The Tamil Nadu government has prepared a proposal but experts say the costs outweigh the benefits of river interlinking
The Tamil Nadu government has readied a proposal to interlink the Cauvery and Godavari rivers. This proposal is not yet available to the public. The Lede has accessed the details of this controversial project, which experts say may not be feasible.
So what does the proposal say?
“A barrage would be constructed at Janampet, about 40 kilometres upstream of Polavaram and water can be diverted southwards through the reservoirs Nagarjuna Sagar along Krishna, and Somasila across Pennar to Cauvery Grand Anicut. About 85 to 100 TMC could be received at the Andhra Pradesh – Tamil Nadu border,” said R Subramanian, chairman of the Cauvery Technical Cell at a conference in Chennai last week.
The original plan of river interlinking was to begin from the river Mahanadi which flows through Odisha and Chhattisgarh. But this has been revised thanks to a lack of consensus amongst the two states.
“The union ministry decided to skip the original plan that starts with Mahanadi. The basin states Odisha and Chhattisgarh could not decide upon their quantum of surplus,” added Subramanian.
As a result, the first stage of linking rivers was confined to the peninsular rivers Godavari and Cauvery.
The Himalayan rivers Brahmaputra and Subarnarekha would be interlinked with the Mahanadi river as part of the second stage of the project once states reach consensus.
The proposed interlinking project of the Godavari and the Cauvery depends upon the reservoirs which form the Telugu Ganga project, that currently supplies water to Chennai city.
This project also transfers flood waters from the rivers Krishna and Pennar to the Poondi reservoir in Tamil Nadu.
There are four major reservoirs at Velugodu, Chenmanukkapali, Somasila and Kandaleru.
An already controversial and troubled water project which has caused tensions between Tamil Nadu, Andhra Pradesh and Telangana, is all set to be used to convey water as part of the river linking project.
Earlier this year, then Minister for Water Resources Nitin Gadkari said that the detailed project report for Godavari-Cauvery linking was prepared with a project estimate of over Rs 60,000 crore.
He added that since the government expected funding from World Bank or Asian Development Bank, there could be a possibility of using steel pipes in place of open canals to prevent evaporation losses during transmission.
“It has been widely said that 20% of money is consumed in operations and maintenance,” said S Janakarajan, Professor and President, SaciWATERs. “From where are you going to get the additional money for maintenance?” he asked the Cauvery Technical Cell chairman.
“All these river linking projects are Chiranjeevi projects. They remain on paper. They never get realised because no one is able to arrive at a consensus between states,” said S Raghavan, former director of the Regional Meteorological Centre, Chennai.
The proposed river linking project does not promise to be smooth sailing.
As per the latest draft, water from the Janampet barrage across the Godavari is lifted 140 metres uphill in three stages to reach the Nagarjuna Sagar across Krishna.
From there on the flow become gravitational.
Adding a 400 km journey each, to the Telugu Ganga project and Cauvery respectively, it is almost a 1200 km travel itinerary for the water from central India to the southern peninsula.
The Pattisam lift scheme completed two years ago was a similar project. But it was smaller in scale.
It also was a state project, making it easier for then Chief Minister Chandrababu Naidu to complete.
But the Godavari-Cauvery linking proposal caters to 20 lakh hectares of irrigation and nearly 70 TMC of water towards domestic and industrial uses, as stated by the Jal Shakti Ministry in Lok Sabha last year.
It is an inter-state project involving Odisha, Maharashtra, Andhra Pradesh Karnataka, Chhattisgarh, Tamil Nadu, Kerala and Puducherry. It would certainly need a mammoth effort to bring in consensus among the states for an agreement on the share of water resources.
Bureaucrats are visibly overloaded with negotiations over various issues related to water sharing – for instance, Karnataka Chief Minister BS Yeddyurappa sparked off a controversy on Monday when he stated that the state did not require permission from Tamil Nadu for building the Mekedatu dam. This has sent Tamil Nadu’s bureaucracy into overdrive. Similar problems arise seasonally over the Cauvery and Mullaiperiyar water sharing agreements.
While consensus is hard to come by, the risk to environment and ecology too needs to be factored in.
Pumping huge amounts of water uphill is not only an expensive proposition but also affects the sub-surface aquifers and the tectonic zones further below. There are mineral deposits like bauxite underneath the peninsular plateau.
It is not known whether ecological costs have been evaluated for the project as the DPR (Detailed Project Report) for the Godavari-Cauvery linking project is yet to be made public.
Tamil Nadu largely depends on the North East monsoon for its water needs. With an average of around 945 mm of rainfall annually, both surface water and groundwater rely on the monsoon.
The total surface water potential of the state is 692.78 TMC. Another 261.7 TMC of water comes from neighbouring states like Andhra Pradesh, Karnataka and Kerala. The total groundwater potential of the state is 22.94 TMC. This data is from the Tamil Nadu Environment Ministry.
“Studying the annual rainfall trends from 1951 to 2010, Tamil Nadu has witnessed a decrease in the South West monsoon but an increase from the North East monsoon,” said S Raghavan, former director of the Regional Meteorological Centre, Chennai. “So the annual rainfall is actually increasing.”
Experts advocate projects like rain water harvesting, schemes to recharge ground water and building more storage for surface water, rather than embarking on ambitious river linking projects.
“There is no need for a macro project,” said K Sivasubramaniyan, Professor at the Madras Institute of Development Studies. “What we need are micro projects.”
The Tamil Nadu government might consider a rethink on its plan to provide more water for the state. Finding ecologically sustainable solutions would be the only long term option before the government.