A Canal's new tunnel already wet
Published Jan. 30, 2004 by Dylan Darling
Drip, drip, drip.
Water taps incessantly on the hard hats of
workers in the A Canal tunnel. In the dank shaft
that runs from Conger Field under a hill to
Oregon Avenue, construction crews are prepping
the century-old floor for a new layer of
The only water in the tunnel during the winter
months is found in puddles on the floor and
dripping from cracks in the walls and ceiling.
But during the irrigation season, from April 1
to Oct. 15, water flows through the tunnel at a
velocity of 8 feet per second.
The continual rush of water has worn dips and divots
in the floor all along the 3,200-foot tunnel. To
keep water flowing smoothly to the Klamath
Reclamation Project, the Klamath Irrigation District
is paying contractors nearly $1 million to fill the
holes and lay a new floor.
"This is our water supply here. If this baby doesn't
flow, we are done," said Ross Flemming, a district
Much of the water Klamath project irrigators spread
on about 180,000 acres passes through the tunnel,
which is just below the project's starting blocks,
the A Canal headgates. If the tunnel should have a
problem during the irrigation season, much of the
project would have to be shut down until repairs
To avoid that scenario, Dave Solem, KID manager,
said the district put a priority on the resurfacing
of the floor. The project is expected to be done by
The straight-shot tunnel was first used in 1906,
replacing a canal that ran parallel to the Link
River and then took a left turn, cutting through
town before feeding the project.
Though it is long and dark, there is light at the
end of the tunnel, with one end visible from the
other during the day. With 8-inch-thick concrete
walls and a 6-inch-thick concrete floor, the tunnel
was built to last.
Solem said the walls and ceiling are in "real good
shape," but district officials keep an eye on them
and patch any major cracks.
In getting the tunnel ready for work, workers first
had to clean it out. Solem said there was algae and
dirt built up in the tunnel, along with other debris
- including a dead deer in a trash sack and a
Now the workers are filling in the holes, pits and
cracks. These defects in the floor vary in size,
from a couple of inches to several feet.
Next, the workers will put in a new concrete floor
that will be at least 5 inches thick, have steel
reinforcement, and a coating of epoxy binding it to
the old floor.
Using motorized wheelbarrows, workers will haul in
the concrete half a cubic yard at a time. In all, 16
workers contracted by Donald W. Thompson Inc. of
North Bend will put down 1,100 cubic yards of
The construction workers aren't afraid of the dark.
And they are used to working in tight spots.
Don Thompson, company president, said his firm often
works in Oregon highway tunnels and under bridges.
Time is the hardest part of this concrete job.
He said the crew has a short calendar before it
wants to get the concrete down and cured in time to
be ready for irrigation season.
"Everything is time-critical," Thompson said.
Though the weather is a bit cold, it's good enough
for concrete pouring, he said. But to make sure
nature doesn't foul up the mix of concrete, workers
make it with warm water and then keep blankets over
After putting down 900 feet of concrete from the
Conger Side, the workers will then start bringing it
in from the Oregon Avenue side and work in the other
The tunnel's new floor will be just the start of
concrete work to spruce up the Klamath project over
the next several years, Solem said.
"The project is full of 100-year-old concrete
structures," he said.
Next on the priority list will be fixing up the C
Canal flume. Other structures on the list include
the Lost River Diversion Dam, Gerber Dam and pump
houses around the project.
Reporter Dylan Darling covers natural resources. He
can be reached at 885-4471, (800) 275-0982, or by
Dimensions: 13 feet wide, 11 feet tall on the sides,
14 feet tall at the top of the arch.
Water flow: Volume: about 1,100 cubic feet a second.
Velocity: 8 feet a second.
Water depth: About 10 feet during irrigation season.
Cost of Project: About $993,000.
Expected completion: March 1.
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