If you plan on spending any time whatsoever off concrete, odds are that you will be walking on a trail. If you aren’t walking on one, any repeated crossing on the same ground will, in fact, yield a trail sooner or later. If built right, trails can last indefinitely. The key phrase here is “built right.” If it is built poorly, then trails can have a very damaging effect, eroding the surrounding environment.
With the right preparation and care you can build a trail that can handle hikers, bikers, horses, and anything else that can tread on dirt. A few simple tips will mean the difference between erosion and permanent enjoyment.
Step 1: Know your slope
If you think about the slope of a trail, you may think simply about the direction people will be walking/biking etc. But the angle of the fall line, or basically the slope that water flows, is very important to the trail that crosses the slope.
Any trail that follows the fall line will not be a trail for long. The slope will just attract water and that will become the next river/creek/stream etc down the hill.
The main rule to follow is the half rule. The half rule is simple: a trail’s angle (grade) can be no more than the grade of the slope it is crossing. So if the hill you are on has a 30 degree slope, your trail can have no more than a 15% grade for it to last.
The other key is to have the downhill side of your trail slightly lower than the uphill side, so that any water can continue to run down the hill. Doing the opposite is a surefire way to become a mud magnet.
If anyone has ever told you to “take the path of least resistance”, it was probably meant figuratively. But in life everybody will take the literal “path of least resistance” if they can. This means cutting corners and switchbacks, or taking a better route around a rock/tree if the trail is not easiest. It is for this reason that you need to be thinking 5 steps ahead, and working alongside the terrain’s natural ebbs and flows.
If a certain route can’t be avoided but you are sure that the route will be compromised, it might be a good idea to put some obstacles in the way, such as a dead log, rock (or a collection of rocks), or other items that would deter people from veering off the path.
Step 3: Stunts are your friend!
This applies mostly to mountain bikes, but can also apply to walking trails — albeit on a much less “gnarly” scale. But if there is sensitive terrain such as a wetland, marshy bit, or water crossing, you can mitigate the human erosion factor by building some fun features such as a ladder or rock bridges, platforms, teeter totters, etc… anything that keeps the trail user(s) from interacting with the ground.
For a hiking trail a simple boardwalk can suffice. It is relatively easy to construct, and depending on the jurisdiction you live in, you can likely use dead wood lying near the trail to make the ultimate in sustainability.
There are many other methods for building a sustainable trail, and I recommend the book Trail Solutions: IMBA’s Gudie to Building Sweet Singletrack, put out by the International Mountain Bicycling Association (IMBA). It is easily the best resource out there, despite it’s limited availability.
Hope to see you out on the trails! Remember to check with the local authorities before building your masterpiece.