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Corps adjusts river level to ease recovery efforts

  • Article by: Tom Meersman and Steve Brandt
  • Star Tribune
  • August 2, 2007 - 11:20 PM

Mississippi River currents remained a challenge to recovery efforts near the collapsed Interstate 35W bridge Thursday.

Meanwhile, the collapse is expected to affect riverfront businesses for months, but so far there are no reports of environmental damage.

Throughout the day, the U.S. Army Corps of Engineers adjusted the river level, reducing it by 1 foot during the morning, then another foot in the early afternoon.

"That created too much turbulence, so we refilled it by 1 foot," said Corps spokeswoman Shannon Bauer. The turbulence would make it difficult for divers to see and work underwater, she said.

The trick is to expand space for workers while keeping the river level high enough for barges carrying heavy equipment needed for recovery operations, Bauer said.

The Corps worked with officials at the Ford Motor Co. to open some roller gates downstream at the Ford dam, Bauer said.

The river at the site of the bridge collapse is about 400 feet wide and ranges from 3 to 11 feet deep, Bauer said. Because of the drought across much of the state, the Mississippi is flowing at only about 15 percent of normal, she said. "The drought is helping," Bauer said. "Otherwise, there would be a huge dam being created by all that debris in the water."

State pollution control officials monitored the river downstream but did not see significant pockets of oil or gas leaked from vehicles, according to Minnesota Pollution Control Agency spokesman Sam Brungardt.

Three railroad cars crushed by the bridge did not contain hazardous materials and are no threat to the environment, he said. Two hopper cars contained plastic pellets and powder; a tanker car was empty.

The rail cars are owned by Minnesota Commercial Railway. Joe Richardson, assistant to the president for the railway, said the tracks beneath the bridge are used for temporary storage, typically for a half-dozen cars waiting to be unloaded. The firm can easily reroute cars to other areas, he said.

The collapse had an immediate effect on north Minneapolis riverfront businesses that rely on barge traffic. Aggregate Industries, which unloads two barges every workday, will turn to trucks for deliveries, according to Bob Bieraugel, a firm vice president, causing "significant disruption" and higher costs.

At Northern Metal Recycling, which bought American Iron, the company can truck scrap metal to its St. Paul port for shipping downriver, said chief executive Andy Staebell. "It won't be crippling, but it'll certainly impact us," he said.

Army Corps spokesman Mark Davidson said he couldn't estimate how long it might take for the debris to be cleared so that shipping can resume to Minneapolis terminals. "They used the term months in the meetings," said Davidson, referring to emergency response discussions Thursday.

The collapse partly buried one of the guide walls extending from Lower St. Anthony Falls Lock and Dam just upstream. That lock, as well as Upper St. Anthony Falls Lock and Dam and Lock and Dam No. 1 (also called the Ford dam), are closed until further notice except for emergency craft, Davidson said.

Meanwhile, two excursion boats operated by Paradise Charter Cruises will keep running from Boom Island in northeast Minneapolis. Owner David Lawrance said he's adding upriver trips to offset travel restrictions imposed by the lock closures. His longer excursions won't extend into the lower gorge area until debris is cleared, he said.

 

Tom Meersman • 612-673-7388 Steve Brandt • 612-673-4438

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