Tamil Nadu is unlikely to face any major problem in water availability this summer, with a comfortable storage in reservoirs and irrigation tanks. This will assume added importance as the Assembly election is due in April-May, when drinking water shortage is normally felt in many parts of the State.
The main reason cited for the present situation is the rainfall received in the last three months. Nine districts received excess rainfall, while 16 registered normal rainfall with positive departure. As against the expected 45 cm, the State registered 47 cm of rain.
Though Cauvery water realisation during 2020-21 was not so high as it was in the previous year, the State got about 30 thousand million cubic feet (tmc ft) more than its due between June and December. Around 195 tmc ft was realised by the State on the inter-State border, as measured by the Central Water Commission.
Around 30% of the irrigation tanks are full, compared with 23% a year ago. Likewise, the storage is 90% and above in around 41% of the tanks, while the figure for 2019 was around 36%.
20 tmc ft less
The present combined storage of reservoirs is about 20 tmc ft less than what it was at the end of 2019. This was owing to the storage in the Mettur dam, which was around 91 tmc ft a year ago. The dam’s storage stood on Friday at about 71.8 tmc ft. Water managers expect that about 15 tmc ft more will have to be released in the next few weeks, and when the dam’s shutters are brought down, the storage is expected to be around 55 tmc ft.
Likewise, another 15 tmc ft will have to be released from the Bhavanisagar dam for irrigation. In the southern districts, Papanasam and Manimuthar are having comfortable storage. The sore point is the storage of Vaigai, which has about 3.3 tmc ft against the capacity of 6.091 tmc ft.
The water managers are confident of meeting Chennai city’s drinking water needs in the coming months as the storage in all the reservoirs is, on an average, around 90%. Until Friday, about 5.2 tmc ft of Krishna water was received by Tamil Nadu from Andhra Pradesh.