IMBA World Summit 2010 Resources - All Weather Trails
Designing and Building All-Weather Trails
Woody Keen, Trail Dynamics; President, Professional Trailbuilders Association; Dan Hudson, IMBA Trail Specialist; Rich Edwards, IMBA Trail Solutions Manager
The speakers discussed the best way to build trails for all-weather riding, and focused on how to prevent damage to trails that are typically dry, with occasional periods of wetness. In the ideal world, trail users would avoid using trails when they are wet, whether from rain or snow melt during the spring. Since keeping all users off the trail is unlikely, land managers and trailbuilders need to take measures to prevent damage, without negatively affecting trails when they are dry.
If you’ve modified a trail to be wet-weather friendly, spread the word in your local club and around the community. That way, if people decide to ride in the rain, they can choose the trail that’s most appropriate for the weather, and let the others dry out.
Following IMBA’s trailbuilding guidelines is the best way to create trails that manage water and dry out quickly. However, there are situations where you cannot move existing trails or want to create trails that can be ridden while wet. If that’s the case, consider the following options:
- This method involves modifying the landscape using on-site materials to create raised tread, causeways, basins and mounds.
- The goals is to manipulate the topography to maximize drainage.
- This is a great approach for flatter areas with otherwise good soils.
- This method requires trailbuilders to excavate the area to be reinforced, install a layer of stone, and then cover the stone foundation with native soil.
- Stone foundations improve drainage beneath the trail and provide a hard under-layer, while maintaining the look and feel of the local surroundings.
- You may need to bring in stone from a quarry for foundation. Rock size depends on trail user weight.
- Put rocks close together to create an interlocking puzzle.
- The foundation should be wide enough to accommodate drift in the trail, as riders find the true line.
- Surfacing creates a trail tread using stone-based material (i.e. road-base gravel, fines, flagstones, or a combination of materials).
- The goal is a result that flows like a trail, but is built like a road.
- When surfacing an entire loop, don’t skip areas that seem to be dry. After some usage, seemingly dry areas may not be.
Elevated Wooden Structures
- These structures are also known as boardwalks, log rides and puncheons.
- Elevated wooden structures can be used to change the challenge and/or character of the trail.
- Repairs/rebuilding needs to happen every about five years. Even rot-resistant materials have a limited life.
- Wooden structures carry a higher duty of care to make sure they stay in good condition.
- Wood needs to be ground-contact rated.
- When using treated wood, keep in mind that preservatives will eat away at nails and other fasteners. Whenever the wood is cut or drilled, the newly exposed portions will require additional treatment.
- Ditch and culvert: This method captures water and directs it under the trail using large half-culverts. It’s like building a road, and will likely require the trail corridor to be re-contoured.
- Geotextiles: When there are no other options, Geocloth and other similar measures may be used.
- This method is very costly to install, even more expensive to remove after failure, and will not remedy poor trail layouts (such as fall-line grades).
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