Robot finds sewage line in flood drain

MUMBAI: A broken pipeline, an illegal sewage connection, crossing cables, and large stones and thick silt are some of the “unfortunate discoveries” that the BMC made while cleaning just 300 metres of its 70km-long complicated British era storm water drain (SWD) system in the island city with a remote control robot for the first time.




Some sections of the drain exit in flood-prone Hindmata and Fitwala Lane, among others.

Until now, the BMC would hire a worker to clean one metre of the drain on either side of every manhole along the 70km stretch, leaving the rest as it was for decades. Civic officials said labourers were unable to enter the narrow stretch. (See box).

They have begun to prepare a report on the discoveries made for action required as well as for future reference. Officials said right now they are focusing on removing the silt to increase the drain’s monsoon water capacity but work is progressing slowly due to the hurdles.

The BMC took up cleaning work at Shahid Bhagat Singh Road in Colaba and Fitwala Lane in Prabhadevi where Dr Deepak Amarapurkar fell into a manhole and died while wading through a flooded stretch during monsoon in 2017.

The island city—from Colaba to Mahim-Sion—has a 522km-long storm water drain system, most of which is underground and needs to be cleaned annually to avoid flooding during monsoon.

As the BMC’s machines cannot reach the complicated, narrow 70km stretch, it recently got a robot for the job. The robot, fitted with a camera, uses a suction system in the drain after negotiating minor hurdles. An operator examines visuals on his computer screen and accordingly directs the robot to apply water pressure to clean the silt.

The island city’s entire underground drain system—between five feet and 15 feet under the roads—has manholes at a distance of 30 metres each on the stretch. Civic officials said they clean the drain with the robot at night. Additional municipal commissioner Vijay Singhal said, “We are cleaning the entire drain network for the first time with robotic machine and most of the drain network is from the British era.”