A look at data of inflow and outflow to and from reservoirs in Kerala shows that though the outflows from the reservoirs began days before the time of the flood, it was not sufficient to mitigate the disaster due to the intensity of the rains.
Kerala received 39% more rainfall than normal during the South West Monsoon according to IMD data. This is classified as ‘Excess’. The State received 302.7mm actual average rainfall — more than thrice the normal average — during August 16-22. Here's a look at the rainfall data. As observed from the below graph, the rainfall (blue) has been much higher than the average (red line).
The rains led to an increase in inflows to the reservoirs, peaking on August 16. The following graph shows the inflows into all major reservoirs.
Storage levels were driven up by the constant inflows. The following graph shows that as on August 23, the reservoirs are on average still above 95% capacity.
While outflows from the reservoirs were minimal between July 25 and August 9, they began showing an increase as early as August 10, as seen in the graph below. Relentless rainfall coupled with periodic release of water ended up being a double whammy for the State.
