
Workers pump out rainwater at Mount-Poonamallee Road in Porur on October 21, 2025.
| Photo Credit: B. Velankanni Raj
A real-time flood forecast and spatial decision support system (RTFF & SDSS) has become completely operational for Chennai.
Billed as a comprehensive urban flood management system and the first of its kind in the country, the Chennai RTFF & SDSS, estimated to cost about ₹107.2 crore, covers lakes, rivers, storm water drainage system and the sea. It envisages not only the provision of reliable forecasts of water level in rivers and tanks but also that of street-level inundation forecasts for vulnerable areas of the city such as Pulianthope, Nungambakkam, Mambalam, Saidapet, Velachery, Meenambakkam and Mudichur.
Even though its focus area is Chennai city, the system covers an area of approximately 4,974 sq km, encompassing Chennai, Tiruvallur, Kancheepuram, Chengalpattu and Ranipet districts. The Adyar, Cooum, Kosasthalaiyar and Kovalam river sub-basins are being observed under the system.
“For the last couple of years, we [at the State Disaster Management Authority] had calibrated forecast and arrived at norms for the forecast. Till now, we did not consider whatever data generated for decision making. Since the onset of the current Northeast monsoon, we have started sharing the forecast with departments concerned for decision making,” say senior officials. They added the new system has been fully integrated with TNSMART, a web-based decision support system for all types of disaster. The beneficiary-agencies of the State government are the Water Resources Department (WRD), the Commissionerate for Revenue Administration (CRA), the Greater Chennai Corporation (GCC) and the Commissionerate of Municipal Administration (CMA).
Selectively, findings of the RTFF & SDSS will be disseminated through TN-Alert, a mobile application, among the public, one of the officials observes. Executed with the World Bank’s financial support, the Chennai RTFF & SDSS project has seen the involvement of the Tamil Nadu Urban Infrastructure Financial Services (TNUIFSL), which handles the project fund, through the project consultants SECON-JBA, under the technical oversight of Indian Institute of Technology (IIT)-Madras. An inter-departmental team, comprising officials of the WRD and the GCC has been proposed to deal with the system, under the overall supervision of the CRA.
Published – October 22, 2025 05:45 am IST