T’puram: The proposed 62.7-km Thiruvananthapuram outer ring road (ORR) connecting Navaikulam and Vizhinjam obtained the recommendation for environment clearance subject to stringent conditions. A major focus of the conditions is protection of wetlands, paddy fields and marshy areas along the alignment. The expert appraisal committee (EAC) of Union ministry of environment, forest and climate change directed that elevated structures such as viaducts and flyovers should be used with minimum footprints to maintain natural drainage and water flow.The committee has raised particular concerns over the proposed cut-and-cover sections of tunnels, warning of possible landslides and soil erosion, especially around tunnel mouths. National Highways Authority of India (NHAI) has been asked to revisit the tunnel design and explore further reduction in cut-and-cover stretches. Construction of such portions and at-grade roads in mountainous areas should, as far as technically feasible, be carried out between rainy seasons.Flood management is another key condition. The project proponent has been required to base bridge and viaduct designs on detailed hydrological and hydraulic studies, including worst-case flood scenarios and a 100-year return period. The project already incorporates 149 box culverts, 17 minor bridges, two major bridges and 50 viaducts with a cumulative length of 11.974-km.Wildlife protection has also received emphasis. A KFRI biodiversity assessment identified 84 potentially vulnerable species and 12 roadkill hotspots, prompting provisions including wildlife crossings, underpasses, fencing, speed regulation and warning signage. EAC has also sought safeguards for animal movement near Neyyar Wildlife Sanctuary.The selected alignment is reported to require the felling of around 21,000 trees, lower than the two alternatives assessed by the project proponent. EAC has directed that the option with the least environmental impact be adopted and that viaducts and openings be maximised wherever feasible.A senior official associated with the project said the environmental conditions would be incorporated into the project’s implementation framework. “The recommendation provides a clear environmental roadmap for the project. The safeguards relating to wetlands, drainage, tunnels, wildlife and vegetation will have to be strictly integrated into construction and design,” the official said.The ORR is being developed as NH 866 from Navaikulam to Vizhinjam. NHAI has already floated the construction tender for the 62.7-km corridor, estimated at around Rs 8,004.72 crore.EAC recommended environmental clearance on Aug 13. With the EC recommendation, Central cabinet is likely to approve the project in the cabinet meeting scheduled in Sept. Once it is approved, the compensation disbursal will begin for the affected landowners.
