Grays Harbor

The Grays Harbor navigation project is a large coastal inlet on the central coast of Washington.

Contact Us

Chief, Navigation Section
(206) 764-6908   
Chief, Waterway Maintenance Unit
(206) 764-3429   
Seattle District
Navigation Section
4735 East Marginal Way S.
Seattle, WA 98134-2385


Grays Harbor Navigation

Twin jetties (17,200 feet and 13,734 feet) secure the mouth of the harbor with a deep draft 22-mile channel from the Pacific Ocean to the city of Aberdeen. Westport Marina provides moorage for a fishing fleet and the U.S. Coast Guard Station. The deep draft channel is 350 feet wide, increasing to 1,000 feet over the bar. Channel depth is 36 feet up to the major Port docks at Cow Point and then 32 feet from there to the last dock at South Aberdeen. This project is necessary to keep the federal navigation channel open for increasing exports from this harbor.

The deep draft channel is dredged annually at an average cost of $9 million. The volume removed averages 1.7 million cubic yards annually. Westport Marina and the entrance channel require infrequent maintenance dredging. However, periodic maintenance of the groin, revetment, and breakwater structures is currently required. Revetments are showing wear and while some repairs were made in 2010, extensive rebuilding will be required when funding is available. Erosion of the Half Moon Bay land area has been an ongoing problem, requiring the renourishment of the area to prevent a breach and exposing the South Jetty to damage.

Between 2016 and 2018, the U.S. Army Corps of Engineers deepened the federal navigation deep-draft channel in Grays Harbor from the previously maintained depth of -36 feet MLLW to the fully authorized depth of -38 feet MLLW.  The deepening occurred from the South Reach upstream to Cow Point Reach where the Port of Grays Harbor Terminal 4 is located.  This project (Grays Harbor Navigation Improvement Project) deepened approximately 14.5 miles of the 27.5-mile channel.  The purpose of the project was to improve the efficiency of deep-draft vessel navigation in Grays Harbor.  The project was intended to alleviate restrictions on large vessels imposed by insufficient channel depths. 

Grays Harbor Long Term Maintenance Strategy

The U.S. Army Corps of Engineers initiated the Long-Term Management Strategy study because of the recognition that shoreline erosion in the vicinity of the South Jetty could again result in the breaching of the landmass adjacent to the jetty and adversely impact the federal navigation project. The objective of the Long-Term Management Strategy study is to assess the risk that such a breach may occur, to evaluate the threat of adverse impact to the Grays Harbor Navigation Project resulting from any breach, and – if action is determined to be warranted – assess and recommend the most appropriate long-term strategy for continued maintenance of the authorized Grays Harbor navigation project features.

This LTMS study is being conducted under the Corps’ authority to operate and maintain the completed federal navigation project in the most efficient and effective manner. The current investigation is being completed at 100 percent federal cost. The study area under consideration includes those project features and adjacent environment affected by the erosion. The area includes the south jetty, revetment, navigation channel, South Beach, Half Moon Bay, and east to Whitcomb Flats.