Unlike most of the buildings in the maximum city of Mumbai that rely on water tankers, the Sealine Housing Society at Union Park in Khar is carefree. This building, overlooking the Arabian sea, has ten flats, and champions eco-friendly practices such as rainwater harvesting, harnessing solar energy, and treating 100 per cent wet waste at source.
90-year-old Navin Chandra, Chairman of the residential complex, is behind the sustainable goals set in the 2000s after witnessing the grim reality of Mumbai’s water needs.
“In 2000, when we moved to this society, I was appalled to see how the residents didn’t mind shelling a hefty amount every week to purchase water tankers. The water was not even clean. I decided to find a solution and catch every drop of rainwater. So, I turned towards rainwater harvesting, which also became our segue to other measures like waste management and harnessing sunlight,” Navin tells The Better India.
He convinced every resident of the building to invest in a rainwater harvesting facility (costing Rs 7 lakh), solar panels and windmill (Rs 13 lakh), and a composting pit (around Rs 1 lakh). He assured them that they would not only recover the cost in a few years but also reduce their utility expenses.
And they did so by 2012.
The collective efforts went on to inspire several buildings to implement at least one of the sustainable measures. The Sealine also impressed former Chief Minister Devendra Fadnavis who awarded the building as ‘Clean Crusader for Innovation’ in 2016.
Here’s What Your Society Can Learn:
1. Rainwater Harvesting
Navin carefully studied his building plot (770 sq m) and the terrace (220 sq m) and realised that catching every drop of rainwater could help save close to five lakh litres of water every monsoon.
With this in mind, water accumulated on the terrace and floor was transported to the underground filtration plant, where trenches are built and layered with sand and pebbles to capture run-off water as well. The water treatment plant in the society also promotes greywater recycling.
Taking a step further, society has also installed a reverse osmosis plant that can filter 200 litres of water within an hour. The unfiltered water, meanwhile, is used for non-potable needs such as washing utensils and cars, toilet flushing, and gardening.
These measures have reaped astonishing results. “We have stopped purchasing tank water, and can even fulfil the water needs of our neighbouring buildings. However, the best part has been the recharging of groundwater tables,” says Navin.
Every monsoon, they save a minimum of two lakh litres of water.
2. Solar Panels and Windmill
Sealine is partially (50 per cent) independent when it comes to its electricity needs, thanks to the solar panels and a windmill.
The idea behind installing both facilities was to optimise the monsoons and summers judiciously. “Since we are facing the sea, we get ample wind energy in the monsoons, which compensates for the lack of solar energy. We are never short of energy.”
About 200 lights and fans in common spaces and corridors run on the 4-watt power procured in one hour by harnessing sunlight. The solar energy also helps run the water heating system that supplies hot water to around 40 bathrooms in the building.
Through solar panels and windmill, the society managed to cut down 50 per cent of their monthly electricity bills.
3. Waste Management
Long before the call to manage waste penetrated Indian households under the Swachh Bharat Abhiyan, Sealine was already segregating and composting.
Dry garbage is handed over to the Brihanmumbai Municipal Corporation (BMC) for recycling, while wet/organic waste is composted and used in gardening. It is deposited in the 3×3 feet vermicomposting pit, where worms decompose more than 100 kilos of waste into 10 kilos of manure every month.
Why Your Building Needs a Sustainable Route
Navin opines that people need to realise the seriousness of climate change and its effects.
“The only way out is to opt for a sustainable lifestyle and utilise nature innovatively. Otherwise, you will be writing your death warrant.”
Echoing his words, water conservation expert Laxman Singh believes that urban dwellers will witness worse water crises than people residing in villages.
“Unlike villages, cities have minimal spaces to store water, and their populations are massive. Building lakes or ponds is not feasible in metros like Mumbai, Chennai, or Delhi. Thus, adopting smart rainwater harvesting systems as per the building space and needs, like in the case of Sealine, is a solution. Every building can store water from its terrace or floor during the monsoon every year,” Laxman says. He has revived multiple ponds with his ‘Chauka’ system, making his village in Rajasthan water-sufficient.
Read his story here.
Presently, Mumbai has two gripping problems — waterlogging and flooding during monsoons, and high electricity bills. But Sealine is one housing society free from both.
(Edited by Shruti Singhal)