ROCHESTER – Dave Francksen and Bill Chelmowski are getting a good look at the Mississippi River, from the bottom up.
The pair are running a survey boat for the U.S. Army Corps of Engineers as it works to clear dredge material out of the 9-foot navigation channel in Lower Pool 4 between the mouth of the Chippewa River and Lock and Dam 4.
"We want to get everything we need and nothing we don't," Francksen said.
Taking runs up and back along a short stretch of the river, the pair use a boat equipped with six sounding buoys that measure the depth to the river bottom. Francksen said right now they are conducting a post-dredge survey to ensure the navigation channel has been cut to the proper depth.
The survey, when compared to the pre-dredge survey, also determines the amount of dredge material that has been removed from the river, the Post-Bulletin reported.
The navigation channel — roughly 300 feet wide in straightaways and closer to 500 feet wide around corners — is an annual job of the Corps as it works to ensure safe passage for barge traffic that moves grain and other goods up and down the river, said Paul Machajewski, a dredged material manager for the Corps' St. Paul District Office.
Right now, the river is about 8 feet higher than its LCP (low control pool) level. The extra height on the river means barge traffic could run up and down the river without the dredging, Machajewski said. But eventually, that extra water will flow downriver.
Despite the clear sailing in the Upper Mississippi River, Machajewski said closed locks and high water from central Iowa south toward St. Louis has kept barge traffic light so far this year. That said, the Corps wants to ensure the navigation channel is open once the river is ready for traffic from St. Paul to New Orleans.
