The State government’s effort to promote the use of rain water by making Rain Water Harvesting (RWH) mandatory in the city seems to have failed to produce the expected results. Less than 10 per cent of the building owners who have installed the RWH systems are using the harvested rain water.
The move was expected to reduce the burden on Bangalore Water Supply and Sewerage Board (BWSSB) and the excessive dependence on Cauvery water.
BWSSB Chief Engineer Kempramaiah said, “According to the data collected by us, only 3,600 building owners in the city are using the harvested rain water. Though more than 38,000 building owners have installed the RWH systems, they are using the harvested rain water to recharge the ground water despite the fact that rain water is very safe for drinking and other purposes.”
Chandrakala, a resident of Mahalakshmipuram, said, “We have installed the RWH system in our building. As the rain water flows from the terrace and other areas, where we normally walk, we do not feel like using it for drinking. Therefore, we use it to recharge the ground water.”
A R Shivkumar, Principal Investigator, Rainwater Harvesting, Karnataka State Council for Science and Technology, Indian Institute of Science said, “In fact, rain water is very soft water and is safer than ground water that is drawn through borewells as the water becomes hard while percolating to the aquifers. Ground water has to be treated through reverse osmosis and other methods to remove the hardness in it. But one can consume rainwater just by disinfecting it.”
Shivkumar uses rain water that is harvested in his house at Vijaynagar for drinking and other purposes and does not rely on the Cauvery water supplied by the BWSSB. He says people should use harvested rainwater to effectively recharge the ground water only if they cannot use it due to their inhibitions or other reasons.
The State government had passed the Bangalore Water Supply and Sewerage (Amendment) Bill 2009 to make RWH mandatory in the city. It stipulated that those who construct buildings in an area of 1,200 sq meters or more should install RWH systems in their buildings within nine months.
However, many building owners have not installed RWH systems. “We are not authorised to take any action against the building owners who have not complied with the RWH rules. Therefore, we are unable to implement the rules as mentioned in the bill,” a BWSSB official said.