The Okkiyam Maduvu project, a Rs. 27 crore flood-mitigation initiative linking the Pallikaranai marshland to the Buckingham Canal, is nearing completion and is expected to improve drainage in several flood-prone areas of south Chennai.
The 2.65-km channel is intended to carry rainwater from Velachery, Pallikaranai and Perumbakkam towards the Buckingham Canal. The canal carries the flow further towards Muttukadu and the Kovalam estuary, where it drains into the sea. The project is also expected to benefit Perungudi, Thoraipakkam, Semmencherry and low-lying areas along the Old Mahabalipuram Road.
Residents in these neighbourhoods have repeatedly faced flooding during the northeast monsoon. Water entering residential areas has led to boat rescues, temporary relocation to relatives’ homes and damage to household belongings. Some residents have also parked their cars on nearby flyovers during floods to protect them from rising water.
The Water Resources Department decided to expand and restore the channel after water plants obstructed the Okkiyam Maduvu in 2024. Ministers and officials who inspected the waterbody concluded that improving its capacity would be an important measure for addressing flooding in south Chennai and its suburbs.
As part of the work, the government decided to dig a channel through patta land belonging to a private college near the waterbody. The landowner is to receive proper compensation or alternative land, according to the report.
In the Sholinganallur zone, the active water opening has been widened from 10 metres to 98 metres to allow water to move more quickly into the Buckingham Canal. The department also plans to remove more than 2 lakh cubic metres of silt and deepen critical stretches by 2 metres. A 520-metre flood-retaining wall is being built to help prevent flooding in areas including Kannagi Nagar.
The project is designed to keep the channel above sea-water level and facilitate faster movement of stormwater. The report notes that drainage can slow during the rainy season when the sea level rises, causing water to enter the sea more slowly. The improved channel is intended to reduce this backflow effect, which has contributed to flooding in Madipakkam and Ram Nagar.
The drainage route will run through areas between the Old Mahabalipuram Road and the East Coast Road before reaching the sea near VGP Universal Kingdom at Injambakkam. The completed works are expected to carry floodwater from Perungudi, Semmenchery and other neighbourhoods along the Old Mahabalipuram Road. The project’s effectiveness will depend on the restored channel, widened opening, desilting and retaining-wall works operating together during heavy monsoon rainfall.
