Cutting dual wall plastic culvert pipe in half

[58Yeoman]

I've got a drainage ditch between a 12" culvert pipe and an 18" culvert that is 50' long. I had it graded and grass planted last year, but it all washed out, so I filled the 'ditch' with rocks. Well, the rocks got filled in with fine gravel and silt from up the road, then washed out along the rocks, making the ditch wider.

My thought now is to buy the 15" double wall plastic pipe at Menard's and cut it in half lengthwise to make a trough for the water, then fill in the sides with more dirt. This should be a solid wall pipe, so I shouldn't have any problems, right?

https://tinyurl.com/yxnb3hxr

 

[Spook001]

I’d just leave it alone. Besides, the pipe would be a pain to cut, not stay where you put it, and it will fill itself in anyway.

I like your sig line.

 

[Diesel Dan]

Seen many ditches that only flow during heavy down pours with concrete liner/bottom.
This may work better for you.

 

[Ing3018]

It's not a solid wall pipe. Rather, 2 layers, a corrugated outer and thin and smooth inside layer.
Salvage your stones, re-shape the ditch to a flat bottomed trapezoid, line it with geotextile fabric, then replace your stones. Angular stones would resist the shear force of the flowing water better. The flow velocity and slope are really what will determine what will work. On steep ditches, check dams are used to moderate the velocity.
They do sell plastic ditch liners. Smartditch is one l have seen used.
My preference would be to use a permanent turf reinforcing mat and just get a good deep rooted grass established.

 

[starquestMM]

They make what you are describing. When you cut plastic (or metal) lengthwise it becomes pretty flimsy. The smartditch stuff uses an anchor system that gets driven into the soil to hold it down.