From the U.S. Forest Service Handbook:Draining Water Off Existing TrailsKnicks
Puddles that form in flat areas on existing trails may cause several kinds of tread damage. Traffic going around puddles widens the trail (and eventually the puddle). Standing water usually weakens the tread and the backslopes. Water can cause a bog to develop if the soils are right. Traffic on the soft lower edge of a puddle can lead to step-throughs
, where users step through the edge of the trail, breaking it down. Step-throughs are one of the causes of tread creep.
is an effective outsloped drain. Knicks are constructed into existing trails
(figure 13). For a knick to be effective, the trail tread must have a lower ground next to it so the water has a place to drain.
A knick is a shaved down semicircle about 3 meters (10 feet) long that is outsloped about 15 percent in the center (figure 14). Knicks are smooth and subtle and should be unnoticeable to users.
If terrain prevents such outsloping, the next best solution is to cut a puddle drain
at least 600 millimeters (24 inches) wide, extending across the entire width of the tread. Feather the edges of the drain into the tread so trail users don't trip. Plant rocks or other large stationary objects (guide structures) along the lower edge of the tread to keep traffic in the center. In a really long puddle, construct several drains at what appear to be the deepest spots.
Are "puddle drains" the solution?