Deccan Chronicle 22.09.2009
BBMP has flood harvest plan
Bengaluru, sept. 21: In the aftermath of several people dying in rain-related incidents in the city, Bruhat Bengaluru Mahanagar Palike has come up with an ambitious plan to prevent flooding in the city: The civic body proposes to construct a complex of structures on all roads in Bengaluru to harvest rainwater and stop the regular inundation of localities in the city.
BMMP claims that the arrangement will also help recharge ground water.
BBMP commissioner Bharat Lal Meena told Deccan Chronicle that the system has already been implemented in some parts of the city including Byatarayanapura and Yelahanka. “It will be mandatory for all new roads. The system will be extended across the entire city in phases,” he said.
The rainwater harvesting structures will be constructed alongside drains on either side of the road by sinking deep holes 50 metres to 100 metres apart. “Porous material will be put in these pits, allowing water to sink into the ground,” Mr Meena explained.
Footpaths will also get porous paving to prevent rainwater from collecting, said BBMP special commissioner Maheshwar Rao.
Experts agree that the plan could be effective. “The city on an average receives 1,000 mm of rainfall every year. Not even 1 per cent of the rainwater is utilised,” says Vishwanath, a rainwater harvesting expert.
A scientific study carried out by the mines and geologies department in association with the Central Ground Water Board says the ground water availability situation in Bengaluru Urban and Bengaluru Rural districts is “critical”.
According to Mr Vishwanath, the average ground water level in the city has dropped to 900 feet from 600 feet in recent times. There are over 4,00,000 borewells in Bengaluru but only 5 per cent these have been recharged. Around 20 per cent of the city’s borewells have gone dry.
BWSSB meets the water requirements of only 40 to 45 per cent of the city’s population. The demand for water is 1,125 million liters per day (mld) but the board supplies only 870 mld.
BBMP believes that its rainwater harvesting system could prevent flooding and recharge the city’s ground water at the same time.
