Using a trencher questions

I need to get some drain pipe into certain areas of my yard that I can barely mow even when it hasn't rained in a while. I've been checking into one of those walk behind trenchers. I'd like to rent it now, thinking that it won't sink into the bad areas because of the frost still in the ground (although there's a bit of water on those areas now). The rental place said to wait a couple weeks. Does anyone have experience with using these things on ground at the end of winter? The one area is pretty much like a swamp and it just seems it would make more sense to do the work now, provided the teeth can trench into the ground....

Also, I realize that the deeper I put the pipe, the more area it will drain, but I need to stub the end out somewhere, right? How deep is the pipe usually put in the ground? I'm guessing that is based on where the low end will be? So it is exposed and will drain? I'm running it towards a ditch that winds up in a creek, but there's no way to get machinery into that ditch because of shrubs on one side and a steep banck on the other, even if I rented a mini excavator. I'll try to get up a couple pics later.

Any help would be appreciated. Thanks.

Here's a couple pics. Sorry for the quality, it's early yet.
An overall shot. The area I want to trench runs from close to my well, on the right, to the left past that swamp area. Right where you can just make out the greener grass past the long shadow.
And, the swamp.

It looks pretty level, or maybe just a bit downhill, but I know I can only trench so low and still stub the pipe out like what I was saying. And that ditch along my neighbors house runs pretty level, too, but I don't care if that area stays wet. Still, I'll probably at least run the pipe to the creek.

depth of pipe should have nothing to do with how much it will drain - that will be a function of the way the land lies.
I would look at going at least 24" and maybe 36" deep and no less than 12" wide if you have a bad problem with drainage.
the key to this will be the rock you fill the trench with to surround your drain tile - and remembering to put a filter sock around the drain tile.

A friend of mine had a french drain dug in her back yard a couple of years ago and they put 40 tons of washed rock in the 150' long trench with landscape fabric and 6" of topsoil above it. (this was an extreme one - everything in the area slopes towards her house and she had a spring come up in her crawl space after a 14" rain)

Thanks for replying, Erik.
I thought the deeper the pipe, the more land on either side it pulled moisture from. Like if it was only 12" deep I would need branches out either side, but if it was deeper I wouldn't. A farmer out here told me that, but like I said, if I go too deep, like I want to, then I won't be able to stub it out into that ditch. I'd be well below the grade because the land doesn't have a natural fall to it.
Another rental place I spoke with thought he had a machine that would work on frozen ground. I'm going to look at it today. I'm shooting for next Tuesday and it will be warm the next few days, so we'll see.

I've used the walk along with trenchers. I used it for burying electric line and water line.. They are nice because they only make a 4 or 5" wide trench. The ones I rented was rated to dig down 36 inches but that seemed impossible. We could get 27 inches pretty easy but any more was a chore.
I would not want to use these types of trenchers in any soggy or swampy area. I figure it would get stuck and they weigh a lot.
From what you described and what the farmer told you about wider might pull from more area, I would suggest a back hoe / excavator. Even if you had to pay an operator to dig the trench, lay the pipe, fill the trench with rock then cover with dirt and excavator would sure make all that work easier. Understood it sure would cost you more dollars though.

Thanks Doc. I figure if I get it stuck..... well.... I'll take pics! (lol).
I've got a 4WD one lined up for Mon afternoon through Tues. Hopefully I can talk the place I get gravel from to get their rear in gear. They were pretty much just opening today when I called them. The co-op has the pipe for .32/ft, so that's pretty reasonable. If I can't get a trench through that swampy area I'll have to figure out what to do later, but at least I'll have the pipe layed in the yard.

A 4wd one might make all the difference. I was thinking you might put chains on it, but didn't know 4wd was even an option. Good idea.

if you have really sandy soil, deeper might make a difference, but I still doubt you need to go more than 24" down.
if it's wet/gummy, the clay will pack the trencher and lock it up solid.
if you're halfway thawed, you might be OK.
whatever you do, lining the trench with weed barrier fabric is a good idea to keep it all from silting in over the first 5 years, but will still allow water to seep in.
good luck and keep us posted.

I'm a little confused.

Where is the water coming from that turns that particular area into a swamp? I don't have a lot of experience digging field drains, only having dug one in my life, but I thought the idea was to divert the groundwater before it got to the swampy area. Having done that the swampy area would dry up on it's own. If you lay the drain through the swampy area itself, depending on the soil, you might only be draining a few feet on either side of the field drain. To drain it better would require a whole bunch of laterals to collect the water from the rest of the swampy area and deliver it to the main run for disposal in the ditch.

As I said, I've only ever dug one, and that was a long time ago, so help me out here. I'm trying to understand. Remember that I'm old and not too sharp any more so keep it simple.

