Moves are afoot to convert the brackish Pulicat lake into a freshwater one to supply water to Madras city and authorities seem to have little regard for the ecological and environmental consequences.

Various schemes have been thought of to tackle Madras' water scarcity.

Lakes are being lost or altered because of the disruption of natural processes by intensification of agriculture, urbanisation, pollution and construction of dams. A look at the state of some Indian lakes today

A pristine lake that once drew birds of several species today lies clogged with weeds, a victim of unplanned economic development.

On the basis of hydrochemical and biological studies, a trophic gradient has been established between the inshore and the offshore areas of the Dal lake. The inshore areas receive large quantities of raw sewage and agricultural runoff as a result of which high nutrient concentration of water and the presence of dense phytoplankton populations have been registered at these sites.

The Kandy lake, situated in the heart of Sri Lanka's second largest city with a population of nearly 120,000, has been monitored to probe the extent of heavy metal pollution. Although the lake is a source of drinking water to the city, a large number of effluent canals drain into the lake carrying a continuous flow of industrial and domestic waste matter. A total of 66 surface water samples were analyzed for their Fe2+, total Fe, total V, SO 4 2− , Cd2+, and Pb2+ contents.

Two drinking water lakes of Hyderabad - Osman Sagar and Mir Alam, were studied for their chemistry for two years (1977-78). Mir Alam, the older of the two, showed higher silicate content. Dissolved component formed 91-27% of the total silicate content in these lakes.

The mid-canal of Kandy, a 8-km effluent canal that runs through the city, collects massive quantities of domestic, municipal, and agricultural waste products. In this study, 37 samples from canal water and 13 from nearby drinking water wells were analyzed for their total Pb, Cd, V, Fe, and ferrous ion content. The following average values for the canal water were recorded: Pb, 269 μg/liter; Cd, 138 μg/liter; V, 18 μg/liter; total Fe, 4 mg/liter. These values indicate the relative levels of metal input from the effluent sources of the city of Kandy, the second largest city in Sri Lanka.