Drainage Ditches

[Aragon]

I have to maintain the drainage ditches on the sides of my gravel driveway to prevent them from growing wider and cutting into the driveway. I am looking at approximately 400' of ditches that need work so it's not a small job in my opinion. Is a loader or backhoe in my future to maintain the ditches or would it be best to bury drainage pipe and be done with it? If I go with plastic drainage pipe, wouldn't a tractor crush it if it's only buried a foot deep? Would rocks (the size they use on lake shorelines) be a better choice? Other suggestions?

Thanks in advance for helping a newcomer to this board.

 

[DannyD]

I have 4 inch corrugated pipe buried under about 6 inches of rock, and have driven over it with my 23 and not crushed it. The pipe gives but does not break and the gravel kind of supports it. If you cover it with dirt and let it go back to hard, you will have no trouble. Be sure to put gravel around it before covering it over.

Check out my album on this forum for what I did

 

[Aragon]

Danny, your project album looks great. I hadn't been to the photos on this board so now I have another great source of information. I like what you did with the drainpipe and it is reassuring to know that I should be able to drive over it. Thanks so much for your reply.

 

[Junkman]

How wide are the drainage ditches and how much water is directed into them? A picture would also be a help. What are the drainage ditches present made of? We would need to know a lot more of the details before we could make some educated guesses as to what would be appropriate. I have seen some drainage ditches that are bone dry and 15 minutes after the rain starts, they look like you could go fishing in them, the water is so deep and moving so fast.

 

[Aragon]

Junkman, the ditches aren't too big, maybe 2' wide and deep at worst. Pretty much solid red Georgia clay and some rock at that depth. I think the driveway has been there about 3 years so the ditch is not growing at a rapid rate but it is unsightly, dangerous if you're not careful and will get my driveway someday. I wish I could tell you how much water they push, but I just moved in and haven't taken the time to go out in a downpour to find out. I'm going to do that the next chance I get. Considering the size of the existing ditches it would be pretty easy to throw in 4" piping and cover with gravel and fabric. If I see that the ditch is moving more water than I think a 4" pipe will handle, then I guess I will have to move up to the next size, whatever that is.
And then there are the flat areas between the slopes where there is no real ditch to speak of. The water just goes every which way, and then a new ditch starts running at the next slope. To run a continuous pipe I will need to trench these flat areas between the slopes and I don't have any equipment that will do that. The more I think about the job the more I like the idea of having someone with a backhoe come out and do it right. Then I can put in the pipe and gravel myself.
My other concern was driving over the pipe but then remembered that I am going to put a fence along the driveway next year so that's not going to be an issue. Wherever I put a gate, I will put a nice culvert to drive over, but the ditch definitely needs fixing before the fence goes in. Let me know if you have any other ideas on how I should tackle this job before the rainy season hits.

 

[Junkman]

If the ditch is 2' x 2', I don't believe that a 4" pipe is going to do much. Saturday, we got a heavy downpour that amounted to 3" of rain in an hour. My 4" pipe couldn't handle the amount of water that was coming into it. I would think that a 20" pipe might be necessary to contain all the water that might come your way.

 

[Currmudgeon]

It’s pretty hard to design a ditch or a pipe without knowing how much water it will carry. A ditch, even a small one, will carry a helluva lot more water than a pipe would, so piping may be less than effective.

One solution may be to grade out your ditch sides to flatter slopes. I like to keep side slopes to 3:1 so they are mowable. Flattening out the side grades will move the flowline away from the edge of the driveway, protecting the driveway better from the water, and protecting cars from the ditch. Undercut the ditch grades by about four inches, put in 4 inches of topsoil, and seed. That’s about the best erosion protection you can get. You can improve on this, particularly until the seed takes, by lining the ditch with jute or straw fabric. It comes in rolls, and some even has the grass seed in the fabric. It eventually rots away, leaving a well established turf. For really steep or high flow situations, they make a permanent turf reinforcement mat with plastic that kinda gives you reinforced grass.

The longitudinal ditch grade should be 2% or ¼ inch per foot drop minimum, or you’ll develop mini-wetlands where the ditch doesn’t drain. You can fix that, and dry up the ditch for minor rains, by putting a French Drain down the flowline. You can do the trenching with a ditchwitch, lay in perf pipe, and backfill with drainage gravel. The small flows will stay in the pipe, while greater flows will be carried by the ditch.

 

[Aragon]

I think you all have done this work before. I thought about re-grading the sides of the ditch, but I am not sure on the best way to go about doing that using a tractor. Do I just tear into the ditch walls with a loader? It may be impossible to do in some sections because there is a hill on one side of the ditch and my driveway on the other so there isn't always a lot of room to work with. The pipe may be the only solution in those conditions. Right? Maybe I lay in pipe and gravel to fill the ditch, then slope the sides as gently as possible to allow grass to grow on top?

 

[bebster]

Great opportunity to cost-justify a backhoe! If the ditches have been there for a while and not gotten too bad, then chances are you'll have time to do the job yourself in segments (if you have the time and inclination). If you have the time, then taking time to research and engineer the right solution like you are now is a good start. If you can give the TBN'rs lots of data, they'll help you work out a good approach.

