07 October,2026 09:21 AM IST | Mumbai | Rumani Gabhare
The team works on a prototype of the sensor, FloodGuard
It's safe to say that when Mumbai's rain gods arrive, they bring more than just puddles. Drains overflow, roads turn into streams, and a commute can turn into a nightmare. Rian Kothari, Aditya Gupta, Aarush Gupta, and Revant Singhania, four 17-year-old students from The Cathedral and John Connon Senior School, Fort, have devised a possible solution, Project FloodGuard, which is a sensor system placed inside stormwater drains to monitor water flow and use mathematical modelling to predict overflows.
A prototype of the device
The prototype is set to be submitted to the Brihanmumbai Municipal Corporation (BMC) on October 9. Following the submission, the team plans to test and fine-tune the system before deploying it in selected stormwater drains across the city, where it can be monitored in real-world conditions.
"Our goal was to design a cheap and efficient tool that would help detect and reduce flooding and protect life in the city while making monsoons more comfortable," says the team. The quartet has been working on the project since July. They first tested it in a tub of water, observing different water-flow levels, simulated debris, and reverse-flow conditions.
The team behind the device (from left) Aarush Gupta, Aditya Gupta, Rian Kothari, and Revant Singhania. Pics courtesy/Rian Kothari
The team also compared Mumbai's drainage infrastructure with systems in Singapore and Tokyo. Alongside the preparations, Aditya handled the Mathematics, modelling, engineering, and coding; Revant worked on stakeholder and public relations; Aarush focused on green chemistry, materials, and sustainability; and Rian anchored business operations and environmental considerations.
The research examined how water speed affects the turbine. In controlled tests, the turbine rotated slowly when water moved gently but spun faster as the flow increased. Tests with debris also showed that blockages could slow the turbine, giving another indication of an obstruction. These findings helped establish preliminary thresholds, although recalibration will be needed once tested inside actual drains.
A closer view of the main circuit board with ESP32 microcontroller and sensors
"We've not tried it inside drains specifically. After the pilot deployment, we'll try to get some real-life data and then make changes to the prototype to implement it in drains. Beyond prediction, the machine is also a safety tool as early warnings could allow BMC teams to intervene before drains become dangerously clogged, and identify areas at greater risk. Through this device, we hope to help pre-empt plans to prevent the floods from actually forming in the first place or reaching the levels they would," the team explains.
At the heart of FloodGuard is a turbine placed inside a stormwater drain. As water flows through the drain, the turbine spins, and an optical sensor records its rotational speed, or RPM. The system converts this into a measure of water flow.
An ESP32 microcontroller (a low-cost system-on-chip with built-in connectivity) processes the readings and compares them with pre-set thresholds. The prototype also monitors inlet and outlet pressure to identify possible blockages. These readings feed into an online dashboard showing flow rate, pressure, blockage, and flood probability. The mathematical model combines these factors to estimate flood risk and trigger an early warning for authorities.
