The tunnels under Chetpet Lake will link KMC metro station with Chetpet as the two stations are part of corridor-3 from Madhavaram to Siruseri. The 118.9km phase-2 has a deadline of 2026. CMRL awarded the contract for constructing tunnels from Kellys to Taramani, which includes stretches under Chetpet Lake and Adyar River, to Larsen & Toubro. Soil test at Adyar River will be completed in a month and after that the contractor will begin soil investigation at Chetpet Lake. From KMC metro station, tunnels may have a depth of 30m below the existing phase-1 tunnels at Poonamallee High Road before the tunnels take a turn towards Chetpet Lake. Tunnelling is not expected to be as tough in Chetpet area as the soil is mostly sandstone compared to locations like Thirumaylai and Thiruvanmiyur, where there are charnockite rocks.
