This summer, as temperatures soared to between 40 and 45 degrees Celsius across Hyderabad, many borewells dried up. However, the Rolling Hills gated community in Gachibowli, home to nearly 100 villas, did not need to rely on water tankers. The community’s sprawling campus is equipped with 16 injection borewells and 28 rainwater harvesting (RWH) pits, which have been crucial in recharging the groundwater system. As a result, they haven’t needed water tankers in recent years. But this wasn’t always the case. In 2009, when architect Kalpana Ramesh became one of the first residents, she and a few others regularly pooled money to buy tanker water.
As a strong advocate of water harvesting and recycling, Kalpana Ramesh began by implementing systems in her own home to capture rainwater and recycle greywater. She then encouraged the installation of similar water harvesting and recycling systems throughout the gated community, including on roads, in gardens, and in common areas. “Last year, we captured nearly 1.5 crore litres of rainwater. Besides saving on the cost of tanker water during the summer, it’s gratifying to know that we’re not contributing to urban flooding during the monsoons. Instead, the water is directed for domestic use and recharging borewells,” she explains, pointing out some of the pits and injection bores.
Government public service messages on rainwater harvesting (RWH) often face public indifference, partly due to the misconception that RWH pits are space-consuming. However, Kalpana Ramesh, who collaborates with SAHE (Society for Advancement of Human Endeavours) Foundation and initiated The Rainwater Project to provide water solutions for individuals, institutions, and communities, counters this belief. She emphasizes that there are plenty of modern solutions that are both functional and aesthetically pleasing.
She highlights the availability of compact, modular systems that make rainwater harvesting feasible even in limited spaces, demonstrating that effective water solutions can be both practical and visually appealing.
Throughout Rolling Hills, modular rainwater catchment pits equipped with desilting filters are strategically placed, each leading to an adjacent injection borewell. A geologist assists in identifying the optimal spots for setting up these injection bores. These modular systems act as water banks, discreetly positioned beneath green covers or even in the middle of roads, without disrupting the flow of people or vehicles. The network of modular pits and trenches across the community effectively channels rainwater, recharging the borewells and contributing to a sustainable water supply.
Kalpana Ramesh emphasizes that individuals can make a significant impact on water conservation. She notes that many people mistakenly believe there’s no need to harvest rainwater or recycle greywater if they can afford bottled drinking water, tanker services, or have access to sufficient municipal water. However, the water crisis in Cape Town, South Africa, a few years ago, and the severe water shortages in Bengaluru this summer, highlight the urgent need for better water management.
Kalpana explains that rooftops of houses, apartment complexes, and institutions are perfect for collecting and channeling rainwater. “The water draining from rooftops can be directed into a storage sump, where centrifugal filters can help purify the rainwater. For new constructions, it’s advisable to install separate storage sumps specifically for rainwater. Older buildings can channel rainwater into existing sumps. Plumbers can offer various solutions to make this possible,” she says. She also suggests that excess rainwater can be used to recharge existing borewells or to establish new injection borewells.
Kalpana adds that recharging the shallow aquifer is another key benefit of rainwater harvesting. By directing excess rainwater into shallow injection borewells, the community can help replenish the local groundwater levels, ensuring a more sustainable water supply. This approach not only reduces dependence on external water sources but also strengthens the resilience of the area’s water resources.
Kalpana highlights a frequently overlooked aspect of water harvesting—tapping into shallow aquifers. “The shallow aquifer is the zone between the topsoil and the first rock layer, which accumulates significant amounts of water during the monsoon. Traditional borewells often miss this opportunity because their casing pipes lack slots to access water from this shallow region; they only draw water from deeper underground. However, the shallow aquifer extends horizontally for kilometers, and by tapping into it, we can channel this water further down to help replenish borewells. Modern borewell systems are now designed with slots to access this vital water source,” she explains.
In Hyderabad, where rocky terrain is common, there’s a misconception that tapping rainwater is challenging. “Geologists and architects can indeed devise solutions for harvesting water in such rocky areas,” Kalpana asserts. She cites the example of Rashtrapathi Nilayam in Bolarum, Secunderabad, where, with the support of the Infosys Foundation, existing wells were recharged and mechanisms were implemented to improve water percolation. “The 75-acre property had sheet rocks and non-percolative soil. To address this, rigs were used to break up the mud and enhance percolation. Scientific tests can identify effective groundwater recharge points in such scenarios,” she explains.
Kalpana emphasizes that there is significant potential for rainwater harvesting, whether it’s for individual use in offices and apartment complexes or for larger-scale projects like stepwells. For example, The Rainwater Project has successfully recharged Bansilalpet Stepwell and several others in Hyderabad and Telangana. “When filtered rainwater is directed to sumps and used domestically, it prevents salt deposits in taps and pipelines,” she notes.
She also believes that real change will only come when we view water as a public asset. “Hyderabad once had 6,000 baolis (wells), many of which have been encroached upon. We often receive requests to address flooding issues in apartment basements, and older maps reveal that these areas were once home to baolis. If we interfere with Nature, Nature will retaliate throughout our lives,” Kalpana warns.
