City

Flood-prone areas in Chennai: how to check your risk

GCC has marked 219 waterlogging-prone spots this year. Here is how to judge your own street's risk and prepare before the next heavy spell.

20 October 2026

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The Greater Chennai Corporation has identified 219 waterlogging-prone locations across the city this year, and Perungudi zone tops the list with more than 40, News Today reported on 16 October. Sholinganallur, Anna Nagar and Tondiarpet zones each have more than 20 such spots.

That list is the starting point for any household that wants to know its risk. But flooding in Chennai comes from three different sources, and a street can be safe from one and exposed to another. This guide explains how to tell which applies to you and what to do before the next heavy spell.

Three ways Chennai floods

Local waterlogging. Intense rain falls faster than drains can carry it. This is the most common kind of flooding in the city, and it is what several neighbourhoods saw in the first heavy spells after the monsoon set in on 15 October, when water stood on stretches the Corporation already treats as problem spots. It usually drains within hours to a day, but it cuts off roads, damages vehicles and gets into ground-floor homes in low streets.
River and reservoir releases. When Chembarambakkam and Poondi fill, surplus water goes down the Adyar and Kosasthalaiyar. In October 2025, the Water Resources Department raised releases and put riverside localities on alert, including Sirukalathur, Kundrathur, Thirumudivakkam and Thiruneermalai on the Adyar, and Nambakkam, Athur, Manali New Town and Sadayankuppam on the Kosasthalaiyar, The News Minute reported.
Coastal and tidal backing. During cyclones and high tides, rivers and canals drain slowly into the sea, so water lingers in low areas near the Buckingham Canal and river mouths.

Many localities face more than one of these. A street in the south of the city can see local waterlogging in a short burst of heavy rain and river flooding a week later if the reservoirs upstream start releasing. Think about all three when you judge your risk.

How to check your own area

Look up your zone. The Corporation’s 15 zones run from Thiruvottiyur (Zone 1) to Sholinganallur (Zone 15). Your property tax receipt shows your zone and ward.
Find your nearest relief centre. The GCC relief centre list names 215 centres, mostly schools, with ward, capacity and the officials in charge. Capacities range from 30 people to 3,000 at sites such as the Choolaimedu primary school and the government higher secondary school on OMR at Sholinganallur.
Read the city disaster plan. The GCC website links a City Disaster Management Perspective Plan and monsoon notices in Tamil.
Install TN-Alert. The TN-Alert app, part of the state’s TNSMART system, sends location-based flood risk alerts and weather warnings. Its emergency alerts are designed to sound even in silent mode.
Ask long-time neighbours. The level water reached in December 2015 or December 2023 is still the most reliable local guide. Mark it on a wall or gate.

Lessons from past floods

The floods of late 2015 and the rain brought by Cyclone Michaung in December 2023 remain the city’s reference points. In both, the worst damage came where homes stood on low land, old lake beds or close to rivers and canals, and where drains could not carry water away fast enough. Power was switched off across large areas, and some neighbourhoods were cut off for days. If your street went under in either year, treat it as high risk, however dry recent monsoons have been.

The practical lessons residents still repeat:

Water rises fast at night. Do not wait until morning to move a vehicle or an elderly relative.
Ground floors and basement parking in low streets are the first to go. Keep documents and medicines above table height.
Power is switched off in flooded areas for safety. Phones and torches need to be charged before the rain, not during it.
Riverside areas downstream of reservoirs get the least warning. Follow official release notices closely.

Prepare before the next spell

The Corporation says it is preparing for extreme rainfall of 20 to 30 cm in a day. That figure is useful for households too. If your street floods at 10 cm, plan for something two or three times worse.

Clear the drain in front of your gate and report blocked storm water drains on 1913 or through the Namma Chennai app.
Keep a bag ready with ID copies, prescriptions, cash, a power bank and a torch.
Move cars to higher ground when IMD issues an orange or red alert for Chennai district.
Know two routes to your relief centre in case one road is under water.
If you rent, ask the owner or the residents’ association where water reached in past floods before you move furniture or appliances to the ground floor.
Keep elderly relatives’ medicines and a list of their doctors’ numbers in the same dry bag as your documents.

After a heavy night, the Corporation’s teams clear stagnation street by street. On 16 October, the Commissioner inspected spots such as B V Colony in Vyasarpadi and Besant Road, which DT Next described as a recurring problem stretch.

Quick answers

Which zones have the most flood-prone spots?

Perungudi has more than 40 of the 219 locations identified this year, followed by Sholinganallur, Anna Nagar and Tondiarpet with over 20 each, according to a 16 October report.

Where can I find my nearest relief centre?

The Corporation publishes a zone-wise list of 215 relief centres with addresses and capacities on its website.

How will I know if a reservoir is releasing water?

The Water Resources Department and district administrations announce releases and list affected localities. TN-Alert also sends location-based alerts.

Who do I call if my street is flooded?

Call the Corporation on 1913. For life-threatening emergencies, call 1070 (state) or 1077 (district).

Information checked against official sources on 18 October 2026. Fees, dates and rules can change; confirm on the linked official pages before acting.