The Greater Chennai Corporation says about 1,314 km of the 1,385 km of storm water drains taken up since 2022 has been completed, roughly 95% of the programme, at a total cost of ₹6,066.80 crore, DT Next reported on 24 September. The gaps that remain, though short, are often exactly where water collects.
If your street floods, the fastest route to a fix is a specific complaint on 1913 or the Namma Chennai app. This guide explains what has been built, what is still pending and how to report a blocked drain so it gets cleared.
What has been built, basin by basin
| Project | Completed | Funding |
|---|---|---|
| Kosasthalaiyar basin (north and north-west) | 651.10 of 652.40 km | Asian Development Bank, ₹3,059 crore |
| Kovalam basin (south, OMR and ECR side) | 272.80 of 310 km | KfW (German development bank) |
| Corporation capital fund works | 120.10 of 131.70 km | ₹470.50 crore |
| Arcot Road | 7.20 of 18 km | ₹103 crore |
Figures are from the Corporation as reported in September. Arcot Road is the main bottleneck, with police allowing work only between midnight and 4 am because of traffic. The Kovalam basin, which serves fast-growing southern areas such as Perungudi and Sholinganallur, still has about 37 km to go.
The Corporation has also been working on 105 “missing links”, short stretches where new drains did not connect to the network. By late September, 37 had been joined and 68 were in progress, Deccan Chronicle reported.
Desilting and pumps before the monsoon
Building drains is half the job. They also have to be clean. In early October, Commissioner G.S. Sameeran said about 1,400 km of the network had been desilted, with the rest due within a week, and that a second round of cleaning was under way at about 1.1 lakh silt catch pits, DT Next reported.
Canals that receive drain water are being cleaned too. The Corporation reported improvement work on 8,439 metres of the Captain Cotton, Secretariat Colony, Otteri nullah and Virugambakkam canals, with 6,977 metres done by late September, and desilting and water hyacinth removal on 44 Corporation waterways, 13 Water Resources Department canals, the Cooum, the Adyar and the Buckingham Canal. Drains running under 28 railway minor bridges are also being cleared.
For spots where drains alone cannot cope, the Corporation has readied more than 1,000 pumps, 500 of them tractor-mounted, News Today reported on 16 October. Pumps are also installed in 19 Corporation subways and five highways department subways. Drains have been built at 93 of the 219 waterlogging-prone locations identified this year, with work at 19 more and sumps installed at 21.
The command centre at Ripon Building is also being upgraded. Plans include 40 floodometers to measure waterlogging, more rain gauges and remote monitoring of Corporation pumps, Urban Acres reported.
How to report waterlogging or a blocked drain
- Call 1913, the Corporation’s 24×7 complaint line. The Commissioner has said complaints will be addressed within 72 hours, though stagnation during heavy rain is usually prioritised.
- WhatsApp a photo and location to 94450 61913 or 94455 51913, the chatbot numbers on the GCC website.
- Use the Namma Chennai app to file with a photo, pin and category. You get a complaint number to track.
- File online on the Corporation’s public grievance portal.
- Escalate to your ward councillor or the zonal office if the same spot floods after every rain.
Be precise. “Water stagnation, 3rd Cross Street, near the temple, ward 180, Zone 13, about knee deep” gets a crew faster than “road flooded”.
Know whose drain it is
- Storm water drains and canals inside city limits: Greater Chennai Corporation.
- Sewage overflow from manholes: Chennai Metro Water on 1916 or 044-4567 4567, per its complaints page. Storm drains are not meant to carry sewage, and mixing the two is a common complaint.
- Rivers, large canals and river mouths: Water Resources Department, which is desilting four river mouths this season.
- National highway stretches: the highway authority, though the Corporation forwards complaints.
What residents can do
- Do not cover catch pits in front of your gate with concrete ramps.
- Keep garbage and plastic out of drains. Most blockages are waste, not silt.
- Report open or broken drain covers immediately. They are a serious hazard when roads are under water.
Quick answers
How much of Chennai’s new storm water drain network is complete?
About 1,314 km of 1,385 km taken up since 2022, according to the Corporation in September 2026.
How do I report a blocked drain?
Call 1913, WhatsApp 94450 61913, or use the Namma Chennai app with a photo.
Who handles sewage overflowing into a storm drain?
Chennai Metro Water, on 1916 or 044-4567 4567.
Why does my street still flood?
Often because of a missing link, a blocked catch pit or work still pending in your basin. Report the exact spot.
Information checked against official sources on 18 October 2026. Fees, dates and rules can change; confirm on the linked official pages before acting.
Sources
- Greater Chennai Corporation website (complaints, WhatsApp, app)
- Online Public Grievance portal (Greater Chennai Corporation)
- CMWSSB complaint redressal (Chennai Metro Water)
- Only 5% of SWD works remain, says GCC (DT Next)
- Chennai Corporation’s multi-pronged approach to monsoon preparedness (Deccan Chronicle)
- GCC prepared to handle northeast monsoon (DT Next)
- GCC readies over 1,000 pumps (News Today)
- Chennai ICCC upgrade adds 40 floodometers (Urban Acres)
