BENGALURU: In all, 21 out of 210 lakes in Bengaluru city have excellent water quality, which can be used for drinking purposes, according to a study. The study conducted by the CSIR-National Environmental Engineering Research Institute (NEERI) reveals that out of 21 lakes, which is 10 per cent of total lakes in the city, the Yelahanka Zone of BBMP alone has 11 with excellent water quality. In the report of Phase-1, NEERI not only studied the status of lakes but also suggested both short-term and long-term measures for their rejuvenation. The NEERI report was submitted before a division bench of Chief Justice Abhay Shreeniwas Oka and Justice Sachin Shankar Magadum on Tuesday.
The CSIR-NEERI was appointed by the Bruhat Bangalore Mahanagara Palike (BBMP) to study the lakes in Bengaluru, in response to the directions issued by the Karnataka High Court on a batch of public interest litigations relating to lakes.
Out of 210 lakes, the water quality of 36 lakes is very poor, which means that the water cannot be used for any purpose; and the water quality of 63 lakes is poor which can be used for irrigation but with restricted usage. Samples of some of the lakes could not be collected due to weeds and also as some were dry.
The main objective included the study of the causes of pollution of lakes, suggest short-term and long-term measures for their protection, ascertain the location of lakes which have disappeared with passage of time, and preparation of a master plan for rejuvenation and restoration of the existing ones. As the inlet to the lake mostly carries the sewage along with the storm water, according to NEERI, technologies can be installed for the treatment of drain water and this treated water can be let into the lake.
The two technologies of NEERI -- RENEU (In situ drain treatment of the lake) and Phytorid (a wetland system based sewage treatment) -- are proposed to be installed for the drain treatment of the lakes.
The Detailed Master Plan for restoration of lake water quality for each lake will be addressed in Phase-II report, NEERI said. It has suggested long-term measures like a multi-disciplinary approach for the conservation of the lakes. It has also suggested a management planning framework to provide a balance between ecosystem restoration and conservation for ensuring ecological integrity of lakes.