Water crisis: Researchers unveil innovative rooftop rainwater harvesting solution

In a bid to address the ongoing water crisis in Bengaluru, researchers from the GKVK Agricultural University have unveiled a groundbreaking solution through rooftop rainwater harvesting technology. The city has been grappling with a lack of rainfall, which has taken a severe toll on its water supply, including the crucial Cauvery River.

Despite recent irregular weather patterns in the region, historical data shows that Bengaluru’s average annual rainfall remains at 950 mm. For a standard 40×60 feet household, this provides sufficient rainwater to support a family of four. During the Desi Conference exhibition, GKVK University scientists showcased how rooftop rainwater harvesting could collect and save significant water volumes for the entire year.

Rooftop rainwater harvesting involves the installation of PVC pipes along the edges of a house’s terrace. These pipes are then equipped with water treatment filters, one on each side. The left-side filter is connected to a sump for water storage, with an overflow mechanism to redirect excess water into a recharge pit. Meanwhile, the right-side filter connects to a borewell for replenishing groundwater. The entire system can be implemented for as little as Rs. 4,000, preventing the wastage of rainwater into drains.

For efficient water collection, it’s essential to construct the recharge pit, known as “Ingugundi,”. Boreholes of approximately 10 to 12 feet depth in Bengaluru’s subsoil can provide a suitable recharge zone. A bedrock layer should be established 1.2 meters below the surface, followed by layers of gravel and sand. Researchers at GKVK Agricultural University assert that this setup allows for the automatic accumulation of rainwater in the pit.

Additionally, residential borewells can be repurposed for water collection. These borewells should have a 1.2-meter bedstone at the base, covered by layers of gravel, charcoal, and sand. A casing pipe with specific dimensions is installed in the sand, surrounded by a one-meter trench. When a filter water pipe is connected to this casing, the rainwater is effectively collected in the land where the borewell is located.

This innovative rooftop rainwater harvesting technology offers a cost-effective and sustainable solution to Bengaluru’s water scarcity, conserving a valuable resource while helping address the city’s pressing water challenges, said a scientist who has researched this technology.