Reasons

  • Lack of infrastructure planning.
  • Drastic land use changes due to rapid urbanization.
  • Encroachment into natural habitats.
  • Destruction of natural channel flow.
  • Converting Lakes and tanks into public and private layouts.
  • Haphazard development of drainage system & improper drainages in new areas.
  • Reduction in the carrying capacity of the drains due to siltation and encroachments.
  • Reduction in the tank numbers and live storage and recharge capacity.
  • Outfalls being encroached.
  • Layouts in the tank bed areas which are the low laying areas.
  • Dumping of solid waste into the storm water drains.
  • Climate change causing micro climates in the city area resulting in Urban Heat Islands.
  • Overall urbanization has increased the runoff coefficient from 30% -40% to 80%-90% and has reduced the ground water capacity.
  • Over exploitation of the groundwater has resulted in depletion of groundwater levels which has led to failure of bore wells and also deteriorated the ground water quality.