1. Latin America and Caribbean Region
Biodiversity Conservation in Road Projects: Lessons from World Bank Experience in Latin America
George Ledec, Lead Ecologist
Paula Posas, Environmental Specialist
Latin America and Caribbean Region
The World Bank

2. What is Biodiversity? Biodiversity The Current Loss of Biodiversity
The variety of life on Earth, in terms of ecosystems, species, and genes.
The Current Loss of Biodiversity
One of the world’s major environmental problems.
Irreversible (extinction is forever).

3. Main Causes of Biodiversity Loss
Most important cause today is the loss and degradation of natural habitats upon which most animal and plant species depend for survival.
Other important causes are direct over-exploitation and the spread of non-native, invasive species.

4. Adverse Impacts from Roads on Biodiversity – Induced and Direct
Induced impacts result from human activities facilitated by the road construction or improvement, rather than from the road works themselves. Often called “indirect impacts”.
Direct impacts are the effects of the road works themselves (construction, improvement, rehabilitation, or maintenance) on natural habitats or species of conservation concern.

5. Examples of Potential Adverse Impacts of Road Works on Biodiversity
Induced Impacts:
Settlement of remote areas
Deforestation or other land clearing
Excessive wood cutting
Hunting of vulnerable species
Direct Impacts:
Direct loss of natural habitats (ROW and complementary works)
Fragmentation of natural habitats
Altered drainage patterns
Pollution or sedimentation of aquatic ecosystems
Disturbance from construction workers
Wildlife road kills

6. How to Mitigate the Induced Impacts
Two Basic Options:
1. Choose the road alignment to avoid or minimize adverse impacts.
2. Use protected areas to reduce or compensate for adverse impacts.

7. Road Alignment Choose alignments which:
Avoid or minimize contact with critical natural habitats (existing and proposed protected areas, and other sites of high conservation value).
Avoid or minimize contact with natural forests, which are especially vulnerable to road-induced land use changes.
Serve more densely-settled rural areas, while avoiding the “agricultural frontier”.

8. Protected Areas
If contact with natural habitats is inevitable, it may be feasible to establish strict protection zones alongside the road (e.g. extending Braulio Carrillo National Park in Costa Rica).
Where significant natural habitat loss is likely, road projects should support compensatory protected areas (e.g. protecting the Rio Negro Canyon as part of the Colombia Bogota-Medellin Toll Road Project).

9. Mitigating the Direct Impacts
Typically easier than mitigating the induced impacts (more under direct control of roads agencies).
The following recommendations also apply to other linear projects (railways, power lines, pipelines, etc.).

10. Road Alignment
Choose alignments which avoid or minimize contact with critical natural habitats (important regarding direct, as well as induced, impacts).
To minimize natural habitat fragmentation, roads should be sited to share the same corridor with existing (or planned) railways, pipelines, or power lines.

11. Road Engineering Maintaining Natural Water Flows:
Include proper drainage works to avoid blocking natural flows (especially in large wetlands).
Minimizing Fragmentation of Natural Habitats:
Where feasible, maintain tree canopy cover over parts of the road, for arboreal animal crossings.
In sensitive sites, install underpasses or other animal passage facilities.

12. Complementary Works
Locate construction camps, storage yards, and related facilities so as to avoid or minimize the removal of natural vegetation.

13. Construction and Maintenance Practices
Control erosion and runoff, to avoid damaging waterways and wetlands (important for aquatic biodiversity).
Ensure that all solid and liquid construction wastes (including excavated earth) do not enter waterways and wetlands.
Avoid washing vehicles or changing lubricants in waterways and wetlands.

14. Obtaining Construction Materials
Avoid critical natural habitats and other sensitive sites (wet river beds, nesting beaches, etc.) when extracting rocks, gravel, sand, wood, or other construction material.

15. Restoring Borrow Pits
Where feasible after construction, restore borrow pits as a useful wildlife habitat. Undrained borrow pits can become biodiversity-friendly artificial wetlands, especially if they have gently-sloping banks and an irregular shape, without straight lines (NOT like an Olympic swimming pool).

16. Vegetation in the Right-of-Way
Maintain the maximum possible natural vegetation in the ROW, consistent with drainage and traffic safety requirements.
Relatively broad ROWs with natural vegetation can serve as useful biological corridors between larger natural habitat patches (e.g. ungrazed ROWs in Uruguayan grasslands).

17. Options to Minimize Wildlife Road Kills
Animal passage facilities—underpasses, overpasses, tree canopy “bridges”.
Reduce road speeds through structural means—maintain roads to lower standards, install speed bumps, signs, etc.
Enforce speed limits.
Restrict night-time traffic in highly sensitive areas.

18. Worker Behavior
Prohibit hunting, fishing, wildlife capture, plant collection, or burning of natural vegetation by construction workers or contractors.
Only security personnel should have firearms.

19. Environmental Supervision
Ensure strict supervision of compliance with environmental requirements in the field.
Bidding documents and contracts need to specify the environmental rules, including penalties for non-compliance.

20. The Biodiversity Conservation Challenge for Road Projects
Create and improve transportation infrastructure, without significant harm--induced or direct--to natural habitats or to species of conservation concern.