National Geographic : 1914 Feb
THE SAFETY VALVE FOR THE CHAGRES RIVER AND GATUN LAKE: THE GATUN SPILLWAY The surplus waters of the Gatun Lake escape to the Atlantic Ocean through this spillway. It is alarge semicircular concrete dam, along the top of which are 13 piers, which furnish it with 14 outlets. These outlets are closed by huge steelgates, 45feet wide and 2ofeet high, each weighing 42 tons. Should the Chagres River fill Gatun Lake so full of water as to endanger the locks atGatun, this spillway would actasthe safety valve. Even if the lake rose to the improbable height of 92 feet above sea-level-its normal height is85feet-it would notbenecessary to open all the gates on the spillway. Three or four of them would carry off all the water necessary toavert danger.