City a concrete pool: Experts

The havoc caused by rains Chennai has raised many questions among Bengalureans and experts as to how safe the City is in case of a heavy rainfall.

Urban planners are of the view that Bengaluru cannot handle heavy downpour because it has turned into a ‘concrete pool.’  Bengaluru recorded the highest rainfall of the century for the month of November this year, when it City received 272 mm rains.

The Indian Meteorological Department officials state that rain patterns are changing and more rains can occur in future because of climate change. In the wake of this, experts opine that Bengaluru cannot handle even short spells because the drainage system, valleys and green spaces are being lost and the City is concretised.

Prof T V Ramachandra, Energy and Wetlands Research Group, Centre for Ecological Sciences, IISc, said Bengaluru has experienced unprecedented urbanisation since 1990s due to concentrated developmental activities with impetus on industrialisation for economic development.

“Our study of temporal remote sensing data shows that there has been a 925 per cent increase in built-up area (concretisation, paved surfaces) in the City from 1973 to 2013 with a sharp decline of 79 per cent area in water bodies affecting the micro-climate and water availability. Wetlands act as sponge and help in mitigating floods. Encroachment of natural drains, alteration of topography involving construction of high-rise buildings, removal of vegetative cover, reclamation of wetlands are the prime reasons for frequent flooding even during normal rainfall, post 2000.”

Prof Ramachandra listed out various factors that can lead to flooding in the City: encroachment of lakebeds, flood plains and lakes themselves; encroachment of rajakaluves or stormwater drains and loss of interconnectivity; lake reclamation for infrastructure activities; topography alterations in lake catchment; unauthorised dumping of municipal solid waste and building debris; sustained inflow of untreated or partially treated sewage and industrial effluents and removal of shoreline riparian vegetation.

Echoing similar views, Leo Saldanha of Environment Support Group said, Bengaluru is becoming a ‘concrete swimming pool.’ The government is creating a flood network in the City. The 800 km of rajakaluves are being turned into sewer lines. The drains are being closed, encroached and choked with garbage and plastic. There is no place for percolation to take place. “Instead of looking at Chennai floods as an eye opener, the government should implement recommendations of Justice N K Patil committee,” he opined.

The High Court-constituted committee had submitted a report titled “Preservation of Lakes in the City of Bangalore” in 2012. Experts from Karnataka State Pollution Control Board, Bangalore Water Supply and Sewerage Board, Forest Department, Bangalore Development Authority, Bruhat Bengaluru Mahanagara Palike, Minor Irrigation Department, Lake Development Authority and Department of Town Planning were part of the committee.