 

[MarkV]

Sounds like your space around the ditch is limited but I have used a rear blade to flatten out the sides of a ditch. With the blade tilted and the soil conditions right it cut down the sides pretty fast. There was still some hand work involved cleaning out the soil that fell in the ditch but it beat the heck out of the shovel and pick method of the past.

Where are you at in NW Georgia? I am about 30 south of Rome and 18 miles north of I20 off of SR 27.

MarkV

 

[Aragon]

Hey MarkV. I'm to the northeast of Rockmart near the Floyd/Polk line. We just moved here a few weeks ago from Kennesaw, which got way too crowded for my liking. Like any recently bought home, we have our share of projects and this ditching job is just one of them.

 

[herdfan]

In my opinion (for what it's worth), I would try and slow the velocity of the water down the ditch with some bigger rocks (rip-rap). You could line the ditch with some fabric and then lay the stone on top. 400 feet isn't really that much to do this way, and it would look nice and be relatively low-maintenance.
The way I see it, the faster the water flow (and the volume), the faster the ditch will get cut out. With my drains, I like to go out during a heavy rain and see where the water is going. I have even made adjustments to the rocks, etc to kinda tweek the flow to avoid problems down the road.
Any pics?

 

[rambler]

</font><font color="blue" class="small">( I think you all have done this work before. )</font>

If you have a 2 x 2 foot ditch that is slightly growing in size, don't bother with 4" drain tile. Might as well burry soda straws and hope that carries the water away.... Not trying to be a smart alick, just adding a little illistration to the issue. /forums/images/graemlins/smile.gif

What you have is dry times, with a whole lot of accumulated & concentrated water flowing every now & then.

You need to design a system that can control the water at it's heaviest times (which is when it does it's damage) and is cheap & not in the way the rest of the time.

Depending on how much water flows, and how steep the hills are, and where the water goes when it gets to the bottom, there are many different ways to do this.

The best is to make grassed over waterways. But these are hard to establish, as every rain will want to wash them out until they are really well rooted & established.

You can slow the water down with rocks or straw bales or make the ditches meander down the hill rather than a straight shot. Depends on the lay of the land - what you can do. Slow moving water does not move mouch dirt, so it will not wash away any more.

You can put in a solid trough (like a curb) to keep the water from washing deeper, and controling the sides. This allows you to use a cheaper smaller trough (concrete, plastic, ???) but in real heavy rain events excess water can still go through. However, if you undersize the troughs too much, the frequent excess water will wash them out.

Only as a last resort do you want to put in a burried pipe. You need to make this pipe really big to handle the heavy rains, but 98% of the time the pipe will be empty & a waste of your money.

Some form of grassing it over & applying rip-rap techiques should get you a nice road shoulder that drains the water without damaging your work. It may take some time, and lots of small steps, and redoing some sections differently, and some luck to get things established without a heavy rain wrecking your efforts & you need to start over.

But figure out your slopes, the amount of water flow, and where it is going before buying any equipment. You will be using a shovel & hand rake more than anything, I'm afraid, to make a good job.

--->Paul

 

[Aragon]

I have to agree that using 4" drain pipe wouldn't do the trick for those heavy rains. From reading the posts I think the best plan is to regrade the ditches to make gradual sloping sidewalls whenever possible, then use rocks and fabric to slow the flow. Once I get the flow down to a reasonable speed and soil loss to a minimum I will look at seeding. Once the vegetation comes in good and strong, maybe I can remove the rocks to simplify the mowing. Sounds like a lot of hard work but it's got to be done.

Any ideas on how I can use my 5' box scraper to best effect on the ditch side walls to make those gradual sloping side walls? Some of those ditches are pretty deep so I have to be cautious about getting stuck or worse. Do you back in perpendicular to the ditch and backfill the deeper sections before working lengthwise?

I'll try to get some pics posted this weekend. Thanks to all for the help.

 

[herdfan]

</font><font color="blue" class="small">( Any ideas on how I can use my 5' box scraper to best effect on the ditch side walls to make those gradual sloping side walls? Some of those ditches are pretty deep so I have to be cautious about getting stuck or worse. Do you back in perpendicular to the ditch and backfill the deeper sections before working lengthwise?
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Working the side, v-ditch length wise with a FEL or box blade is pretty tough (at least for me). I've been stuck doing just that after trying to rework my ditches after removing some slips. Ideally, a dozer operator could knock that out without a problem. Have you checked into hiring someone to just rework the ditch and be done with it? Also, it sounds like you're in a tight spot to maneuver your tractor. Do you think a mini-excavator would help you? We rented one recently - looks like a toy, but is a real work-horse and can get into some pretty tight places.

BTW - how's the rain in GA today? There are several parts of town closed off here in WV due to flooding. (Of course, I spent an hour in the rain tweaking my drainage systems. Mudpies for big kids, huh? /forums/images/graemlins/laugh.gif)

 

[Aragon]

Thanks for the advise, herdfan. I have nothing to lose by trying the box scraper or FEL so I'll do that first. Maintaining the ditches was a reason I gave my wife for needing the tractor so I have to come up with something that works without hiring out the job...even if it means digging by hand at night when she's not looking.

The rain and wind from Ivan wasn't nearly as bad as predicted in our area. No more than a heavy thunderstorm. Sorry to hear you got hit so hard.