PORTLAND, Ore. - The U.S. Army Corps of Engineers says high river levels are concealing some pile dikes in the Columbia River creating additional underwater hazards for boaters and commercial mariners.
Pile dikes, also called wing dams, are wooden structures that extend perpendicular from the shore into the river. The structures have a variety of uses ranging from protecting the shore to managing the flow of the navigation channel.
Corps waterway maintenance managers say the tops of most piles are frequently just below the surface during high water events and can cause serious damage to vessels attempting to transit over them. Commercial and recreational mariners are advised to check the most current navigation maps closely for pile dike locations; maps are available on the Portland District website at http://www.nwp.usace.army.mil/navigation/home.asp.
The Columbia River is running very high due to heavy rains over the past weeks in the Cascade and Rocky mountains in Canada, Eastern Washington, Northern Idaho and Western Montana. In order to relieve local flood conditions and reserve storage space in reservoirs upriver for above average snowpack, dams are releasing more water than usual into the lower Columbia River while attempting to minimize flooding downstream.
The Columbia River at Vancouver is technically about a foot above flood stage right now, although impacts are minor and water levels are receding.