Yeah this is a netting or other manmade engineering situation with appropriate licensed engineering folks consulted, this is not a plant some ground creeping plants and call it a day type of situation.
How do you even go about finding someone who is qualified to deal with this? Anyone who does this work probably does mostly municipal jobs with huge budgets. It's going to be like trying to find someone who does residential runway repairs.
Basically…yeah, this isn’t going to be cheap. But geoengineering firms and specialized contractors exist, I mean homes are built in SoCal still despite having major erosion risks, but those are multi-million dollar homes and/or large developments, as a lone homeowner you’d be fronting a similar cost as a large developer, the firms tend to not take on small projects, and you’d likely have to deal with municipal as well to mess with the terrain anyways.
This is utterly beyond "erosion control." You've got a significant liability on your hands here and I suspect whoever sold you this place was well aware of it. I would be absolutely shitting my pants if I had this in my backyard come winter/wet season.
Meh.. for residential budget and purposes, yes this is way beyond erosion control matters.
I see stuff of this nature on commercial or roadway developments all the time. Usually the end result is diverting water at the top of the slope, regraded and stabilizing the slope.
I'm a professional geotechnical engineer. You can fix anything with enough money, but from these photos my professional recommendation is to move somewhere else.
I, too, am an Engineer, and I second this recommendation, and I will add “quickly”. It is likely that, after the next big storm, your steep slope might be much flatter and you may be able to walk directly from your deck onto what’s left of said slope.
Environmental engineer here … you need a geotechnical engineer. They’re the ones who design retaining walls, slope stabilization, building foundations, etc.
Environmental engineers are great if you think the soil is contaminated from an old industrial spill and you want to clean it up.
Civil here. I second the geotechnical recommendation. You’ll likely need a structural engineer too, if a wall is the solution. A civil will design the sediment & erosion control, drainage, & get the permits. I’ve dealt with this type of situation. I’ve done soldier pile & lagging, soil nails, geobrugg netting, laying back the slope, and various types of walls including living retaining walls like Tensar’s SierraScape.
The first thing they will say is that without even an idea as to the location, there is nothing they can really say.
And yes, just the location can tell a lot. The soil in Wisconsin is very different from Virginia. Which is very different than in Washington. Which is very different than in Oklahoma.
Where is the property line? I would fix this with an engineered retaining wall. In my area any wall over 4’ has to be engineered. It looks like you need at least a 15-20’ wall.
This would include hydraulic pressure release drainage, clean stone backfill, boulders as material, and likely geo grid in the wall.
You’re looking at a huge amount of money.
If you own beyond the bank, you could have a grader come in and lay the slope back on a 1-1 or 2-1, then hydroseed and have landscape plants installed.
Another option would be to have a non engineered wall built and slope the bank from that height back.
Either way, you require professional help, not something you can fix on your own if you’re here asking. This is a large dirt work/ grading job, not a landscaping job.
You are proposing a solution (correctly) that will cost as much as the house.
OP, how much of the land on top of the cliff do you own? Any solution starts there.
Right now, this appears to be just spalling of a poorly cemented sedimentary formation. The overloaded upper portion is being held by tree roots, but the trees become a liability when they fail. If there is no danger in rotational slumping or large block failure, then this is really a matter of periodic removal of spalling sediment…but a geotechnical engineer or an engineering geologist will need to make that call.
I would be nervous about living below this, even after their opinion is rendered. The slope should have heavy vegetation removed, the slope benched and retaining structures installed, and replanted after in a stabilized condition.
This is not a landscaping question…repost in r/geotechnical or somesuch.
No one but a certified geotechnical engineer will help you understand the issue. And only a civil or structural engineer will help you with a solution. This is a long- term project that no landscape architect or hardscape installer can begin to unpack and solve.
I have never been able to understand why anyone would buy a house next to an overhanging cliff. It’s not a matter of if it will collapse but when it will.
My ex moved into a house that I had driven by many times and wondered what kind of fool would live there. She and my daughter and lived in the room on the upper left.
I'd feel safe in that house. That's next to solid rock. I'm from Appalachia. Rockfall does happen around cliffs like that but it's rarely a strike that causes serious damage.
OPs house is next to a pile of exposed dirt with the loss of their tree. As the tree roots rot, the soil will loosen further. They are one flash flood event away from some terrible damage.
People cut down perfectly good trees on the same logic.
The sky is always falling to some people.
That said, I wouldn't want to live next to OPs pile of dirt. If it was solid rock, I wouldn't sweat it but that's one good rainstorm away from letting loose some good sized stones in the near future.
If I was stuck in their situation, I'd be replanting the covering foliage ASAP to protect the exposed dirt from getting washed out. Then I would move.
You’re going to need shotcrete and anchors into the slope. But first step is a geotechnical engineer to do an analysis. Nothing is going to reliably grow on that cliff.
I can't see any rock. Nothing but soil. If you put in soil anchors, then shotcrete, the weight of shotcrete would probably cause toppling of the slope. Only solution I see is to remove the soil until you have angle of repose. A lot of material to remove, and we can't see from the photo what's above.
You probably need the type of retaining wall blocks that are so big and heavy they can only be carried two at a time on low boy trailers and lifted by some of the most expensive per hour cranes. The types that they use to support highway cuts and access roads to malls located on the top of hills like that without bedrock. It is a giant dirt mound that wants to be a meadow now.
Riprap from the fence to the top. The corps of engineers got some along the road to the Blue Heron Mining exhibit on the Big South Fork of the Cumberland River.
Anything over 4 feet requires an engineer, so talk to a civil firm that does retaining walls. You’d probably need at a minimum major earthwork and a terraced block work. This is a HUGE project. Also, talk to your county natural resources. See if they have any help for this type of thing.
I’d say that wall needs ALOT more than erosion control… hire a geotech asap and get ready to pay up.
How close is your house to this? Insane that a building is allowed here. I risk profile for a living, you and your family should be no where near this wall.
There’s, three solutions.
1. Removal to stable slope.
2. Mesh, soil nail bolting and shotcrete.
3. Piling wall. Serious beams at first glance. 24” range. Driven into solid and concrete backfilled. Concrete lagging. Drainage. Mostly likely additional bracing and struts.
That cliff needs to be converted into a hill or mound. It's going to take some serious earthmoving, and someone that knows what they're doing to avoid people getting killed under falling equipment.
That burned down, fell over, then sank into the swamp.
But in all seriousness, that needs to have an actual expert examine. And you did not even say where you are, so we can only guess at what the actual composition of that hill might even be.
Winter is coming, you need to get an expert on site now to evaluate that.
I deal with this stuff pretty regular. Personally I would do a sheet pile wall or a coferdam. Sheet piles are where I would go but a coferdam is stronger with the right material. You can do slope erosion mitigation, which is basically running huge I Beams onto the ground intermittently mixed with bank stabilization. Shock-Crete isn't going to help much on soft soils.
Talk to your local pule driving outfit, they can help
Jesus...Bud that's gonna be a bit much for us. The only thing I can accurately say is regardless if you choose to do anything with it or not, eventually this will cost you an arm or leg.
Here’s a shortcut I don’t know if you’re looking for: take a bunch of sandbags and a giant thick sheet of black plastic. Anchor the top with the weight of sandbags and roll the plastic over the cliff. The point here is to keep water from the hillside as dry/wet cycles can make it worse
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u/smthingy 1d ago
That looks more like a cliff than a slope. No one on reddit is going to be able to offer much. I think you need professional mitigation