11AOTNS
The Hindu, Chennai, 26 December 2005
Water systems map for Chennai urged
T. Ramakrishnan
Using contour map, authorities should prepare a comprehensive drainage plan, says expert
CHENNAI : Even as Chennai is limping back to normality after the recent floods, an urban expert has called for the preparation of a detailed contour map for the entire Chennai Metropolitan Area to find solutions to the problem of flooding.
T. Anantharajan, who was professor of urban engineering in Anna University here, says the details regarding the existing water bodies and courses and drainage systems should be incorporated in the map. Particulars regarding man-made obstructions and encroachments in and along the water bodies should also be obtained.
Emphasising the use of modern tools such as the global information system and satellite imagery for preparing the map, he says the authorities did not have to go to any external agency for this purpose as both Anna University and University of Madras had sufficient resources. If need be, infrastructure available at other local institutions of technology can be utilised.
Using the contour map and other information, the authorities should prepare a comprehensive drainage plan containing an "efficient network" for surface
drainage system to drain flood waters quickly to the sea, Prof. Anantharajan says.
Sewage overflow
Referring to the problem of sewage overflow in parts of some localities such as Velachery, he says raw sewage is still freely overflowing on streets as seen in Sarathy Nagar. This problem had a bearing on public health. The authorities should act immediately to improve sewage collection and disposal in these localities.
One more map, showing the overflowing of sewage from manholes, may also be prepared to address this problem.
The protection of water bodies is another point highlighted by the expert. Its importance was underscored at a recent workshop on urban lakes organised by the Anna University's Centre for Water Resources.
Making a presentation at the workshop, P. Viswanathan, convener of the Chitlapakkam Residents' Associations Coordination Committee, noted than an integrated sewer system should be in place to protect the lakes. Storm water drains should carry only rainwater to the nearest lake/ tank.
Entry of sewage and sullage into the drains should be prevented. Water bodies should never be used as dumping yards of garbage, and government should initiate action against any encroachment of water bodies.
Pointing out that Kancheepuram district (south of Chennai) had about 780 tanks, Mr Viswanathan says the Chengalpattu, Madurantankam and Cheyyur taluks accounted for nearly 400 tanks.
Prof. Anantharajan, Mr Viswanathan and M.B. Nirmal, founder of Exnora, suggest that the water bodies be deepened to increase their capacity. Their bunds can be raised and strengthened.
Mr Nirmal says work on deepening can begin now where there is no storage of water. In a few months, many lakes, particularly small ones, will become dry and the work can be taken up there then.