Infrastructure for wildlife in Nepal
Nepal’s highways saw 108 roadkills of endangered wildlife last year. There were even more hit-and-run fatalities of animals outside protected areas, even though vehicular flow fell during the five months of Covid-19 lockdown.
Many of Nepal’s new infrastructure like highways, railways, irrigation canals and transmission lines crisscross natural habitats and jungle corridors. But infrastructure need not necessarily be a bad word for conservation – there can also be wildlife-friendly infrastructure.
Underpasses and crossings, for instance, have been shown to ease the free movement of large and small mammals, further decreasing the chance that they are hit by speeding trucks and buses. However, much like the haphazard construction of new roads in Nepal, unscientific infrastructure meant to aid wildlife can in fact adversely affect them, sometimes even decimate the last few remaining populations of endangered species.
Read also: Underpasses to reduce roadkill in Nepal, Tufan Neupane
When the city of Davis in California retrofitted a toad tunnel underneath a newly constructed six-lane highway in 1995, instead of protecting local toad and frog populations, they ended up killing them because the heat from lights meant to attract frogs killed them.
The luckier ones were eaten by hungry birds that quickly learned that the tunnel was a free meal takeaway. Conservationists have come a long way since then, and have learnt from their mistakes.
Wildlife corridors across infrastructure need to be designed carefully so that they minimise road carnage, and not result in collateral damage. Nepal has started taking baby steps in developing wildlife-friendly linear infrastructures -- a cross-ministerial approach contributing to natural resources safeguards.
The Department of Roads (DoR) piloted four underpasses across Narayangad-Muglin Highway, two in Ramnagar and the other two in the Aaptari stretch of Barandabhar Corridor Forest. Every two consecutive underpasses were spaced 50m apart and all of them with dimensions, 4 m wide and 5.5 m in height.
When evaluated separately by World Wildlife Fund (WWF) Nepal under Hariyo Ban Program for an intermittent one-month spell thrice in a year, 15 animals were spotted using the tunnels. A National Trust for Nature Conservation (NTNC) study reported 7 wildlife species from a 15-days camera trap monitoring study.
Despite the dimensions, the underpasses seem to have served their preliminary purpose of habitat connectivity. These structures were functional also because waterholes were in close proximity and fences installed 2km along the roadside helped to funnel wildlife through the desired path.
The Banke National Park piloted six canopy crossings for arboreal animals along the busy East-West Highway in collaboration with Hariyo Ban Program II. Afterward, the crossings were found to be used by Rhesus macaque, Tarai gray langur, Asian palm civet among others. These arboreal bridges are not only cost-effective but highly scalable in locations where highways traverse dense forests.
Other infrastructure like railways, transmission lines, and irrigation canals also require consideration since they are such obstacles to animal movement. Flash flood crossing zones constructed over Sikta Irrigation Project's main canals, for instance, act as wildlife overpasses and facilitate migration in the Kamdi Corridor which connects Nepal's Banke National Park to India's Suhelwa Wildlife Sanctuary.
More such structures have been built recently with village road bridges to reduce wildlife drowning, especially in biodiversity hotspot areas. The Mahakali III Irrigation project that directly fragments Shuklaphanta National Park's core area now has incorporated six bridges to allow even the passage of elephant herds.
Wildlife-friendly linear infrastructures is gradually getting recognised by engineers in Nepal as a solution-oriented approach in conservation. This is also thanks to the Nepal government for commissioning environmental units, and getting conservationists and planners to work together.
International standards today restrict developers from any construction activity in key biodiversity areas. But if that is not possible, minimisation is the next action followed by mitigation to lessen the adverse impact. If there are fatalities, compensation must also be factored in.
Nepal now awaits endorsement of wildlife-friendly linear infrastructure guidelines from the Cabinet, prepared in leadership of the Ministry of Forest and Environment (MoFE) – this would be a milestone in smart linear infrastructure as Nepal upgrades connectivity as it aims to reach middle-income status by 2030.
Read also: Nepal needs wildlife friendly highways, Pramod Neupane
In this year’s budget, the government allocated Rs15.34 billion to upgrade highways, and that includes installation of additional wildlife crossings along the E-W highway. But we should design connectivity solutions that are built on best practices in Asia.
Future safeguard designs should reflect the need of almost the entire animal taxa whose habitat has been encroached by the expansion of infrastructure through a combination of overpasses and underpasses. This requires careful design and landscaping the natural environment while retaining its functionality.
Design specifications (usually structure dimension, openness, spacing, and slope considerations), adapted to local conditions, are equally important to ensure such structures become operational after construction. Another important aspect is roadside intervention such as fencing, and restoration of degraded land using native soil and local vegetation.
Finally, post-construction evaluation is an indispensable part of the entire project, to gauge the performance of crossings and determine whether the employed mitigation strategies were effective. A genuine assessment of frequent usage, lowered road mishaps, and reduced human-wildlife conflict will provide valuable feedback to improve the structures.
Biraj Shrestha is the Independent Consultant (Nepal Liaison) for the USAID Linear Infrastructure Safeguards in Asia (LISA) Project. [email protected]
Pramod Neupane is the Sustainable Infrastructure Programs Manager at WWF Nepal.