Corps Engineers awarded $9.7 million contract to Nan McDougall
McKenzie River Reflections
BLUE RIVER – The U.S. Army Corps of Engineers has awarded a $9.7 million contract to Nan McDougall Company of Tualatin to reestablish upstream fish passage at Cougar Dam. Fisheries biologists believe that reconnecting adult spring Chinook and hull trout to this high-quality habitat will substantially support recovery of endangered fish populations in the Willamette River subbasin.The facility will include a fish ladder leading from – the base of the dam up to a fish collection and sorting facility. From there, adult salmon and bull trout will be loaded onto trucks for transport to release locations above Cougar Dam. Construction is scheduled to be completed in about 14 months.
"The construction work below the dam will not require us to draw down the reservoir or affect recreation on the lake” said George Miller, the Corps’ project manager. "We will monitor water quality at the construction site and take action if needed to ensure the project dues not impact downstream on the McKenzie River. Water from the reservoir will flow through the regulating outlets, so there will be no interruption in the river’s flow.”
Cougar Dam was built on the South Fork McKenzie River in the 1960s. Original construction included both adult and juvenile fish passage facilities to help move fish past the dam. However, adult fish no longer migrated to its base due to downstream changes in river temperature resulting from the dam. The Corps abandoned the original adult and juvenile fish passage facilities because they were ineffective.
Cooling towers, completed in 2005. replicate pre-reservoir temperatures in the river below the dam to benefit fish and water quality. Today, salmon return to the area at the same time of the year that they did before dam construction.
Officials say the adult collection facility will complete the Cougar component of the Willamette River Temperature Control project, which originally in-cluded temperature control at both Cougar and Blue River dams. In 2007, the Corps decided to defer work at Blue River and construct and operate a permanent facility at Cougar, which biologists believe provides greater benefits at less cost. The collection facility will also meet the terms and conditions of recent federally issued biological opinions that support the recovery of endangered fish.