Drainage trench width

[shakerator]

Hi

if a drain trench was bucket width, instead of a trencher, standard depth, with the additional bedding gravel underneath and by the side of the pipe to support , would it draw more groundwater because of this increased volume ?

 

[RobAnglia]

Probably, but if intending to trench any significant distance like this, for the purpose of field crop production, the cost of permeable infill will render the project uneconomic.

 

[ih1455xl]

The gravel is the expensive bit 6in trencher with 4in pipe 1ton of gravel does 12m

 

[Spencer]

I would say the pipe layed on a true grade onto a firm bed with 4” chain width of gravel above would outperform a bucket laid drain with twice as much gravel. Or that’s my experience of it anyway. A lot of a drains performance comes from drawing water into itself.

 

[shakerator]

Probably, but if intending to trench any significant distance like this, for the purpose of field crop production, the cost of permeable infill will render the project uneconomic.

Forget about the economics for a minute . Just theoretically interested , do have some short runs to do- but logic tells me the more the volume of the “big pore” spaces, the more it will draw water from tightly held regions ?

 

[Sharpy]

In grassland the more gravel the better, particularly in wet hollows.

 

[Brisel]

I've had a soakaway pipe dug on that reverse principle. 6" pipe with a much bigger trench with gravel to increase the surface area drained. I echo above comments about cost & would recommend doing smaller pipes, smaller trenches with a narrower but greater depth of gravel backfill but more of them closer spaced if money were no object.

 

[shakerator]

I've had a soakaway pipe dug on that reverse principle. 6" pipe with a much bigger trench with gravel to increase the surface area drained. I echo above comments about cost & would recommend doing smaller pipes, smaller trenches with a narrower but greater depth of gravel backfill but more of them closer spaced if money were no object.

were the results good of the soakaway land ?

 

[Brisel]

So far, yes. No overflow in peak rainfall, though I haven't been out to check the end of the pipe where we left contingency to jet it out.

 

[Allanlr]

Hi

if a drain trench was bucket width, instead of a trencher, standard depth, with the additional bedding gravel underneath and by the side of the pipe to support , would it draw more groundwater because of this increased volume ?

Hi, In my experience the more gravel used the more water is moved. I hire out pedestrian trenchers that cut a 4" (100mm) trench upto 900mm depth. If you are interested in hiring one please cntact me. Allan

 

[Allanlr]

Examples below

 

[Lincsman]

For the same cost in materials its better to have 2 drains closer together rather than 1, if its a football pitch you go every 4m rather than one big one in the middle.

 

[yellow belly]

how much an how many metres a hour

 

[Boohoo]

A trencher isn't going to be much use if you need rid of ground water that's 12' deep and you haven't much chance of digging that drain 6" wide, but if you get it right you'll dry 20 acres or more with one drain.

 

[Allanlr]

I disagree. I have drained many wet areas, golf fairways, fields, football pitches etc by using a Herringbone system. One main carry drain with laterals at 2-4m spacings is the best and proven method. The pictures that i have posted were taken in North Yorkshire and carried out in 3 hours, 200-400m is easily carried out in one day.

 

[Tim Howard]

Hi

if a drain trench was bucket width, instead of a trencher, standard depth, with the additional bedding gravel underneath and by the side of the pipe to support , would it draw more groundwater because of this increased volume ?

I have this sat in my yard if you think you can pull it, you can't be too far away.
Max working depth 4' and 4" pipe. I have a gravel bin hear as well.

 

[Boohoo]

I disagree. I have drained many wet areas, golf fairways, fields, football pitches etc by using a Herringbone system. One main carry drain with laterals at 2-4m spacings is the best and proven method. The pictures that i have posted were taken in North Yorkshire and carried out in 3 hours, 200-400m is easily carried out in one day.

That works in some places but not in others. I've seen large areas transformed by 1 drain dug deep to catch the rising water before it got near the surface. There's no set rule for draining land because all land is different.

 

[D14]

My neighbour has his own drainage machine which bought about 60 years ago. They never use any stone and just drop the pipe in then fill in. He says keep it cheap because you need to redrain anyway as even with stones they don’t last. I have to say I think he’s got a point.

 

[Grassman]

How near to the surface with the stone?

 

[Spencer]

If your on marine clay like us, right to the top!