Chennai witnessed the highest rainfall since the 2015 flood on November 7. The city recorded over 200mm of rainfall. Water entered several homes, roads were severely waterlogged and boats had to evacuate many residents living in low-lying areas. So, why did Chennai flood? Were there no lessons learnt from 2015? And who is to blame? TNM  explains. 

For the people of Chennai, the November 7 flooding brought back harrowing memories of the December 2015 deluge, when around 250 people were killed and thousands left homeless. On December 1, 2015, parts of Chennai received 490mm of rainfall over a 24 hour period.

But heavy rains alone do not cause a city like Chennai to flood. In 2015, the Chembarambakkam reservoir, which was full, was blamed for flooding the city, with officials mismanaging the release of waters. The sudden discharge of the water caused the Adyar River to breach its banks in a few areas, resulting in massive flooding. 

This time, however, there was a gradual release of waters from Chennai's reservoirs including Chembarambakkam. So why did Chennai still flood? 

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