Public Notices

Seeking public comments for Maintenance Dredging at Tongue Point and Oregon Slough

Portland District, Corps of Engineers
Published Oct. 14, 2021
Expiration date: 10/28/2021
Public Notice
Availability of
Tongue point, Clatsop County, Oregon and Oregon Slough, Multnomah county, Oregon


                                 Issue Date: October 14, 2021
                                 Expiration Date: October 28, 2021


Interested parties are hereby notified that the U.S. Army Corps of Engineers, Portland District (Corps) proposes to perform maintenance dredging of two federal navigation channels in Oregon State: Tongue Point and Oregon Slough. The purpose of the proposed action is to facilitate safe and reliable navigation. Congress has authorized construction and maintenance of the two navigation channels at various times.

  • Tongue Point Channel was approved by the Chief of Engineers on 14 June 1989 under the authority of Section 107 of the River and Harbor Act of 1960, as amended. The most recent dredging at Tongue Point Channel was for initial construction in 1989.
  • Oregon Slough (20-foot deep channel, river mile (RM) 1.5 to 3.8) was authorized by the Rivers and Harbors Act of 25 July 1912. This FNC was most recently maintained by the Corps in 1963.

Project Description

The Corps proposes to perform maintenance dredging at the Tongue Point and Oregon Slough federal navigation channels. Channels would be maintained to authorized depths using clamshell, mechanical, or pipeline dredges. Tongue Point would be maintained to the authorized depth of 34 feet; Oregon Slough be maintained to the authorized depth of 20 feet. All channels may be dredged to an additional depth of 2 feet greater than the authorized depths for advance maintenance. The Corps would place the dredged materials in the Columbia River from River Mile (RM) 3 to RM 105.5 where water depth is 20 feet or greater. The work would occur from August 1 through December 15. Frequency of dredging for Tongue Point is anticipated to be annually; frequency of dredging for Oregon Slough is anticipated to be 1 out of 5 years. Typical volume of material proposed for removal varies, ranging from 800,000 cubic yards for initial deferred maintenance, then decreasing to approximately 119,000 CY for Tongue Point, and as needed for Oregon Slough.

The proposed action is located at:

  • Tongue Point – near Astoria, Clatsop County, Oregon, Columbia RM 18.5
  • Oregon Slough – near Portland, Multnomah County, Oregon, Columbia RM 1.5 to 3.8

Agency and Public Involvement

The Corps has prepared a draft EA for the proposed action in accordance with the Council on Environmental Quality’s National Environmental Policy Act (NEPA) regulations found at 40 CFR §1501.5(e) and the Corps NEPA Implementation Regulations found at 33 CFR §230.10.

In addition, the content of this public notice fulfills the public notice requirements for discharges of dredged or fill material associated with Corps Civil Works operations and maintenance activities found in 33 CFR §337.1. Any person who has an interest that may be affected by the placement of the dredged material may request a public hearing. The request must be submitted in writing to the district engineer before the comment‑period deadline specified in this notice. The request must also clearly identify the interest that may be affected, including the manner by which the proposed action may affect this interest. At the end of the public comment period, the Corps will consider all comments received or post marked by the expiration date of this public notice.

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.

The draft EA is available for download at:

Environmental Coordination

The Corps is coordinating with numerous Federal, state, and local environmental agencies. A full list appears in Section 5 of the EA.  Section 404 regulates the discharge of dredged or fill material into waters of the United States. Section 404 applies to the proposed action, because the Corps will place dredged material into the Columbia River. The Corps applies the “404(b)(1) guidelines” (40 CFR Part 230) to demonstrate that there is no practicable alternative to placing fill material into a water of the U.S.

The decision whether to discharge dredged or fill material will be based on an evaluation of the probable impact including cumulative impacts of the proposed activity on the public interest. That decision will reflect the national concern for both protection and utilization of important resources. The benefit that reasonably may be expected to accrue from the proposal must be balanced against its reasonably foreseeable detriments. All factors which may be relevant to the proposal will be considered including the cumulative effects thereof; among those are conservation, economics, aesthetics, general environmental concerns, wetlands, historic properties, fish and wildlife values, flood hazards, floodplain values, land use, navigation, shoreline erosion and accretion, recreation, water supply and conservation, water quality, energy needs, safety, food and fiber production, mineral needs, considerations of property ownership and, in general, the needs and welfare of the people.

After taking into account costs, existing technology, logistics, and the fact that existing placement areas are nearing capacity, the Corps determined that in‑water placement is most appropriate for meeting the needs of the dredge program, while minimizing adverse impacts to water quality. The Corps prepared 404(b)(1) evaluations to provide more detail about how the proposed action meets the 404(b)(1) guidelines; these evaluations as an Appendix to the EA. In summary, because the proposed action would not fill wetlands and would only discharge clean fill (suitable dredged material) into waters of the U.S., it complies with Section 404.

The EA also outlines how the Corps will comply with Section 401 of the Clean Water Act, Section 106 of the National Historic Preservation Act, Endangered Species Act, Coastal Zone Management Act, and other environmental statutes and executive orders. 

Additional Information and Comments

Questions or comments regarding the draft EA should be directed to Elizabeth Santana, Environmental Resources Branch, at (503) 808 - 4722,, or to the mailing address below.

District Engineer
U.S. Army Corps of Engineers Portland District
Attn: CENWP-PME-E / Elizabeth Santana
P.O. Box 2946
Portland, Oregon 97208-2946

Mailed comments on this notice must be postmarked by the above expiration date.  In your response, please refer to the above public notice title and date. Should no response be received by the above closing date, a “no comment” response will be assumed.