- Is Chennai ready for Round Two of heavy rainfall?
- Mumbai clearly wasn’t ready for even a 3-day deluge
- When we looked around we found Chennai has mostly itself to blame when it comes to being rain ready
Weather forecasts claim that Chennai will witness heavy rainfalls. Considering what we see in Mumbai, Chennai survived a similar fate not too long ago. Chennai has witnessed a similar deluge in November-December 2015, claiming the lives of 270 people.
Mumbai has paid the price of having bad to worse sewerage system yet again. However, unlike previous years, the weather gods have been merciful to the city and the deluge lasted for just three days, which helped people get back to normal. However, the question that remains is how long can we hope for the weather to hold up. The question holds true for Chennai as well. Is it ready for round two?
So, here's a reality check on the factors that supposedly led to the flood and if there has been any improvement in the situation:
Unrestrained construction was considered to be the prime reason why Chennai was flooded. Indeed a "man-made" disaster, owing to the rampant construction under various governments, the Chennai floods were certainly avoidable. Politicians then did not hesitate to blame the unprecedented rains for the civic humanitarian crisis. However, it is to be noted that Chennai witnesses similar deluge once in 10 years. The years 1969, 1976, 1985, 1996, 1998, 2005, 2015 are etched in everyone's minds.
When hi-tech structures eat up the marshlands
In the year 1976, the Adyar river overflowed its banks and filled the houses on the ground level. However, the government could blame the lack of infrastructure then, to the extent that some even called the city an "overpopulated village". However, things have changed today. Chennai is in the process of ushering in a "Make in Chennai" boom and has expensive and hi-tech infrastructure spread across the city. But the question that remains to be asked is "at what cost?"
A brand new airport was built on the floodplains of river Adyar, a bus terminal was built in flood-prone Koyambedu. A Mass Rapid Transit System was constructed almost wholly over the Buckingham Canal and the Pallikaranai marshlands, expressways and bypass roads constructed forgetting about the tendency of water to flow. Further, an IT corridor and a Knowledge Corridor consisting of engineering colleges were constructed on waterbodies, and automobile and telecom SEZs and gated residential areas were built on important drainage courses and catchments.
Consider this, when we call the rampant constructions as ecological disasters, resulting in a telling effect on the Chennai sewerage system. The Pallikaranai marshlands, for instance, which drains water from a 250 square kilometre catchment has been reduced to just a 4.3 square kilometre water sprawl in the southern suburbs of Chennai. Now, a tenth of its original size, the problem is multiplied by the piled up garbage in the city precincts that test the drainage system even more.
Incidentally, the rest of the marshland has been eaten up, ironically, by the National Institute of Ocean Technology and the IT corridors. So, has the situation changed? Perhaps not. The IT corridors remain where they are and there has not been an inch of sewerage improvisation in the area.
The missing tanks of Vyasarpadi
Chennai initially had a vast network of water bodies that drained out the excess water from the city precincts during heavy rains. In all, there were 16 tanks that did the job, but all have reportedly vanished from the face of Chennai's map. Prof. M. Karmegam of Anna University, an expert in the field said that The Chennai Bypass connecting NH45 to NH4 blocks the east flowing drainage causing flooding in Anna Nagar, Porur, Vanagaram, Maduravoyal, Mugappair and Ambattur.
The Maduravoyal lake has, in fact, shrunk from its original 120 acres to 25. Same is the case with Ambattur, Kodungaiyur and Adambakkam tanks. The Koyambedu drain and the surplus channels from Korattur and Ambattur tanks, which absorbed a major part of the city's excess water are missing. Sections of the Veerangal Odai connecting Adambakkam tank to Pallikaranai are also missing.
The South Buckingham Canal from Adyar creek to Kovalam creek has been squeezed from its original width of 25 metres to 10 metres in many places due to the Mass Rapid Transit System railway stations. Important flood retention structures such as Virugambakkam, Padi and Villivakkam tanks have been officially abandoned.
Untreated sewage issues
The Poonamallee Municipality, according to a Hindu report, has been struggling to dispose of the sewage that ends up in the Cooum river. Lack of drainage systems in the area and proper disposal grounds has led to water overflowing on normal days itself, forget the floods. An underground sewerage system was being planned in the area since the past four years, but no results yet.
Across the years, the population in the area is also said to have increased to 60,000 people, putting further pressure on the already dying waste-water system. Close to eight million litres of sewage is being released every day, but experts believe that the required skill to treat this waste is lacking.
Poor co-ordination and understanding of the city planning
The 2015 deluge in the city bared the missing links between the administrative bodies in the city. Add to it the political rivalry that put a brake to a lot of developmental work. While the construction of the Elevated Express freight corridor from Chennai harbour to Maduravoyal had already reclaimed a substantial portion of the Cooum's southern bank drastically reducing the flood-carrying capacity of the river, the government's apathy to the ecological and hydrological basics added to the plight of the city. Glaring instances include the execution of the Chennai Metropolitan Development Authority-approved plans in Ponneri, which simply ignore the drainage capacity of the area. Incidentally, it was the most affected in the 2015 deluge. Ironically, it has also been listed under the Smart City project.
Chennai does not seem to have learnt its lesson, especially when nothing significant has been done since the past two years and just a month and half ahead of the onset of the next north-east monsoon. Although the municipal administration had attempted studying the drainage system of cities like Mumbai (ironically), little has been done toward the execution. One initiative was to set up the Real Time Flood Forecasting and Spatial Decision Support System for Chennai, which was proposed by the Tamil Nadu Urban Infrastructure Financial Services Ltd (TNUIFSL). However, nothing has been done to implement the plan till date.
So, ultimately it is the weather gods that Chennaiites have to depend on now, hoping and wishing that he would be as merciful as he was with Mumbai.
Last Updated 31, Mar 2018, 6:47 PM