During the US Civil War, Confederate forces near Yorktown use dams to flood the Warwick River and cut off Union troops. “The enemy is pushed behind a branch of the Warwick River in which they control the depths of water by dams. McClellan did not intend to pass that stream at that time, or at that point where the skirmish took place. But the troops, finding the stream fordable went over (under whose immediate orders does not appear) and the water was then deepened so that they were measurably cut off.”
