

Lower Granite’s navigation lock, located at Snake River mile 107.5, is part of the federal inland channel system that provides navigation from the mouth of the Columbia River near Astoria, Ore., to port facilities on the rivers in Lewiston-Clarkston.  Public Notices and other navigation lock information are available on the Walla Walla District Web site at



Public Affairs

Release no. 11-92