River delta to be blasted
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 Upper Klamath Lake from the Williamson because of the cleansing action wetlands will provide.
“This is the most important rehabilitation project in the Upper Basin right now,” Barry said. “If fish recover, it takes the pressure off all of us.”
The U.S. Fish and Wildlife Service lists the shortnosed 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 Williamson River and Upper Klamath Lake.
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 Klamath Falls firm has continued to remove dirt this year from the delta’s interior where the soil is stable enough to allow heavy equipment to work.
The explosives are needed along four exterior dikes, each about a halfmile 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.
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.”