Salvage crews made little progress Wednesday in their attempts to remove three barges wrapped around several concrete piers at the Belleville Lock and Dam.
The barges were among four that crashed into the dam on January 6 during flooding along the river.
The force of the water has wrapped three of the barges around the piers, preventing the US Army Corps of Engineers from closing the dam's eight water control gates.
With all the gates open, water levels in a 42-mile pool between Belleville and Willow Island Lock and Dam above Parkersburg, West Virginia, are now too low for barge traffic to navigate the river.
Corps spokesman Chuck Minsker says crews learned that the fourth barge sank upstream from the dam and isn't interfering with the dam's operation. He says that barge will be the last one removed.
Minsker says the corps hopes to reopen the Belleville lock by Sunday.
Barge companies say closing the river is costing them up to $400 an hour in down time.