Dredging and the Columbia River

Dredging

The Columbia River is a challenging environment, from its mouth, labeled as the 'Graveyard of the Pacific', to its high sediment yields. As early as the 1890’s, dredging and channel training structures were employed to manage river depths manage sedimentation to keep the river clear for shipping.

The Port of Longview plays two major roles in maintaining shipping in the lower Columbia River and to the Port of Longview berths:

Port Maintenance Activities

Occurring most years, the Port schedules and contracts for berth dredging. Dredging requires regular permit updates, monitoring, contracting, funding and engineering in order to provide safe, deep berths for our customers and tenants to use for import and export activities. The Port also maintains Willow Grove Park and Boat Launch where maintenance dredging occurs as needed. 

Dredge Material

The Port disposes dredged material back into the river, also known as in flow placement, in areas identified by the U.S. Army Corps of Engineers. These are typically outside of the Federal Navigation Channel and in water not shallower than 20 feet or deeper than 65 feet. Dredge materials placed in flow land disposal eventually move back into the system which helps ensure the system doesn't become sediment starved.


Lower Columbia River Channel Maintenance PlanLCRCMP Opens in new window

In addition to our local activities, the Port is one of five non-federal sponsors of the Columbia River Federal Navigation Channel. The Ports of Longview, Woodland, Kalama, Vancouver and Portland, OR, work in partnership with the US Army Corps of Engineers, Portland District, to ensure the Columbia River shipping channel is maintained for commercial shipping. This partnership drives the economic health of our region, strengthens our community and keeps the Columbia River navigation channel safe and efficient for deep draft vessels.

The U.S. Army Corps of Engineers (Corps) has developed a draft Dredged Material Management Plan (DMMP) to support continued operation and maintenance of the Lower Columbia River Federal Navigation Channel (LCR FNC) for the next 20 years. The DMMP was subject to environmental review via a draft Environmental Impact Statement (EIS) pursuant to the National Environmental Policy Act (NEPA) and the Washington State Environmental Policy Act (SEPA).  The EIS was jointly prepared by the Corps and the Lower Columbia River Sponsor Ports (Sponsor Ports are the Port of Longview, Washington; the Port of Kalama, Washington; the Port of Woodland, Washington; the Port of Vancouver USA, Washington; and the Port of Portland, Oregon). The Corps was the NEPA lead agency and the Port of Longview was the SEPA nominal lead agency for the Washington Ports. Combined, the DMMP and EIS are an integrated report known as the Draft DMMP-EIS. The Draft DMMP-EIS was prepared in compliance with Corps policy for the preparation of DMMPs, and the requirements of NEPA and SEPA. The Corps will also issue a separate public notification of the proposed discharges of dredged or fill material described in the DMMP-EIS, in accordance with agency regulations and section 103 of the Marine Protection, Research, and Sanctuaries Act (MPRSA, also known as the Ocean Dumping Act) and section 404 of the Clean Water Act.


Columbia River Turning Basin Improvements

The Port of Longview and Port of Kalama jointly signed an agreement with the U.S. Army Corps of Engineers, Portland District, to evaluate changes and improvements to turning basins in the Columbia River to help larger, deeper-drafting vessels, safely navigate when turning.

Currently, there are very few places on the lower Columbia River to turn large, fully loaded ships. These vessels need to be turned around before passing through Longview when Pacific Northwest storms force Columbia River Bar closures due to unsafe conditions. As cargo volumes increase, larger vessels are more frequently calling on the Columbia River, making turning basins necessary for safety and reducing transportation delay costs. 

Read the Army Corps of Engineers press release on the Turning Basin here. 

Current SEPA Notice:

The Port of Longview is providing a Notice of Adoption of Existing Environmental Document for a Determination of Nonsignificance for the U.S. Army Corps of Engineers, Portland District Final Integrated Feasibility Report and Environmental Assessment dated April 2025; Finding of No Significant Impact dated January 21, 2026.

View the SEPA Notice and the Turning Basin Study documents.