The U.S. Army Corps of Engineers, St. Paul District, completed emergency dredging operations in the Mississippi River on August 7.
The Corps dredged temporary 200-feet wide pilot channels in both Pool 4, between Wabasha, Minn., and Alma, Wis., and in Pool 6, near Winona, Minn. The pilot channels allowed the U.S. Coast Guard to officially reopen the 9-foot navigation channel to commercial traffic. The normal authorized channel width is 300 feet. It was originally closed July 19, near Wabasha, and July 23, near Winona.
The Corps completed dredging in Pool 4 yesterday, and the Coast Guard reopened the channel without any restrictions. The channel in Pool 6 was reopened August 3, but required restrictions on the barge configurations. There are no longer any restrictions within either pool.
In all, the Corps had two government dredging operations, the Dredge Goetz and a mechanical dredging crew, along with two contract mechanical dredging operations. Dredging began July 16 when the water elevations were low enough to begin. Collectively, the dredges removed more than 290,000 cubic yards of dredged material from the river. This is nearly 30 percent of the average material removed during an entire year, and it’s enough material to fill a line of 10-cubic-yard dump trucks from Minneapolis to La Crosse, Wis.
In addition to the dredges, the Corps used two channel survey boats to monitor the river channel depth. The surveyors will continue looking for shallow areas in the coming weeks. Together with the dredges, the Corps expects to continue maintenance dredging into the fall.
The Corps coordinated daily with navigation industry officials and the U.S. Coast Guard to ensure everyone understood what was being done to reopen the channel.
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Press Release, August 11, 2014