Source: ET Bureau
Sewage water from over 200 nalas (drainage channels) join the course of the Mithi river — around 11 kilometres from Vihar lake to Mahim — in Mumbai, before it reaches the Arabian Sea.
These nalas, traditionally stormwater drains where the heavy monsoon rains would overflow, have now ended up carrying sewage of the city’s growing population.
As India’s business capital grew, it lost count of the nalas, till a local startup was contracted to survey them using underwater drones. Fluid Robotics, founded by the husband-wife duo Asim Bhalerao and Nidhi Jain, builds underwater drones or robots that can be sent into pipes and drains. The drones, which are easy to assemble, carry sensors that can measure water flow; scan the structure of the pipes for defects and also do geographic information system (GIS) mapping.
These have been among the first GIS maps that the Municipal Corporation of Greater Mumbai generated for the network of drains that link the Mithi river. “Using these drones, we could complete the entire mapping and processing in two weeks,” says Rupesh Gundewar, Principal Consultant with Frischmann Prabhu India Ltd, an engineering consultancy that was tasked by the corporation to map the drains. “Using conventional methods, it would have taken several months”.
Bhalerao, a robotics engineer who returned from the United States, set up Fluid Robotics in 2016 after he found that a broken water pipe to the housing complex of the Tata Institute of Fundamental Research (TIFR) had not been fixed for a few months.
“At TIFR, they have a particle accelerator – the most advanced scientific instrument – and just outside, to find the leaking pipe, they were using sounding rods,” says Bhalerao. Using sounding rods to find leaks in pipes is a centuryold concept that has been replaced globally by sensors that can track water flow. Bhalerao also found that most cities in India did not have maps of water pipelines and nearly 50% of the municipal water was lost in distribution.
Nidhi Jain, who is a software engineer, has built the machine learning algorithm and the visualisation software that enables Fluid Robotics to offer a data driven solution to municipal corporations for decision making.
The underwater drones could be physically sent inside a drain or sewage pipe, to map.
Additional sensors could also be installed in the drones to study the chemical composition of the sewage, which would help health professionals during a crisis.
Based on the success of the Mithi river and an earlier experiment with Powai lake, the Municipal Corporation of Greater Mumbai is adopting drone technology to map the waterflow of all lakes in the city, says Gundewar of Frischmann Prabhu India.
“They have floated a tender calling for drone mapping for all lakes. This is intended to retain those lakes and make it healthier,” he says.