With just a month left before monsoon arrives in the city, the BMC is struggling to complete the de-silting work, especially in the underground drains in the island city. Despite their plans of using technology this year, the robots are unable to remove the silt and the work is stuck.

Last year, the BMC had purchased one such robot at a cost of around Rs 6cr, which could remove the silt from stretches of the underground nullahs that hadn't been cleaned in decades. After conducting a survey of the underground nullahs in the island city, with the help of cameras, civic officials believed that certain stretches contained toxic gases and would be risky to send manual labourers in them. The network of these underground nullahs runs to more than 500 km.