If every Bengaluru household harvested rainwater, Bengaluru’s water woes would drop dramatically. Experts say Bengaluru’s annual rainfall has a potential of meeting nearly 50 per cent of the city’s annual Cauvery water allocation of 19 tmcft.
The city has around 60 rainy days in a year. Spread across 700 sq. km, it receives an average annual rainfall of 972 mm. This means the city has a potential of getting 23 tmcft of rainwater. But, with most of the lakes having dried up or are filled with sewage, the rainwater literally goes down the drain with no collection point. With roads and pavements concretised, the problem only gets compounded. But in the absence of an urban water management institution and “uninterested” service providers, Bengalureans are yet to take the concept of rainwater harvesting (RWH) seriously.
This, despite the Bruhat Bengaluru Mahanagara Palike (BBMP) making RWH mandatory in its revised building bylaws back in 2009 and Bangalore Water Supply and Sewerage Board (BWSSB) amending rules to make RWH mandatory for all new constructions on sites measuring 30 ft x 40 ft and existing buildings on 60 ft x 40 ft sites.
A.R. Shivakumar, principal investigator for RWH at the Karnataka State Council for Science and Technology, Indian Institute of Science, said unless RWH was made compulsory for both old and new buildings on sites of all dimensions, it would not gain public acceptance.
Mr. Shivakumar, who was also a member of the technical committee that framed a policy document for RWH in the State, said it was not enough to have rules and laws to make RWH mandatory. “Easy availability of water in the city is a great boon to people and the main reason for them not looking at alternative sources such as RWH,” he said.
“If the concept is taken seriously, thousands of RWH tanks spread over the city on every property and all the rejuvenated lakes would act as buffer zones to hold water and avoid flooding of storm-water drains and low-lying areas,” he explained.
* Come May 1, Bangalore Water Supply and Sewerage Board will start imposing penalty on those who have not adopted rainwater harvesting system in their buildings
* Citizens will be slapped a penalty of 25 per cent of their water bill for not adopting RWH, for the first three months from May. The penalty will double after three months and will be collected till the building adopts the system.
D.S. Rajshekar, president, Citizens’ Action Forum:
The BWSSB should first ensure all government buildings adopt RWH and penalise them if they don’t. RWH is of course required. Elected representatives with residents’ welfare associations should go door to door to popularise the system.
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T.S. Vidyadhar, R.T. Nagar Residents’ Welfare Association:
There are hundreds of open spaces in the city where rainwater can be harvested such as the open space in front of the Vidhana Soudha and parks. Instead of harvesting rainwater in these spaces and allowing it to percolate into the ground through roads and pavements, the civic body has concretised this infrastructure. Having a rule only for the residents is a narrow approach.
