CHENNAI'S four main water storage reservoirs - Poondi, Red Hills, Chembarambakkam and Cholavaram - have a combined storage capacity of a little more than 11,000 million cubic feet (mcft). Experts say that it is possible to supply to the city only 80 to 100 million litres per day (mld) from this storage. The failure of the Krishna Water Scheme to deliver water to Chennai has been a serious setback to the efforts to get water in bulk from an external source. However, critics of the Veeranam project have argued that the government has ignored other options.
C.S. Kuppuraj, former Chief Engineer in the Tamil Nadu Public Works Department (PWD), says that a viable scheme for supplying water to Chennai needs to ensure that "water in bulk" is obtained from a single source. He argues that the Cauvery is the only source in the State that can afford to divert 10 to 12 tmcft to Chennai. Chennai's population would be about one crore in 2025 and Kuppuraj says that any project needs to take a "long-range view of the city's needs". In 1983, C.A. Srinivasan, then Chief Engineer in the PWD, suggested that the Cauvery be tapped at Pallipalayam, near Erode, just before the confluence of it and Bhavani. The scheme involves taking 12 to 15 tmcft from the Cauvery and diverting it to Chennai, through open channels. This quantum of water, amounting to about 5 per cent of the average volume of water available at that point, would not materially affect the interests of farmers. Kuppuraj told Frontline that this project, estimated to cost about Rs.900 crores, would result in a considerably lower cost of water when compared to the New Veeranam Project.
The bulk of the cost would be utilised to construct the canal, covering a distance of 517 km from Pallipalayam to the Chembarambakkam tank in Chennai. In terms of costs per litre of water delivered to Chennai, the project would be considerably cheaper because unlike in the case of the Veeranam project, there would be no need for pumping water to a high point in order to release it from a gradient. Pallipalayam, being at a mean sea level of 158 metres, compared to 70 metres in the case of Kadampuliyur where Metrowater has established its break pressure point, would be an ideal location to ensure that water flows without having to be pumped. The Pallipalayam scheme would provide 1,035 mld throughout the year, which is equivalent to 13.34 tmcft; in contrast, the Veeranam project is likely to supply only 1.2 tmcft. Kuppuraj said that the cost per litre would work out to Rs.3 per 1,000 litres, which he says is about one-twentieth the cost of water supplied by the Veeranam project. Kuppuraj says that since the scheme would be only drawing water from the Cauvery for drinking water, Karnataka would not challenge it.
Technical experts critical of the Veeranam scheme argue that it is doomed to fail because it is located at the tail-end of the Cauvery system. M. Natarajan, technical adviser to the Cauvery Delta Farmers Welfare Association and a former Superintending Engineer in the State PWD, suggests the construction of seven barrages on the Coleroon, between the Upper and Lower Anicut (a distance of 107 km). According to him, these barrages, each with a capacity ranging from 1.5 tmcft to 2.5 tmcft depending on the width of the river, would enable the impounding of water which is now flowing into the sea. Natarajan told Frontline that currently there was no mechanism to prevent the run-off of water during the rainy season. Natarajan estimates that the barrages can hold about 14 tmcft by end-January. Even assuming a loss of about 4 tmcft owing to evaporation, at least 10 tmcft would be available for supply to Chennai, he argues. He believes that the construction of barrages on the Coleroon would result in benefits for farmers and residents of Chennai.
Some experts believe that alternatives lie within and around Chennai. S. Janakarajan, Professor at the Madras Institute of Development Studies (MIDS), says that the peri-urban belt around Chennai has 600 to 800 tanks, ponds, lakes and other waterbodies that have been neglected or are in a state of disrepair. Worse, many of them have been destroyed forever by land-grabbing real estate developers. As a result, not only have water sources been destroyed, but the recharging of groundwater has been affected. He feels that much more ought to be done within the city and its immediate hinterland before Metrowater seeks water from elsewhere.