In the aftermath of Cyclone Michaung, residents in Manapakkam and Mugalivakkam found themselves navigating hip-deep waters, as the Manapakkam canal, originally designed for irrigation from Chembarambakkam, overflowed into residential areas like Thiruvalluvar Nagar and Arumugam Nagar. The lack of a retaining wall or efforts to deepen the canal, which is crucial for augmenting its capacity, contributed to the flooding, according to Sriram from the Thiruvalluvar Nagar association.
Residents claim that the water resources department has neglected constructing a retaining wall, possibly due to the proximity of compound walls from residential buildings. The Manapakkam canal, repurposed to manage floodwater, is connected to the Porur lake surplus canal, capable of handling 500 cubic feet per second (cusecs) of water. This year, the release of 600 cusecs from Porur lake exceeded the Manapakkam canal’s capacity, resulting in flooding. Similar inundations occurred in 2015 and 2021.
Upstream of the Manapakkam canal divides into canals in Kolapakkam (2 km and 1.3 km) and Gerugambakkam (2.5 km). During the recent event, these canals, terminating in low-lying areas, were closed, leading to the Manapakkam canal bearing the full brunt of floodwater.
To mitigate future overflow and safeguard residential zones, efforts are underway to extend the branching canals to redirect upstream water to the Adyar River. Challenges arise in constructing a retaining wall as the shallow nature of the Manapakkam canal prevents deepening; altering the gradient might impede water drainage. The Water Resources Department (WRD) aims to complete the Rs 88 crore Kolapakkam-Gerugambakkam canal extension before the 2024 monsoon, with ongoing measures such as the removal of 15 patta houses. Residents propose desilting and deepening the canal if the branching canal extension faces delays before the next rainfall, offering a potential solution to alleviate future flood risks.