Drainage ditch - gravel first or not?

   / Drainage ditch - gravel first or not? #1  

PaulT

Gold Member
Joined
Apr 9, 2001
Messages
457
Location
New York - Upstate
Tractor
Kubota 2710
I have been doing some drainage work to dry out a piece of lawn. The lawn runs alongside my driveway for a few hundred feet. Along the edge of the driveway, at the edge of the lawn in question, is a drainage swale that works fine. I'm trying to tie in some other ditches to it, run some drain pipe, and cover it with gravel so that I can use that part of the lawn as extra parking. Once it dries out, it should be fine. The questions are:

1) Seems like I need to use solid, smooth bore pipe so that it can withstand the pressures of cars driving over the gravel and pipe in the ditch. I want to use perforated pipe. Should I use a silt "sock" like I used on the flexible stuff connecting with it?

2) Can I lay the pipe in the bottom of the grassy swale without first laying down a layer of gravel? If not, why?

3) The swale is pretty wide, and I've got some extra dirt from a ditch dug up on the high side. How can I use the dirt to narrow the width of the swale (turn it into a ditch, really) without filling in the area of the swale where the pipe and gravel will go? I guess I could use some plywood and pile the dirt behind it, but remember that the swale/ditch is over 200 feet long. That would require lots of moving and re-staking the plywood sheets. Another problem complicating this is I can't get the tractor over the swale to drag the dirt down into it unless I do it before I put the pipe in, otherwise I'll crack the pipe from driving over it. I guess that means I have to get the dirt there first, without filling in the place where I want to lay the pipe, then lay the pipe and cover with gravel. Its the without filling in the place where I want to lay the pipe part I'm looking for advice on. Any help, please?

PaulT
 
   / Drainage ditch - gravel first or not? #2  
I have used the thin walled 4" drain pipe with holes in a converted ditch. I put some 3/4 stone in first then the pipe and then more stone. Even running it over with a tractor and full hay wagon did not break it.
However you could see the end of it and it did squash a bit. Driving a car over it caused no problems. Just recently I built a pole barn at the far end of this driveway and upgraded the pipe in this section to schedule 40 plastic pipe with no drain holes. I could envision the concrete truck squashing the thin walled pipe with no problem. The schedule 40 pipe I bought at Home Depot in 10ft sections and came out to about $1 per foot. The pipe connectors are about $2 each.
I've also seen the 4" black plastic corrugated pipe that comes in rolls but have not used it. It has slits in it to allow water to enter and is much cheaper. The local hardware store gets $82 for a 250ft roll.
The basic process I use is:
1. Dig/clean out ditch with FEL.
2. Stone.
2. Lay pipe.
3. Cover pipe with stone. Use stone if you want water to run into the pipe along the length of the ditch.

I have seen others put a filter cloth or just hay above the pipe to stop dirt from entering and clogging the pipe. I am by no means an expert on this but my property has wet spots and I try to adjust the way the water flows to make living here a little easier.
I also just ran sched 40 for 60 ft and covered it with dirt. I needed a way to get the tractor from one side of a trench to the other. The trench runs water 365 days per year from a small spring. Since the trench was very wide I had to drive over the pipe in order to cover it with dirt. The sched 40 pipe was not damaged from the Kubota L4310.
 
   / Drainage ditch - gravel first or not?
  • Thread Starter
#3  
Rich,

I think the sched 40 is too expensive. I think the thinwall stuff is only about $4.5/10 ft section, and the black corrugated stuff is about $40/100 ft at Lowes. You say to lay in some stone after cleaning the ditch, then lay the pipe on that. Have you ever considered just laying in the pipe and then stoning over it? What problems might that cause?

PaulT
 
   / Drainage ditch - gravel first or not? #4  
Paul: If you are laying pipe it should be on sand or 3/8" or so gravel so you can grade it to fully support the pipe and get an even gradient. It should also be covered with finer granular material so weight from above will not force a sharp rock through it.
As to the other drainage area the burial depth is very critical to the strenght of pipe required. Have you considered 1/2" plastic pipe in a grid pattern that would connect to a larger plastic pipe for final drainage. This pipe is not the rigid type.
Egon
 
   / Drainage ditch - gravel first or not? #5  
PaulT,

If I am visualizing your area properly, the area you want to use as parking has wet ground on regular bases. What comes to mind, is some of the road fabric that many put down when building new gravel roads. It would seem, that you could cut a piece to put down in the swale, lay your pipe on it, fold the cloth in enough to back fill with the dirt, unfold the cloth, lay the remainder of the fabric over the whole area to be graveled and dump your gravel. This would give you the road fabric above and below your drain tile to keep it from silting and would help keep the gravel on the surface in the damp area.

MarkV
 
   / Drainage ditch - gravel first or not?
  • Thread Starter
#6  
So, if the swale is already graded correctly for the flow, and is smooth on the bottom to evenly support the pipe, I wouldn't need to lay in anything on the bottom. Currently the bottom of the swale is smooth, soft dirt (or mud) with thick grass growing from it. Laying the pipe directly on this grassy surface will also give me a little more depth so that the gravel above it will disperse any vehicle weight better. At least this is the conclusion I draw from reading your suggestions. Have I interpreted everything OK?

PaulT
 
   / Drainage ditch - gravel first or not?
  • Thread Starter
#7  
I think you are imagining it correctly, except that I don't want to gravel over the whole area, just over the pipe in the ditch. AND I also want to make that area (the graveled ditch) as narrow as possible, using fill dirt on the sides, but that is just to save on the cost/amount of gravel required. The goal is to dry out the lawn enough that I can park on it occasionally without sinking into the mire. I will still mow that area and maintain it as lawn. The roadbed fabric would work for the ditch, but since I am not driving over the length of it very often, I think its too expensive. I could use landscape fabric in the ditch over the pipe, or I could use the silt sock, which is easier and priced about the same. Does anyone think I don't need to use a silt screen of some kind if I am using smooth bore pipe? WIll the slit wash through? Is it recommended for the black corrugated just because it will clog up those corrugations? Any experience here with how these two types of pipe/tubing differ?

PaulT
 
   / Drainage ditch - gravel first or not? #8  
There might be another solution.

Are there any utilities in the way? Why not move the drainage swale? Would it be possible for you to move the swale away from your driveway a few feet? Take the material from the new swale to fill the old and create your parking area. Instead of buying drainage pipes, gravel, etc. You could apply your money for more attachments to do the work!!!

Terry
 
   / Drainage ditch - gravel first or not?
  • Thread Starter
#9  
Since the swale is formed by the raised driveway bed at the base of a slope, I'd have to fill the swale up to the level of the driveway - esentially extending the driveway. I would really be fighting gravity and rebuilding the slope. Probably need more fill than the relocated swale would produce.

Q: Why do we have gravity?
A: Because if we didn't, when birds died they would just stay up there and confuse the hunters/w3tcompact/icons/smile.gif
- Steven Wright

PaulT
 
   / Drainage ditch - gravel first or not? #10  
Pault:
Yes you are correct. The purpose of the gravel below the pipe is for support. Have you considered digging the trench a little deeper so the pipe could be supported by gravel?
Egon
 
 
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