The U.S. Army Corps of Engineers, Walla Walla District (USACE), has prepared a draft Tiered Environmental Impact Statement (TEIS) for long-term sediment management within the Federal navigation channel at or near the confluence if the Snake and Clearwater Rivers (Confluence). This TEIS is tiered from the 2014 Programmatic Sediment Management Plan and evaluates alternatives to address recurring sediment accumulation that interferes with safe and reliable commercial navigation at the Confluence. This action is being conducted under existing navigation authorities, including the Rivers and Harbors Act of 1945 and the Flood Control Act of 1962, which authorizes USACE to maintain the congressionally authorized Federal navigation channel, for authorized project purposes.
This TEIS evaluates long-term sediment management alternatives over a 50-year planning horizon to identify a cost-effective, technically feasible, and environmentally acceptable solution.
Public Comment and Review:
The documents associated with this study include the draft Tiered Environmental Impact Statement (TEIS), technical appendices, and supporting materials. These documents can be electronically accessed within the “Links” section on the right-hand side of this webpage.
USACE is soliciting public comments and review on the proposed action.
Comments will be accepted for a 45-day period from May 11 through June 24, 2026.
How can I comment?
There are several ways that you can provide input on this action.
You can submit a comment through the NEPA Online Comment Form or by emailing NEPANWW@usace.army.mil, inserting “TEIS Sediment Management” in the subject line.
You may submit written comments via U.S. Mail to:
U.S. Army Corps of Engineers
Walla Walla District
ATTN: TEIS Sediment Management
201 North 3rd Avenue
Walla Walla, WA 99362-1876
Comments need to be submitted or postmarked no later than June 24, 2026 for consideration. All comments submitted will be considered and become part of the public record.
For more information about this study, please contact Austen Whelan at Austen.P.Whelan@usace.army.mil.