CHENNAI: Mudichur is prone to floods, as witnessed during the heavy rains in 2015, 2017 and 2020. But the situation needn’t have been so bad this year. The State government had drafted Anna University’s Centre for Climate Change and Adaptation Research and the Centre for Water Resources to conduct a study to find a solution to the flooding, and sources said that though the results of the study were submitted to the State Planning Commission a year ago, remedial action was not taken.
Had prompt action been taken, the impact of the floods could have been minimised, the sources added.
The study blamed the Outer Ring Road (ORR) for the flooding in Mudichur, a residential hub near Tambaram that was the worst-affected in the 2015 floods. It found that the ORR increased the area that was flooded by 20.03 per cent.
In recent years, even moderate rains have caused heavy water stagnation on the arterial Tambaram-Mudichur Road near the Maduravoyal Bypass Road junction. “Excess rainwater from the shrinking Periya Eri of Tambaram flows towards the junction of Mudichur road and floods the residential areas,” the study stated. Rainwater that drained into Periya Eri and Seekanan Eri was diverted, and the road had already eaten into a portion of the two waterbodies and cut off the natural inlet channels.
The study submitted to the State government said the ORR influenced the depth of water in Mudichur. The existing drains must be maintained well, and adequate drains must be provided across the ORR and its surroundings to increase the flow of floodwater, it added. It also sought construction of a drain along the service road of the Maduravoyal Bypass Road to divert floodwater into the Adyar river. “Proper channelisation of Adyar river from upstream is also required,” the study stated.
“In Chennai, the primary method of dealing with fluvial and urban floods is through the stormwater drain system, and not integrated flood management,” it added. Interestingly, the study also focussed on Velachery. It identified certain regions as hot spots, and said, “Storm drains in these areas should be redesigned to cope with future flood events.
” The runoff from Velachery zones discharges into Pallikaranai marshland, which receives run-off from adjoining catchment areas, including Velachery, Madipakkam and Perumbakkam. The stormwater eventually passes through the Okkiyam Maduvu channel. Okkiyam Maduvu is a 2.8 km channel that originates as a narrow canal from the Pallikaranai marsh land and drains into Buckingham Canal.
Findings of the report
Outer Ring Road
◆ Influences flood depth in Mudichur
◆ Existing drains must be maintained well
◆ Needs adequate drains across and in the surroundings
◆ Needs a drain along the service road of Maduravoyal Bypass Road to divert floodwater into the Adyar river Hotspots in Velachery
◆ 100 ft road
◆ LIC Colony 2nd Street
◆ Dhandeeswaram 7th Avenue East
◆ Dhandeeswaram 7th Main Road
◆ Southern Arm Inner Ring Road
◆ Vijaya Nagar 7th Main Road
◆ TNHB 3rd Main Road
◆ Srinagar Colony Main Road
◆ Nethaji Colony
Storm drains in these areas should be redesigned
Okkiam Maduvu weir width to be increased from 120 m to 200 m