The Cauvery water sharing debate between Tamil Nadu and Karnataka has resulted in heated arguments, protests and brought the issue of the lack of substantial water resources in a bustling city like Bengaluru to the fore. Scientist A.R. Shivakumar, principal investigator - RWH, Karnataka State Council for Science and Technology, Indian Institute of Science has a simple solution: “Rain water is the purest form of water. I believe it is important to catch and harness rainwater. We must not depend on a single river for all our needs. Though Cauvery can meet 50 percent of our water needs, we must invest in water harvesting and means to recharge the used up ground water, apart from building a mechanism to use sewage water. Treated sewage water can be used for many purposes such as cleaning railway stations and public spaces, for toilets and for farming too.”
Shivakumar believes in leading by example and stays in a house that runs completely on rain water and solar power. “We use rain water for everything. I was always worried about water shortage and began looking for solutions. I found the answer in nature.”
He decided to study rainfall patterns in Bengaluru when he began work on his house in 1984.
“I discovered that the city receives about 1,000 mm rainfall through the year. I also found that the rainfall occurs rather regularly, once in 45 days. On my 60/40 plot, we could receive more than 2.23 lakh litres per year, much over the yearly requirement of about 1.5 lakh litres for a family. I studied rainfall for the last 100 years to come up with this data.”
Talking about the system installed at his house, he says, “Most rainwater falling on the roof is channelled to flow into a tank with a capacity of more than 4,500 litres on the ground floor. I also invented a pop up filter that filters the water before storage. We have a huge underground sump that is used to recharge the ground water. I have not been dependent on water supply from outside the house for the last 15 years. We try and put all the water to good use, including reusing treated sewage water.”
Shivakumar has been involved in creating policy for rain water harvesting that has been adopted by civic agencies such as the BBMP and the BWSSB. “I helped draft a policy and we made it mandatory for constructions in the city to have a rain water harvesting plant. We conducted successful projects in major buildings across the city such as the Vidhana Soudha and the General Post Office a few years ago.
We have trained many people to carry out construction of rainwater harvesting plants in the city. More than a 100,000 houses in the city use rain water harvesting techniques.At the start of his career, Shivakumar and his team at IISC had made solar water heaters popular in Bengaluru. “There was an energy crisis then. We used to go with solar panels fitted on top of a truck. We had to convince people that the sun rays could heat water. It was a very successful project. We got funding from the government too.”Shivakumar is dismissive of desalination plants to solve the water crisis. “We are located 350 kilometres from the coast and desalination plants are very expensive. Solutions such as rain water harvesting plants are much cheaper and are helpful in the long run, since they help regenerate the depleting ground water resources.” In the last few months, in association with the UNESCO, Shivakumar has developed an app that lets users to find rainfall data from across the country. He says, “A Norwegian counsel had visited my house and was very impressed with the RWH plans. That got us noticed by the Unecso too. We have trained many planners, plumbers in setting up rain water harvesting plants in the city and hope that it will become the go to solution for water related issues.”
