Storage, monsoon among factors considered by officials
The Mettur dam will not be opened on June 12, the scheduled date of opening for irrigation.
Authorities have taken into account various factors, including the storage and onset of south-west monsoon. The dam has 41 thousand million cubic feet (tmcft) of water against the capacity of 93.4 tmcft.
The authorities will be happy if the storage builds up to around 60 tmcft, a possibility that now appears to be remote, given the low storage in Karnataka's four reservoirs across the Cauvery.
Assuming that Karnataka sticks to the release of 10.16 tmcft prescribed in the interim order of the Cauvery Water Disputes Tribunal during June, the storage can go up to about 50 tmcft in a month.
A senior official says the situation will be reviewed by the month-end or early next month.
Two years ago, the authorities opened the dam for irrigation on July 28 when the storage was 44 tmcft.
According to information reaching here, the combined storage of Karnataka's reservoirs is approximately 21 tmcft against the total capacity of 114 tmcft.
Recalling Chief Minister Jayalalithaa's charge against the Karnataka government for utilising over 40 tmcft during February-May, another official says had the authorities in the neighbouring State not resorted to the depletion in summer, they would now have been in a position to share early flows of the river with Tamil Nadu.
It was to highlight the act of the Karnataka government in using water “unjustly” that the Chief Minister had demanded that the Cauvery River Authority, a body constituted to oversee the implementation of the interim order of the Tribunal, be convened.
A perusal of the flow data over the years reveals that after the Tribunal gave its interim order in June 1991, the Karnataka government stuck to the quantity of 137 tmcft, prescribed for June-September, in seven years out of a total of 21 years.
In a year, starting from June to May, Karnataka should make available 205 tmcft to Tamil Nadu at the Mettur reservoir with six tmcft for Puducherry.
What is ironical is that in all these years, the total annual realisation fell short of the prescribed quantity of 205 tmcft only in seven years.
This only meant that the State had realised more water during the period subsequent to south-west monsoon, wiping out the earlier deficit. But, it is only during the south-west monsoon that there is greater need for water release from Karnataka as Tamil Nadu does not benefit from the monsoon and receives nearly 50 per cent of its annual rainfall during north-east monsoon (October-December).
Considering all these factors, the Tribunal had drawn up, in the interim order, the monthly schedule of water release, a feature present in the final order too, an expert says.