Work continues as the United States Coast Guard and U.S. Army Corps of Engineers continue salvage operations at Marseilles Lock and Dam, where several barges came to rest against the dam structure after breaking free from their towing vessel this past week.
The Coast Guard said the barges were being towed by the UTV Dale A. Heller through high flood waters and heavy river currents when seven broke free in the Illinois River, sending them toward the Marseilles Dam.
Four of the barges have already been removed from the area, though three remain partially submerged as crews remove iron ore in an effort to lighten them.
In the meantime, the Corps said it has mobilized crews with sonar instrumentation that will allow for underwater analysis of potential damages to the dam.
The Marseilles dam itself is a 600-foot-long concrete structure with eight, 60-foot-wide by 30-foot-high tainter gates that impounds a reservoir approximately 24 miles long with a surface area of 1,454 acres.
Preliminary inspections have already revealed that the barges broke two of the gates and are interfering with three others, though Marseilles' remaining three gates are still operational.
The damaged gates will not increase additional flooding risks for downstream communities, the Corps said, though they could make it difficult to maintain the usual depth of the waterway between Marseilles Lock and Dam and the Dresden Island Lock and Dam.
In addition, the Corps has begun round-the-clock operations to construct a temporary rock dike that will reduce river flows and facilitate repairs to the dam.
"Our crews have already placed more than 900 tons of rock and we plan to add as much as 3,000 tons per day for about 10 days to complete the dike," said Mike Cox of the Corps' Rock Island District. "Assessing damage to the dam and constructing the rock dike will be the primary focus for the Corps in the coming days."
HydroWorld.com reported in March 2012 that the Marseilles Lock and Dam is to become the eventual home of a new 10.26 MW hydropower project. The Marseilles Land & Water Company (MLWC) obtained a license for its development from the Federal Energy Regulatory Commission in December 2011, though work has not yet begun on the plant.