Thursday, December 10, 2015

# Chennai floods – who is responsible for it?

El Nino is a modern term but our land of ancient Tamils had always experienced heavy rains in the solar months of Aippasi and Karthigai. This is made out from the adage “Aippasiyil adai mazhai, Karthigaiyil Gana mazhai”( ஐப்பசியில் அடைமழை, கார்த்திகையில் கனமழை).

 The Paripaadal verse on Pavai Nonbu (verse no 11) describes a scene of flood ravaged land that comes to house smaller water bodies called “KuLam” by the time the month of Margazhi begins. For this reason the month of Margazhi was also known as  “KuLam” (குளம்).

Our ancestors have laid a fantastic system of hydrology to channelize the flood waters and also to store the excess water for use in dry months. This network can be depicted as below.

(Note: Click on the pictures to see enlarged version)

The network comprises of River water overflowing into subsequent and smaller water bodies.
River > Lakes (Yeri) > KaNmai > KaraNai > Thaangal > Yenthal > OoraNi > KuLam > Kuttai.

These names themselves show that Pazhavanthaangal and Vedanthaangal were water bodies once. Even now there are some street names as Thaangal street in different parts of Chennai. It means there was once a water body adjacent to that street.

The topography and hydrology of Chennai is such that Chennai is a low lying area with an average elevation of only 6.7 metres above the mean sea level, with many parts of it actually at sea level. This landscape of Chennai makes it a marshy land that drains rain water into the adjacent sea. Chennai was indeed dotted with numerous tanks and lakes as per old maps of the British. Agricultural activity was going on at that time supported by these tanks.

The oldest map that I could get from a Google search was of 1893. It shows a long semi curved tank spanning in between Coovum river and Adyar river. (Below)

At that time this tank was identified at two places (in the map) as Nungambakkam tank and Mylapur tank.  The ‘Long Tank Regatta’ was held in 1893 “on the fine expanse of water that starts from the Cathedral Corner (once where Gemini Studio’s property was) to Sydapet”.

The southern end of this tank is linked to Adyar river near Saidapet. The map of 1914 gives clear details of this tank which by then acquired the name “Long Tank”. The inset in the 1914 map (below) shows that this link between Long tank and Adyar river is man-made. This must have existed much before the British came. This is the proof of how our ancients thoughtfully connected the waterways and the drainage system.

The Vyasar padi tank in this map was also a huge one at that time. But it is missing at present. The Vyasarpadi Tank was one of the most important tanks of Chennai along with 9 other tanks namely Perambur, Peravallur, Madavakkam, Chetput, Spur, Nungambakkam, Mylapore/Mambalam, Kottur and Kalikundram. All of them have vanished now.

The first official encroachment of water bodies in Madras started in 1923 with the plan to reclaim land from the Long Tank. The party that was in power at that time was none other than the root cause of the Dravidian ideology namely the Justice Party. The party that was unambiguously based on anti-Brahmanism and atheism and had brain washed the masses with a non-existent Dravida ideology found no qualms in destroying a major water source of Madras.  

Reclamation of land from this tank was started from 1930 by the same Justice Party, to create the Mambalam Housing Scheme on 1600 acres that gave rise to Theagaroya Nagar or T. Nagar (named after the founder of Justice Party).  Destruction of hydro system in the name of development was started by these Dravidian ideologists.

From 1941 onwards, further reclamation was done in Nungambakkam. At the westernmost end of the Tank, 54 acres were reclaimed for the Loyola College campus.

In 1974 what was left of the Tank was reclaimed to give the city the Valluvar Kottam campus alongside Tank Bund Road by none other than Karunanidhi

It must be noted that Valluvar Kottam was constructed right at the deepest part of the Long Tank. Old timers recall that for many years and year after year, Valluvar Kottam was water logged during the rainy season. It would have been apt had they named it as Valluvar Ottam or Valluvar Theppam (Float)!

The following map is that of Chennai today. The location of the missing Long Tank (rough sketch)  is shown in the next map.

