The Mumbai Metro Line 3 is close to finish tunnelling under the main water channel of the Mithi river making it the second Metro corridor in India to achieve this feat after Kolkata Metro. The stretch under the riverbed is about 1.18-km-long. Tunnelling on the 1.48-km stretch is likely to be over by March-end

The portion under the river is between Bandra Kurla Complex (BKC) and Dharavi stations and is part of the 1.48-km-long tunnels being built between the two stations. There are three tunnels, one for up line, one for down line and the third for train siding or to reverse trains.