A modular RWH pit on the side of the desilted water channel to the injection well. | Photo credit: Nagara Gopal
This summer, when the temperature in Hyderabad hovers around 40 to 45 degrees Celsius and many wells run dry, the gated community of Rolling Hills in Gachibowli, which has nearly 100 villas, did not seek the help of water tankers. The sprawling campus has 16 injection wells and 28 rainwater harvesting (RWH) wells that have helped recharge the groundwater system. People have stopped relying on water tankers in the past few years. But that is not always the case. In 2009, when one of the first residents, architect Kalpana Ramesh, moved in, she and a few other residents collected money periodically to buy a water tanker.
An advocate of water harvesting and recycling, he began making changes to his home to tap rainwater and recycle gray water. He advocated setting up water harvesting and recycling systems on roads, gardens and common areas in gated communities. “We tapped almost 1.5 crore liters of rainwater last year. In addition to avoiding paying for tanker water in the summer, there is satisfaction because it does not contribute to urban flooding during the rainy season, because the water is channeled for domestic purposes and filling bore wells,” he said. , showing several pits and injection holes.
Every year, the government’s public service orders at RWH are met with indifference. One reason is the perception that RWH bikes waste space. Kalpana, who works with the SAHE Foundation (Society for Advancement of Human Endeavors) and mooted The Rainwater Project to facilitate water solutions for individuals, institutions and communities says that there is no shortage of functional and aesthetic contemporary solutions.
Compact modular system
Architect Kalpana Ramesh. | Photo credit: Nagara Gopal
In several places in Rolling Hills there are modular rainwater catchment holes equipped with filters for desilting, drains leading to nearby injection well facilities. The point to set the injection hole was identified with the help of geologists. This modular system functions as a water bank under the green cover or even in the middle of the road, without disturbing the movement of people and vehicles. Modular pits and ditches throughout the community help channel rainwater and fill borewells.
Harvesting rainwater in the garden
Extensive measures for rainwater management are being implemented in major parks in Hyderabad as part of the Amrut 2.0 urban pilot project, by GHMC (Greater Hyderabad Municipal Corporation) in collaboration with The Rainwater Project. For example, in Indira Park, the annual target is to recharge 25-30 lakh liters of water with RWH intervention. The project includes the creation of injection wells and filling wells around them, with silt traps, desilting wells and lining wells to stop soil erosion, thus optimizing rainwater recharge and preventing excess rainwater from entering the drainage network.
Similar interventions have been implemented in Sainikpuri Park, KLN Yadav Park in Sanath Nagar, Haritha Vanam circular park in Kakatiya Nagar in Habsiguda, and GHMC Techno Park in Madhapur.
A lot can be done at the individual level, explains Kalpana. “Many are of the opinion that if they can buy bottled drinking water and tankers for domestic use, or if their homes get enough municipal water, there is no need to collect rainwater or process gray water. The water crisis in Cape Town, South Africa, a few years ago and the situation in Bengaluru this summer is an example that drives home the need for better water management.
The roofs of houses, apartment complexes and institutions, Kalpana explained, are ideal for collecting and channeling rainwater. “The source of water drainage from the roof can be connected to a storage sump. A centrifugal filter will help filter rainwater. If possible, new construction can install separate storage sumps for rainwater. Older construction can channel rainwater to existing sumps. Plumbers can help several solutions.Excess rainwater, he added, could be used to fill existing boreholes or set up new injection wells.
Shallow aquifers
At modular RWH pits in Rolling Hills, Gachibowli. | Photo credit: Nagara Gopal
Kalpana points to a common neglected area – tapping shallow aquifers. “The area between the upper soil layer and the first layer of rock is a shallow aquifer area that collects a lot of water during the monsoon season. The casing pipe of traditional borewells does not have slots to tap water from this shallow area. The bore only releases water from the middle and deep underground areas. In contrast, shallow aquifers run horizontally for kilometers. When water seeps into this zone and is sent further down, it can help replenish bores. Contemporary borewell systems now have slots to tap this water.
Some of the recycled water is used for gardening in the community. | Photo credit: Nagara Gopal
In Hyderabad, where rocky terrain is common, another myth is that it is difficult to tap rainwater. “Geologists and architects can find solutions to produce water in rocky areas.” Kalpana cited the example of Rashtrapathi Nilayam in Bolarum, Secunderabad, where, with the help of the Infosys Foundation, an existing well was recharged and a mechanism put in place to improve water percolation. “The property located in 75 hectares has sheet rock and the soil is not percolative. Rigs are used to open the mud to increase percolation. In such cases, scientific tests can be carried out to find the point of filling the ground water.
Whether one wants to generate individual capacity rainwater for offices and apartment complexes, or stepwells (the Rainwater Project has helped recharge the Bansilalpet Stepwell and several others in Hyderabad and Telangana), Kalpana says there is a lot of scope. “If the filtered rainwater is directed to the sump and used for domestic purposes, the taps and pipes are free of salt deposits.”
Kalpana says that changes only happen when we treat water as a public asset. “Hyderabad used to have 6000 baolis (wells). Many are now encroached upon. When we got a call asking for a solution to prevent basement flooding in an apartment complex, an old map showed that the area had baoli. If you destroy Nature, Nature will disturb you are all alive.”
