News Release
| Release Number: | 02-182 |
| Dated: | 11/14/2002 |
| Contact: | Heidi Y. Helwig, 503-808-4510 |
Portland, Ore.-There should be less turbidity in the McKenzie River than last season when the 2003 fishing, tourism and recreation season begins despite ongoing construction at Cougar Dam, according to the U.S. Army Corps of Engineers.
Beginning this month, the Corps will attempt to maintain the pool behind Cougar Dam at elevation 1,400 feet-a new target pool elevation for the winter flood damage reduction season-by passing water at a draw-down rate of 6 feet per day, if necessary.
Though this plan may cause more variable flow and higher turbidity levels in the winter, it increases the probability that the waters will be clear as the fly fishing and general recreation season begins in April next year, said George Miller, project manager for the Corps' Willamette River Temperature Control Project (WTCP). In comparison, the starting elevation prior to the Spring 2002 draw down was at 1,532 feet; the reservoir was drawn down to 1,400 feet at a rate of only 3 feet per day, Miller said.
In a draft Supplemental Information Report (SIR), which Miller hopes is completed this month, the Corps details the results of its additional data collection and technical review relating to turbidity and environmental effects from the reservoir draw down. The modified draw-down plan is the most important recommendation that came from the technical review.
"Though the final report is not complete, the science tells us that we can revise our operations and adopt best management practices to lessen the turbidity in the 2003 recreation season," Miller said, adding the caveat, however, that when it comes to Mother Nature, "there are no guarantees."
When the draft SIR is completed, it and an accompanying environmental assessment amendment will be available for a 30-day public review and will be discussed at a public meeting (date and time yet to be determined). The documents will be posted on the Corps' website at www.nwp.usace.army.mil and copies will be provided to local libraries. Paper copies of the documents will be available upon request by calling the Corps' Environmental Resources Branch at (503) 808-4761.
The additional data collection and in-depth technical review addresses changes in turbidity, the results of water quality, sediment and fisheries monitoring efforts and the environmental effects associated with the recommended change in draw down. The need for the SIR was generated this spring when draw down of Cougar Reservoir caused more turbidity in the water than expected during the height of the fly fishing and recreation season.
The WTCP includes construction of a multi-level intake tower at the dam. The tower will allow the Corps to draw water from differing depths in the reservoir, mixing it to the optimum water temperature for release below the dam to more closely match natural conditions needed by fish. The changes will improve river conditions for salmon and resident fish in the South Fork McKenzie and McKenzie rivers.