It was early morning 2 am on Wednesday, Dec. 2. Murugesan, auto rickshaw driver, was minting money offering short trips to people stranded in the rains in T.Nagar, downtown Chennai. When he got a call from his wife Ganga in those wee hours, he knew his happiness could not last any longer. Cooum river has swollen and drowned his home in Aminjikarai in Central Chennai. Ganga and over five thousand people were evacuated to safety from Kathiravan Nagar which is built right on the banks of Cooum river like the Ampa Skywalk Mall, housing businesses and cinemas. Kosasthalaiyar, the river which touches northern boundary of Chennai city near Ennore Creek has already overflown and cut off Manali Puthunagar, Kargil Nagar from rest of the city. People were evacuated in fishing boats thanks to the proximity of fishing communities from Pulicat to Kasimedu in Northern Chennai.
In the meantime, Adyar river, in south Chennai, has flown into the Chennai Airport by 7 pm on Dec 1 and the flight operations were stopped from 9 pm Tuesday night. It was historic that the airport had to be shut until Sunday, causing airliners losses to the tune of 1000 crore according to a report in The New Indian Express http://www.newindianexpress.com/cities/chennai/Whopping-Rs-1000-Crore-Loss-To-Aviation-Sector/2015/12/10/article3170212.ece. It was around 11 am on Dec. 2, Adyar river started touching the Maraimalai Adigal Bridge in Saidapet. This bridge is the mainline to Anna Salai (erstwhile Mount Road) from Chennai Airport and Tambaram. The bridge was closed to vehicular traffic until next afternoon; making Chennai City into islands on one side by overflowing Adyar river, in the central part by a flooded Cooum river and on the northern part by overflowing Kosasthalaiyar river. The 49 cm rains in Tambaram and 47 cm rains in Chembarambakkam on Dec. 2 caught the city unawares. Even by the admission of the state Chief Secretary Gnanadesikan, the breaches in Nandivaram, Mannivakkam, Urapakkam and Adanur lakes in southern parts of the city poured more water into the already-overflowing Adyar river. This, to some extent, explains the inundation at the three-level underground parking in the 45-acre SEZ DLF IT city on the banks of Adyar river on Dec. 3. http://www.thehindubusinessline.com/companies/a-chennai-sez-still-battling-to-clear-22acre-3level-basement/article7971981.ece
The Chennai newsrooms and those writing for upcountry publications mostly reside in south Chennai where Adyar is the only river. Their perspective of the city geography is limited by their surroundings. That is why a content analysis of media reports on Chennai deluge show that seventy per cent of the reports talk about Adyar river overflowing; In fact, all the three rivers in the city overflowed and marooned dwellings. A data analysis of the floods in the past four decades available in the public domain would tell us that Adyar did overflow ten years back with 40,000 cusecs (PDF file attached). The reason it did not maroon hundreds of homes then was that there were not many encroachments on the banks of Adyar river as it enters the city.
Encroachments include an iron bridge in the Army Quarters in Nandambakkam and the extended backyards of bureaucrats in Manapakkam and the gardens of industrialists in Boat Club; However, media outlets talk of huts of migrant workers and indigenous people on Adyar river banks as the "only" encroachments.
