The damages were almost $4 million for the barges and cargo, $10 million for temporary repairs, and $35 or $50 million (I've seen both numbers) for permanent repairs. And shipping was sometimes shutdown on the river after the accident to lower the pool to reduce the pressure on the broken gates and the cofferdam that was being built to help with the repairs.
The Corps had created a slide presentation that describes the incident, both the barge allision and the earthen dike damage, and the temporary repairs.
Update: Hercules, a 60-foot barge mounted crane, helped remove the barges.
Massman's project web page contains eight photos with the comment:
The Corps of Engineers awarded Massman Construction Co. a contract to perform repairs to the Marseilles Dam in Marseilles, Illinois. The dam was damaged from several runaway barges that collided with the dam as a result of strong river currents from heavy rainfall. Massman completely replaced three tainter gates and repaired two others.
Erection of the shoring system to support Gates 2 and 3 during the replacement of the trunnion girder began once the riprap was removed. All material had to be picked from the barge located upstream of the dam using the Manitowoc 4100 and moved over the dam to be set in place on the downstream side. Crew accessed the shoring installation from 2 Snorkel man-lifts located downstream on the existing rock dike. The shoring system, consisting of six (three per gate) HP 12 x 53 shoring piles tied back to the concrete piers, was installed and the gates were lowered onto the shoring. Two platforms were then erected off the shoring piles on either side of Pier 2 and the drill platform was erected on the downstream face of Pier 2.
The crew successfully removed the trunnion pins at Pier 2 from Gates 2 and 3 to release all load from the temporary trunnion girder. Once the pins were removed, the existing temporary trunnion girder was removed from the downstream side of Pier 2. This cleared the area for core drilling of 8 each 3 inch diameter holes into Pier 2. These holes will then have eight 1.75 inch diameter threaded bars installed for the anchorage of the new trunnion girder. Gate 3 repair work started following the installation of the new trunnion girder.
Massman removed the riprap from the downstream side of Gate 2 and Gate 3 to provide a clean surface for installation of the shoring.