Pinnacle Removal Resumes On Upper Miss Near Thebes

By David Murray
January 1, 2018


Taking advantage of extreme low water, the Corps of Engineers resumed rock removal dredging operations near Thebes, Ill., on December 13 in an area of the Mississippi River stretching from 38 to 46 miles above its confluence with the Ohio River.

The Corps’ rock removal contractor, Massman Construction, had begun work in October but paused when water levels rose. Massman is completing work begun in 2013 to remove potentially hazardous rock pinnacles. Enough work was completed then to allow safe transit at most river levels. Additional work had to wait until water levels dropped to very low levels, as they have now.

The pinnacles were a concerning issue in late 2012 through early 2013, when river levels were so low that the submerged pinnacles could have prevented safe navigation in that area. During January 2013, partial rock removal operations and timely regional rainfall made water levels safe for navigation.

The U.S. Coast Guard is stopping all barge and other traffic while work is being done during daylight hours, seven days a week. However, there will be no closure today (January 1). During non-work hours at night, barge traffic is not restricted.

According to Dawn Lamm, a hydraulic engineer with the St. Louis Engineer District, the pinnacles do not affect navigation except at extremely low levels. The rock removal work will continue “as long as river levels remain below 15 feet on the Cape Girardeau gage and ice doesn’t become a safety issue,” said Lamm. Massman has two rigs working, one near the Thebes railroad bridge and another at the bend.