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The Half Rule
Ensure the grade of the trail doesn’t
exceed half the side slope. Otherwise
water will flow down the trail and not
across it resulting in erosion.Water is the enemy of all trails
The 10% Grade
Average
An average grade for the trail of below 10% is the
most sustainable.This may not be achievable
throughout the trail but it is important to use this as the baseline for construction
Grade Reversal
Periodic Grade reversals ensure that water is not
trapped on the trail and flows slowly of the edge and not down the fall-line
Outslope
An outsloped trails ensures that the
water drains gently in a non erosive
manner via “ sheet flow”
Knicks
Like grade reversals and
de-berming trails these allow water to escape slowly from the side of the trail. These
can add in a trail feature for riders
Rolling Grade Dips
These are larger
features than Knicks and provide consistent
drainage on up slopes
and climbs
Climbing Turns
These allow controlled climbs on
steep slopes without the
erosion associated
with a direct climb
Rolling Crown Switch Back
This requires a more advanced
approach by using retaining walls but allows sustainable
construction in upland situations
where high rainfall
is present