Resolve Cauvery dispute by reviving the chain tank system

Politicians of the day have made it seem like that the dispute over Cauvery water-sharing is a conflict without a solution.

They have been so successful in this that today farmers of the riparian states of Karnataka and Tamil Nadu believe there is no life for them without Cauvery waters and hence are willing to stake their lives for the cause.

In reality, this is yet another example of how a short-sighted vision can complicate matters for one and all. There can be, and there is, a prosperous life for farmers of the riparian states beyond Cauvery waters. The concept of water sharing in India is as old as the early civilisation of the land. History stands testimony to this. 

The sharing of waters went on without any noticeable acrimony till the 1960s. Till then, there existed arrangements among people which ensured that what was available was shared amicably among the riparian states in an equitable manner.

One such arrangement was a formal agreement entered into in 1860 between the government of the Maharaja of Mysore and the Madras Presidency, under British administration on how the waters of the Cauvery would be shared for the next 100 years. In 1960, this 100-year agreement came to an end but was not renewed by those in power.

But more than such agreements, what had ensured a harmonious sharing was the fact that both these states did not solely depend upon river Cauvery for their water needs.

They had a decentralised form of water harnessing called the chain tank system, which met their water needs. The Cauvery was only a supplementary source to the chain tank system. However, in the last 50 years of modern development, both Karnataka and Tamil Nadu have neglected the decentralised form of water harnessing, which was a sustainable form of water replenishing.

The chain tank system of the Carnatic was conceived and built about 1500 years ago, around 500 CE to 900 CE. It was built on the leeward side of the Western Ghats taking into cognisance the gradient of the land, sloping towards the Bay of Bengal. This region was known as the Carnatic.

Chain tank system

Every village in this region had tanks which formed part of a chain tank system. The tanks were called ‘Kere’ in Karnataka, ‘Eri’ in Tamil Nadu and ‘Cheruvu’ in Andhra Pradesh. In a chain, the Kere, Eri and Cheruvu of every village was linked to the other, right from the Western Ghats to Bay of Bengal. Rain waters were collected and stored in these local tanks as and when the rains came.

Once a tank filled up, the overflow was channelled to the next in the gradient. The water thus collected flowed through every village of the Carnatic, from the slopes of the Western Ghats to the Bay of Bengal. This chain of tanks ensured that every village in this region got water irrespective of whether it had rained there or not.

This chain tank was decentralised and did not depend only on Cauvery waters. Just as the river Cauvery uses the gradient to flow from Western Ghats, the chain tank system too used the same gradient of land. Cauvery was an arterial river in this web of feeder and distribution canals.  

The ingenuity lies in how the rain water was harnessed in this land across generations, ensuring prosperity to the land for thousands of years. However, in the last 50 years of modern development, this chain tank system has become defunct.

The decentralised approach which was the back bone of the agrarian society has been replaced by a centralised approach of solely depending on Cauvery for both agriculture and industries as well as for water table management. This has created an unnecessary strain on the water resources.

Though there exists a web of feeder canals to and from the Cauvery and the chain tanks, they are blocked with silt owing to lack of maintenance over the last seven decades. Making them functional again will create a situation for balancing water between the chain tank and the river.

Water sharing agreements, however satisfying they may be, only address rainy season needs. The real sustainable solution lies in making the decentralised system of water harnessing using the chain tank system, functional again. This system can harness the water when it rains, where it rains and make it available to the people when they need it, in every nook and corner of the land.

The surplus waters from this system, which will be in plenty when the system functions, can be shared with the rivers like Cauvery of this region. The excess from the rivers such as Cauvery, when in spate can also be shared with the chain tanks, thus balancing the water flows. This will ensure that seasonal floods and droughts are avoided.

As a civilised society, if we can restore what our ancestors had created for us, we can
again be prosperous and harmonious for centuries to come.

The acrimony over scarce Cauvery waters should have pushed modern-day politicians and administrators to clever ways of harnessing waters. Sadly, it has been long used as a political tool. In reality a solution to this vexed problem in not so far away. It is just a few decades back in the past.

(The writers are authors and research collators)