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Recurring urban floods

  Dec 06, 2021

Recurring urban floods

Q Why is it in News ?

A Flood in Chennai has revived memories of the devastating Chennai floods of 2015, a collective trauma that its residents are yet to outlive.

Q What is role of climate change ?

  • In August this year, as monsoon floods raged across the subcontinent, IPCC’s 6th Assessment Report (AR6) was published.
  • The report noted the increasing frequency of heavy precipitation events since the 1950s and inferred that they were being driven by human-induced climate change.
  • The climate crisis, is here.
  • It has made extreme rainfall events more severe and unpredictable than ever before.

Q What is role of poor planning and encroachment ?

  • In 2015, the National Green Tribunal in India formed a committee to report on the status of natural stormwater drains in Delhi.
  • On inspection, out of the 201 “drains” recorded in 1976, 44 were found to be “missing.
  • Geospatial imaging established that 376 km of natural storm drains — encroached on and paved over — had disappeared from Bengaluru.
  • In both cases, these “missing” waterways were either encroached and built over or connected to sewage drains.
  • Poor design and corruption significantly contribute to urban floods.
  • By violating environmental laws and municipal bye-laws, open spaces, wetlands and floodplains have been mercilessly built over, making cities impermeable and hostile to rainwater.

Q What can be way forward ?

  • We need to move away from land-centric urbanisation and recognise cities as waterscapes.
  • We need to let urban rivers breathe by returning them to their floodplains.
  • The entire urban watershed needs to heal, and for that to happen, we need less concrete and more democracy and science at the grassroots.
  • Ever since concretisation became shorthand for urbanisation, rainfall in a changing climate no longer finds its way towards subterranean capillaries or surface water bodies.