Home > Missions > Projects > Programmatic Sediment Management Plan

Programmatic Sediment Management Plan

Water Quality Certification Public Comment period extended - Public comments about proposed dredging action now due April 30

(April 9, 2013) To allow for wider public input, the Walla Walla District of the U.S. Army Corps of Engineers is extending the public comment period regarding a proposed dredging and in-water disposal action to be taken as part of a proposed Programmatic Sediment Management Plan (PSMP). Comments on the proposed in-water work are now due to the Corps by April 30. A separate but related public comment period for the Washington Dept. of Ecology regarding the same proposed in-water work has also been extended to April 30.

Two types of comments regarding proposed dredging and in-water disposal action will be considered separately by the Corps and Washington Dept. of Ecology.

First, the Corps invites public comments on CWA “Section 404” requirements for an immediate need action of dredging plus in-water disposal of dredged materials. This proposed Corps dredging activity is subject to the provisions of Section 404 of the Clean Water Act of 1977 (Public Law 95-217). The Clean Water Act requires that all civil works projects be evaluated as to the effect of discharge of dredged or fill material into waters of the United States prior to making the discharge.

Second, the public may comment to the Washington Dept. of Ecology regarding CWA “Section 401” water quality certification. The Corps has requested that Washington Dept. of Ecology certify that the discharges of dredged material will not violate existing state water quality standards.

See links at right for 1) a Corps Public Notice containing details of Clean Water Act requirements, 2) Notice of Application to Washington Department of Ecology, 3) Extension of Clean Water Act public comment period.

The Corps proposes to perform maintenance dredging activities at three locations in the Lower Granite reservoir plus one location , just downstream of Ice Harbor Dam in the McNary reservoir. All dredged materials are proposed to be disposed in-water at Snake River mile 116, just upstream of Knoxway Canyon and 23 miles downstream of Clarkston.

Public comments to the Corps about Section 404 requirements regarding the proposed dredging and in-water disposal of dredged materials are now due no later than April 30, 2013. Comments may be emailed to psmp@usace.army.mil or sent via U.S. Mail to U.S. Army Corps of Engineers, Walla Walla District, PSMP/EIS, ATTN: Sandra Shelin, CENWW-PM-PD-EC, 201 N. 3rd Avenue, Walla Walla, WA 99362-1876. U.S. Mail comments must be postmarked by April 30.

Public comments to the Washington Dept. of Ecology about Section 401 water quality certification are also now due no later than April 30, 2013. Comments may be emailed to ecyrefedpermits@ecy.wa.gov or sent via U.S. Mail to Washington Department of Ecology, ATTN: Federal Permit Coordinator – SEA Program, P.O. Box 47600, Olympia, WA 98504-7600.  

Any person who has an interest that may be affected by the disposal of this dredged material may also request the Corps of Engineers have a public hearing. The request must be submitted in writing to the District Engineer at the same Corps address as above no later than April 30 and must clearly set forth the interest that may be affected and the manner in which the interest may be affected by this activity.

Dredging is one of several tools outlined in the PSMP EIS for managing lower Snake River problem sediment. It is proposed at this time because sediment is interfering with commercial navigation and dredging is the only available short-term solution to restore the federal navigation channel to its Congressionally authorized dimensions of 14 feet deep by 250 feet wide at minimum operating pool. Dredging is proposed to occur during a winter “in-water work window” from Dec. 15 to March 1. Maintenance dredging has not been performed since the winter of 2005-2006.

The PSMP EIS Comment period closed March 26, 2013; the following information is provided for reference:

Environmental Impact Statement (EIS) - Public comments about EIS and PSMP due March 26

The U.S. Army Corps of Engineers (Corps) Walla Walla District proposes to adopt and implement a Programmatic Sediment Management Plan (PSMP) for managing sediment within the lower Snake River system to meet the authorized project purposes that are affected by sediment deposition. These purposes are commercial navigation, recreation, and fish and wildlife conservation and mitigation. The Corps has prepared a Draft PSMP Environmental Impact Statement (EIS) that evaluates several management strategies for a long term plan to manage sediment accumulation that affects authorized purposes of the four dams and reservoirs (Ice Harbor, Lower Monumental, Little Goose, and Lower Granite) constructed by the Corps on the lower Snake River in southeastern Washington and north central Idaho.