The Long Tank formed the western boundary of Madras of those years. The Mount road was laid to the east of it. Today’s Mambalam, Mylapore, Panagal Park, Nungambakkam etc were built on this Tank. No wonder when Adyar river overflowed, the waters found their natural slopes in these areas in the recent floods.

A map drawn  65 years ago shows a sprinkle of numerous water bodies such as Yeris and Kulams all over present day Chennai. They were also well connected to drain extra water in times of flood. This map is shown below.

The gray areas are the water bodies which would remain dry in summer but can house rain water in the rainy season.

Today the gray areas are all closed down with habitations. Needless to say why most parts of Chennai is water logged even by short spell of rains.

The presently available water bodies –from among the network in the above map - are shown in the picture below.

In a good monsoon year, where will the rain water go? All the gray areas become water logged.

A compilation of reports on areas of Chennai which were once water bodies or drainage canals.

·         Two main rivers Cooum and Adayar cross Chennai.  Chennai’s periphery once hosted a massive wetland, which provided a natural flood control barrier in the past.

·         Adyar, Cooum, Kosasthaliyar and the man-made Buckingham canal are the macro drainages. They have a huge capacity to carry flood waters which is by now reduced to half the capacity due to encroachments.

·         The river Coovum which was once a fresh water source is now reduced to a massive, stinking sewer heaped with the waste generated by a heaving metropolis.

·         Similarly, rampant encroachment and urbanisation in its upstream reaches has sapped the ability of the Adyar river to carry flood water.

·         Another key waterway, the Buckingham Canal, is also choked with silt and sewage. So, when Chennai floods, there aren’t enough unobstructed channels for the water to get out.

·         Around eight medium drainage canals drain in to these rivers. These are the Otteri Nallah, Virugambakkam canal, Arumbakkam canal, Kodungaiyur canal, Captain Cotton canal, Velachery canal, Veerangal Odai and Mambalam canal. They are all missing now.

·         Two decades ago, Chennai had  650 water bodies—including big lakes, ponds and storage tanks.  The current number stands at around 27, according to the NIDM study. Even those water bodies that have managed to survive are much smaller than before. For instance, the total area of 19 major lakes in the city has nearly halved from 1,130 hectares to about 645 hectares.

·         Other water bodies such as Ullagaram, Adambakkam, Thalakanacheri, Mogappair and Senneerkuppam are considered beyond restoration. In the case of water channels like inlet and outlet they have completely disappeared

·         There are about 3000 tanks and ponds big and small in the Chennai area. Some of the important tanks are Madipakkam, Velachery, Thoraipakkam, Pallavaram, Madambakkam, Maraimalainagar, Kilkattalai, Pallikaranai, Adhambakkam, Puzhudhivakkam, Thalakanancheri, Kovilambakkam, Chitlapakkam and so on. These tanks can be classified as ENDANGERED.

·         The Adambakkam Lake is being closed due to the Metro Rail work and a concretised road leading from Velachery to GST Road is being built.

·         Madipakkam Lake has become a dumping yard for garbage and the water is not fit for any use. And on the other side construction of buildings is going on apace.

·          Puzhudhivakkam Lake was once an important reservoir and used to host a number of rare birds. This valuable natural resource has now been gradually converted into a housing colony. Inundation in Puzhudhivakkam and Madipakkam is caused by the disappearance of the Veerangal Odai which connects the Adambakkam and the Pallikaranai marsh.

·         Chitlapakkam Lake was once the water source for the Sembakkam and Hastinapuram villages. The total area of this lake is 86.86 acres which has subsequently shrunk to 47 acres due to encroachments such as the development of the district court, bus terminal and the Tambaram taluk office.

·         Chitlapakkam lake is getting water through 3 channels from the foothills. However, in this region the water table level is higher than in other areas. This lake is further contaminated by household sewage and waste from commercial establishments.

·         Chennai, Thiruvallur, Kancheepuram and Chengalpattu are hydrologically integrated. As per the tank memoir prepared by the British, there are 3,600 tanks in these districts and the surplus from around 20 tanks have also contributed to inflow in Chembarambakkam. All these have been encroached now.

