18 hours ago
Residents welcome Corpn. move to revamp Otteri Nullah, demand steps to remove encroachments
Many people living near Otteri Nullah face a crisis everyday. As untreated sewage and garbage accumulate in the waterbody, residents find the air becoming increasingly toxic by the day.
The Greater Chennai Corporation (GCC) has rolled out a ₹65-crore plan to desilt and raise the walls of the 10.8-km-long Otteri Nullah. The maintenance of the canal was transferred from the Water Resources Department (WRD) to the GCC in October 2024.
Meanwhile, residents say that unless the effluent discharge is stopped and encroachments removed, floods will continue to plague the city during monsoon, and health risks abound.
Welcoming the GCC project, Sandhya Vedullapallai of the Federation of Anna Nagar Residents' Association said, 'A study to analyse the air quality, as well as measures to curb the release of effluents, such as household sewage and wastewater from factories in Pattaravakkam and Ambattur Industrial Estate, into the waterbody are crucial.'
People living close to the canal need to replace their air conditioners every three months as the air is toxic, she added.
According to her, dredging and rejuvenation alone will not fully prevent inundation in Anna Nagar and Perambur, and flood diversions have been planned to address this.
Surplus water
'Flooding is mainly because of surplus water received by Otteri Nullah from Ayapakkam, Ambattur, Kolathur, and Villivakkam lakes during the monsoon. This leads to backflow of water from the Buckingham Canal, which in turn results in overflow from the canal,' Ms. Vedullapalli further said.
According to J.M.S. Nagarajan of the Alliance of Residents' Welfare Associations and Anna Nagar Western Extension Association, a Madras High Court ruling had directed the Corporation Commissioner to look for encroachments adjacent to the Otteri Nullah, and remove them.
'But this exercise is yet to be undertaken. Encroachments and the dumping of garbage reduce the width of the Nullah considerably,' he added.
Detailed Project Report
The GCC's project is planned to be taken up in Royapuram, Thiru-Vi-Ka Nagar, and Anna Nagar Zones (V, VI and VIII) from near Padi Flyover to Buckingham Canal.
The DPR proposed bridge and infrastructure improvements, canal maintenance and desilting, pollution control, prevention of encroachments, and the creation of a blue-green corridor.
'Bathymetry and drone LiDAR surveys have been conducted for topographical and hydraulic assessment. The tender for this project is expected to be finalised on July 7. Work will begin after this. Roughly ₹5 crore is allocated for cleaning waste and desilting alone. The project includes the removal of 2.95 lakh cubic metres of sludge, plastic waste, and weeds, using machines that can dig up to 8 metres,' an official in the Storm Water Drain Department of the Chennai Corporation said.
'Bathymetry and drone LiDAR surveys have been conducted for topographical and hydraulic assessment. The tender for this project is expected to be finalised on July 7. Work will begin after this. Roughly ₹5 crore is allocated only for cleaning waste and desilting. The project includes the removal of 2.95 lakh cubic metres of sludge, plastic waste, and weeds using machines that can dig up to 8 metres,' said an official in the Storm Water Drain Department of the Chennai Corporation.
Otteri Nullah GCC overview
Canal Name: Otteri Nullah
Length: 10.8 km
Longest drainage channel with multiple connecting drains, prone to encroachments.
The Otteri Nullah begins at the 100 Feet Road near Anna Nagar 18th Street and flows through Anna Nagar, RV Nagar, VOC Nagar, Kilpauk Garden, Kellys, Perambur, and Kannigapuram, before discharging into the North Buckingham Canal near Basin Bridge
The maximum depth of Otteri Nullah is 2.5 metres, according to Greater Chennai Corporation' DPR.
It carries a flood discharge of 3,600 cusecs as per WRD records. The canal intersects with 32 cross culverts and has 27 existing bridges, of which seven are identified as major bottlenecks. Flooding issues in Chennai's Urban Drainage system
GCC noted that there is an increasing frequency of urban flooding as experienced in 1943, 1976, 1985, 2005, 2015, 2017, 2021, and 2023 due to heavy rainfall and cyclonic activity. Hotspots
After recurrent floods during the North-East Monsoon in 2017, 2021 and 2023, six flooding hotspots were identified along the canal: from Thirumangalam Road Bridge to GCC Park; along Anna Nagar 6th Avenue Road; near the K4 Police Station Bridge; in tree-lined street flanks; across the Avadi Road Bridge near a collection pond; and areas adjacent to SPR City and other high-rise developments, GCC's Detailed Project Report (DPR) stated.
