# Trail Armoring



## kevmortensen (Aug 4, 2006)

We recently finished up a new trail and when we got to the bottom we ran into a 30+ foot section that was muck from the 7+ inches of rain we received here in So Cal in December. 
It was just a matter of that Huge volume of water seeping down thru the hill. We knew that every winter we would have the same problem 


















So here's what we did. . .

We dug down 12" sloping the bottom of the 'floor' and cutting out drainages running down the hillside. Armored the entire 33' length with large rocks that we harvested off of an old fire road we were shutting down and re-habing. Than we back filled on top of the rocks.
We received some rain right after we completed this and it drained perfect. Day after the rain the armored section was bone dry and hard as cement, the areas on either side were wet .














































Lots More photos of the whole process here

https://s1104.photobucket.com/albums/h333/morty1980/Crestridge Trail Work/?start=all
AND 
https://s278.photobucket.com/albums/kk118/kevmortensen/Crestridge/IMBA Crestridge/?start=all


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## Trail Ninja (Sep 25, 2008)

That's the biggest French drain I've ever seen. Nice work!


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## bsieb (Aug 23, 2003)

If the water is seeping down through the hill what will prevent the rocks from silting in and the water from saturating the whole thing again? Just a thought... I certainly haven't seen the site 'cause I'm snowed/mudded in on some god forsaken mountain in the middle of nowhere.


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## kevmortensen (Aug 4, 2006)

The "floor" of the trench is sloped towards the drains that lead out of the trench and onto the side of the hill. .The water that seeps into this french drain runs thru/around the rocks and out these drains. (i checked this out while it was raining, and you could actually see water flowing out of these drains. . . pretty remarkable) 
This also allows the water that is falling onto the top soil to quickly drain downward thru the topsoil, thru the rocks, and out the drains as well.
So the Q is -'What about the seepage running into the top soil from the hill?
We went uphill about 5' and cut a sloping trench just a few inches deep this takes the water that is seeping thru the top layer of the soil and directs it away from this drain. This technique drastically reduces the volume of water that is seeping down the hillside within the top 6" of soil.
I'll draw up a sketch of everything that we did later tonight. This was an experimental kind of test that we did here and it's worked pretty well. Were about to get another storm here in so cal starting tomorrow, I'll hike out to this spot on Friday and shoot some pics of the water flowing out the drains.


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## justinwp (Nov 12, 2010)

a suggestion for the french drain, top it with a layer of smaller crushed rock. just put a little extra rock on top and bring a sledge hammer to break it up. in my experience, french drains have a limited lifespan if not done properly as they become clogged. a layer of crushed rock or even a synthetic material keeps the mud from filling all the gaps and blocking water flow


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