LAKES IN BANGALORE- The source of ground water (Ecowatch - Mar 4 2007)
Lakes were created basically for hydrological reasons. The main idea was to save the monsoon run off in the valleys for use in lean seasons. This also helped in checking floods, recharging and maintaining the ground water table. Lakes and tanks also act as sediment traps and prevent clogging up of natural valleys and reduce erosion by regulating run off. Lakes and Tanks belong to wetland ecosystem and have a larger biological and ecological role. The lake biodiversity is so rich that it supports lot of life forms in and around the lake.
Every lake has three components viz, the catchment area, the lake itself and the irrigated area downstream. All of these combine together to form the lake eco system. The catchment area of the lake consists of a natural drainage basin or a watershed, with a number of small streams and nullahs draining the run off into a major valley system.