> Canal locks at each end lift ships up to Gatun Lake, an artificial freshwater lake 26 meters (85 ft) above sea level, created by damming up the Chagres River and Lake Alajuela to reduce the amount of excavation work required for the canal, and then lower the ships at the other end. An average of 200,000,000 L (52,000,000 US gal) of fresh water are used in a single passing of a ship.