Most of the irrigation reservoirs in Tamil Nadu have now less storage compared to the position a year ago. Be it Bhavanisagar, ranked immediately behind Mettur, the largest dam in terms of storage, or Vaigai in the southern part of the State or Krishnagiri in the northwestern belt, the story is the same.
The situation in Pechiparai and Perunchani, both in the southernmost district of Kanyakumari, is no different.
Bhavanisagar, which can hold 32.8 thousand million cubic feet (tmc), is having about 5.1 tmc of water, according to the position of the reservoirs as on Friday (October 7). On the same day the previous year, the dam’s storage was around 8.8 tmc. In respect of the Vaigi dam, the situation is miserable. Against the storage of 1.9 tmc, it is barely 215 million cubic feet (mcft).
In the Krishnagiri dam, the position is not that bad. The present storage of 1.3 tmc is about 200 mcft short of the 2015 storage. But, the storage in two reservoirs in Kanyakumari is abysmally poor. Perunchani now has 68 mcft, whereas it had 1.8 tmc a year ago. The current storage of Pechiparai is 1.1 tmc against 2.5 tmc last year.
The Parambikulam dam, which is used for irrigation in western districts of the State despite being located in Kerala, presents a similar picture. Its existing storage is 4.6 tmc, while it had 9.8 tmc a year ago.
A few exceptions
However, there a few exceptions. The Mettur dam, now in the limelight in view of the Cauvery dispute, has marginally higher storage than what it had last year. Compared to 32.3 tmc on October 7 in 2015, the dam’s present storage is around 35 tmc. In respect of the Sathanur dam, situated in the northwestern district of Tiruvannamalai, the situation is evidently much better with around 2.7 tmc, almost twice the storage it had previous year.
The main reason for the current poor storage of the reservoirs is that this year’s southwest monsoon (June-September) did not lead to bountiful rainfall. Also, there has been a huge shortfall in the realisation of the Cauvery water from Karnataka.
During the four-month period, Tamil Nadu as a whole recorded 25.5 cm against the anticipated 32 cm, a departure of minus 20 per cent. Kanyakumari was one of the districts which were badly hit. In the four months, the district was expected to receive 47 cm, whereas it got 30 cm only this time.
The deficit monsoon experienced by the neighbouring Kerala has also been reflected in the storage of the Parambikulam, Sholayar and Mullaperiyar reservoirs, which are located there, but are used for irrigation in Tamil Nadu.
This is why the northeast monsoon (October-December), expected to set in during the third week of this month, assumes more significance, both for drinking water supply and irrigation requirements of the State.
Poor southwest monsoon and shortfall in realisation of Cauvery water this year to blame
