Will a Hugelkultur bed help with this erosion?

Hi Friends,

Our house has an erosion problem. We have a downhill driveway and the steep wall between the road and driveway is always on the move. We live in an arid climate with very sandy soil and when we get heavy rains a large rock or two always pops out. I've posted some photos. Will several tiered hugelkultur beds (over time) help with this? The driveway is excessively long and I've tried piling a few branches to get an idea. That's a lot of effort so my thought is starting with one area and building from there. The  slope itself is south facing so could be a great growing area (if I can figure out how to water, ha!). Advice please? I read somewhere that I should go for 5' and then mound with dirt, then plant a cover crop. Thank you

I'm not sure that hugelkultur beds are the best for erosion control of this type. If you were going to use them you would want to make sure the water had a place to go so that the hugelkultur beds were not acting like a swale. Otherwise the hugelkultur beds could be blown out causing worse erosion - they are not meant to hold water like a swale. I also question their ability to function as a toe wall without being built a fair bit differently then they are normally.

What seems to be happening to me is that when the hillside was cut to put in the road it messed up the natural slope and now the hill is essentially regrading its self but of course this is causing problems for you. One option that might help here would be terraces of some sort. You would need to use rocks or something similar that would be strong enough for this sort of work. I don't have much experience with terraces but potentially this could help in the worse areas. You would want to support and build up the base of the slope where it meets the road (a toe wall) - I'm guessing this was what you wanted hugelkultur beds to do. I'm just nervous about the ability of a hugelkultur bed to be able to handle this. I think using rocks or something similar would work better but there are also other methods using woven vegetation (see Contour Wattling) that can work but may be difficult in your arid climate - you would have to determine what sort of plants to use.

I also think an issue is the lack of vegetation on the slope. I'm not sure what type of plants would grow best in your arid climate but I think the lack of vegetation is a major cause for the erosion. But without something stabilizing the base of the slope it will be difficult to get vegetation established near the erosion area. It may also be necessary to have additional stabilizing features higher up to give the plants time to get established - this is how the contour wattling method works.

Here are some links with information that might help:

http://www.unce.unr.edu/publications/files/nr/2010/fs1047.pdf
http://www.laspilitas.com/garden/howto/slope.html
http://www.ecy.wa.gov/programs/sea/pubs/93-30/contwattle.html
http://extensionpublications.unl.edu/assets/pdf/g1307.pdf

Hope that helps and gives you some ideas!

Thank you so much for taking the time to post such a thoughtful reply. Terracing and eventual vegetation to anchor the soil was my goal, and I thought perhaps hugelkultur might be the way to achieve it. I'll check out the links, am unfamiliar with contour wattling and am interested to learn more.

Would it be possible to move the road away from the cut to allow room for the slope to reach the angle of repose (when it will stop moving)?  Otherwise you may be fighting it for decades.

I hadn't thought of moving the driveway - could be cheaper and easier than shoring up the slope. Thanks for the suggestion!

Angle of repose is quite shallow for sandy soil; 25 - 35 degrees.  You might be able to calculate pretty accurately how far over you would need to move the road.  There are various diagrams online if you search the phrase "sandy soil angle of repose."

We had bad cuts into our slopes and there was no vegetation either. We have been building terraces with urbanite. The local concrete companies have been happy to dump it off here for us (free). Even though the terraces are not yet planted we noticed a huge difference with the massive amount of rain we got here in the formerly drought area of California.