News Release
| Release Number: | 99-064 |
| Dated: | 7/23/1999 |
| Contact: | Matt Rabe, 503-808-4510 |
Portland, Ore.--The Portland District, U.S. Army Corps of Engineers, is seeking public comments on a draft Environmental Assessment that addresses impacts of a Cougar Dam construction project.
To benefit salmon and resident fish in the McKenzie River, the Corps plans to add water temperature control capabilities to the dam's existing intake tower. Construction of a new, ported, multiple-level intake tower, attached to the face of the existing tower, will let the Corps draw water from differing depths in the lake to vary water temperatures.
Under current conditions, unnaturally cold water is released in early to mid-summer, discouraging adult spawners from migrating into the South Fork McKenzie River. By late summer, unnaturally warm water is released, causing eggs deposited in the fall by spawning fish to hatch prematurely.
In FY 2000, construction will begin at a programmed amount of $1.7 million. More details about the actual construction and its impacts at Cougar Dam are included in the draft EA. For a copy of the EA, or to comment on the project, contact Lynne Hamilton at (503) 808-4772, or write to District Engineer, U.S. Army Corps of Engineers District, Portland, Attn: CENWP-PM-E, P.O. Box 2946, Portland, Oregon 97208-2946. The EA also has been placed on the Corps' Internet site at http://www.usace.army.mil/ec/e/enhome.htm. Responses should include reference to public notice number CENWP-EC-E-99-04. Comments must be postmarked by Aug. 16, 1999.
In 1995, the Corps released a final Environmental Impact Statement for construction of the temperature control project. In 1998, however, the Corps modified its design for construction.
Changes in design include a larger residual - or temporary - pool, an unscreened opening for the diversion tunnel and placement of two cofferdams to manage water flows during construction. A portion of one of the cofferdams will be permanent to provide additional sediment control after construction. With the cofferdam in place, sediment will build up at the base of the cofferdam instead of at the base of and inside the intake structure.
These changes required the Corps to further review environmental impacts of the construction and prepare an environmental assessment.
Construction of the new intake tower will require the Corps to lower Cougar Lake to near-stream level from April to October for three years beginning in 2001. During this time, the Corps will continue to operate the project to manage flows and minimize flood damages.
As described previously in the 1995 EIS, beginning in 2001 lake recreation will be impacted because the lake's three boat ramps will not be useable. Also, flows near Vida, Ore., during construction could be reduced anywhere from five percent to 20 percent. The Corps does not expect there to be any downstream impacts to recreation.
The aquatic species most affected by these design changes would be resident populations of bull trout, recently listed as a threatened species under the Endangered Species Act. To minimize the impacts, the Corps plans to collect juvenile bull trout upstream of the lake and either transport them to another release site downstream, or maintain them in a hatchery. This collection and transport plan would begin one year before the lake level is lowered and continue through construction. The Corps is working with the U.S. Fish and Wildlife Service to develop this plan.
A number of other resource agencies also are reviewing the draft EA. Those agencies include the Environmental Protection Agency, the U.S. Forest Service, the National Marine Fisheries Service, Oregon Department of Environmental Quality and the Oregon Department of Fish and Wildlife.
Upon completion of the intake tower at Cougar Dam, the Corps plans to begin similar work at its Blue River Dam. This work at Cougar Dam, on the South Fork McKenzie River, and Blue River Dam, on Blue River, constitutes the Willamette Temperature Control Project.