The U.S. Army Corps of Engineers, Portland District (USACE) has developed an environmental analysis in accordance with the National Environmental Policy Act of 1969, as amended. The Supplemental Environmental Assessment (SEA) dated 10 February 2026, for the Avian Dissuasion at Lower Columbia River Federal Navigation Channel Dredged Material Placement Sites addresses the need to add additional avian dissuasion measures for piscivorous colonial waterbirds attempting to nest on existing placement sites used for maintenance of River Mile (RM) 3 to 106.5 of the federal navigation channel (FNC), Oregon and Washington.
To read the full FONSI and FSEA click the related links below: