I’ve spent time the last couple of weekends on erosion control. Reinforced a few small gully heads in the valley with hardwood, and a significant gully besides the main road with rocks. Also collapsed and evened out a tunnel in the western slope (still several more of them to go!).
Idea behind blocking up the erosion face is simply to stop progression of the head by providing some support to the existing face and any soil that collapses from it.
Different gully this one. Not so concerned about it as I suspect the swale further up the hill will prevent water flow over it and thereby limit further erosion. That reminds me that I haven’t written about or shown the swale yet!
Another larger head. What happens is the softer clay based subsoil erodes away out from under the topsoil, which then collapses down.
Here’s a photo of the gully beside the main road in, part way through its lining with rock. The side wall have been collapsing following the recent rain. That then gets washed downhill and the process continues. The rock should provide some support to stop the on-going collapse.
Video of the finished product
A little further up the hill I’ve tried to support another collapsing face also. Not sure if it will be successful as the foundation rocks aren’t really supported/bedded into anything firm – they are mostly just sitting on top of sandstone. Will have to wait and see if they hold.
This is where all the rock in the above photos has come from – a small area where it wasn’t even obvious there was any rock, thanks to a covering of lantana. It is on the final slope just prior to arriving at the campsite. Still plenty there too…
Here’s some initial in-fill of erosion in the main road with small rocks, prior to filling in with dirt and gravel.
Finally, the rewarding view after hard work. 🙂 This one is from Saturday evening.
Why not finish off with a roasted marshmallow also!
Where did you get the idea of using timber. I have seen plenty of articles on using rock but not timber. Been in the back paddock recently and noticed that fallen tree’s and limbs hold back a lot of soil.
John (previous owner) used to dump timber/trunks/branches into gullys, and can see in some instances where it is holding soil up and preventing it eroding away. Depends on circumstances/arrangement though – have also seen other instances where the water goes around it and widens the erosion channel!
Also seen some using logs on youtube, though in a slightly different way.
Whilst the logs won’t last forever, they are hardwood and will last a long time – enough to stabilise the soil and get a good groundcover growing I expect.