The damage totaled more than $33 million, the complaint alleges, with the replacement of one tainter gate alone costing $29 million. Ten of the barges floated downriver to the LG&E hydroelectric plant and McAlpine lower dam, according to the lawsuit. The McAlpine Dam controls a 72.9-mile-long navigation pool with two separate dams regulating water levels within the pool. McAlpine’s two dams, which are known as the “upper” and “lower” dams, are separated by a concrete fixed weir that is approximately 1.25 miles long. The lower dam tainter gates are each 100 feet wide and 22 feet tall.