Drops of hope-Bangalore-Cities-The Times of India
As the government grapples with making rooftop water harvesting mandatory in new constructions in the city, some housing layouts are a
lready way ahead.
Rainbow Drive Layout on Sarjapur Road has put in place over 20 rooftop water-harvesting systems and 10 groundwater-recharging systems in stormwater drains since February 2008. The residents are delighted that they no more have to depend on the uncertain supply of borewell water or spend on tankers. They are ecologically storing abundant water to sustain themselves. Added to this is the incentive that their layout doesn't flood after rain, because all the water gets stored in stormwater drain recharge wells.
Committee member of the Resident Welfare Association (RWA) of Rainbow Drive Layout, Jayawanth Bharadwaj, was one of the first to take up rainwater-harvesting project. "We were completely dependent on borewell water till a year ago. When the borewell used to dry up, we would get tankers, which are very expensive. I realized there has to be a way out. That is when I started a door-to-door campaign in my layout to get people to set up rainwater harvesting systems. Some understood its importance, while some were wary of the investment. Gradually, it picked up."
The RWA has also set up 10 groundwater-recharging systems in stormwater drains in the layout. They also have a system of giving Rs 100 discount on the water bill to houses that have installed rooftop water harvesting.
According to the Rainwater Club, a group of activists working towards sustaining water, Bangalore gets around 970 mm of water every year. If this water is harvested in a 30x40 ft rooftop (average roof size), then the water generated can sustain a family of four for five to six months.
Nathan Stell, a member of Rainwater Club, points out the larger bounty from rainwater harvesting. Bangalore pumps water from the Cauvery, which is around 100 km away from the city and 500 metres below the city's elevation. The amount of energy required to pump water to the millions of households is enormous, while an important feature of rainwater harvesting is saving energy. The water supply is far less expensive than tankers, that costs about Rs 50 per kilolitre. Groundwater recharging helps replenish borewells and raises the groundwater table. He also added that the quality of rainwater from the roof is high, and can be used for all kinds of household work and even filtered for drinking.
"We have seen an increase in demand for rainwater-harvesting systems since the past four years. The first reason I think is the scale at which the city is growing. Borewells are not sustainable. The policy by BWSSB to make rainwater-harvesting mandatory in new houses is also leading to a shift in perspective. But there is still a lot of untapped potential in the city," adds Nathan.