Gatun Dam

The dam is situated in the valley of the Chagres River, about 10 kilometres (6.2 mi) from its mouth in the Caribbean Sea.

The spillway dam itself measures 225 metres (738 ft) along the top; its crest is at 16 feet (4.9 m) below the normal lake level.

The spillway is designed so that water pouring over the semi-circular dam converges at the bottom from opposite directions and neutralises its own force, thus minimising erosion below.

These gates, which are electrically operated, are raised or lowered to control the flow of water; with the lake level at 26.5 metres (87 ft), its planned maximum level, the capacity of the spillway is 4,100 cubic metres (140,000 cu ft) per second, more than the maximum flow of the Chagres River.

The dam incorporates a hydro-electric generating station, which is situated on the east side of the spillway discharge channel.

[2] This uses water from the lake to drive a number of turbine-generators; as first commissioned, three generators were installed, producing a total of 6 megawatts (8,000 hp) of electricity.

Almost two years were spent in infra-structure preparation, mosquito abatement (the newly discovered vector spreading Yellow fever and Malaria), Panama Railroad improvements, and planning before the work got up to full speed.

After reviewing the options and costs, in 1906 a lock-based canal was decided upon and agreed to by President Theodore Roosevelt.

The Madden Dam was constructed much higher up the Chagres River to provide a reservoir and hydroelectric power for Panama City, opening in 1935.