By Army Corps of EngineersAugust 8, 2007
MINNEAPOLIS, Minn. (Army Corps of Engineers, Aug. 8, 2007) -- The U.S. Army Corps of Engineers is helping with the recovery efforts, following the I-35W bridge collapse on Aug. 1.
The Corps has been using a 100-ton crane barge over the past week, and this has lowered the level of the water to help in the recovery efforts. There are seven Corps' employees operating the crane barge on the river near the Lower St. Anthony Falls lock and dam.
Corps' water regulators are working to keep the pool elevation in the Lower St. Anthony Falls area at elevation 723.1. The river is flowing at 1,200 cubic feet per second, at that location.
The Corps is working with the Ford Plant water regulators, located across the river from the Corps' Lock and Dam 1, Minneapolis, said Scott Bratten, a hydrologist with the Corps. The pool level at Lower St. Anthony Falls is regulated at the Ford Plant.
"Normal elevation for this type of flow condition in the pool would be 725.1," said Mr. Bratten. "We lowered the pool two feet to help the divers searching the river."
On Aug. 3, the Corps provided dive teams with the Corps' handi-flat barge for search and recovery efforts. The platform barge is 15 feet by 40 feet with a steel hull and operated by two Corps' workers.
On Aug. 2, the U.S. Coast Guard established a temporary safety zone on the Mississippi River from mile markers 847 to 854, until further notice. Entry into the zone is prohibited to all vessels and persons unless specifically authorized by the Coast Guard's Captain of the Port.
On the evening of Aug. 1, Corps employees working at both Upper and Lower St. Anthony Falls lock and dams responded to the collapse of the bridge by calling 911 to alert public safety officials and then launched Corps' life boats to help rescue operations. Corps' employees assisted City of Minneapolis Fire and Rescue efforts into the night.