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. The Grays Harbor Navigation Improvement Project deepened approximately 14.5 miles of the 27.5-mile channel.
Previously, the Corps removed an average of 1.2 million cubic yards of sediment annually from the channel. The dredged material is disposed of at various approved disposal sites, including open-water disposal at the Point Chehalis, South Beach, South Jetty, and Southwest disposal sites, as well as beneficial use for beach nourishment at Half Moon Bay.
The Corps awarded a $27.1 million dredging contract to American Construction Company for combined deepening and maintenance dredging of the Grays Harbor Inner Harbor federal navigation channel. Maintenance and deepening included dredging approximately 3.5 million cubic yards of material. The contract contained three distinct work windows: October 1, 2016 - February 14, 2017; July 16, 2017 - February 14, 2018; and July 16 - December 30, 2018.
The Grays Harbor Navigation Improvement Project is located 50 miles west of Olympia on the central coast of Washington. The cities of Aberdeen, Hoquiam, Ocean Shores, and Westport surround Grays Harbor. Based on a General Design Memorandum dated February 1989, the deep draft channel was deepened to -36 feet mean lower low water (MLLW), two feet less than the fully-authorized depth of -38 feet MLLW. The Port of Grays Harbor requested deepening the channel the additional two feet to better accommodate current vessel traffic for existing Port tenants and commodities.
The purpose of the project is to improve the efficiency of deep-draft vessel navigation in Grays Harbor. The project is intended to alleviate large vessel restrictions imposed by the insufficient channel depths.