Deepening the navigational channel is a response to heavy rains, not drought.
A six-week project to dredge a portion of the Mississippi River upstream of downtown Minneapolis began this week, intended to clean up the lingering effects of heavy rains in spring and summer.
The U.S. Army Corps of Engineers project will remove 60,000 cubic yards of silt deposited by heavy river flows earlier this season from about Nicollet Island nearly 3 miles upstream to the head of navigation, near North Mississippi Regional Park. The project will restore depth to the navigational channel in the area. No boats or barges have been hampered by the silted-in river bottom; the project is regarded as preventive.
The sand -- enough to cover an entire football field at a height of more than 27 feet -- will be deposited at a site near Lowry Avenue.
Dredging is continuing on parts of the Mississippi south of St. Louis because of low water, an effect of lingering drought in the central United States.
The Minneapolis dredging is because of the opposite dynamic. River flows in the metro approached 40,000 cubic feet per second twice in June, nearly four times normal for that time of year. Flows on Tuesday were about 11 percent of that volume.
The Twin Cities had their second-wettest May on record, and record-setting rains June 19-20 across northern and central Minnesota caused high levels on the Mississippi and extensive flooding. That water also flowed into the metro area.