Repair of Fern Ridge Dam this summer will affect farmers, boaters, businesses and animals ranging from bald eagles to pond turtles, according to a report by the U.S. Army Corps of Engineers.
EUGENE, Ore. Repair of Fern Ridge Dam this summer will affect farmers, boaters, businesses and animals ranging from bald eagles to pond turtles, according to a report by the U.S. Army Corps of Engineers.
The corps has released an environmental assessment of the planned overhaul of the 64-year-old dam's failing drainage system, a project that would run from May to November. Public feedback will be accepted through April 15.
Completing the $40 million project will require keeping Fern Ridge Lake between 348 and 353 feet above sea level, which is 20.5 feet to 25.5 feet below its normal summertime level.
The corps acknowledged sweeping repercussions to water quality, aquatic life, crop irrigation, recreation and marsh habitats and the fish and wildlife that depend on them.
"However, these impacts will be temporary and limited to one season, and the fish and wildlife ... should recover fairly quickly once normal reservoir operation is restored in the fall," the corps said. Planned improvements also will benefit some environmental resources.
In the report, the corps said fish may die above the dam because of reduction and changes to the pools there, or downstream, due to changes in the temperature and oxygen level, and they may be killed passing through the dam.
Of the threatened or endangered species in the area, bald eagles may thrive because fish will be concentrated in smaller, shallower pools, but the project may cause some to abandon their nests. Spring chinook salmon and Fender's blue butterflies probably won't be affected, the agency said.
Northwestern pond turtles aren't so lucky: The loss of habitat will leave them vulnerable to predators and without easy nesting spots.
"The potential loss of adult turtles are of particular concern," the corps said in the report. "The corps and the Oregon Department of Fish & Wildlife will work together to determine if areas of the lake should be signed to protect pond turtles from harassment and capture."
The lower reservoir could expose lake bottom that has never been surveyed, and that worries the Confederated Tribes of the Grand Ronde, which has urged the corps to secure sites where ancestral remains or cultural items may be found.
Most recreation will be lost this year, cutting deeply into the $13.6 million that visitors spend annually in the area, the corps said.
Likewise, farmers who irrigate from the dam may suffer: The corps will allow all water into the reservoir to pass through without control, so flows may be as low as 5 to 10 cubic feet per second by late August. Farmers generally rely on 15 to 25 cfs. There may be little stored water to meet Bureau of Reclamation water service contracts.
Native plants on the downstream face of the dam will be preserved, but there may be fewer waterfowl for hunters early in the season because of reduced food and water for waterfowl, the corps said.
FERN RIDGE DAM:
--What: The U.S. Army Corps of Engineers has released a report on the environmental impact of a project this summer to fix the failing dam.
--To find it: Visit www.nwp.usace.army.mil/issues/fernridge /cms/documents.asp
Source: Knight Ridderr/Tribune Business News