How Kerala's Wayanad-Kozhikode Tunnel Secured Environmental Clearance in a Landslide-Prone Zone

A landslide at the Kalladi end of the proposed Wayanad-Kozhikode tunnel road has brought fresh attention to the project's environmental clearance, with questions resurfacing over the safeguards approved for construction in one of Kerala's most landslide-prone regions. While the cause of the incident is still being examined, official records show the project underwent several rounds of environmental scrutiny before receiving clearance in March 2025.

The ₹2,043.74-crore project proposes an 8.753-km tunnel connecting Kalladi in Wayanad with Anakkampoyil in Kozhikode. Touted as a major infrastructure initiative, it aims to cut travel time between the two districts and reduce dependence on the existing ghat roads. However, much of the alignment passes through ecologically sensitive hill terrain that has witnessed some of Kerala's deadliest landslides in recent years.

The State-Level Expert Appraisal Committee (SEAC) granted environmental clearance on March 2, 2025, only after seeking additional technical studies and clarifications from the Public Works Department (PWD). Minutes of the committee's meetings show members closely examined issues ranging from slope stability and tunnel blasting to forest loss, wildlife movement and the area's history of landslides before recommending the project.

A Project Through Fragile Terrain

The proposed tunnel cuts through a landscape that is both environmentally significant and geologically vulnerable.

Nearly 5.76 km of the 8.753-km tunnel-around 80 per cent of its total length-passes beneath forest land. The project requires the diversion of 17.263 hectares of forest and lies close to the Nilgiri Biosphere Reserve, one of India's richest biodiversity hotspots.

SEAC records note that the surrounding landscape supports several endemic and threatened species, including the Banasura Chilappan and the Nilgiri Sholakili. The committee also flagged elephant movement in the area and warned that the project could increase human-wildlife conflict if adequate safeguards were not put in place.

The alignment also passes near villages classified as Ecologically Sensitive Areas, including Thiruvambady in Kozhikode district and Vellarimala in Wayanad.

Beyond its ecological impact, the project also has social implications. Four tribal settlements lie within 500 metres to 1.5 km of the proposed alignment. Among them is the Aranamala Kattunaikka Colony, home to 27 families, which has been identified as a project-affected settlement eligible for compensation, rehabilitation and resettlement.

SEAC Sought More Information Before Granting Clearance

The project did not receive environmental clearance immediately.

After reviewing the initial proposal, SEAC asked the PWD to submit 28 additional documents, observing that the original application did not sufficiently assess the impact of tunnel blasting in a landslide-prone region.

The committee also sought a detailed analysis of previous landslides and asked whether construction activity could destabilise slopes or trigger fresh failures. The review specifically referred to the devastating landslides at Puthumala in 2019 and Mundakkai-Chooralmala in 2024, both of which highlighted the vulnerability of the region.

In response, the PWD submitted a revised assessment acknowledging that the project falls within an environmentally fragile and high landslide hazard zone.

The updated report examined geological conditions, slope stability, drainage patterns, groundwater seepage, rock characteristics, seismic activity and debris-flow behaviour. It also assessed the possible impact of tunnel blasting, including vibration, overpressure, tunnel stability and the risk of water ingress during excavation.

The department told the committee that construction would rely on controlled blasting techniques and careful engineering practices. It also proposed using either the New Austrian Tunnelling Method or a Tunnel Boring Machine, depending on geological conditions encountered during construction.

SEAC's appraisal further identified two minor geological lineaments along the project corridor. While the committee concluded they were not significant enough to deny environmental clearance, it recommended continuous monitoring during construction because of the terrain's sensitivity.

Clearance Came With Conditions

Environmental safeguards became another major focus during the appraisal process.

SEAC found the project's initial allocation of ₹1.02 crore for environmental mitigation inadequate and directed the PWD to increase it to ₹15 crore. Even after the revision, the committee observed that the amount might still not fully cover commitments such as elephant corridor restoration and the rehabilitation of affected tribal communities.

The project eventually received environmental clearance after SEAC assessed its environmental cost-benefit ratio at 23.7. At the same time, the committee imposed 25 conditions that the PWD must comply with during construction and operation.

Among those conditions was a direction that excavated material should not be dumped on public roads, pavements or land outside the project area. Other conditions relate to drainage management, slope protection, waste disposal, environmental monitoring and measures to minimise ecological disturbance during construction.