Learning to live with water

Context: Recurring floods in major cities point to need for moving away from land-centric urbanism.

Underlying factors behind rising cases of urban floods in India

• Land-centrism weakens urban drainage: All cities in the subcontinent are waterscapes. Cities are planned to subjugate water, not live with it. It is.
• Poor design and corruption: Significantly contributing to urban floods. Either design guidelines are missing, or the outlets are too small to accommodate peak flow in most South Asian countries. 
• Violation of environmental laws and municipal bye-laws: Open spaces, wetlands and floodplains have been mercilessly built over, making cities impermeable and hostile to rainwater. Mostly South Asian cities have been built on stormwater drains.
• Encroachment in urban areas:  Encroachment of urban poor who live precariously in low-lying drainage areas because of inadequate social housing are always blamed. 
  • Devastating Chennai floods of 2015: Experts pointed out that the biggest encroacher of urban waterways and wetlands was TN.
• Concretisation became shorthand for urbanisation: Rainfall in a changing climate no longer finds its way towards subterranean capillaries or surface water bodies. 
  • Massive quantities of water released during intense short-duration rainfall get diverted towards drainage networks which are either “missing”, or choked.
• Political response to floods transfers the blame to the skies: Floods were viewed as products of “fickle” monsoons and “unruly” rivers. Millions of tons of concrete are continued to poured into constructing dams, embankments, culverts, and sea walls.

Way Forward: 

• Construction of stormwater drains: The size of their outlets should be based on the intensity of rainfall (mm/per hour) and the peak flow inside the drains.
• Need to move away from land-centric urbanisation and recognise cities as waterscapes.
• Need to let urban rivers breathe by returning them to their floodplains. 
• Entire urban watershed needs to heal by minimizing concrete and more democracy and science at the grassroots.

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