The National Green Tribunal has directed agencies constructing the Chennai Peripheral Ring Road in Tiruvallur to ensure that road works over Kannigaiper Lake do not obstruct, divert or impede the natural flow of water into the lake. The southern bench said the project must follow technical and safety standards, departmental clearances and the recommendations of Tamil Nadu’s Water Resources Department.
The order relates to a 280-metre section of the peripheral ring road passing over the lake. A suo motu case was taken up by the Tribunal in 2025 after a letter petition raised concerns that the road works could reduce the lake’s storage capacity and increase flooding risks for nearly 50 villages on its western side.
The petitioners alleged that the Water Resources Department had issued a no-objection certificate for the project without adequately assessing its impact. The Tribunal’s order, however, recorded details from a report submitted by the Tamil Nadu Road Infrastructure Development Company, or TNRIDC, regarding the structure planned across the lake.
According to the report, the project has two components: a high-level structure extending for 100 metres and an embankment covering the remaining 180 metres. The Water Resources Department had issued an NOC for the high-level structure but had not approved the embankment. Instead, it recommended a separate structure for the embankment to prevent the road from obstructing water movement.
TNRIDC subsequently examined the feasibility of constructing the additional structure. The proposal provides for spans of 25 metres between each pier. The Tribunal said this arrangement would provide adequate clearance for uninterrupted water flow. The bench comprising Justice Pushpa Sathyanarayana and Prashant Gargava disposed of the petition after recording the project details and the proposed design response.
The direction places the water-flow requirement at the centre of execution for this section of the Chennai Peripheral Ring Road. It also requires the agencies involved in design and construction to adhere strictly to the Water Resources Department’s recommendations and obtain the necessary departmental clearances. The order does not authorise any obstruction or diversion of the lake’s natural inflow during construction or after completion.
