Constructing Roads, Landings and Quarries
The following section summarizes the recommended best management
practices for constructing roads, landings and quarries. As these
are only brief summaries, you should also check out more
in the Karst
Management Handbook for British Columbia.
Low Vulnerability Areas
The following best management practices are recommended:
- Conduct safety briefings for appropriate personnel.
- Flag karst features and/or values within the operating area.
- Notify the Forest Service district office if landslides or
other disturbances occur which could affect karst features.
- Modify or cease operations if previously unidentified karst
features or values are encountered during road, landing or quarry
construction, and notify
the Forest Service district office.
- Avoid construction activities during periods of heavy rainfall.
- Avoid importing ballast from non-karst terrain.
- Stabilize disturbed areas, such as quarries, to reduce erosion
- When constructing temporary access structures, avoid karst
features, maintain surface drainage patterns, and minimize runoff
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Moderate Vulnerability Areas
In addition to the recommendations for low vulnerability areas,
the following best management practices are recommended on moderate
- Directionally fall and yard right-of-way trees away from roadside
- Pile surplus construction material away from surface
karst features, exposed epikarst, and
streams leading into features.
- Avoid drilling or blasting near karst features, or if this
is not possible, use mitigative strategies such as delayed charges,
blasting mats, etc.
- Use overlanding road construction methods near roadside
- Avoid fueling or servicing machinery near surface karst features
and cave entrances.
- Keep the wheels or tracks of equipment at least 5 metres from
the edge of roadside karst features. If not possible, keep wheels
or tracks parallel to the edge of features.
- Avoid removing gravel or fill from roadside depression
- Minimize clearing of roadside vegetation.
- Use sediment traps and vegetated infiltration areas to prevent
road runoff entering exposed epikarst, surface karst features,
cave entrances or sinking streams.
- Complete construction activities so that cut and fill slopes
have time to revegetate before the wetter months of the year.
- Reduce road runoff by leaving roads on exposed carbonate
bedrock unsealed. Use geotextile
materials if sedimentation of groundwater is a potential
- Crown the surface of sealed roads to facilitate lateral diffuse
- Direct runoff from bridge decks away from stream channels
and into vegetated cover along stream banks.
- Minimize potential sedimentation problems by using geotextile
materials on bridge decks and around bridge ends.
- Avoid the use of chemically treated wood for bridges.
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High Vulnerability Areas
In addition to the recommendations for low and moderate vulnerability
areas, the following best management practices are recommended
- Exposed, well-developed epikarst should only be crossed by
relatively short segments of temporary road that can be readily
Consider the following specialized road construction techniques:
- Use overlanding road construction methods as much as possible.
- Avoid or minimize grubbing;
flush cut stumps, and avoid pulling stumps.
- Minimize clearing widths, road widths and landing surface
- Use the largest possible ballast material
to build up roads, to span or infill epikarst cavities, and
runoff from the road surface.
- Avoid using fine materials for road building.
- Roadside ditches are generally not necessary since runoff
percolates directly into the bedrock.
- Obtain ballast material from nearby low or moderate vulnerability
- Use geotextile materials to minimize sediment transfer
into subsurface drainage systems.
- Consider the use of geogrids for spanning epikarst cavities.
- Consider using bridging mechanisms to raise or span
roads over short sections of significant epikarst features.
- Where practical, use rock drilling/hammering instead of blasting
on well-developed epikarst. Where blasting is used, seek the
advice of a qualified professional.
- Post public warning signs and close areas while blasting
near surface karst features or caves that may be used for recreation.
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