Rs 50,000 cr infra loss due to 2015 Chennai floods: Niti Aayog

The massive devastation brought about by Chennai floods in 2015, which inflicted an estimated loss and damages of Rs 50,000 to Rs 1 lakh crore, was brought about not only by torrential rains but also by ‘compound wall effect’, said a report by Niti Aayog.

The report was part of the central think tank’s effort to study the causes, effects and losses of 15 flood-related events across the country between 2011 and 2020. Analysing the causes of Chennai floods, Niti Aayog pointed out that urbanisation had reduced the infiltration component of the hydrological cycle.

“Chennai during the floods had experienced the ‘compound wall effect’. Compound walls were built around almost all institutions to save them from encroachment. This resulted in the alteration of local overland flow paths. which in turn blocked the local channels. This turn changed the local flooding patterns, protecting some and endangering some areas. In some cases, by blocking the natural flow and cross drainage they contributed to localised flooding,” the report said.

It was one of the worst floods of the decade which claimed about 500 lives, and affected 18 lakh people in the city, the report added. The damages and losses range from Rs 50,000 crore to Rs 1 lakh crore, making it the costliest natural disaster to have occurred in 2015.

“The final spell on December 2, 2015, flooded densely populated areas of Chennai metropolis and adjoining districts of Kancheepuram and Tiruvallur. This unprecedented rainfall in a short duration led to devastating flash floods causing major damages to irrigation infrastructure, roads and public amenities as well as loss of human lives and livestock,” the report said.

The report lauded the State government for learning from it and strengthening disaster preparedness during Cyclone Vardah.