Irrigation likely to be hit if Kerala goes ahead with the dam proposal

The strong reaction in Tamil Nadu to the Kerala government’s decision to revive its proposal for a dam across the Siruvani river stems out of the fact that the river is a major source of drinking water to Coimbatore.

On an average, the Siruvani accounts for the supply of 85 million litres a day (MLD) to the city. The Pilloor, another major source, contributes around 65 MLD. Both rivers form part of the Bhavani sub-basin.

Even though plans are under way to draw more water from the Pilloor and the Aliyar to feed the city and neighbouring areas, it is the Siruvani that symbolises the drinking water supply system of Coimbatore.

It is against this backdrop that one has to view the reaction to the proposed revival of the dam project at Attapadi, which is essentially an irrigation scheme. As the city’s other source, Pilloor, is also part of the Bhavani sub-basin, the Kerala government’s decision has evoked concerns among people in the western belt of Tamil Nadu.

It is not merely for the reason of possible adverse impact on the drinking water requirements of Coimbatore that political parties in the State are expressing their disapproval of the Kerala move.

The other reason is that irrigation needs of about 2.5 lakh acres may also be affected. These come under the Lower Bhavani Project (LBP) system, Thadappalli and Arrankottai channel system and Kalingarayan channel system.

Coimbatore is entitled to 1.3 thousand million cubic feet (tmcft) of water under the inter-State agreement signed in May 1969. As Chief Minister Jayalalithaa pointed out in her letter to Prime Minister last week, Kerala has been allocated 2.87 tmc ft of water as per the final order of the Cauvery Water Disputes Tribunal. There are reports that Kerala is planning to build a dam of 2.2 tmcft and eventually harness 4.5 tmcft through two fillings.