Willamette River Dredged Material Management Plan
The U.S. Army Corps of Engineers is charged with maintaining the navigation channels of the Willamette and Columbia rivers. As part of that responsibility, in 2007 and 2008, the Corps worked on a dredged material management plan for the existing 40-foot deep Lower Willamette River navigation channel. The Port of Portland was an active participant in that process. The Willamette River's federal navigation channel stretches from the Broadway Bridge in downtown Portland downstream to the Columbia River. A completed DMMP would lay out a 20-year plan for managing material dredged from this channel to maintain its authorized depth and provide safe navigation.
In September 2008, the Corps suspended work on the DMMP pending the outcome of the Portland Harbor Superfund investigation and cleanup. The Environmental Protection Agency has overseen studies of the Portland Harbor since it was listed as a Superfund site in 2000. A draft feasibility study of cleanup options is due to be completed in spring 2012 and will be followed by an EPA-developed proposed plan and record of decision.
The Willamette's navigation channel was last maintained by the Corps in the summer of 2011 when a small, hazardous shoal was removed from the channel at Post Office Bar, just south of where the Willamette flows into the Columbia River. This project removed about 50,000 cubic yards of material. This material was placed at the approved dredge material placement site on West Hayden island.
Historically, the Corps dredged between 500,000 to 750,000 cubic yards of sediment from the channel every three to five years. The lack of ongoing maintenance dredging since 1997 presents a continuing impairment to navigation, access to Willamette River terminals and berths, and regional commerce in general.
The permitting process required for all Willamette River dredging actions ultimately determines the appropriate disposition of dredged material, including potential beneficial use as upland fill. As the non-federal sponsor of the Lower Willamette River navigation channel, the Port is obligated to provide the lands, easements, and rights-of-way for upland placement of dredged material by the Corps.
Acting in its role as non-federal sponsor, the Port assists the Corps in disseminating information about the navigational dredging and the handling and management of dredged materials by hosting this Web site. Information will be added as the DMMP project continues.