Understanding sustainable flows
The Arkavathy is no longer counted as a reliable source and the Cauvery has become the river of primary dependency for the city of Bangalore
News about water in India and some countries is about rain, river and the flow that talks of divisions. The Cauvery water dispute, the Indus river disagreement between India and Pakistan, the perceived threat of the sharing of the Brahmaputra waters coming from China…are all national and international disputes that have been simmering and occasionally exploding. Even at the local scale, upstream and downstream conflicts are likely to increase as waters are collected
and harvested in the catchments and people downstream feel this will deprive them of their historical share.
Let us look at the city of Bangalore itself. Since it draws its waters from the Cauvery, it is much dependant on the rainfall in Kodagu and Wayanad. It is the catchments of the Kabini, Cauvery and Hemavathi which are important players in the safe, sustainable availability of water for Bangalore. What happens when catchments change?
We have evidence close to Bangalore, from the Arkavathy itself. This river starting from the Nandi Hills was the main source of water for Bangalore from 1896 when the Hessarghatta reservoir was built and water drawn from brick aqueducts to the city.
In the 1930s came the Thippagondanahalli reservoir which augmented waters for Bangalore. These two schemes were sufficient for the city till the river started to dry up.
The Arkavathy is no longer counted as a reliable source and the Cauvery has become the river of primary dependency for the city of Bangalore. Even Chennai city sources water from it through the Veeranam project. Why did this happen and why has the Arkavathy dried up?
Catchment management strategy
The river dried up due to the complete absence of a catchment management strategy and plan. The tanks and the channels linking up to the tanks were neglected. Water stopped coming to the tanks in adequate quantity for them to fill up and overflow. The catchment land itself was converted to agricultural land. This process of levelling and ploughing dried up the runoff from the land to the tanks.
Indiscriminate use of ground water depleted the levels, stopping completely base flows into the channels and rivers. The river simply stooped flowing and dried up. Dodaballapur town, 30 kilometres from Bangalore and with a population of 90,000 people, dependant on the river for all its water, saw its huge tank completely dry. Now borewells 900 feet and deeper provide water to this town and the tank is still dry.
Lessons to be learnt
What are the key lessons then to be learnt? If the Arkavathy can go dry, why can’t the Cauvery? Is that unthinkable? What should we do to ensure river flows?
Understanding river basins and managing the water resources carefully is of primary importance. Institutionally we need a river basin agency to at least help us understand and plan for all waters in the river system including groundwater.
Managing catchment of the source is also important. New York city, for example, has bought up 10,000 hectares of the Catskill Mountains since this is the primary catchment providing water to the city. By protecting and preserving the catchment and the forest, it is able to ensure both quantity and quality of the river water flows, so much so that it need not even filter or treat the water but pump it directly to the city for consumption.
Can Bangalore buy up 10,000 hectares in the Arkavathy catchment and try to restore flows? If the Aravari river in Rajasthan could be revived, why not the Arkavathy?
Can simply giving up a source and moving farther to the next source be a sustainable solution for a growing city? By increasing ecological footprints do we not increase the conflict potential? Difficult questions that need some relevant heads to come together for some answers.
What can we do as individuals
Though many of the questions seem solvable only by high level government institutions, communities and people are getting into the act.
Public interest litigations have resulted in a buffer zone being created around the Thippagondanahalli reservoir to try and prevent it from getting polluted.
Legislation has made it mandatory for industries and developments in this area to come out with a clear water management plan and also to harvest rainwater compulsorily.
Groups have coalesced around the Kumudhavati and the Arkavathy and have conducted many an awareness campaign to highlight the deteriorating situation and to galvanise the community into action.
One of the actions has been to revive a tank in the upstream reaches of the Arkavathy and plan for rejuvenation of many more tanks with the involvement of the community. Illegal quarrying has also been halted by the keen action of these groups. Individuals and organisations have led campaigns to harvest rooftop rainwater and adopt ecological sanitation systems to halt pollution of water. Traditional water bodies have been cleaned up and an enthusiastic and water literate community has emerged in this town.
Deeper understanding of the surface water and ground water inter-phase, the sustainable withdrawal of ground water and the recharging of the aquifer, harvesting rainwater, treating urban waste water and reusing it, managing urban waste disposal properly without impacting water quality, and rejuvenation of all the tanks would all be steps necessary for revival of our rivers.
Pioneering work at understanding these dynamics is being done by Shekar Muddu and team in the Indian Institute of Science.
It is only through individual understanding and action, community involvement in solutions and an institutional strategy and structure to address core problem would we see revival of our rivers, the lessening of conflicts and the sustainability of our water sources.
www.rainwaterclub.org www.arghyam.org Ph: 23641690
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