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Need some help with this one

860 Views 6 Replies 6 Participants Last post by  Trail Ninja
I don't know how to fix this - it's a giant hole cause by erosion. It's a spot on the canal trail in Augusta, GA. The canal trail sees a lot of different users (kids, newbies, runners, dogs, etc) and it's just a matter of time before someone falls into this thing. I have no idea how to fix it...or if it even is fixable.

I've been riding this trail a little over two years, and there's always been a rut here - and it hasn't changed the whole time. But recently our area had a lot of rain. Steady rain for two weeks straight it seemed like. The rut is now gone, replaced by a giant hole.

Here it is, my bike is there to give a sense of scale.

The natural line to follow riding CCW will put your front tire right into that piece of rock...then you're going in the hole.

Looks like the trail was armored a long time ago, but then people started riding around it. The armored section has actually held up pretty well, it's only in the hole because it lost support and fell in.

On the high side, the trail is funneling water into the hole. It's like a little gulley. The soil is very sandy in this area.

Again, for a sense of scale:

So...lets hear some ideas.
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Is it possible to bring in fill? In a truck? That would help a lot.

The picture appears to show the eroded section directly on the fall line, is that correct?

Evaluate how far you have to divert water to keep it out of your problem area. Start at the top of the slope, dig a channel (use the spoil to build up the downhill side) at a ~45 degree angle to the slope. Use some of the spoil to fill across the proto-ravine to divert water into your drainage channel.

Repeat the process at several points down the eroded trail. Obviously, this will only work in the heavily eroded area if you have a bunch of fill to bring the bottom up high enough to roll the water off to the side of the trail. The limiting factor is how much fill you can move, then secondly how well you shape it to keep the same thing from happening again.

The idea is to divert as much water as possible from the top of the trail, before it rolls down into the eroded section.

You'd be better off if the trail could be relocated somewhere else, and the repaired section was allowed to grow vegetation to hold it together.

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You will have to deal with the underlying drainage problem that caused the damage (obviously :)), otherwise it will move to another spot and/or wash out the fill, just as it has done. Having done that, you can fill the groove with gravel, stone, or even busted out concrete, add a topcoat of suitable soil or other amoring, depending on the site.
Re-claim & Re-route

F that hole, fill it in with slash and debris, which will catch the sediment in the runoff, then get away from it. Reroute your trail following the half rule to avoid future problems.

Good Luck!
Does the water ever cross the trail? It looks like you have a man made dike there and your problem hole is water trying to get to the river/canal on the left side of the dike/trail. If you help it along with a culvert uphill near the hole (you can't fight water), you can fill the rest and the water shouldn't erode that side of the trail.

If I'm wrong and the water needs to be on the right side of the trail, maybe moving the rock to shore up the trail edge and letting the water flow further to the right where the rock is now, will work.
From the pics it looks like the trail runs down a pretty massive gully. It's gonna be real tough to fix that with such a huge ditch. Water is going to want to run down it unless you make some serious changes. I'd agree that re-routing the trail may be the best option.

There's certainly no easy fix. If re-routing isn't an option, you could consider filling the hole with rock, and a lot of it. Dirt won't work because it will keep washing out. I would normally recommend water bars but a ditch this big doesn't allow for it.

As a temporary fix, you could try to knock some of that dirt down and smooth out the ditch. Maybe build a little rock fence/wall before it so people have some idea that it's there and don't follow the line of the trail into it. Big ups for trying to fix it!
Hmmm... There's water on both sides of that trail. the canal on one side and the river on the other. The trail is on a dike. That hole could be a sink hole. Depending on where on the Canal Trail that spot is, it may not be possible to reroute it.

In that case I'd suggest BIG rock to fill it and to try to keep the trail from falling in. I'm sure the city engineers will want to have a hand in it.

Make sure they are aware of it.
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