Satellite town in a flood plain

One of the lessons the December floods taught the administrators is to ensure the free flow of water; blocking the natural flow of water in the flood plain close to Chennai will only lead to disaster, locals say.

January 06, 2016 10:00 am | Updated November 17, 2021 02:19 am IST - Chennai

The battle against the Tirumazhisai township has been long drawn for the villagers of Kuthambakkam, Vellavedu, Parvatharajapuram, Narasingapuram, and Chembarambakkam.

“In truth, this is the second time the project has come up. We have been opposing this for a very long time, since its inception during the DMK regime,” explains R.Elango, former president, Kuthambakkam Village Panchayat. “The main reason for that is that this is the natural flood plain and has a natural gradient that allows water from 22 water bodies to drain into the Nemam and Chembarambakkam reservoirs. This year, there were sheets of water flowing in heavy current, even swamping the nearby national highway (to Bengaluru).”

He goes on to describe the possible consequences of locating an entire township on this plain. “We have spoken to geologists and water experts, the natural consequence of blocking the water course will be, in case of a repeat of the December floods, the devastation of the town of Tirumazhisai will be complete. He further explains, “Since water won’t have any space to flow, it will spill over into the Couum, and in its fury drown the north of Chennai. It will not be a gentle or rapid rise in water levels as the city witnessed during these rains; it will be like a river, with the force of a tsunami wave that will brook no hurdles in its progress to the sea.”

Interestingly, the government has been aware that it is acquiring land in a water course region. In 2011, the Tashildar of Poonamallee writes to the Chief Engineer, PWD, Kosasthalayar River Basin, requesting the department to issue a no-objection certificate to enable the TNHB to alienate 5.12 acres of “water-course poromboke lands” in the five villages. Those regions are all classified as “odai” (stream), “vaikkal” (canal), “maduvankarai” (embankment) and PWD “kalvai” (canal).

The TNHB assured the villagers that it would build a 100 m channel for flood run off, but the experience of December has showed that that such a canal will be completely incapable of handling any serious flood.

Villagers, largely paddy farmers, from the five villages have come together to oppose the project. “We even went to the National Green Tribunal, but at that time, there was no real proof, just our theories. Even today, so many days after the floods, there is all the proof, right in front of our eyes. It is dangerous to build the township there, the authorities must come and see for themselves, ” says C.Bhaskar, a farmer from Tirumazhisai.

Another farmer from the neighbouring Kuthambakkam, V. Venkateswarulu says there were recent attempts to begin filling up the area. “A contractor started filling up the area acquired by the government just a few days before the rains started. Most of it was washed away with the flood waters, but you can still see some sandy patches from when they filled up the area.” Indeed, there is a sand lick in the middle of the water that still floods the farmlands off Tirumazhisai.

The run off area has been so beautifully designed, or rather the villages built around it, that only the farmlands are affected, and none of the villages that fall in the path, the villagers say. “This is a natural advantage and we need to preserve this,” Mr. Elango adds. “29,000 cusecs went through this terrain easily because it was flat. If there were buildings in the area, the devastation would have been worse.”

Also read: >Thirumazhisai - A satellite town the city can do without>

Three crops (of paddy) are cultivated in this fertile region that has ample water for irrigation. While the township will take away this source of grains, the crucial issue is that the locals in the area have seen equally bad flooding in the past.

Thandavamoorthy, probably the oldest farmer in the collective, says with authority, that in 1979, there was four feet of water in Kuthambakkam village. “Every one says this was a 100-year record rainfall, but this time we had only two feet of water running through part of the village. We were not overawed by this flood, I’m 33, and even I have seen such water thrice; we know where to cut the road to get the water to flow out,” adds Kamala Kannan, a young BSc graduate who has opted to take up his family trade of agriculture.

S. Janakarajan, professor at the Madras Institute of Development Studies and water expert, says, “You cannot build structures within 500 metres of the river on both sides. This is the buffer zone, the flood plain.” However, he points out that the world over, cities as they grow, have occupied flood plains. “But these countries have learnt the lessons after one or two floods. Building over a flood plain is mindless activity.”

“If you fill up a low-lying area, water will have to go elsewhere — it is common sense. If upstream flood plains are occupied, the water diverts to the city — there is no ambiguity in that. To know this and go ahead, would be irresponsibility on the part of the government, and will sow the seeds of disasters for the future,” he adds.

"The land is not part of any water body, nor had they encroached on water channels. There is a mix of both wet (nanjai) and dry (punjai) lands."

The problem occurred due to unprecedented rainfall over three spells – in early and middle of November and first week of December. Areas around Chembarambakkam recorded over 45 centimetres of rainfall in just a day, sources add.

"The worst case of water stagnation had already been taken into account and a retaining wall will be constructed. Nevertheless, the board has now taken up detailed studies once again to incorporate all safety measures into the project design in the event of a similar flood."

(With inputs from K. Manikandan)

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