While Mumbaiites have been complaining about the heavy rains in the last two weeks, some housing complexes and educational institutions have been harvesting the water for use later in the year.
The 10-acre campus of DG Ruparel College in Matunga, has a rainwater harvesting system that collects rain water from three campus buildings.
“Our project began in 2008-09, where we have managed to save close to 8,000 kilolitres,” said Tushar Desai, principal, Ruparel College. One kilolitre equals 1000 litres.
The 50-acre Somaiya Vidyavihar campus needs a huge quantum of water to meet its drinking and non-potable needs. During each monsoon, the campus collects approximately 12,500 kilolitres of rainwater from the catchment area every year.
Water conservationist Janak Daftari shows the storage tank for rainwater harvesting of Arunodaya society at Andheri. (Pratham Gokhale/ HT photo)
“Rain falls on the terraces (catchment area) of the college buildings, which is directly diverted to the existing water tanks through advanced filters. The collected water is used for non-drinking purposes only,” said Dinesh Acharya, manager grounds and security of the college.
Some societies are putting the heavy rains to good use. Canosa Building in Hiranandani Estate, Thane and Arunodaya CHS in Andheri, have been utilising rainwater to work their flush pipes and save 300 kilolitres and 800 kilolitres respectively.
“With water scarcity in the city, we thought of installing such a plant in the building to keep the water table intact. Residents paid a total of Rs 4.5 lakh to setup the plant,” said Shankar Shrinivasan, resident of Canosa.
Water conservationists have said that more colonies and institutions have to take up the onus of conserving rainwater.
Janak Daftari, convener, Jal Biradari and water conservationist said, “There was a law that said after 2007, any builder who constructs a new building should include rainwater harvesting plants, however, there is no check on their design and thus rendering them inadequate.”
Sachin Kulkarni, a hydrogeologist and a rainwater harvesting consultant said that while many societies come to ask for quotations and plan to fix a plant, only two (Canosa and Arunodaya) came forward to get it fixed. “A majority of societies may find it expensive. However, they need to realise that this is a step for long-term gains” he said.