Ottawa Mountain Bike Association

PWT re-route

Mathieu Albert October 12, 2020
PWT re-route
A section of PWT Trail at South March Highlands has been closed and re-routed.

If you want to understand why we made this change and learn a thing or two about erosion, trail maintenance, working with landowners, and mountain bike advocacy, read on.

Most mountain bikers acknowledge that severe erosion is bad for trails and must be addressed, but many assume that erosion = mud, therefore only muddy sections of trail should be fixed. This isn’t quite accurate.

Erosion is the movement of soil, rock or dissolved material from one location to another by surface processes – often water flow, but sometimes wind or human-induced or other forces. So sometimes mud can lead to erosion when mud is dispersed to the sides of the trail or transported elsewhere on the feet and tires of trail users, but severe erosion often occurs on trails where mud isn’t the problem.

pwt reroute


That’s the case at the section of PWT that has been re-routed. If you ride PWT starting from Dogsled trail, after you pass the feature known as “Impaler”, you’ll pass through a low, frequently muddy area and encounter a steep, rooty, technical climb. The climb got that way over the course of two decades via the erosive forces of rainfall, hikers’ boots, and skidding tires.

The reason the climb became severely eroded has to do with its steepness. Generally, rainwater wants to take the quickest path down a hillside, and when we provide a quick path in the form of a steep trail, water is only too happy to oblige and destroy the trail.

There are several trail building best practices and rules of thumb when it comes to trail steepness. One is that the average trail grade should not exceed 10%. Another is that the maximum grade should not exceed 15% except on natural rock or built features. Another is that the maximum trail grade should not exceed half of the slope of the hill. So if the slope of the hill is 12%, then the maximum sustainable trail grade on that particular slope is not 15% or 10%, but 6%.

Some common best practices are to route trails roughly perpendicular to slopes instead of straight up and down them, so they “surf” the contours of a hillside, and avoid “fall line” trails that run straight up or down hills, regardless of how steep or gentle the hill is. Another best practice is to incorporate grade reversals and knicks into trails at regular intervals to help divert rainwater off the trail. Another best practice is to build trails as benches or “benchcut” trails on hillsides, and avoid “rake-and-ride” trail construction.

The eroded, rooty climb basically breaks all of those best practices and rules of thumb, so we re-routed it so it follows a less direct and more sustainable path up the hill, primarily on bedrock. We also re-routed the trail to avoid the low muddy area.

The feature known as “Impaler” breaks some of those rules, but it is situated mainly on rock and has not eroded to the same extent as the climb that follows it, so we retained that feature as an optional out-and-back detour that riders can do if they want before returning to the main PWT trail and continuing on.

Some of you will claim that the climb has been like that forever. It hasn’t. I’ve spoken to people that were riding PWT when it was constructed, and they acknowledge that the climb initially started out smooth and became eroded over time. This climb was identified as not sustainable over a decade ago, and it has only gotten worse in the interim, despite attempts to repair the damage.

Some of you will ask why we didn’t keep the trail where it is and simply provide a ride-around or rock armour it. We considered that, but determined that it would require significantly more effort than simply re-routing it, and rock amouring would make the hill even more treacherous when wet, and rainfall would gradually eat away at the foundations of the armouring and destroy it over time.

Some of you will claim that we changed the trail because we suck at riding and we lowered the trail down to our skill level. I don’t know about you, but I have about a 75% success rate on this particular climb, and I am fine with not cleaning it every time. I like challenging trails, and I really liked the challenge that this particular climb gave to me, and it was rewarding when I did manage to clean it. I miss this climb, but at the same time, I recognize that the climb was not sustainable and would continue to erode until it was no longer ridable by even the best, and at some point people would take matters into their own hands and build poorly constructed ride-arounds which would also fall apart.

I also recognize that severely eroded sections of trail like this one give the mountain bike community a bad reputation. This section of trail got that way because of the way it was built, not because of who uses it. However, you know as well as I that the finger of blame is often pointed at the mountain bike community when poorly built trails fall apart with use. Those opposed to mountain biking love cases like this to make their arguments. I don’t know about you, but I’d rather not give ammunition to the enemy.

I’d rather demonstrate that we are responsible trail users and stewards and that we have skill, knowledge and expertise to bring to the table. When it comes to advocating for more trail access, we get further by demonstrating to landowners that we have solutions to their problems, rather than coming to them with a list of wants and demands. Our reputation of good stewardship at South March Highlands has helped open doors for us in Gatineau Park, Carlington Park, Larose Forest, and elsewhere. We continually have to work on maintaining that reputation if we want more places and a greater variety of places to ride.

I would also like to point out that we maintain these trails not for the most skilled rider or the least skilled. We maintain them following best practices, first and foremost, in accordance with our agreement with the landowner. We also we attempt to maintain them to the intended skill level of the trail. So sometimes that means an eroded section of trail will be repaired and brought back to an intermediate or beginner level if that’s what the trail calls for.

If there is an opportunity to build or retain a challenging advanced optional line and keep it sustainable, we’ll do that if it makes sense from a best practices and effort standpoint. We’ve done that at Eye Opener and we’ve done that by retaining Impaler instead of removing it from the trail system entirely. But for the eroded climb, we considered it and decided it wasn’t feasible.

The photo below shows the eroded climb that was re-routed. The yellow lines indicate roughly how wide the trail should be, and the red lines indicate how wide it has grown due to erosion and people doing everything they can to avoid the roots.

The re-route is now open for riding. I’m sure the re-route is not perfect and if you have ideas for making it better and you are prepared to roll up your sleeves and get your hands dirty, contact me and I will put you in touch with the builders.

I ask you to please respect the trail closure and not attempt to reopen it. The city approved this work with the understanding that the original section would be closed for good. Ignoring that and reopening the trail makes the mountain bike community look selfish and can potentially sabotage our efforts to expand riding elsewhere.