ABSTRACT
The largest hydroelectric dam in the world is being built in China at the Three Gorges on the Yangtze River. This new marvel is in contrast to many old and small dams on other Asian rivers which have been used for generations to control malaria mosquitoes by periodic flushing. In many islands of the Pacific Ocean, flushing siphons, and the filling of swamps and simple drainage systems, have also been successfully used for almost a century in the fight against malaria. It is instructive to compare these old systems with the new projects.