·         Pallikaranai marshlands, which drains water from a 250 square kilometre catchment, was a 50 sq km water sprawl in the southern suburbs of Chennai. Now, it is 4.3 sq km—less than a tenth of its original.

·         Pallikaranai marsh acted as a natural flood sink when the rains overwhelmed Chennai. “The marsh that was till about 30 years ago spread over an area of more than 5000 ha (hectares) has been reduced to around one-tenth of its original extent due to anthropogenic (manmade) pressures. The free flow of water within the entire marsh has been totally disrupted due to mega construction activities and consequent road laying,” a 2007 study  by a group of German and Indian scientists noted.

·         The growing finger of a garbage dump sticks out like a cancerous tumour in the northern part of the marshland.

·         Two major roads cut through Pallikaranai waterbody with a few pitifully small culverts that are not up to the job of transferring the rain water flows from such a large catchment. The edges have been eaten into by institutes like the National Institute of Ocean Technology (NIOT). Ironically, NIOT is an accredited consultant to prepare environmental impact assessments on various subjects, including on the implications of constructing on water bodies.

·         There were 16 tanks downstream of Retteri called Vyasarpadi chain of tanks. Kodungaiyur tank was one among them. Now, there is no sign of them.

·         There was also a tank in Thirumangalam area which is missing now.

·         There were once 13 water bodies in Neelankarai (the name itself shows that this place was on the banks of a water body). Only 2 lakes remain now.

·         The Virugambakkam drain was 6.5 km long and drained into the Nungambakkam tank. It  is now present only for an of extent of 4.5 km. The remaining two km stretch of the drain is missing.

·         Nungambakkam tank (part of Long Tank) was completely filled and built. This along with the loss of Koyambedu drain has resulted in the periodic flooding of Koyambedu and Virugambakkam areas.

·         The surplus channels connecting various water bodies in western suburbs such as Ambattur and Korattur have been encroached upon.

·         The water body in Mogappair has almost disappeared. 

·         The Veerangal Odai that connects the Adambakkam lake with Pallikaranai marsh ends abruptly after 550 m from its origin and the remaining part is not to be seen. This causes inundation in places such as Puzhithivakkam and Madipakkam.

·         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 shrunk from 120 acres to 25 acres. Same with Ambattur, Kodungaiyur and Adambakkam tanks.

·         The Koyambedu drain and the surplus channels from Korattur and Ambattur tanks are 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 are no longer there.

·         Elevated Express freight corridor from Chennai harbour to Maduravoyal had  reclaimed a substantial portion of the Coovum’s southern bank drastically reducing the flood-carrying capacity of the river.

·         The lost water body of Velacheri between the year 2000 and 2015 is shown below.

·         The two drainage canals that went missing when I.T park was developed in Siruseri.

·         Water bodies shrunk by the Sholinganallur I.T park is shown below.

·         A comparison of the Chennai topography with the missing Long Tank is shown below.  In the figure, No1 shows Coovum river. No 2 shows Adyar river. Where is No 3?

The lesson

We have robbed the natural habitation of Chennai’s water routes. They have paid us back.


Sources for this compilation:-


R.Ramanathan said...

Thanks Madam. Great article. With the hierarchy of water bodies you have explained i am able to connect various villages in madurai from Vaigai river->thathaneeri->(Not sure about a place with name karanai)-> Laadaneendal->Karupayi oorani->uumacchi kulam

Aravind M said...

Very detailed article on the water management of yesteryear Chennai. One thing that I personally believe is that with the course of time, the pull of urbanization is eventually going to eat up all our waterways. This is not only true to the developing world but has already been seen in much of the developed world as well. The need of the hour is effective engineering to ensure we save our lakes or 'transfer' the lakes to an alternate location away from the city such that we can divert our water into these waterbodies. When Chicago could raise it's buildings in the 1800s to save itself from perennial flooding, why can't we take a leaf out of that?

Refer - Wikipedia- Raising_of_Chicago

Ramesh Mahalingam said...

If only we knew the connection Chennai and the Hollywood movie "Evan Almighty" had : Long Lake !

Raghunathan K said...


