OLYMPIC NATIONAL PARK — The masses of water flowing over the Elwha and Glines Canyon dams on the Elwha River during sustained rainfall over the last week didn’t disrupt work being done to dismantle the two dams.
“The coffer dam and the work being done at the dams has been planned and designed to take high flows into account,” said Barb Maynes, park spokeswoman, Tuesday.
Higher flows encouraged the erosion of sediment from the delta near the Elwha Dam, she said.
“The river is effectively transporting the sediment, which is what we’ve been hoping for,” Maynes said.
“It’s all working according to plan.”
Peak flows
In the last week, during the first winter storms of the season, the rain-swollen river reached two peaks from its pre-rainfall flow of 700 cubic feet per second: 10,200 cfs the day before Thanksgiving and just over 9,000 cfs on Sunday.
Last Tuesday it was down to 4,500 cfs, according to the U.S. Geological Survey’s gauge at the U.S. Highway 101 bridge near the turnoff to Olympic Hot Springs Road.
“At no time have we been close to flood stage,” which is 20 feet at that point, Maynes said.
At its highest point Wednesday, the river was measured as being 16.83 feet high.
No effect on work
The higher flows didn’t affect the work now under way, said Barnard Construction Co. project manager Brian Krohmer, who is overseeing the demolition of the Elwha and Glines Canyon dams.
The removal of the river’s two dams — built without fish ladders — is part of a $325 million federal project to restore the river’s once-famous salmon runs.
Since mid-September, Barnard Construction crew members have removed 48 feet of the Elwha Dam — which was built in 1913 five miles from the mouth of the river — and 32 feet of the Glines Canyon Dam — built 14 miles upriver in 1927.
No more of the dams themselves will be removed before the first of the year because the company’s crew of about a dozen workers is barred from working in the river during fish migratory periods, known as fish windows.
Removing power house
In the meantime, workers are continuing to remove the powerhouse at the Elwha Dam, to take down some nine miles of power lines from the two dams and to prepare for resumption of dam removal at Glines Canyon Dam, Krohmer said Tuesday.
At Glines Canyon Dam, a ringer crane is being modified to increase its capacity and the length of its reach for lifting dam pieces off a barge when work to take the dam down resumes Jan. 3, Krohmer said.
The Elwha Dam can be seen from the overlook trail, accessed from a gate just south of the Elwha RV Park on Lower Dam Road off state Highway 112.
There is no access to a vantage point for the Glines Canyon Dam right now, and there won’t be at least for the rest for the year, because Whiskey Bend Road off Olympic Hot Springs Road is closed for repairs.
Images from National Park Service webcams can be found at http://tinyurl.com/damwebcams
