Recycling Rainwater Has Helped This Bengaluru Family Meet All Its Water Needs For 28 Years

For 28 years, A R Shivakumar and his family have lived in a house they built in Vijayanagara in Bengaluru. And in all these years, they have met all their water needs completely with rainwater. When Shivakumar studied rainfall data from the India Meteorological Department (IMD) he realised Bengaluru received enough rain to make this very feasible.

Mr. Shivakumar said, "Bengaluru receives nearly 900 mm plus, nearly 40 inches of rainfall every year. For a 60x40 plot, it translates into 2,23,000 litres of water in a year. Then I calculated how much water we require for the whole year. It was 1,50,000, I thought if we harvest this water we will have water for the whole year. And the longest gap between two good showers of rain that we can harvest is only 100 days. So if we have water stored for 100 days, then throughout the year we can manage.”

He further explained, "How much is the 100 Days requirement? We are water conservative people and I thought we should use not more than 400 litres - 100 litres per capita per day for 4 people. 40,000 storage can tide over your requirement. We built 45,000 litres of storage - safety for drought years and guests. From that day till now - this is the 28th year running and we don't have a city municipal water supply at all. We don't receive tankers or any other water source. We have crystal clear rainwater for drinking and all other purposes in our house. I have not paid a bill in my life for water."

The roof area is around 1800 sq feet. Mr. Shivakumar has calculated the amount of rainwater received and needed for usage by the family.

“It all begins on the roof of the house, which has been painted white to keep things cooler. The roof is the main component in our house where the clean water falls,” he said. 

“There is a gentle slope. And there is a pipe that carries that water into a filter. The filter is required because we have dust, bird droppings and all that.”

Every drop of water which falls on the roof, which on an average year is around 1.5 to 1.8 lakh litres, is collected. The Shivakumar family harvests between 2 lakhs to 2 lakh 20 thousand litres of water. The family uses around 1.5 lakh litres and the excess the family recharges into the ground for social good.

Water from the kitchen and washing machine is re-used. From the kitchen sink, a pipe comes out of the house and leads into a watering can that can be used for the garden. The overflow goes into a tank top which also receives used water from the washing machine. This water is used for flushing the toilets.

It hasn't always been easy. Shivakumar's wife, Suma, said, “The difficulty came when he started recycling the water. Water kept for some days starts smelling. He wanted an eco-friendly way of treating the water. I was actually telling him - ‘use some chemicals - it is very easy.' But he was against that, saying we should never go against nature. So he started experimenting. So we had hardships for many years to tackle that smell! But we survived. Everything needs everybody's cooperation. So we are all in it.”

Mr. Shivakumar's career at the Indian Institute of Science overlapped with his passion for green living and his job also involves spreading awareness about rainwater harvesting. 

"Rainwater harvesting is a very simple process. We have our house, our roof, and a drain water pipe built into every house. What we have done - at the end of the pipe, we have fixed a filter which I have developed. A good filter is basically to separate dust, bird droppings, and leaf litter. Clean water should go into your sump. That is all,” he said. 

“My work, as well as my passion, was the same. In the IISC campus, we have Karnataka State Council for Science and Technology. I spent 38 years there. What I have done here, we have demonstrated in many theme parks and resource centres. We have shown how cost-effective, and how simple it is. We don't need complicated technology. Simple tools can make roof water available throughout the year."

All the water needs of this household are met from the rainfall that the city of Bengaluru receives annually. From cooking to washing to flushing, and for the beautiful garden that surrounds the house, the family is showing what is possible with a little bit of thought and planning.

There are five people living in the house now, including Shivakumar's grandson who is just a few months old. No doubt the little one will grow up with the family values of respecting the precious resource of water and take the sustainable way of life of the Shivkumar family forward.