Cycling in Waterloo Region

[ookpik]

But, seeing as the gravel already washes out, it may be true that asphalt may also wash out over time as well.

That is my concern. On a flat trail away from flowing water there's no doubt that pavement will last longer. But on a sloped trail or one that's subject to flooding my concern is that water could find its way under the pavement, erode the soil below and thus cause the pavement to collapse. I've seen this happen on paved hiking/walking trails in Europe. We've all seen photos in the media of roads that have collapsed due to flooding or underground water flows (so-called Sinkholes.)

Here are paved trails on flat ground in the aftermath of last year's Calgary flood that illustrate the sorts of issues that could arise.

I asked a civil engineering faculty colleague of mine: when water gets underneath asphalt, it does move the asphalt (even potentially uphill). We'll have to see what happens with this path in the next few years.

Interesting. So there is a risk.

P.S. Just to be clear, I'm not against paving this trail. I simply want to understand if washouts could still be an issue after it's done.