Between October 1 and 27, Tamil Nadu recorded an average of 217.2 mm against the period’s normal of 144.2 mm – a surplus of 51%. Tamil Nadu’s rainfall improves dramatically in 27 days as 18 deficit districts move to normal/excess, narrowing the statewide deficit. CHENNAI: Water storage in Tamil Nadu’s reservoirs has dropped to a critical level, with 63 of the state’s 90 reservoirs holding less than 25% of their capacity on.