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Rainy day tips: Harvest water now for happy days ahead

Community initiatives are leading the way in solving thirsty Mumbai’s water woes, with rainwater collection initiatives and everyone chipping in.

real estate Updated: Jun 24, 2017 17:56 IST
Gayatri Belpathak
Gayatri Belpathak
Hindustan Times
Rainwater Harvesting,Blossom CHS Marol,Oxford CHS Thane

“It has been a miracle,” says Caroline D’Souza, former chairperson of the Blossom cooperative housing society in Andheri, referring to the rainwater harvesting (RWH) system installed in 2010.

This 51-year-old housing society spread over 5 acres in Marol dug six recharge pits and began collecting rainwater to recharge the two borewells on the premises, seven years ago. Setting up the system cost them just Rs 1.20 lakh.

“Within the same year, we recovered that investment many times over,” D’Souza says. “We did major structural repairs on all our 11 buildings and did not need to order a single tanker of water for the cement curing process. The repair work lasted about five years and at the rate of Rs 800 to Rs 1,200 per tanker, we had a gross saving of Rs 8 lakh to Rs 10 lakh right there.”

Many people fear that an RWH will require extensive maintenance, she adds, but all the maintenance theirs has needed is an annual cleaning of the pits and a fresh layer of sand and porous brick powder. “We breed guppy fish and frogs in the water, which helps keep it clean naturally,” D’Souza adds.

The Maharashtra Nature Park, located in the heart of Mumbai, uses about 1 lakh litres of harvested rainwater per watering day just for its trees. ( Satish Bate / HT Photo )

“Community-driven, de-centralised initiatives in rainwater harvesting are most urgent and mandatory for the city of Mumbai,” says water conservationist and Magsaysay awardee Rajendra Singh. “There needs to be effective management, monitoring and supervision by the government. But for their part, citizens can start with a catchment system on the roof of their home or building and extend that to community initiatives in their neighbourhoods.”

Citizen initiative is important in Mumbai, since there is no rule making it compulsory for existing housing societies to harvest rainwater — and the rule saying new buildings must do so is not enforced beyond the blueprint stage.

“RWH has been compulsory for all new constructions in Mumbai since 2002,” says Ajit Gokhale, founder of environmental consultancy Natural Solutions. “The Thane municipal corporation, which made it compulsory for all new constructions in 2005, is even offering a 0.5% waiver in property tax.”

But in Mumbai, there are no records even of how many new buildings are actually installing the systems, say experts. “There is no monitoring or incentive for development of an RWH; no penalty for a lack thereof,” Roshni Udyavar, architect and head of the environmental architecture department at Rachana Sansad college. “There needs to be enforcement in the right manner, with certification only after implementation of the RWH system.”

“Community-driven, de-centralised initiatives in rainwater harvesting are most urgent and mandatory for the city of Mumbai,” says water conservationist and Magsaysay awardee Rajendra Singh.

Sandeep Adhyapak, CMD of consultancy Waterfield Technologies, calls it civic lip service. “If you propose the construction of a new building, you need an architect to submit a design, a structural engineer for the licensing system, a licenced plumber for the pipes, but for rainwater harvesting? Anybody can do it, so nobody does it,” he says.


So what does it take to get rainwater harvesting right?

“To make it a success, you need thorough knowledge of geographic location, climate, geology, soil, land use, water requirements and the existing water supply system,” says Rajeeb Dash, head of corporate marketing at Tata Housing. “It doesn’t always have to be about filling up storage tanks. In urban areas, rainwater flows away as surface runoff and is wasted. Instead, it can be caught and used to recharge aquifers and replenish the groundwater system.”

Understand the principles of RWH and then implement them diligently in your community, advises Prabodh Halde, president of the Oxford co-operative housing society in Hiranandani Estates, Thane. He spearheaded the RWH project here in 2011, as CHS secretary. It involved building three underground tanks, connections to borewells and beautification of the premises, and cost Rs 2 lakh.

“There has been a rise in private efforts, with ordinary citizens coming together in housing societies to harvest rainwater, thus reducing their dependence on the municipal corporation. Sadly, as far as the BMC is concerned, the entire focus is on supply, while demand-side measures such as RWH are overlooked,” says Dhaval Desai, vice president at the city-based thinktank Observer Research Foundation. “There are large gated communities coming up across the city, and we are led to believe that they are compliant with rainwater harvesting. How much of it is functional needs to be studied independently and audited. As a city, we are expanding resources such as Shahpur for our water needs, but how sustainable is this going to be in the future?”

First Published: Jun 24, 2017 17:56 IST