PORTLAND The U.S. Army Corps of Engineers advises boaters and commercial mariners to be aware that some Columbia River pile dikes may be underwater. 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. 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.
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 www.nwp.usace.army.mil/Missions/Navigation.aspx