Alright, this is probably not going to be the easiest thing to read as Im not great at explaining things by typing them out so bear with me. I recently built a new shop on my property. I didn’t have alot of great options since basically all of my property is at the very least on a slight downhill slope. I chose to tear down an old barn and rebuild where it was since the site was already fairly level, solid ground with a 12x15 concrete pad right next to it. Here’s where it’s going to get long winded. The barn appeared to have been built with its left wall, if looking at the front of it, built right up against about a 2.5-3’ bank. So after the barn was down I rented a mini excavator and dug the bank back about 10’ the smoothed it out to what I thought was an acceptable grade. I doing know the percent but it falls about 5’ over about a 20ish’ distance. Right when it levels back out I dug a French drain starting at about a foot deep that goes about 5’ past the back of the shop, makes a very gradual turn, while running down the side of the shop, in front of the shop before the exit that is right at 100’ from the start and at a depth of about 2.5-3’. under the wrapped 4” perforated pipe is about 2” of creek rock that I found under an old gravel drive way on my property, then I filled the ditch with the creek gravel except for the top 5” or so which I finished off with the same size gravel used for the base under my new concrete slab. Honestly, I don’t know if that is the “right“ amount of slope for the pipe or not, I just know that it is I. Fact running downhill the whole way, I made sure for there to be no low spots in the pipe. I almost forgot to mention that the soil Im working with is good old south eastern USA red clay. So aside from the pipe I was expecting for the trence it’s self to be able to carry a fair amount of water. My intentions were for the French drain to catch the run off from the rest of the slightly elevated property and keep it from getting under my slab. Here’s the issue, after a couple good heavy rains, something happened that I had not expected the red clay to do. It’s actually wound up eroding where I smoothed the bank out into a more gradual slope, and eroded it pretty bad, to the point to where the fine red clay particles washed down over my 1”-1.5” gravel and basically stopped up the part of my French drain that runs down the side of my shop, causing water to pool very bad and even get up under the slab imsure. At the exit of the French drain there will be a lot of water coming out but nothing. Near as much as I would think that 4” pipe plus the ditch is self could flow. Any tips on what I can do to keep the erosion from coverimf the top of my ditch? Should I cut it back and lessen the slope more? I could a little but not as much as would probably be needed. also equipment is very costly to rent around here. I’m kind of at a loss. I’ll attach a couple of pics from my security cameras to give you a bit of a visual. The first pic is normal dry conditions, the second pic, I would almost say is a pretty extreme example but it seems like huge, fast moving storms that dump massive amounts of rain in just a few minutes are getting more common, on just a more normal storm or rainy day this doesnt happen anywhere newr this extent
Major drainage issue.
- Thread starter Bradc1989
- Start date
jack stand
Well-known member
Sounds like you are just a victim of a heavy rain prior to your grass growing.
If I understand this correctly, I think that if you "clean up" the silt as best as you can from your French drain and restore it, then re grade & replant the grass with "curlex" or some other method of retaining the soil and seed. Then crossed fingers until you've established the grass.
Gutters will help and put a larger downspout at the low side of the grade.
If you can, some "up grade" swales that will take or divert some of the downpour BEFORE it gets near you building.
Curlex is a almost woven wood shavings with a layer of plastic "mesh" that you roll out and use landscape staples to secure it. Run it like you would tar paper with overlaps facing down hill. It will become part of the grass and kinda just go away.
If I understand this correctly, I think that if you "clean up" the silt as best as you can from your French drain and restore it, then re grade & replant the grass with "curlex" or some other method of retaining the soil and seed. Then crossed fingers until you've established the grass.
Gutters will help and put a larger downspout at the low side of the grade.
If you can, some "up grade" swales that will take or divert some of the downpour BEFORE it gets near you building.
Curlex is a almost woven wood shavings with a layer of plastic "mesh" that you roll out and use landscape staples to secure it. Run it like you would tar paper with overlaps facing down hill. It will become part of the grass and kinda just go away.
cvairwerks
Well-known member
Hard to tell while on my phone, but looks like you have a grade problem that is daming the natural water flow. First thing you need to do right now is shoot a grade map of the area. From there, you can figure out how to correct the drainage.
