Privacy berm slopes 2

[VanBurenSoilGuy]

I have a land developer who wants to put in a properly engineered privacy berm between his subdivision and the neighbooring subdivision. He wants it around 9' tall. What are the standard slopes of a berm? Neglecting soil type. I am looking for the average slope steepness.

 

[fattdad]

Neglecting soil type, there is no answer to your question.

f-d

¡papá gordo ain’t no madre flaca!

 

[cvg]

grass or graveled? clay or sand? is safety a concern? what about multi-use opportunities? lacking anything more, I would go with at least 3:1 or flatter.

 

[beej67]

You can't neglect soil type with this, as your soil type basically drives the answer to your question, and the answer will vary by region because of it.

For example, 2:1 is the usual limit for stuff in central to north Georgia, which has clayey soils, but 3:1 is often required if you're going to seed it instead of sod it. 4:1 is generally the limit down in Florida, where land is flat and soils are sandy. Sometimes regulatory agencies in hillier areas with clay soils will allow you to go 1.5:1 if you sod it, and you *stake* the sod.

Your local land development code usually addresses this issue, and increasingly those are available online. Fish around Google, or possibly Municode. Also don't be shy about talking to your local reviewing agency. Chances are you'll have to get a permit anyway, especially if you're including any drainage works in your plan, which it may very well need.

Basically, you're looking at a berm that's anywhere from 27 to 72 feet wide, depending on local regs. I don't know what your land plan is like, but if losing that real estate gives your developer heart burn, which I find it often does, he'll change his plan fairly quickly from "earthen berm" to "privacy fence with vegetation."

If you get to the point where you are indeed going to do a berm of some height, pay a lot of attention to the drainage so you don't create any birdbaths on either side of it. You may need breaks in the berm, or culverts of some kind. The first time you flood your neighbors out, that berm gets a lot more expensive.




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http://www.campbellcivil.com

 

[jgailla]

beejb7 has an excellent summary.

If it's going to be grassed and mowed, anything below steeper than 4:1 won't work.
We designed some stormwater ponds recently and had the slopes at 3:1 by the request of the client.
I feel sorry for the maintenance staff. The entire area has to be trimmed with a weedeater.

 

[fattdad]

I'd use 3H:1V if you have to mow it. That said, I'd also specify a soil type and a minimum level of compaction.

beejb7 - a fine post!

f-d

¡papá gordo ain’t no madre flaca!

 

[BigH]

Can't remember the name, but there was a product (Greenwall?) which looked like fireplace log holders that could stack on each other - fill the inside with earth and then you can vegetage both sides - flowers, plants, etc. Would take up very little room and be a whole lot more pleasing perhaps.

 

[brandoncdg]

I saw 2:1 or 3:1 with 5'-10' wide flat at the top on most newer projects out in the boonies of Southern California. Don't forget to make that thing drain properly.

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Los Angeles Civil Engineering specializing in Hillside Grading

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