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H&N photo
by Steve Kadel |
Dike will be removed to create wetlands along the Williamson
By
STEVE KADEL
H&N Staff Writer
Two
miles of dike will be blasted with explosives this fall to create
wetlands in the
The project, spearheaded by The Nature Conservancy in conjunction with
federal and state agencies, will occur sometime after Oct. 15 when the A
Canal is closed and the irrigation season is over.
The primary reason for taking out the dikes is to provide better
conditions for larval suckers, said Matt Barry, director of the
Williamson River Delta Preserve for the Conservancy.
It’s also hoped that less phosphorous will reach
“This
is the most important rehabilitation project in the
The U.S. Fish and Wildlife Service lists the short-nosed and Lost River
suckers as endangered. Both are present in the Williamson and Sprague
rivers, with spawning occurring primarily in the latter water body.
Two dike-removal test projects in 1999 and another in 2003 have shown
positive results. In those areas, lots of willows and tules have grown
up in what used to be alfalfa fields.
Barry said studies show fish get healthier and grow faster in the
created wetlands than they did before in the
The one-centimeter larval suckers have high mortality if they’re
pushed out into the lake. That’s due to predation and strong winds
buffeting the water. In a wetlands setting, they’re able to find
calmer, more sheltered water. The Nature Conservancy also believes
wetlands might provide better nutrition than in the lake.
“We’re basically providing them with a nursery environment,” Barry
said.
LTM Inc. workers removed about 700,000 cubic yards of dirt from dikes
last year. The
Soft
soil
The explosives are
needed along four exterior dikes, each about a half-mile in length,
because the soil there is too soft to support heavy equipment. LTM
construction foreman Warren Olson said Wallace Technical Blasting of
Woodland, Wash., has been hired to do the job.
“I’ve known Jerry Wallace for 25 years,” Olson said. “He’s got
extensive experience in the blasting field, in the hands-on part.
They’ll do the loading and coordination of the blasting.”
Olson said he and Wallace have worked together on what Olson calls
“several very technical and successful projects.” They did a test
blast last March on an interior dike and things went as planned. Olson
said that will be the basis for the bigger explosions this fall.
Explosives will be imbedded in plastic tubes in the four dikes. They
will be set off at the same time, although an exact date will be kept
secret to avoid drawing curiosity-seekers who might endanger themselves,
Barry said.
A guard station will be set up on the sole road into the delta, with
access allowed only to authorized personnel.
Although there have
been rumors the explosions will lower the lake by 2 feet, computer
models by the Bureau of Reclamation indicate the drop will be slightly
less than 2 inches.
Barry emphasized there will be no ill effects to adjacent property or to
fish in the lake.
“We will do seismological monitoring during the blasts to know how far
the shock waves travel,” he said.
Storage
capacity
The lake will have
added storage capacity afterward. Barry said the Bureau of Reclamation
indicates the lake will be able to hold an additional 18,000-acre-feet
of water when the work is done.
Barry acknowledges some people may feel nostalgic about farming in the
delta area, and hate to see it come to an end. He said the tradeoff will
be positive.
“There will be enormous benefits,” he said. “If you want
sustainable farming, you have to couple it with some conservation
actions.”
About the
How did restoration of the
The delta was mostly wetlands in the 1940s, before it
was drained for agriculture. Suckers were listed as endangered in 1988,
followed in the early 1990s by a threatened water shut-off due to
drought.
Not long afterward, U.S. Sen. Mark Hatfield of
The Nature Conservancy purchased land north of the
Three years later the organization bought Goose Bay
Ranch.
Restoration efforts to date have focused on the area
north of the river. Matt Barry of The Nature Conservancy said the
organization hopes to restore the

Plastic
pipes in the ground will be filled with explosives to blast away four
dikes, including this one being prepared.
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Source: http://www.heraldandnews.com/articles/2007/09/15/featured_
story/doc46eb7701a2125592272130.txt