Rains will continue to batter Tamil Nadu for the next seven days and the next 48 hours are "very crucial", the India Meteorological Department has said.
IMD Director General Laxman Singh Rathore attributed the heavy rains to a "trough of low" over Southwest Bay of Bengal off Tamil Nadu and Sri Lanka coast which will continue to bring rains over the next three days. Thereafter, the state will see an anti-cyclone activity which will be associated with "heavy rains" at some places.
"The phenomenon will continue for the next seven days, but the next 48 hours are very crucial. Neighbouring states will also see rainfall activity," Rathore said.
Though the heavy rains that lashed the city and the suburbs and neighbouring districts of Kancheepuram, Tiruvallur and Cuddalore for more than a day on Tuesday have shown a let up since this morning, a continuous drizzle under overcast skies spelled further trouble for citizens.
He said the Union Home Secretary Rajiv Mehrishi chaired a high-level meeting with the "stake holders", including officials of National Disaster Management Authority, which was attended by Tamil Nadu Chief Secretary through a video conference.
The IMD also briefed about the weather forecast. A warning has also been issued for coastal districts of Tamil Nadu, Puducherry, Andhra Pradesh (especially Nellore and Chittoor), interior Tamil Nadu and Rayalseema region of Andhra Pradesh.
The period October to December is referred to as Northeast Monsoon season over peninsular India. It is a major period of rainfall activity over the southern peninsula, particularly Coastal Andhra Pradesh, Rayalaseema, Tamil Nadu and Puducherry.
For Tamil Nadu this is the main rainy season accounting for about 48 per cent of the annual rainfall. Coastal districts of the state get nearly 60 per cent of the annual rainfall and the interior districts about 40-50 per cent of the precipitation.
However, this season Tamil Nadu alone has witnessed 50 per cent excess rainfall by December 1 itself. "Almost all districts of Tamil Nadu have received excess rainfall ranging from 10 to 150 per cent," Rathore said.
Teams of army, navy, coast guard and National Disaster Response Force have been deployed in the worst-affected areas of Tambaram, the southern gateway to the city, Mudichur and Oorapakkam.
The NDRF is rushing about 600 personnel and over 40 inflatable boats to be deployed in relief and rescue operations in rain-battered Chennai.
According to the IMD data, Chennai has seen 89 per cent more than normal rainfall this season, while the districts of Kancheepuram, Tiruvallur, Vellore and Tirunveliveli received 154 per cent, 139 per cent, 136 per cent and 110 per cent excess precipitation respectively so far.
As the Chennai airport and nearby landing facilities are shut down, 15 teams airlifted from Bhubaneswar and Delhi by the Indian Air Force, will be landing at the 'INS Rajali' airbase in Arakkonam, about 60 km west of Chennai, National Disaster Response Force chief O P Singh.
Police and fire service personnel were also involved in rescue operations. The Coast Guard has deployed its boats in some areas in the city that has witnessed unprecedented rains in a short period of time in recent memory.
Teams have also been pressed into service in Jafarkhanpet, Saidapet and Kotturpuram on the banks of Adyar and Vadapalani and Valasaravakkam and several areas in the western parts of the city which have been flooded with waters entering residential homes.
The southern suburbs of Chennai including Velachery, Madipakkam and neighbouring areas which had suffered heavily in the earlier spells of rain in November were again hit badly by the downpour that has again flooded homes.
The Grand Southern Trunk road connecting Chennai with Madurai and beyond, the old Mahabalipuram road and the East Coastal road through which Chennai can be accessed have been cut off with waters washing away the roads in several places including Guduvancheri.
While travellers from southern districts have been stranded midway, a number of passengers were also left helpless in Chennai Central and Egmore stations. Suburban railway services in Chennai have also been suspended because of flooding of tracks.
The flooding of the city and the suburbs has been caused essentially by the surplusing of waters from the reservoirs like Chembarambakkam, Poondi and Puzhal into Adyar and Cooum that criss-cross the city flooding several areas along the banks and displacing people from homes.
An unprecedented 30,000 cusecs of water has been released from the Chembarambakkam lake as the reservoir has been getting heavy supplies from the rain in catchment areas.
