An Analytic Case Study of Lentic Ecosystem and Rejuvenation of Bellandur and Varthur Lakes in Bengaluru, India

Abstract

Bengaluru, the town of Kempegowda was known as the city of lakes till the sixties decade of the twentieth century now transformed into pools of sewage over the years. The natural drainage system has been completely obliterated in the name of development and resulting in unprecedented floods in the south eastern part of the city during the 2022 monsoon and before. There were 612 lakes (live as well as disused) in the present area of Bengaluru city (except Anekal taluka). It is observed that the rejuvenation of lakes could not be succeeded because of the continuous inflow of sewage in them. Bellandur and Varthur lakes are no exception. Public and judiciary intervention has put pressure on the State to attempt rejuvenation of many lakes. Despite regular monitoring of rejuvenation works in the initial stages by a Committee appointed by National Green Tribunal, the works are not yet completed. Treatment of sewage generated in the catchment  of Belandure and Varthuru lakes is around 453.50 MLD million litter per day (MLD) against the flow of 553 MLD. To regulate the outflow and foam formation, sluice gates are constructed and waste wear are renovated in both lakes. Desilting is a major task among the other works for rejuvenation. The silt removed from Varthuru lake is non-hazardous and used by farmers in their fields but the silt removed from Bellandur lake is dumped in the abandoned stone quaries since being contaminated. The results of soil analysis have been given in various tables. The groundwater is fond non -contaminated. Belandure lake play a role of buffer zone for Varthur lake.