The Corps has identified Alternative 7, Comprehensive (Full System and Sediment Management Measures) as its preferred alternative. This alternative includes dredging and dredged material management along with other sediment and system management measures, and provides the Corps with a complete toolbox for addressing sediment that interferes with the authorized purposes of the dams and reservoirs.

The draft EIS also addresses an immediate need action, consistent with the Plan, to reestablish the navigation channel at four locations: Ice Harbor Lock and Dam downstream navigation lock approach, Federal channel at the Snake/Clearwater Rivers confluence, Port of Clarkston, and Port of Lewiston. The Corps proposes to dredge these areas and use the dredged material to create shallow-water habitat for juvenile salmon.

The Corps invites your comments on the Draft Lower Snake River Programmatic Sediment Management Plan/Environmental Impact Statement (PSMP/EIS). The draft PSMP/EIS public comment period started on December 21, 2012, (date of publication in the Federal Register) and will run through March 26, 2013. Comments must be e-mailed or postmarked no later than March 26, 2013 to be considered. You must submit comments via e-mail to psmp@usace.army.mil or mail comments to: U.S. Army Corps of Engineers, Walla Walla District, PSMP/EIS, Attention: Sandy Shelin, CENWW-PM-PD-EC, 201 North Third Avenue, Walla Walla, Washington 99362-1876. 

The draft PSMP/EIS is available through several means. The full document is available in electronic form through the links on the right side of this page. You may also request a paper copy or compact disc (CD) by sending an e-mail to the address above, by writing to the Corps at the address above, or by calling Ms. Sandy Shelin, Environmental Coordinator, at 509-527-7265.

The Corps held an open house and public information meeting on the draft PSMP/EIS in Lewiston, Wash., on Thursday, January 24, 2013.

If you have questions about this draft PSMP/EIS, please contact Ms. Shelin as above or Mr. Richard Turner, Project Manager, at 509-527-7625.

Collapse All Expand All

The study area extends from the mouth of the Snake River upstream to the communities of Lewiston, Idaho, and Clarkston, Washington. It also includes the lower 2 miles of the Clearwater River, from its confluence with the Snake River in Lewiston upstream to the U.S. Highway 12 Bridge. All tributaries that significantly contribute sediment to the lower Snake River have been included in the study. See link to the study area map in upper right-hand corner.

Although the Corps does not have the authority to manage lands outside of the reservoir project boundaries, management strategies for non-Corps property have been identified and evaluated.

While site-specific locations are not addressed in this draft EIS, the coordination and environmental review steps required to accomplish subsequent site-specific actions are presented.


The Local Sediment Management Group (LSMG), originally formed in 2000, provides agency and stakeholder input to the U.S. Army Corps of Engineers, Walla Walla District, on sediment management within the lower Snake River drainage area.

The LSMG plays an important role in the implementation of Corps sediment management activities, and is a forum to address regional sediment issues. LSMG members include tribes plus state and federal agency representatives. Public ports within the study area also participate, as do other entities with an interest in sediment management such as  land management agencies, environmental groups, and transportation interests.



While the LSMG originally focused primarily on dredged material management, its purpose has been expanded. The LSMG now assists with the identification of sediment sources in all tributary watersheds to the lower Snake River reservoirs and with informing the group of recent studies, projects, and techniques related to sediment management in the region. This group's formation and direction is consistent with the guidance on formation of local planning groups provided by the National Dredging Team (NDT). The LSMG will continue to develop in accordance with policies and procedures for the EPA’s Regional Dredging Team (RDT) , as referred in the April 26, 2002, policy letter jointly signed by Brigadier General David A. Fastabend (Corps of Engineers, Northwestern Division Commander) and L. John Iani (EPA, Region 10, Administrator).  The LSMG charter defines the roles and responsibilities of the LSMG members and set up the group structure.