Electricity has been cut off in most parts of the city as a precautionary measure while people went without essential supplies like milk and water.
Air Force helicopters were seen distributing food packets in some of the worst-hit areas.
The Southern Railways cancelled 16 trains and diverted 12 others both on the Chennai Central and Egmore sections following breaching of tracks in several areas.
Flight services in and out of ChennaiAirport will remain suspended until Thursday morning due to the heavy rains and water logging on the runway.
The airports Authority of India has issued a NOTAM (Notice to Airmen) to all air operators in this regard, AAI spokesperson said.
ChennaiAirport authorities had initially shut operations till Wednesday morning but due to incessant rains it has now decided to extend it till 6 am on Thursday.
NOTAM is a notice containing information concerning the establishment, condition, or change in any facility, service or procedure, among others, in airspace management.
All airlines have cancelled their operations from Chennai airport.
Spicejet has cancelled all its flights till Thursday, while Jet Airways has cancelled all its flights to and from Chennai for Wednesday.
Union Minister for Civil Aviation Pusapati Ashok Gajapathi Raju said everything has been paralysed at the airport.
"A lot of things are stranded at the airport. So the chairman of Airport Authority has tried to develop a plan to make available some essential material like drinking water, and food...staff is also trying. Everything is paralysed," he said.
Asked when the flights can resume, he said, "If the rain stops then only we can give you some type of time frame but if it won't stop then we can't say anything as Chennai and neighbouring districts are badly affected. If water recedes then only we will be able to to do something".
Home Minister Rajnath Singh said in Delhi that in view of the situation, the Centre has deployed army, navy and NDRF teams in sufficient numbers.
“The prime minister has issued a memorandum and we have deployed our Central team there to assess the situation and make a report so that every possible help can also reach there,” Singh said.
Two columns of army’s Garrison Infantry Battalion have been pressed into service in Tambaram and Oorapakkam after the Tamil Nadu government sought military assistance. The navy has also been deployed to assist in the operations.
“More army personnel are coming to Chennai from Bengaluru,” a Defence Public Relations official said.
Navy personnel have been deployed in Sadiapet area of Chennai to rescue people marooned in low-lying areas.
The NDRF is airlifting another 15 teams to the rain-battered state. While 10 teams are being airlifted from Bhubaneshwar to Tirupati, another five teams are being lifted from Delhi, NDRF DG O P Singh said. Each team comprises 40 personnel.
The teams are also carrying 20 inflatable boats along with them for the rescue operations.
NDRF DIG and commanding officer have been stationed in Chennai to take stock of the operations, he said.
Singh said that he is also in constant touch with the relief commissioner of Tamil Nadu.
Talking about the navy’s operations, Rear Admiral Alok Bhatnagar said the navy has deployed a team comprising two boats, two helicopters and a remotely piloted aircraft for relief and rescue operations.
Defence Minister Manohar Parrikar said more forces will be deployed to tackle the situation.
"However, We are facing difficulty in bringing them (forces) there as the airport is also not operating,” he said.
Meanwhile, during a discussion in Rajya Sabha over the rain fury in Tamil Nadu, members offered to utilise Members of Parliament Local Area Development Scheme funds for relief and rehabilitation work and some even announced contributions of varying amounts for the cause.
The House took up a discussion on the issue on urgent basis with Parliamentary Affairs Minister Venkaiah Naidu saying the flood situation in Chennai is worrisome.
Communist Party of India-Marxist leader Sitaram Yechury said, "We can allow MPLADS funds for relief work in Chennai."
Yechury's suggestion was supported by Leader of Opposition Ghulam Nabi Azad.
Under the MPLADS, the district authorities spend money on works recommended by member of both the Houses from time to time.
The Chennai Corporation has announced emergency numbers for all the regional zones in the city. people can contact the following numbers in case of any emergency due to the floods. Numbers: Tree fall, waterlogging - 1913; Sewage overflow - 45674567, 22200335; State Emergency - 1070; District Emergency - 1077; Electricity - 1912; Fire & Rescue -101.