Madden Dam - Panama Canal

Madden Dam, on the Chagres River, east of the Canal Zone in Panama.

The dam regulates the amount of water that flows into Gatun Lake, which is part of the Canal Zone. If the dam was not there, the Chagres River could not feed Gatun Lake on-demand, and the water level of the lake, left unchecked, could drop to the point where ships could not pass through. In Panama's dry season, this could easily happen if the dam was not there.