…..the word according to IMBA...THE most important rule of all

“KEEP WATER OFF THE TRAIL.” Allow water to flow OVER the trail not…… DOWN it.
       
How:

1) A smooth and gentle backslope.

2) Trail tread with 5 deg. outslope minimum

3) Grade reversals before and after ALL turns.

4) De-berm downhill side of trail so water can flow off trail easily
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5) Employ rolling grade dips and nicks to divert water off trail

6) Never direct trail down the fall line. Trail grade should not exceed more than 50% of the hillside it is built on. Even apparently flat ground.

7) Use natural structure eg. Rocks, Ledges, Steps, Dips, Mounds, and Sideslope to divert water flow off the trail.

     MAINTAIN FLOW: avoid sharp transitions ie. tight turns after long fast sections. This encourages          harsh braking which will destroy smooth trail surface. If it’s tight keep it tight, if open keep it open.

    WHO IS IT FOR :determine what ability of rider the whole trail is for, and stick to it.

    TURNS: can be a maintenance nightmare if not designed well. Keep them on the flattest grades, keep them wide, and build in natural chokes on the upside to encourage gradual braking or slowing.

    SMOOTH EDGES : last longer, minimize erosion and look better.

    STRAIGHT SECTIONS: are for roadies, turning is fun, avoid long straight sections.

    BERMS: make sure all water is diverted off the trail before and immediately after.

    APEXES: where possible use existing trees, rocks and natural features to create permanent apexes that can’t be cut.

IF YOU HAVE WATER RUNNING  DOWN  THE TRAIL, THEN IT IS A DESIGN PROBLEM.

Great trails look and work even better with rain on them.

SUGGESTED READIING: “Building Better Trails,”  IMBA ,or checkout their website…..