USA: Comments Sought on Lower Snake River Dredging Plan

The public has two more opportunities to comment on water quality aspects of a proposed U.S. Army Corps of Engineers’ dredging action in the lower Snake River.

This is in addition to the current public comment period that began Dec. 21 and ends March 26 for the Corps’ Lower Snake River Programmatic Sediment Management Plan (PSMP) draft Environmental Impact Statement (EIS). Public comments on the dredging action are due to the Corps and/or Washington Department of Ecology by April 11, 2013.

First, the Corps invites public comments on Clean Water Act (CWA) “Section 404” requirements regarding a proposed 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 CWA 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 also 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.

Dredging is one of several tools outlined in the PSMP draft EIS for managing lower Snake River problem sediment. Dredging 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 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.

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Press Release, March 12, 2013