Public Notices

Draft Environmental Assessment of Lower Columbia River Anchorage Dredging Open for Public Comment

Portland District, U.S. Army Corps of Engineers
Published June 10, 2024

Public Notice
Public Comment Period Open for Draft Environmental Assessment of Annual Dredging to Remove Shoaling at USCG Anchorage Points on Lower Columbia River

Issue Date: June 10, 2024
Comment Period End Date: June 25, 2024

Interested parties are hereby notified that the U.S. Army Corps of Engineers, Portland District (Corps) proposes to perform annual dredging by the Corps and/or its contractor to remove shoaling at seven existing, U.S. Coast Guard (USCG)-designated anchorage grounds and Corps Civil Works program anchorages located in the Lower Columbia River (LCR), adjacent to the Federal Navigation Channel (FNC), between RM 14 and 106, and placement of the dredged material between RM 3 and 106.

Project Description:
The Corps proposes to perform annual dredging of seven anchorage areas (listed in 33 C.F.R. §110.228(a)(1)–(4), (7), (9), (10)), designated by the USCG. There are four additional designated anchorage areas in the LCR that are not proposed for dredging (33 C.F.R. § 110.228(a)(5), (6), (8), (11)). The Corps would dredge an annual average of approximately 200,000 to 250,000 cubic yards (CY) of native, riverine sediments from seven anchorage grounds located in the Columbia River, adjacent to the FNC, between RM 14 and 106. The material dredged would be transported and placed in areas of the Columbia River where water is 20 feet deep or greater, referenced to mean lower low water from RM 3 to RM 22 and referenced to adopted low water (Columbia River Datum [CRD]) upstream of RM 22. This area is referred to as the “flowlane.” The material to be dredged from the proposed anchorage areas is suitable for in-water placement. The Corps routinely places material dredged from the FNCs into the Columbia River flowlane from RM 3 through RM 145. The Columbia River is a dynamic environment of sediment movement, where bed-load material often forms moving sand-wave ripples along the river bottom. The Corps is proposing to use the same in-water dredged material placement locations as what is currently used for O&M of the LCR FNCs. Locations for in-water placement vary, depending on the depth of the river bottom each year. As deeper areas in the river are filled with dredged material over time, new deep areas are formed elsewhere through natural river processes. The Corps’ in-water placement strives to emulate natural processes by allowing dredged sediment to be re-distributed back onto the river’s morphology, sustaining the river’s sediment budget, and maintaining habitats that rely on sediment.

The Corps has prepared a draft Environmental Assessment for the proposed action in accordance with the Council on Environmental Quality’s National Environmental Policy Act (NEPA) regulations found at 40 CFR §1500-1508 and the Corps implementing regulations found at 33 CFR §230.10. The Corps has made a preliminary determination that the effects of the proposed action would not be significant, and that the preparation of an Environmental Impact Statement (EIS) is not warranted. Following public review, the Corps will make a final determination on whether to make a Finding of No Significant Impact (FONSI) or prepare an EIS.

Environmental Document:
The draft EA is available at the USACE Digital Library here: Library Link, PDF Link

Public Comment Period:
The draft EA will be available for public comment for 14 days after the date of this public notice. The public comment period is intended to provide those interested in or affected by this action an opportunity to make their concerns or comments known.

Comment Submittal: Please submit written comments to the U.S. Army Corps of Engineers, Portland District by June 25, 2024. Written comments may be sent via email to Darren Bradford, Environmental Resources Branch at Darren.L.Bradford@usace.army.mil, or to the mailing address below:

District Engineer
U.S. Army Corps of Engineers Portland District
Attn: CENWP-PME-E / Lower Columbia River Anchorage Dredging
P.O. Box 2946 Portland, Oregon 97208-2946

Mailed comments on this notice must be postmarked by the above expiration date. All comments received will become part of the administrative record and are subject to public release under the Freedom of Information Act, including any personally identifiable information such as name, phone numbers, and addresses. The Corps will respond to public comments in the final EA. In your comments, please include in the subject line: Lower Columbia River Anchorage Dredging - EA Comment, and the date.