Floods are back in news, thanks to the havoc caused by rains in Mumbai. The Maximum City’s struggles are a remainder of harrowing experiences faced by Chennaiities in 2015.
Express finds that steps promised by the government to improve situation in the city are either incomplete or in the planning stage...
CHENNAI: It lies hundreds of kilometres away, but the way Mumbai is drowning under torrential rain evokes a familiar sinking feeling here in Chennai. Mumbai, clearly, has not learned lessons from the mistakes in the past. And as things stand now, Chennai seems to be no better since the disastrous floods two Decembers ago.
Following the floods in 2015, the municipal administration had gone into an overdrive, chalking out elaborate plans to forecast and tackle a similar situation in future. While the plans may be part of a long-term vision, Chennai is likely to witness scenes similar to that of Mumbai if the monsoon is heavy this time.
One such initiative was the setting up of a Real Time Flood Forecasting and Spatial Decision Support System for Chennai, proposed by the Tamil Nadu Urban Infrastructure Financial Services Ltd (TNUIFSL).
Ironically, corporation officials, along with representatives from TNUIFSL, had visited Mumbai in 2015 to see the dedicated flood control room and its operations to evaluate its scope and objectives. They had also studied the operations of an early flood warning system installed for Bhima and Krishna basins.
However, about 20 months after the destructive floods and with only 45 days left for the onset of the next north-east monsoon, the project is still in its tender phase, admitted sources in TNUIFSL.
The project had incorporated concepts based on the National Disaster Management Guidelines on Management of Urban Flooding. It called for establishment of automatic rain gauges for real time monitoring, an urban flood early warning system and inventory of storm water drains (SWD) in Geographical Information System. Said SS Ramakrishnan, Professor and Director of Institute of Remote Sensing, Anna University, “We have completed the research part of it with the rainfall data that is available. Now, the corporation has to scale it up further by integrating sensors and making it a real time model.”
Storm water drains and waterbodies still unprepared
While these advanced projects are still in the tender phase, the authorities have failed to undertake even the basic flood preparedness measures such as storm water drain maintenance and full desilting of lakes.
As far as the Integrated Storm Water Drain project is concerned, expansion works in Kosasthalaiyar and Kovalam basins are yet to begin while about a third of the work in Adyar and Cooum basins have not been completed yet.
According to a senior corporation official, work in Adyar and Cooum basins is expected to be complete by the first week of October. This would mean that even a slight delay in the completion of the project would mean the city would have to brace itself for the worst when monsoon hits.
The total length of storm water drain projects is presently at 1894 kms, an estimated increase of 356 kilometres from 2015. However, experts argue that the length of the drains is inadequate considering the length of the road network in the city.
“Although any increase in length is welcome, the rule of thumb would be for the length of the storm water drains to be equal to the total length of the roads in the city. If we have 5,000 kms of roads, the length of the storm water drains should be equal to that number,” said Balaji Narasimhan, associate professor, Civil Engineering department, IIT- Madras.
According to the corporation, it maintains 2,697 kms of roads, including 2,244 kms of interior roads. On the other hand, increasing the length of the storm water drains by itself would be of little use. According to corporation data, around a lakh illegal storm water drain connections have been identified. With sewage already flowing through the drains meant for storm water, it would reach capacity even during moderate showers.
Strategies envisaged
1. Setting up of flood control room and equipment required Status: Yet to be implemented
2. River flood forecasting for Adyar, Cooum, Kosasthalaiyar and lake management system Status: Yet to be implemented
3. Setting up of urban street flooding model, the first of its kind in India. This will be limited to Greater Chennai Corporation and surrounding urban local bodies such as Tambaram, Pallavaram, Poonamallee, Kancheepuram, Thiruverkadu and other areas Status: Yet to be implemented.