All over the world, the first victims of water pollution from sewage are the Water Bodies like ponds, lakes and reservoirs so much so that even one time drinking water source reservoirs like Upper Lake in Bhopal and Himayatsagar and Osmansager lakes in Hyderabad are now facing the crisis. In the last half of 20th Century the lakes underwent un-precedented environmental degradation on account of (a) population explosion, (b) large scale industrialization, (c) chemical intensive agriculture, and (d) water intensive lifestyles. The factors that lead to degradation of lakes include urbanization, pollution of water due to sewage, nutrient rich agricultural run-off and industrial toxic liquid waste and reclamation leading to siltation and loss of morphometry. The quality of water of lakes can be assessed with help of a checklist on designated best use, enclosed at Annexure-I.
Urbanization and/or industrialization of the lake catchments in particular has had its extremely adverse impact as they have become dumping sites for untreated domestic sewage, industrial effluents and municipal solid waste. The case of small water bodies (Kuntas) is still pathetic; many of these are already reclaimed and the remaining are being systematically destroyed by dumping waste, garbage and silt. The total water spread and depth of all the major reservoirs is progressively reducing due to siltation from natural and man made factors. A city of about 3 million population is estimated to produce nearly 10 crore litres of waste water daily which can be re-cycled and re-used, to amply meet the local/non-potable needs.