Your roof's your new water purifier now
HYDERABAD: Back in the early 1900s, when Hyderabad’s very own Musi river overflowed due to heavy downpour, the Nizams had instructed an engineer to build a few artificial lakes in the city. With 534 lakes, Hyderabad was earned the moniker ‘City of Lakes.’ Cut to 100 years ahead to now, barely half the lakes are alive. Almost 70 per cent of Hyderabad’s bore wells have either low yield or have dried up. This scenario exists despite the rainfall we had this year, which was not just satisfactory but also sufficient for, at the very least, a couple of years.
A couple who were frowning about the water crisis in the city didn’t want to be one of those who just sulk and crib. They wore their thinking caps to research about rainwater harvesting. Architect Asghar Ali Khan and his colleagues researched about rainwater harvesting for his projects.
But dissatisfaction with the existing methods compelled him to go further explore the available systems and methodologies. That is when he came across the rainy filter in Bengaluru and was floored by its technology and design. He decided to launch it in Hyderabad as dealers. Thus Raincheck System happened.
Then his wife, Dr Sara Ali, an associate professor at Shadan Engineering College, joined hands to take this initiative forward.
While Sara handles the marketing and office chores of their company Raincheck systems, her husband takes care of the sites. They have several technical teams who report to both of them. The company is registered with JustDial and also indulges in conventional marketing techniques.”Although I work as an associate professor and have a three-year-old daughter , this was something that I really wanted to be a part of as water conservation is the need of the hour,” she smiles.
“Undertaking a rainwater harvesting system on an individual or at a community level is the most practical solution to this problem. Rainwater harvesting also reduces dependence on tankers and even municipal water supply to a great extent. It’s like, you have got nature to work for you, and nature is an efficient employee,” Sara adds.
According to an astounding fact on the GHMC website, if one were to theoretically hold a vessel large enough to cover the entire city, the amount of water collected in one season would be sufficient to cater to the current population for two years. This simply means that there is more than enough precipitation happening over Hyderabad and yet, there is a critical shortage of consumable water faced every year during the summers.
Sara explains about the two types of rainwater harvesting. “There is a park in Jayanagar, Bengaluru called Rainwater Park. It has more than 25 methods for rainwater harvesting, ranging from the crude and basic to the sophisticated ones. But broadly, rainwater harvesting is of two types - ground water harvesting and roof water harvesting.”
Ground water harvesting is advisable for projects where the open area of the site is much more than the built structure, in a school or college campus, a farm, a gated community etc. Under this system, there are various methods like the percolation pit, the injection well or the stepped well (kund)
Roof water harvesting is useful for sites which are mostly covered by the building block such as independent houses, apartments or commercial buildings. In this case, most of the rain that falls onto the site is collected on the roof itself, enabling us to arrest and control the flow of water using storm drain pipes and filters. This is by far the most efficient method for individual projects as well as community projects like apartments.
“Water that falls onto the roof of the building flows down naturally through the existing storm drain pipes. At the base of the pipe, a rainwater harvesting filter is connected, used to remove the impurities in the rainwater. The filter purifies the water thoroughly, and this water can be sent straight to the existing municipal sump and also to the bore well on site,” she adds.
“On an average, Hyderabad gets about 750 mm of rainfall a year. This quantum, captured on a roof area of even as small as 1,000 square feet can yield up to 70,000 litres of rainfall in a year; a quantity that is sufficient for a family of four for more than three months,” the professor imparts some inputs.