trench/channel drain in gravel driveway

[Streetcar]

Most contractors that install guardrail will sell the old pieces

 

[3Ts]

Anybody have a good solution for a trench or channel drain across a gravel (crusher run) driveway? Right now I have a very shallow swale in the driveway in front of my barn door, which helps divert water that flows down the driveway towards the barn. Works well, but I have to scrape it out periodically since it fills with pine needles, loose gravel, dirt/mud from tractor tires, etc. Over time, the swale tends to fill and flatten back out.

I was thinking about putting in one of those pre-fab channel drains, but they are plastic with a sheet-metal top grate, and I don't think they would hold up under the tractor tires for an extended time. And the grate openings are pretty small, so I suspect gravel will plug them up.

The cleverest solution I saw was recommended by the US Forest Service -- they use metal guardrail (which has a sort of flat "W" shape) bedded down into the gravel to make a permanent swale that is easy to scrape out. Unfortunately I haven't found a way to buy guardrail around here. Another solution I have seen is to dig down some treated 4x4 timbers with a gap between them to act like a channel.

The ideas above will probably work better and less work in maintenance than a covered trench drain. If you really want to go the route of the trench drain the heavier duty grates are available thru amazon. Here is one example. They can be had in multiple widths:

https://www.amazon.com/Standartpark-inch-ductile-grate-slotted/dp/B01C0SZU5Y/ref=sr_1_21_sspa?keywords=drain+grate&qid=1579174685&sr=8-21-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyN0RFVkFOTUlZNTFWJmVuY3J5cHRlZElkPUEwMDgwNDA1Mk40S0JQWkFMT0ZOUiZlbmNyeXB0ZWRBZElkPUEwNjMyOTEyNkdSNFAzODRXT1JTJndpZGdldE5hbWU9c3BfbXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

And the definition of the various classes for load bearing is:

https://www.mifab.com/Catalog/Library/Grate_Load_Class_Definitions_TDSS-2016.pdf

 

[s219]

So I haven't had any luck finding used guardrail; closest source is about 4 hours away and it doesn't make sense to do an 8-hour round trip for the limited amount I need. I can get new guardrail but it is insanely expensive and out of consideration.

Best option I am thinking of is using treated 4x4 timbers to box in the trench and then put a grate over the top where I need to drive across. Grate isn't cheap either, but at least I can get it locally or even buy some bar stock and weld up my own.

Here's what I am dealing with -- just finished digging the trench today. Came across a stump that delayed progress but now I have a fairly clean trench ready to accept whatever solution I can figure out.



This slopes about 7" across a 32' run. I want to make the top of the drain channel level across the whole 32' width, but leave the bottom sloped so water will run downhill. If I use the 4x4 approach, the trench would be one 4x4 high at the uphill end and three 4x4's high at the downhill end.

 

[airbiscuit]

Do you have a steel yard or recycling center near you. It would be nice if you could find some used ctwalk (Steel Bar Grate),or catthe guard.

 

[3Ts]

Seems to me that you have more slope than what you need from what I see in the pictures. I use 1/8" per foot for my slopes and it seems to work well. The minimum I use is 0.1"/ft and max of 0.25"/ft. The more drop you have, the more erosion you're likely to have. You're at about 1/4" per foot. It also seems to me that you could make a swale instead of the trench and avoid a lot of work and it should work just as well and be easier maintenance.

 

[s219]

Seems to me that you have more slope than what you need from what I see in the pictures. I use 1/8" per foot for my slopes and it seems to work well. The minimum I use is 0.1"/ft and max of 0.25"/ft. The more drop you have, the more erosion you're likely to have. You're at about 1/4" per foot. It also seems to me that you could make a swale instead of the trench and avoid a lot of work and it should work just as well and be easier maintenance.

I had a swale there before, but over time it sort of flattens out. I believe part of the problem is that I track mud through there on the tractor tires all the time, and it ends up accumulating in the swale. And then fines from the gravel probably wash down over time too. I remember it being 4" below the concrete apron when I first graded around the barn 6 years ago, and it decreased to a 2" drop before I dug out that trench.

 

[s219]

I went to a local scrap yard on my lunch break to look for bar grating. They had a few pieces, but not enough to do what I wanted and one of them was mangled a bit. As I was wandering around musing at all the wonders, I spotted a pile of fork lift forks. I was thinking of all the things I could do with them and even took a picture.



You'll notice something peeking out the left side of the picture. I almost skipped over them. Hard to believe I would miss them, but there lay three 13.5' sections of guardrail, all in good shape. Total 281 lbs at 30 cents per lb, so I got all three for $84. This will work perfect. It's rare for me to score so well at the scrap yard.



They also had some scrap diamond plate, about 18" wide and 9' long, and I grabbed two pieces in case I want to make ramps over the guardrail trench, or for general project use.

 

[ovrszd]

You definitely scored!!! Looking forward to the finished job and the results.

 

[airbiscuit]

Perfect! There's also a pallet there you could set up in a field, but that's another thread.

 

[s219]

Got the guardrail in and am almost finished grading the area. So far so good.