Your article proves beyond doubt that the Dravidian parties have grabbing in their genes, to create business for their realtors and provide space for their vote banks, all at the cost of common good. They are happy as long as their coffers are filled, even if the land goes dry.

I request a small help. While I have, from various dictionaries, found out the origin and the derived meaning of all the words from Aaru to Kuttai, somehow I have not been able to locate the source, and hence the meaning, for Karanai. Would be grateful if you could help me in this regard.

jayasree said...

Thanks for Mr Ramanathan, Mr Arvavind, Mr Ramesh and Mr Raghunathan for sharing their thoughts.

On Mr Raghunathan's query on karaNai, KaraNai is a swamp or wetland that is characterized by vegetation and can withstand standing waters. Wiki articles on swamp and wetland would give details of how it works in the hydro chain of draining flood waters. Check wiki article on Pallikaranai also which has become (in)famous for more than one reason in the recent floods, to know how a Karanai fits in the chain.

Usually karaNai means collection of water or fluids along with other substances. The disease Cirrhosis is known as KaraNai disease in Tamil as it pertains to collection of fluids. Generally any tissue or cell that swells with fluids is known a karaNai in Tamil.

I will check my old Tamil books for the root of this word, which I can do only after a few days as they are all packed up for now.

Going by the word and its meaning and relevance, I guess this word is derived from 'araN' (அரண்) which means 'thaduppu'(தடுப்பு) or barrier. The excess water from KaNmai when it passes through marshy lands gets dipped and trapped there. When KaraNai also swells, the water is drained into 'Yenthal' The term Yenthal means that which receives (ஏந்திக் கொள்ளுதல்). This word indicates that Yenthal is a low trough closer to KaraNi into which the excess water from KaraNai oozes in. This water will be clear and would further get collected into OoraNi and Kulam. In this chain, upto KaraNai, habitation will be sparse or nil.

In this chain, a KarNai need not always be present unless the landscape and the vegetation are supportive of it. And also a KaraNai needs to be regularly exposed to water logging to make it become a KaraNai. Therefore a karaNai can be formed in or near flood plains.

In the hydro chain that Mr Ramanathan wrote, karaNai is missing. It may or may not existed in that particular chain he is referring.

jayasree said...

Chennai is overcast at the moment. NE monsoon is still active in South TN. As I wrote in my blog on astrological pointers for the current rains (, a few hours ago, Moon has entered the 5th house from Mars, one of the factors causing the plentiful rainfall for a month now. As per the rule, this will cause rains until 16th but it will be of moderate nature. In the absence of other 2 planets (Saturn and sun) not in such an angle with Moon, rains will be moderate. We will wait and watch. In the meantime I am collecting the old records of high rainfall and also scant rainfall to check the strength of the ativrsihti and anavrishti yogas. I will write a blog on them once I get a concrete pattern on those findings.

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Samba Murthy said...

It is a beautiful account of what had been and what is now and clearly reveals that the present disaster is man-made only though over a period and not natural as described in certain sections. Thank you

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Yamini Vasanth said...

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ice skyfall said...

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jayasree said...

This article has been re-posted in

Ramesh Mahalingam said...

Really sad that creative people like Kamal who earn their livelihood from the erstwhile "Long Lake"- today called Kodambakkam (with all the resources available at their disposal ) were making films about useless topics for India like "international terrorism" (Vishwaroopam ) instead of making a film about the dangers of "Chembarambakkam" ! :-). That was my point. I am just an ordinary citizen who was inspired by your timely blog. That's all. Thanks for mentioning my name in your reply !.

smk said...

so almost all the water tanks were encroached during the anti indian dravidian justice party and JJ govt is told the cause for floods.What a pity dmk and other parties hungry for power are stooping to such levels.

Siddharth Indrajit said...

Came across an article and thought of commenting on a old blog! Chennai came across the highest rainfall in the century. We all heard the negative news about media but of course there are some positive things happened as well! Entrepreneurs from Chennai came up a initiative to help the needy ad this how the help was provided to the needy people. Entrepreneur like Varun Manian, Founder & MD Radiance Realty has come up Radiance Genies to help the poor and needy!
To know more visit -