Repairs complete at canal; upgrade to follow

Water is again flowing through an irrigation canal that failed nearly three weeks ago in a landslide that spewed thick, clayish mud into Big Butte Creek and part of the upper Rogue River.

The Eagle Point Irrigation District on Tuesday slowly began diverting Big Butte Creek water into its 18-mile-long main canal after rebuilding and fortifying a 160-foot section that sloughed away off Cobleigh Road.

They started with about 20 cubic feet per second of water, and the district plans to add a little more water daily while monitoring the area for signs of instability or increased water turbidity, EPID manager David Ford said.

"We're going to bring it up slowly," Ford said. "It'll take up to three weeks."

The district runs water year-round in the canal because the water spins turbines in a 1-megawatt hydropower plant near EPID's headquarters, Ford said.

The state Department of Environmental Quality is still investigating what caused the Oct. 2 slide and whether it was preventable, said Bill Meyers, the DEQ's Rogue River Basin coordinator.

Meyers said he plans to review old engineering reports to see whether the area had been flagged as potentially prone to slides or predicted for a slide.

"Obviously the hillside had some instability in it," Meyers said. "The question is, was the district aware of it."

Ford said he has not seen any reports indicating that particular piece of hillside was identified as slide-prone, and that any such studies would have predated his time with the district.

The cause remained undetermined this week, but Ford said he suspected groundwater uphill of the canal played a role. Construction crews discovered groundwater leaking into the canal area and had to build a drainage system for it before the canal could be rebuilt, Ford said.

Also, a canal patrolman did not notice anything unusual in the area before the slide, Ford said.

At the DEQ's behest, the district will upgrade its gauge systems in the canal so any abrupt rise or drop in canal flows will be immediately known.

The four gauges now in the canal send reports to a computer inside the EPID headquarters, but those reports are seen only during regular business hours, Ford said.

The district will bring in a computer technician next week to revamp the system so any abrupt changes in flows will trigger cellphone alerts, as well, Ford said.

Such an alert might have significantly reduced the mud flows because the gauge alert showed water fluctuations in the canal began about 3 a.m., Ford said. The first public report of muddy water flowing over Cobleigh Road came to 9-1-1 at 3:37 a.m., but district employees were not notified of the failure until 5:30 a.m., Ford said.

Water to the canal was turned off about 6 a.m., he said.

The rebuilt stretch of canal now sports a flexible liner to hold water, where the old stretch was just dirt, Ford said. No cost estimates of the new construction were available, Ford said.

The muddy water flowed over wild spring chinook salmon egg nests, called redds, which had been laid in gravel along the lower section of Big Butte Creek and about two miles of the upper Rogue below the creek mouth.

Biologists initially feared the clay would settle on the redds and suffocate millions of incubating chinook eggs.

But surveys have not turned up any dead redds, said Dan VanDyke, the Oregon Department of Fish and Wildlife's Rogue District fish biologist.

"We have not yet documented impacts lethal to salmon," VanDyke said. "I think there's been an impact, but nothing like it could have been."

Reach reporter Mark Freeman at 541-776-4470, or email at mfreeman@mailtribune.com.

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