You’re right, basically the building is right in the way of the natural run off, as my entire property is on a slope . I added the French drain to try to catch and divert the natural run off away from the building. what wound up happening though is after a couple of heavy rains, red clay silt has accumulated on top of the gravel that fills the trench and basically stopped it up.
that stuff crossed my mind, I think I’m passed time to sew grass? Either way some erosion mat should help. I also had kind of thought about what you said about the swales but I was thinking maybe dig another ditch at the top of the grade to divert water before it makes it to it that way all the French drain has to deal with is what falls directly on the grade
jar944
Well-known member
Re-grade with a low point away from the barn. You need the slope to work with you not against you. Or add ditch and swale to divert water around the barn.
Then fix the grass issue as already mentioned.
Then fix the grass issue as already mentioned.
jack stand
Well-known member
As long as you have water, you can grow grass. The curlex will take care of those areas, and for others just mulch with straw or hay. The cover helps with the sun, erosion and moisture retention. Grass will hold your soil together after the mulch gets mowed away or breaks down.
You've done everything right, just fix it and get some grass established. Your building is in the way of a lot of water. You can't fight with mother nature but she'll work with you.
wssix99
Well-known member
You are going to have a problem no matter what is growing there.
At the point where there is a cut (from the slope to a level portion), water releases energy when it falls down the cut. (Think of it like a low power, slow waterfall.) If grass were there, that area will still erode over time. A rut will be cut at the base of the drop off and silt will flow off the hill and naturally fill that section back in.
I would just add a short retaining wall or railroad timbers around the perimeter of that level section. Then backfill on the slope side with gravel and sand, as you would any properly built/backfilled retaining wall. That should "catch" the water flowing down the hill and properly drain it out to the driveway instead of onto the level side yard.
At the point where there is a cut (from the slope to a level portion), water releases energy when it falls down the cut. (Think of it like a low power, slow waterfall.) If grass were there, that area will still erode over time. A rut will be cut at the base of the drop off and silt will flow off the hill and naturally fill that section back in.
I would just add a short retaining wall or railroad timbers around the perimeter of that level section. Then backfill on the slope side with gravel and sand, as you would any properly built/backfilled retaining wall. That should "catch" the water flowing down the hill and properly drain it out to the driveway instead of onto the level side yard.
Here’s a better picture to tell what I got going on.excuse the mess, Ive Still got temporary stuff ran and 50 other projects to juggle. I kinda piled up some of the dirt along the gravel to try to keep the water from getting under the slab too bad, helped a little, don’t beat me up too bad about my slab being too wide, some mis communication with the concrete guys, she’s sealed on the outside and the in side tho and so far with all these heavy rains no water has made it inside.
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rjacobs
Well-known member
How level is the area immediately in front of your shop?
Might look at getting like a 12"+ corrugated metal pipe and lay it in in front of your shop(obviously dug down) and then gravel over it to make your drive level. Then cut a swale along the side of your shop and turn it to run into your corrugated pipe. Because it already looks like the water wants to run towards the front of your shop(guessing your land slopes left to right and front to back).
Might look at getting like a 12"+ corrugated metal pipe and lay it in in front of your shop(obviously dug down) and then gravel over it to make your drive level. Then cut a swale along the side of your shop and turn it to run into your corrugated pipe. Because it already looks like the water wants to run towards the front of your shop(guessing your land slopes left to right and front to back).
dcg9381
Well-known member
I think that problem is very solvable. I have a similar setup, only the grade on the back side (downhill) is not quite as steep. Our barn is "higher" which helps, but the solution is really to create a path for the water to run around the barn - probably the back side in your case. You might have to do it in what we call "bull rock" (or similar) - meaning large septic type rock. I'd cut the grade and fill it with rock.
Yea, you'll need some equipment - but I don't think more than a day.
Gutters will help, but i think most of your problem is uphill.
Yea, you'll need some equipment - but I don't think more than a day.
Gutters will help, but i think most of your problem is uphill.
wssix99
Well-known member
That is a different view. I would start with the gutters on the building and see what happens first. The water coming off the roof is going to have a lot more energy than the flow off the hill.