EFFICACY OF REJUVENATION OF LAKES IN BENGALURU, INDIA

Purpose of the study: The main objective of the present work is to assess the efficacy of the restoration endeavour in Bengaluru lakes, Karnataka, India. Rapid urbanisation coupled with industrialisation in urban areas has greatly stressed the available water resources qualitatively and quantitatively. This has also resulted in the generation of enormous sewage and wastewater after independence. Method:  Environmental monitoring of 40 restored lakes was carried out to identify the key issues and assessing water quality (physical, chemical and biological). Weighted arithmetic water quality index (WQI) and Pearson’s correlation coefficient (r) was determined using data of physicochemical parameters of lakes. Principal Component Analysis (PCA) performed using PAST3 software to identify the factors responsible for variations in water quality. Main Findings: The monitored forty lakes distributed across the three major watersheds namely Koramangala and Challaghatta valley, Vrishabhavathi valley and Hebbal valley were grouped under three different WQI status like good water quality (10%); poor water quality (37%) and very poor water quality (53%). Majority of these restored lakes has become polluted which indicates improper decontamination and poor maintenance of restored lakes. Application of this study: This study provides vital information for policymakers to understand the gaps which helps in the course correction while implementing further rejuvenation of lakes. Novelty/Originality of this study: The efficacy of rejuvenation was assessed through integrated cost-effective scientific approaches for the lake monitoring.  Monitoring during the pre and post rejuvenation period has aided in assessing the efficacy of rejuvenation, which is done for the first time in India.