The term “white glove” can be commonly associated with providing meticulous and delicate attention to a service provided, and to “handle with care”. On this World Environment Day, we’d like to share a new approach that takes this concept and applies it to our natural world. After all, we only have one Earth and its natural habitat should be treated with care to ensure there is clean air, fresh water and thriving ecosystems for current and future generations.
Minimizing impacts to critical natural habitat from transmission lines
First, let’s talk about another precious resource that is also provided by nature: Electricity. Providing electricity to previously unsupplied regions means more than late night television; it provides light for children to study and learn, refrigeration to allow food and medicines a longer shelf life, lower energy costs, fewer emissions, and significantly increases the economic productivity and potential of the area. Certainly, providing and maintaining a reliable electric service to an area brings economic and social benefits to the inhabitants and, of course, profit to the supplier. However, this growth and development could pose direct and indirect risks to the natural environment.
Direct impacts include:
- Vegetation loss;
- Wildlife mortality due to loss of habitat, collision or electrocution;
- Edge effect; and
- Fragmentation, or barrier effect, on animals.
Indirect impacts include:
- Ongoing deforestation;
- Introduction of non-native or invasive species; and
- Disturbance due to increased access and use by humans resulting in illegal hunting, dumping and mining.
These effects can be most damaging in Critical Natural Habitat (CNH) areas such as national parks, wildlife refuges, biodiversity hotspots and other protected areas.
To tackle this challenge, the Inter-American Development Bank (IDB) partnered with The Nature Conservancy (TNC) to develop the White Glove Approach, a guidance note on how to best avoid and minimize impacts from the planning and design, construction, operation, maintenance and decommissioning of transmission and distribution lines in Critical Natural Habitats.
The concept is simple and follows the standard Mitigation Hierarchy:
- Avoidance: measures taken to avoid creating impacts from the outset such as careful spatial or temporal placement of elements of infrastructure
- Minimization: measures taken to reduce the duration, intensity and / or extent of impacts (including direct, indirect and cumulative impacts) which cannot be completely avoided
- Restoration/Rehabilitation: measures taken to restore altered ecosystems or rehabilitate degraded ecosystems following exposure to impacts that cannot be completely avoided or minimized
- Offset/Compensate: measures taken to compensate for any residual significant, adverse impacts that cannot be avoided, minimized, rehabilitated or restored, in order to achieve no net loss or a net gain of biodiversity
With these principles in mind, the White Glove Approach seeks to establish a few simple best practice approaches in the development of transmission lines with the ultimate goal of protecting these sensitive environments.
The process begins in the feasibility and design phase. Project planners should identify potential alignments or alternative routing that stay outside of these protected environments; the best way to avoid impacts to CNH is to stay outside of CNH. The design phase should also consider specific design features to reduce impacts including: right-of-way width, pole type and height, span lengths, conductor cable (wire) alignment as well as the option of an underground cable rather than overhead lines, in certain situations.
When transmission lines must pass through CNH, a few simple tweaks to standard engineering design can greatly minimize potential impacts.
- Projects should avoid the creation of new access roads. This can be accomplished by using existing roads or infrastructure corridors such as pipelines, railroads and other transmission lines. Avoiding the creation of new access roads reduces deforestation and eliminates long-term indirect impacts such as barrier effect and increased human access and use. Construction and monitoring of the transmission line will be affected as all materials and personnel will have to be transported to the tower sites via helicopter, on donkeys or on foot.
- Projects should avoid vegetation removal along the right-of-way in between structures including forest canopy. This activity can be accomplished by constructing taller towers and changing the spacing in between towers. These measures greatly reduce the impacts to wildlife and biodiversity in general.
- Work areas such as tower sites, laydown yards, and work camps should be situated outside the protected area and restored or rehabilitated following construction activities. A Revegetation Plan to restore the work areas should be prepared using native species. In addition, a Monitoring Plan should be prepared to check on the regrowth of the revegetated areas for a minimum of 5 years.
- Projects must consider a biodiversity offset to compensate for losses not mitigated by the measures described above and to ensure no net loss to biodiversity. Offsets should be developed based on the magnitude of the project’s impacts and can range from restoration of degraded areas to establishment and management of a federally designated protected area.
- Other measures can be implemented based on site specific impacts such as the preparation of an Avian Protection Plan (APP) in line with the Avian Power Line Interaction Committee (APLIC) standards. This plan may include installation of bird diverters (which could reduce bird collision frequency by at least 50-60%), nesting boxes, or anti-perching devices. Off-site tower construction can also minimize the size of work areas in protected area. Lastly, a robust access control plan can reduce or eliminate indirect impacts from other users.