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Posted 9/15/2017

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Issue Date: September 15, 2017
Closing Date: November 6, 2017

The U.S. Army Corps of Engineers, Portland District (USACE) is making available for public review the revised Draft Supplemental Environmental Impact Statement (DSEIS) for our Mount St. Helens Long-Term Sediment Management Plan. USACE is the lead agency for the revised DSEIS under the National Environmental Policy Act of 1969 (NEPA), 42 U.S.C. §§ 4321–4347.

A DSEIS was issued in October 2014. Following the completion of the public comment period for the DSEIS, USACE engaged in consultation with the National Marine Fisheries Service (NMFS) as required by the Endangered Species Act (ESA). This consultation resulted in the need to develop alternatives to ensure the sediment management plan would not jeopardize listed species or adversely modify or destroy the species’ critical habitat. USACE is providing a second public comment period on the DSEIS to give the public an opportunity to comment on revisions to the DSEIS, including alternatives to ensure the sediment management plan complies with the ESA. 

Proposed Action
In 1984, USACE issued an EIS which evaluated alternatives in managing sediment flowing downstream from the debris avalanche to avoid flooding in the Cowlitz River and disruption of navigation on the Columbia River caused by sediment buildup. The 1985 Mount St. Helens Sediment Management Decision Document included construction of a sediment retention structure (SRS), levee improvements and dredging. The 1985 Decision Document recognized the likely need for a future re-evaluation of the long-term sediment management measures based on changes in future conditions. The SRS was completed in 1989. Since the SRS began operating as a run-of-the-river structure in 1998, increased sediment from the North Fork Toutle River basin is being transported downstream and accumulating in the lower Cowlitz River.  USACE has conducted a limited re-evaluation of sediment management in the North Fork Toutle River and is proposing to implement updated sediment management measures to manage flood risk to established levels for the Washington cities of Castle Rock, Lexington, Kelso, and Longview through the year 2035. In addition to a No Action alternative, three sediment management alternatives were identified and evaluated that would address the flood risks associated with sediment build up through 2035. They are:

  • Cowlitz River dredging only
  • SRS spillway and embankment raise

A phased construction plan (preferred alternative) consisting of:

  • SRS spillway crest raises
  • Grade-building structures
  • Dredging, as needed

The revised DSEIS also includes an evaluation of the alternatives (fish conservation measures) that were developed to ensure the proposed sediment management plan will not jeopardize the continued existence of any endangered or threatened species or adversely modify or destroy the species’ designated critical habitat. Fish conservation alternatives evaluated include:

  • Replace the fish collection facility on the North Fork Toutle River operated and maintained by the Washington Department of Fish Wildlife (WDFW) and establish a fish release site on Deer Creek
  • Modify the fish collection facility on the North Fork Toutle River and establish a fish release site on Deer Creek

Environmental impacts of the no action, sediment management and fish conservation alternatives are evaluated in the revised DSEIS.

The revised DSEIS includes information on the discharge of dredged or fill material that may occur during construction of the preferred alternative, as well as information on waters of the United States present within the project area and the impacts on those waters under Section 404 of the Clean Water Act (CWA). Dredging in the lower Cowlitz River would include dredging, dredged material placement and storage, and monitoring.  Mechanisms for potential effects include the movement of sediment from the river channel, up through the water column, and onto upland storage stockpile locations.  Dredging activities would be conducted by two to three hydraulic dredges operating at various reaches of the lower Cowlitz River. Dredging would occur during the in water work window, as determined in coordination with WDFW.  Prior to dredge material placement, a field wetland determination would be conducted to confirm the absence or presence and acreage of wetlands.  A sample of past dredged material placement sites, that could potentially serve as future placement sites, were surveyed in 2013 for wetland and habitat conditions.  Of nine sites surveyed, only one site had wetlands.

Endangered Species
USACE has completed formal consultation with the National Marine Fisheries Service (NMFS) as required by Section 7 of the ESA. NMFS issued a Biological Opinion (BiOp) in August 2017. The BiOp concluded that the preferred alternative was likely to jeopardize the continued existence of threatened Lower Columbia River (LCR) coho salmon and LCR steelhead and likely to result in the adverse modification of both species’ designated critical habitat.  The BiOp includes a Reasonable and Prudent Alternative (RPA) to ensure the preferred phased construction alternative does not jeopardize the continued existence of any endangered species or threatened species or result in the destruction or adverse modification of designated critical habitat.

Historic Properties/Cultural Resources: Section 106 of the National Historic Preservation Act of 1966, as amended (54 USC 306108), requires Federal agencies to consult with the appropriate State to take into account the effects of actions they undertake on historic properties listed in or eligible for listing in the National Register of Historic Places.  The USACE’s preliminary review indicates to the best of our knowledge, the described activity will affect a property eligible for registration (i.e., the SRS). USACE, in consultation with DAHP, the Cowlitz Tribe and other interested parties, would develop a programmatic agreement that will layout out a mutually agreed upon approach to the management of those NRHP-eligible resources potentially adversely effected by this action.

Public Hearing
person who has an interest which may be affected by impacts to waters of the United States may request a public hearing. The request must be submitted in writing to the District Engineer within the comment period of this notice and must clearly set forth which interest may be affected by the activity and the manner in which the interest may be affected.

Discharge of dredged or fill material will be evaluated using the guidelines under Section 404(b)(1) of the CWA.

Public Comment
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. Upon completion of the public comment period, USACE will consider all comments submitted on the 2014 DSEIS and the revised DSEIS prior to issuing a final SEIS. The final SEIS will include responses to comments received on both the DSEIS published in August 2014 and on the revised DSEIS.

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.

Public Comment Timeframe
The revised DSEIS will be available for public comment for 45 days after publication of the notice of availability in the Federal Register by the U.S. Environmental Protection Agency.  Comments must be received by November 6, 2017.  An electronic copy of the revised DSEIS is available for download from the project webpage at: www.nwp.usace.army.mil/mount-st-helens.

Written comments may be sent via email to MSHLongTermPlan@usace.army.mil or by traditional mail to:

U.S. Army Corps of Engineers, CENWP-PM
ATTN: Ann Hodgson
P.O. Box 2946
Portland, OR 97208-2946

EIS environmental impact statement Mount St. Helens public comment public notice rdseis SEIS