CHENNAI: The northeast monsoon has set in and the prospect of urban flooding looms large but the ambitious Real-Time Flood Forecasting and Spatial Decision Support System (RTFF & SDSS) for the Chennai basin, which was supposed to be operational by now, has yet to take off in full throttle. The main cause is the delay in setting up a network of critical field equipment that will collect the rainfall, weather and water level data and telemetrically transfer them to the control room in the Tamil Nadu capital.
Although the system has technically been operational from September, 2022, it is still using data from the ‘limited’ field equipment already in place. Proposed for Rs 71 crore with World Bank funding, the project was to be a first-of-its-kind initiative in India. However, government sources said issues have cropped up with the company, which won the tender. They said not a single piece of field equipment has been installed hurting the disaster response capability of the authorities. A Salem-based company and a Hyderabad firm came together and won the contract earlier this year with the lowest bid of `76 crore. Nine months later, the work has not started. “There were some concerns related to the bank guarantee sought. The issue is yet to be resolved,” a source said.
Under the project, there is a key component called the Real-time Data Acquisition System (RTDAS), which comprises of a network of 86 Automatic Rain Gauges (ARG) to collect rainfall data; 14 Automatic Weather Stations (AWS) to measure weather parameters; 141 Automatic Water Level Recorders to measure the water level in the lakes, tanks and rivers; and 80 Gate Sensors to measure the gate openings in the lakes, tanks and rivers. Currently, there are 106 rain gauge stations, of which 49 are automatic stations providing an update every hour, while the others provide one average rainfall reading in a day.
Installation of 1,400 rain gauges to start in Dec
“Once the RTDAS is ready with its full network of field equipment, the reliability of the real-time flood early warning system will improve. Even now, the weather models can/be run and forecast generated, but the system can be fully optimised only when all the components of the project are executed,” an official said.
The Chennai basin is spread over 5,000 sq.km. As part of the project, flood modelling control rooms were also proposed. They were planned at strategic locations to receive the data sent by the field equipment, process the data with hydrological modelling and issue flood alerts over a Web-DSS. This apart, one flood monitoring centre was to be set up at each of the district collectorates in Kancheepuram, Tiruvallur, Chengalpattu and Ranipet.
“The work on the control rooms has also not been completed,” sources confirmed. A senior official of Tamil Nadu State Disaster Management Authority acknowledged that there were certain problems, but efforts were being made to resolve them. “Meanwhile, the state government had sanctioned `25 crore for installing 1,400 automatic rain gauges and 100 automatic weather stations in TN. The equipment is being manufactured and the installation will start from December,” the official said.
Heavy rainfall till Nov 8
Several districts will experience heavy rainfall till November 8, said a bulletin from the regional meteorological centre. Heavy rainfall warning was issued for Nilgiris, Coimbatore, Tiruppur, Erode, Krishnagiri, Tirupattur, Dharmapuri, Salem, Namakkal, Karur, Theni and Dindigul for Monday. Madurai, Virudhunagar, Sivaganga, Ramanathapuram, Thoothukudi and Pudukkottai will also get rainfall. In Chennai, moderate rainfall with thunderstorms and lightning is likely in some areas.