Public Notices

Draft EA and IFR: Willamette River floodplain restoration

Published March 12, 2013

PUBLIC NOTICE: Draft Integrated Feasibility Report / Environmental Assessment 

Willamette River Floodplain Restoration Study, Lane Co., Ore.

CENWP-PM-E-13-05

30-Day Notice    Issue Date: March 11, 2013 Expiration Date: April 10, 2013

 

Interested parties are hereby notified that the Portland District, U.S. Army Corps of Engineers issued a draft Integrated Feasibility Study/Environmental Assessment addressing the impacts associated with implementation of floodplain restoration actions along the lower Coast and Middle Forks of the Willamette River in Lane Co., Ore.

 

The proposed action would restore five sites on the lower Coast and Middle forks that have formerly been gravel mined. Restoration actions would include:

  1. removal of invasive plant species;
  2. re-vegetation of the floodplain with native riparian and wetland species;
  3. grading of former gravel mined ponds to increase shallow water areas;
  4. excavation of channels and banks to connect former gravel mined ponds to each other and provide backwater connections to the rivers;
  5. installation of engineered log jams on bar apexes and in specific bank areas on the rivers to promote natural scour/deposition and flow splits to maintain side channels;
  6. placement of additional wood in the floodplain and off-channel areas;
  7. debris removal; and
  8. monitoring and adaptive management.

The purpose of the proposed action is to restore natural floodplain ecosystem functions along the lower Coast and Middle Forks of the Willamette River. These functions include fish and wildlife habitat, groundwater recharge, incidental flood storage, and sediment and erosion processes.
Currently, there are large floodplain sites along the river that are impaired, and in their current condition are not contributing to recovery of important fish and wildlife in the area.

 

This project is needed to restoration these areas in order to contribute to the recovery of sensitive fish and wildlife species in the subbasins.

 

Without Federal action, other stakeholders in the subbasins would not have the funds or means to accomplish this same scale of restoration. Construction of multiple dams and revetments in the subbasin contributed to substantial changes in the natural riverine and floodplain process. As a result, many of the habitats that sustain fish and wildlife populations are disappearing and becoming degraded or developed. Large-scale restoration of floodplains provides the best opportunity to restore the natural formation of habitats and provide important off-channel rearing and refuge habitats for multiple species.

 

Floodplains help moderate peak runoff events and allow groundwater recharge that contributes to the maintenance of low flows. This function of dissipating high energy and high flows becomes increasingly important as climate change continues to occur. It is likely that winter snowpack in the Pacific Northwest would decline, whereas more variable rainfall would lead to higher peak runoff events and lower sustained flows.

 

As part of the review process, the Corps will host an open house in the Eugene / Springfield area of Oregon in late March or early April. Once a location and time are determined, the Corps will notify the public with this information.

 

The Corps prepared the portion of the FS/EA that relates to the National Environmental Policy Act in accordance with the Council on Environmental Quality’s NEPA regulations [Federal Register 40 CFR 1508.9(a)]. The Corps will consider all comments on the FS/EA received by the public notice expiration date and consider them in the finalization of the FS/EA.

 

Document: The draft FS/EA is available for public review and comment on the Corps’ Web site:
http://www.nwp.usace.army.mil/Media/Announcements.aspx

 

Additional Information, questions and/or comments regarding the draft FS/EA should be directed to Gregory Smith, 503-808-4783, Gregory.M.Smith@usace.army.mil, or at the address below. Mailed comments must be postmarked by the above closing date and sent to:

District Engineer
U.S. Army Corps of Engineer District, Portland
Attn: CENWP-PM-E / Greg Smith
P.O. Box 2946
Portland, OR 97208-2946

In your response, refer to the above public notice number, title, and date. A “no comment” response will be assumed if no response is received prior to or postmarked by the above expiration date.