I don't know exactly where the water comes from, Frank. The sky? If you look at my first pic, which was taken from the road, you can see that the wet area sits lower than both the road and the land where the treeline is (which is where a creek runs). There's clay in this area about two ft down, so I'm thinking that any water in the form of rain pools into this low area and superstaturates the ground. That's a lot of land that can collect water and funnel it so to speak.
When I first moved in here, there was a ditch running the length of this wet area, but closer to the road by about ten ft. I couldn't mow within ten ft on either side of this ditch. The grass would grow a few ft high by the time fall came and then I could brush hog it down for next year. The one neighbor just told me a short time ago that the old owner had a sickle mower he used on it.
So a few years ago the guy across the street from me built a huge addition and asks me if I want the fill for my ditch. I said sure. All this did was move the saturated area closer to the creek, but I could at least get on to it to keep it mowed (with some sinking), except for the swampy area. There wasn't enough fill to do the whole yard, btw, and that's why I have the swampy area. In effect I just kind of shuffled the water on down and relocated it.

So I guess my goal is to "put that ditch back in", but in the form of a drain pipe, so the water has somewhere to run. I'm not sure how deep I'll be able to go. I'm going to put some T posts in today, string a line and see if there's any kind of fall at all. I've never done this before, but I know I can't run from 2' deep to 3' deep and be below the grade by the time I get to the swamp. Otherwise, how would the pipe drain?

I'm still trying to decide if it would be better to try and lower the trencher as I go (or raise it, whichever directiion I run it in), or run it at a constant depth and use the trenched dirt to give me my fall....

We had a big ole area like you are trying to fix. this covered the middle of 4 river lots. We got together and had it fixed by burying a 20" pipe, and covering with gravel much like you are considering. So I know it will work. The soil is more clay than sandy for sure. The question is will the trencher trench wide enough to do the job?
The trencher will put dirt off to the side so it's impossible to made it wider. The whole idea of a trencher is a narrow trench.
Eric's idea of the weed barrier fabric is a good one.

You just need a little slope to the pipe so I would try to keep the same depth and adjust the pipe manually as you run it. You'll see once you start running the trencher that it would be tricky to make a shallow slope as you are digging. Rocks and roots and whatnot will get in the way of a perfectly level bottom.

Well the gravel will be here Monday, so things are moving along. I'll be picking up the pipe today. Hopefully we don't get hit with too much rain over the next few days.

We have a beautiful weekend forecast here, a bit south of you. 73 today and the same high predicted for Sat & Sun. Very nice. I hope you are seeing some of the same.
Take pics of your project as you can. You know we love pics.

I'd like to be doing it this weekend, Doc, but I'm too swamped at work. I sure don't want the ground to soften up anymore than what it is, but it will....
It's about 10 degrees cooler here, but it sure felt warm enough all day. Very humid and calling for thunderstorms the next few days.

a 1 in 48 drop is all you actually need to drain successfully (that 1 inch every 4 feet) more won't improve things, but less will make a mess.
if you use a water level, you can get an idea of what kind of drop you have overall from the swamp to the ditch you want it to drain into.

the other option you might consider is to make a "goldfish pond" out of the swamp area. dig a hole 3-4 feet deep, slightly bigger than the swamp area now, and use some of the clay you dig up to seal the sides, and let it fill on its own.

1/4" per foot? That seems like a lot of drop. Even sewage pipes are only 1/4" per 4'. At least around here. I thought I read somewhere 6" - 12" per 100' when I was Googling trench drains. Anyway, I know I could get fall over to the swamp, but I want to bury the pipe in the swamp so it drains that area too. And that's where the problem lies, unless I do what you say. I have thought in the past of turning the wet area into a type of bird sanctuary or something... getting some wet ground trees, letting it grow up, putting in some bird houses, rocks..... but then I thought, why would I want to do all that over by my neighbor's house? I wouldn't even be able to see it from my porch.... Yeah, I think I'll be happier if this area was dried up. A small pond somewhere else might be in my future though.

you know, that's not a half bad idea - plant a couple cottonless cottonwoods near the swamp and they'll keep it fairly dry. Or maybe a lavender bush.

and you're probably right about the 1/4" in 4' - I was thinking sewage drains, not de-irrigation.

Or Willow Trees. I planted 3 of them in a swampy drainage area and it helped. The trees sure grew FAST in those conditions. ;thumb:

But be sure your attempt at yard drainage will not adversely impact anyone else’s land. Otherwise, installing a French drain could land you a lawsuit!

Check your city codes before digging. Another preliminary step that could save you headaches later is checking with your local utilities concerning the whereabouts of underground cables and the like, so that you'll know where not to excavate for a French drain. There's a quick way to check: just dial the Dig Safe phone number.

A grade of 1% (i.e., a drop of 1 foot for every 100 feet in length) is often recommended for French drains; others advise a drop of 6" for every 100'. Getting the water to go where you wish is essential for improving yard drainage; the grade will facilitate your efforts.

Trench width will depend on the magnitude of your moisture problem. Bigger moisture problems call for wider trenches. Small trenches are often dug to a width of 5”-6”.

Before applying gravel, line the trench with landscape fabric. The landscape fabric will keep dirt out of the gravel. You want to preserve the porosity of the gravel, which promotes percolation of water through it -- one of the underlying principles that make covered French drains work. Shovel a coarse gravel onto the landscape fabric. Wrap the ends of the landscape fabric over the top of the gravel layer.

You now essentially have a tube of landscape fabric filled with gravel. To fill in the rest of the trench, shovel in a layer of coarse sand, cover it with more landscape fabric, add 4" of topsoil and lay sod on top.

How about an update chowhound. Did you get er done?