39-Hydrological and ecological balance of urban lakes

Abstract

Urban lakes are basically impouading of water against an embankment. As time passes after the formation, these lakes start to play an important role in sustaining the socio-economic, ecological and cultural fiber of that area. Increasing water demand, degradation of catchments, blockages and encroachment in inlet channels and lake beds along with disturbances in rainfall pattern, intensity and duration, have severely deteriorated the hydrological, ecological and limnological balances of almost all urban lakes. There are the years when one cannot find even a drop of water entering in to these lakes. Sedimentation is another problems, which has reduced the water storage capacities. Anthropogenic and cultural pollution along with sedimentation are the major factors of eutrophication. Many lakes are now extinct and others are on the verge of extinction. There is an urgent need of more rationalized scientific and engineering considerations, wholesome management policies, reforms in legal provisions and effective institutional building for the hydrological and ecological rejuvenation of urban lakes. The author has a long experience of conservation of urban lakes both as an activist and as water Engineer. The measures suggested are applicable to almost all urban lakes. There is an elaborative analysis of cost benefit aspect of desilting is furnished in the end of the paper.