NHAI-WII Study Shows Wildlife Thriving Along Delhi–Dehradun Corridor, Sets Benchmark for Green Infrastructure

In a landmark achievement for sustainable infrastructure development, the National Highways Authority of India (NHAI), in collaboration with the Wildlife Institute of India (WII), has released a groundbreaking report titled 'Landscapes Reconnected', providing the first empirical evidence of wildlife actively using specially designed animal underpasses along the Delhi–Dehradun Economic Corridor.

The findings mark a significant milestone in demonstrating that large-scale infrastructure projects can successfully coexist with ecological preservation, especially in environmentally sensitive regions such as the Shivalik landscape.

A First-of-Its-Kind Scientific Validation

The WII study offers robust, data-driven validation of wildlife mitigation measures, documenting how engineered underpasses are enabling safe and natural animal movement across a critical forested stretch.

Conducted over an 18 km section between Ganeshpur and Asharodi, the study aimed to:

• Assess patterns of wildlife movement through underpasses

• Evaluate species-specific usage behavior

• Measure the effectiveness of mitigation structures

This region is ecologically rich and serves as a habitat for endangered and sensitive species including:

• Asian elephants

• Tigers

• Greater hornbills

• King cobras

Engineering Marvel: Asia's Largest Wildlife Corridor

A standout feature of the project is the 20 km-long stretch incorporating 10.97 km of dedicated animal underpasses, forming one of the most extensive wildlife passage systems in Asia.

The corridor includes:

• Elevated wildlife structures averaging 6–7 meters in height

• Design compatibility for large mammals such as elephants

• Continuous connectivity across diverse terrain

These structures represent a major engineering breakthrough, ensuring uninterrupted wildlife movement while maintaining high-speed transport efficiency.

Advanced Monitoring: Technology Meets Conservation

The study deployed cutting-edge monitoring systems over a 40-day period, including:

• 150 high-resolution camera traps

• 29 AudioMoth acoustic recorders

This effort generated a massive dataset of 111,234 images, capturing interactions of humans, domestic animals, and wildlife.

Key findings include:

• 40,444 images of wildlife, representing 18 distinct species

• Frequent sightings of Golden Jackal, Nilgai, Sambar, and Spotted Deer

• Consistent movement of smaller mammals like the Indian Hare

• 60 recorded instances of elephants safely using the underpasses

These findings confirm that even the largest and most sensitive species are adapting to and utilizing the infrastructure effectively.

Soundscape Management: A Critical Factor

One of the most innovative insights from the study is the role of acoustic ecology in influencing animal behavior.

The research found that:

• Generalist species (e.g., jackals, wild boar) tolerate higher noise levels

• Sensitive species (e.g., elephants, spotted deer) prefer quieter underpass zones

This has led to recommendations for:

• Targeted sound barriers

• Noise mitigation strategies in high-crossing zones

Such measures are expected to further enhance the usability of corridors for noise-sensitive wildlife.

Ecological and Social Impact

The Delhi–Dehradun Economic Corridor is emerging as a model for balancing development with conservation by:

• Reducing human-wildlife conflict

• Preventing habitat fragmentation and population isolation

• Maintaining genetic flow across wildlife populations

The Shivalik region, a critical biodiversity hotspot, stands to benefit significantly from these interventions, ensuring long-term ecological stability.

Zonal Analysis for Better Planning

The study area was divided into three zones to capture terrain diversity:

• Zone I (5.43 km): Ganeshpur to Mohand

• Zone II (9.80 km): Mohand to Asharodi check post

• Zone III (3.14 km): Asharodi to Mohabewala (Doon Valley)

These zones encompass riverbeds, hilly terrain, and dense Sal forests, allowing for comprehensive ecological assessment.

Setting a New Standard for Infrastructure Development

The report underscores that well-planned infrastructure—integrating underpasses, elevated corridors, and environmental design—can serve both development and conservation goals.

India, which is rapidly expanding its highway network, is increasingly adopting eco-sensitive design frameworks, aligning with global sustainability standards.

NHAI's Commitment to Green Highways

Reaffirming its commitment, NHAI stated that future highway projects will continue to incorporate:

• Data-driven environmental planning

• Advanced wildlife mitigation structures

• Innovative sustainable construction practices

The 'Landscapes Reconnected' report is expected to serve as a benchmark for infrastructure projects worldwide, showcasing India's leadership in integrating biodiversity conservation with economic growth.