Phase II network spans 118.9 km across 4 corridors. Corridor 3 covers 45.8 km, running from Madhavaram through Royapettah and Thousand Lights to SIPCOT. Tunnelling from Royapettah to Thousand Lights began early 2025 and will finish by end of October 2026. This stretch was among the toughest for the tunnel boring machine (TBM). Hard rock encountered at 22 metres depth at Royapettah and 16 metres at Thousand Lights over approximately 900 metres. TBM cutterhead parts changed 78 times due to wear from rock boring. Station shaft at Thousand Lights not yet ready, preventing TBM breakthrough. Diaphragm wall construction involved controlled blasting due to hard rock presence.

The India Meteorological Department forecast normal Northeast monsoon rainfall, with a strong El Niño likely to intensify it later in 2026. Greater Chennai Corporation (GCC) flood-vulnerable locations fell from nearly 800 in 2015 to 389 in 2023 and 219 for the 2026 monsoon; officials review the list using field assessments, rainfall patterns and completed mitigation works. Micro-level stormwater-drain works are 95% complete, but capacity constraints remain along the Buckingham Canal, Adyar and Sholinganallur. GCC is coordinating with the Railways and Chennai Metro Rail Limited; temporary pumping facilities are in place. Central Chennai works are 52% complete; western-region works, 56%. Five drinking-water reservoirs hold 4.5 TMC of 11.7 TMC capacity. Residents and councillors cite delayed desilting, including at Kodungaiyur Canal. Previously inundated areas include Medavakkam, Chitlapakkam, Hasthinapuram, Kadaperi, Ambedkar Road, Jothi Nagar and Sunnambu Kolathur. Officials and experts cite urbanisation, encroachments, blocked waterways and silting as flood risks, and call for wetland protection, redesigned drains, desilting and flood-plain zoning.

Nearly 48% of tunnelling for Chennai Metro Rail’s 118.9-km Phase II project is complete: 33.22 km of its 69.05 km underground network across three corridors. In the past three days, tunnel boring machines completed work on three stretches.

• Corridor 3, Madhavaram–SIPCOT, has 43.04 km of underground stretches, with 22.63 km tunnelled.
• About 62% of corridor 4, Poonamallee–Light House, is complete; corridor 5, Madhavaram–Sholinganallur, is 27% complete.
• Chetpet–Kilpauk Medical College: 685 metres, including beneath five railway tracks, Chetpet Eco Park and KMC Hospital; the machine drilled 6.1 metres below the Phase I tunnel.
• Villivakkam Railway Station–Villivakkam Bus Terminus: 601 metres, beneath five railway tracks.
• Royapettah–Radhakrishnan Salai: 915 metres, beneath structures on Royapettah High Road, including Peters Bridge, the EPFO building and a school.

The State Highways Department is discussing a pilot handover to the Greater Chennai Corporation (GCC) of footpaths and stormwater drains along a 12-km stretch of Anna Salai and parts of Grand Southern Trunk (GST) Road up to the airport, excluding the Teynampet–Saidapet flyover section. The stretch runs from Quaid-e-Millath Bridge in Park Town to the airport. GCC would maintain footpaths and clear drains, while the department would maintain main carriageways. The Chennai Unified Metropolitan Transport Authority is identifying and finalising stretches; the department will issue a no-objection certificate before work begins. If the pilot succeeds, Poonamallee High Road, Jawaharlal Nehru Salai and other city highways may also be handed over. GCC Commissioner GS Sameeran said the corporation already manages solid waste and footpath enforcement. A Royapettah resident cited encroachments at GP Road and Anna Salai, blocked sections, missing paving and unstable paving blocks.

Thousand Lights Metro station opened on February 10, 2019, beneath Anna Salai. It has improved access around Mount Road and Anna Salai, helping commuters avoid peak-hour traffic and reach the hospital on Greams Road and nearby shopping. Residential areas around Royapettah, Gopalapuram and lanes branching off Greams Road have seen property prices rise steadily over the last few years.