KOCHI: Mumbai in 2005, Surat in 2006, Kolkata in 2007 and Jamshedpur in 2008 were in the news for one reason — flood. Loss of life and property in these floods was massive. Power disruptions and epidemics followed.
The situation warrants a more coordinated and planned attempt to meet the tragedy, according to officials of the National Disaster Management Authority (NDMA), which has the Prime Minister as its chairman. In 2001, there were 285 million people residing in 35 metro cities, each having a population of more than one million. By 2021, this is expected to exceed 600 million residing in over a 100 metro cities. Rapid urban development and the pressures of population have resulted in constructions in flood-prone areas and the urban population is now more vulnerable to urban flooding. Heavy rainfall occurs mainly during the monsoon. Hence unique solutions are required for Indian cities. The change in global climate is resulting in different weather patterns such as increased intensities of rainfall and lesser number of rainfalls. This points to the need for special provisions for mitigation of floods in cities located along the coastal areas, river banks or downstream of major dams. Urban flooding is different from rural flooding as urbanisation increases flood risk up to three times. Peak flows result in flooding very quickly.
Urban flooding can be reduced through measures such as maintaining drainage channels, providing alternate drainage paths, onsite storage of rainwater and preventing solid waste entering the drainage systems.