Urban floods in Bangalore and Chennai: risk management challenges and lessons for sustainable urban ecology

A number of major cities and towns in India reported a series of devastating urban floods in the recent decade. Mumbai flood 2005 followed by other major cities of South Asia like Dhaka, Islamabad, Rawalpindi also suffered with urban flooding. Census 2001 figured 285 million people in 35 metro cities of India, and is estimated to cross 600 million with 100 metro cities in 2021. Regional ecological challenges coupled with climatic variability are noted to aggravate flood risks and impact on affected communities. Urban flooding was primarily a concern of municipal and environmental governance, has now attained the status of 'disaster', which has drawn the attention of environmental scientists and disaster managers. Challenges of urban flooding in terms of drainage and flood mitigation including structural and non-structural measures and key issues of urban ecology in two major metropolitan cities of India - Bangalore and Chennai, have been studied. Risk management challenges in the context of land-use, city and population growth, wetland degeneration, waste disposal have been discussed.