Water bars are simply little trenches built on grades to assist water
drainage and prevent erosion of your trail. They are bandaids for improperly
built trails (trails that go straight down the fall line). They are mandatory
to keep your trail alive if water runs down your trail. Walk over your
trail during a rainstorm. Anywhere water drains down your trail is where
you should use a water bar. You don't need drainage where water flows across
your trail. Puddles are okay but watch the don't spill off down your trail.
If you have a lot of clay in your soil you might consider providing drainage
After experience with all kinds of waterbars and visiting the IMBA
site I have discovered that the rolling grade dip is the only way to go.
Rolling Grade Dip
Thanks to: Krisztina Holly of Mountain
Bike Magazine that I copied this from.
If you don't want this posted here just e-mail me.
Start with a properly cut sidehill trail (one that hugs the side of the
hill), with the outslope (outside) edge of the trail 3 degrees lower than
the backslope. This won't work on a trail going staight up the fall line.
Find out where to put your dips. Visit the trail when it's raining, put
the dips right below the water entry points. Avoid rocks and roots if you
Mark the center of each stucture with two stakes at either side of the
trail. the line between the stakes should not be quite perpendicular to
the trail, at about 60 degrees. When you're laying out the structure, imagine
the dip having the cross section of a soup spoon. The dip is like the bowl
of the soup spoon , with a small berm rising up below it like a curved
Begin digging the dip into the trail surface about 5-6 feet above the stakes,
and work your way down. The deepest point, about two feet from the stakes
and near the outslope edge, need only be about 3-4 inches deep. Near the
backslope edge, the dip should become short and shallow so that it blends
in with the hill.
Use the excavated dirt to build a 6-9 inch-high berm across the trail below
the stakes. Build a ramp from the top of the berm to the trail surface
8 feet down the trail.(Note: These specifications are appropriate for a
12 % grade trail, for steeper trails make the stuctures deeper and and
Smooth out the dip with a hoe or rake so that it's barely noticable. Compact
the surface with the back of a shovel. remove the stakes and you're ready