The U.S. Army Corps of Engineers has received an application from the Rose City Yacht Club to continue dredging of the Columbia River in Multnomah County, Oregon.
According to the permit application, the applicant proposes to continue dredging approximately 9,000 cubic yards of sand (~81%), silt (~14%), and clay (~5%) sediments annually for a period of 10 years, totaling the approximately 90,000 CY.
The dimensions of the dredging area are approximately 550 feet long by 400 feet wide (~5 acres) and up to seven feet thick to elevation -7 feet Columbia River Datum (CRD). The project site is located along the south bank of the Columbia River, Mile 109.1, adjacent to 3737 NE Marine Drive, in Portland.
The proposed dredging method is an eight-inch diameter suction cutter head dredge on the river bottom that will pump sediments to an adjacent upland settling pond using a six-inch floating pipeline.
Dredging work is proposed during the in-water work window from November 1 through February 28.