South Chennai likely to get respite from flooding as restoration of Okkiyam Maduvu channel nears completion

The long-standing problem of inundation in parts of south Chennai is expected to ease as the project to restore Okkiyam Maduvu, a key floodwater channel, is likely to be completed by the end of this month.

The 2.65 km-long channel connects floodwater from Pallikaranai marshland to the sea through the southern portion of Buckingham Canal. The aim to comprehensively restore the channel, at a cost of ₹27 crore, is part of various flood mitigation interventions by the Water Resources Department (WRD).

WRD officials said that while minor works were carried out in the past, the channel has undergone a comprehensive rejuvenation through the project, with a focus on vulnerable portions.

The width of the channel, which receives surplus water from 62 tanks in the upstream portions of the southern suburbs, varies from 120 metres to 200 metres in various stretches. To enhance water flow, it was widened by at least 10 metres over an 800-metre stretch.

However, the channel was found to be narrow in some portions, including near Thangavelu Engineering College and Kannagi Nagar, leading to inundation in surrounding areas. In its effort to reduce flood impact in areas like Pallikaranai, some vulnerable portions of the Okkiyam Maduvu were deepened by two metres, and about two lakh cubic metres of silt were cleared to boost the flood carrying capacity of the waterway.

“We have so far completed building a retaining wall for nearly 470 metres out of the total 520 metres proposed in the project. Neighbouring areas like Kannagi Nagar have already experienced respite from inundation during the previous monsoon. The five-metre-high retaining wall, built along the channel, has helped prevent breaching,” said an official.

Residents noted that restoration efforts must also focus on long-term sustainability and also support groundwater recharge apart from mitigating floods.

Sathish. G., a resident of Semmancheri, said the authorities must ensure that sewage released into the channel is blocked and integrate a periodic water testing and monitoring system. It can also be developed as a public space for residents with bird-attracting vegetation and biodiversity corridors to enhance its ecological value.