Drainage recommendations

randombar

Hi All,


With all this rain we're getting I'm realizing I need to sort out the drainage in the garden, like a bog after the rain and stays that way for days after.


https://www.dropbox.com/s/kk8jta5mhs8tl59/Screenshot%202020-08-24%20at%2013.37.46.png?dl=0


So I dug out the garden a few years ago to level it with the wall. Plenty of drainage at the wall to take water away.



Good bit of top toil on top of a very clay like sub soil.


I'm trying to figure out what's best to do (without digging it all out again).


I was thinking of a very small digger and digging maybe 6 channels from the bottom of the slope to the wall and putting some land drainage it. Not ideal as the garden would be up in a heap for a while. Also I'm not sure if that would work for the parts in between the channels, i.e. would I have nice dry channel areas and wet out in between.


A guy I know was telling me about a v shaped yoke like a harrow that cuts trenches in the ground but leaves the top as is. That sounds like a temporary solution to me though and I presume the ground would close up again underneath.


Has anyone done anything like this in the past?

standardg60

When you say plenty of drainage at the wall do you mean that the water can just flow over it?

randombar

standardg60 wrote: »

When you say plenty of drainage at the wall do you mean that the water can just flow over it?

Sorry I meant there's load of stone and drainage pipe and weep holes to take water away.

Large bottle small glass

For longevity of land drains I'd be inclined to
*have bottom of drain clean and get stone and pipe in immediately after digging
*use a large stone
*have stone above and below the drainage pipe
*cover the top of stones with a sheet of plastic. A damaged roll of silage bale wrap is ideal.

I did that 20 year ago in a 9 acre field and it's still perfect.

randombar

Large bottle small glass wrote: »

For longevity of land drains I'd be inclined to
*have bottom of drain clean and get stone and pipe in immediately after digging
*use a large stone
*have stone above and below the drainage pipe
*cover the top of stones with a sheet of plastic. A damaged roll of silage bale wrap is ideal.

I did that 20 year ago in a 9 acre field and it's still perfect.

I guess the question is how many drains do you put in? Will you end up with a situation where you have great drainage above the land drainage but poor in between the drains still.


I was looking at one of these yokes but not sure if I can pick one up in Ireland and if it would be big enough.

https://youtu.be/sdtib4YU1Rk

standardg60

GaryCocs wrote: »

Sorry I meant there's load of stone and drainage pipe and weep holes to take water away.

It probably would have been better to have sloped the subsoil towards the wall before putting on the topsoil so, it will just take a bit longer for the water to find it's way over.
I'd start with one trench from the middle, but sloping the subsoil too, and see how it goes before adding others.
It has been unseasonally torrential though, heavy rain on dried clay will always pool.

randombar

standardg60 wrote: »

It probably would have been better to have sloped the subsoil towards the wall before putting on the topsoil so, it will just take a bit longer for the water to find it's way over.
I'd start with one trench from the middle, but sloping the subsoil too, and see how it goes before adding others.
It has been unseasonally torrential though, heavy rain on dried clay will always pool.

Ya if I was doing it all over I’d definitely do it a bit different but it is what it is.

I might put a few in if I’m renting a machine but I’ll see what my options are.

aw

GaryCocs wrote: »

I guess the question is how many drains do you put in? Will you end up with a situation where you have great drainage above the land drainage but poor in between the drains still.


I was looking at one of these yokes but not sure if I can pick one up in Ireland and if it would be big enough.

https://youtu.be/sdtib4YU1Rk

Your idea to dig some channels towards a main draingage channel near the wall is good and is what you should do. If you do it when the ground is dry and are neat, or hire somone tidy with a minidigger, it can be done neatly without causing too much damage. Do it now so it can have 6 months to settle before the kids are back out and using the garden every day again.

Check out this site for some useful advice: https://www.pavingexpert.com/drain03

Particularly towards the end of the page where it give advice:
"Where land drainage is used to drain a larger garden, it should be installed in the classic herringbone pattern to ensure no point within the area is more than 2.5m from a drain".
This might help you visualise it.

randombar

aw wrote: »

Your idea to dig some channels towards a main draingage channel near the wall is good and is what you should do. If you do it when the ground is dry and are neat, or hire somone tidy with a minidigger, it can be done neatly without causing too much damage. Do it now so it can have 6 months to settle before the kids are back out and using the garden every day again.

Check out this site for some useful advice: https://www.pavingexpert.com/drain03

Particularly towards the end of the page where it give advice:
"Where land drainage is used to drain a larger garden, it should be installed in the classic herringbone pattern to ensure no point within the area is more than 2.5m from a drain".
This might help you visualise it.

That does make sense. 2.5m away is good. So I could have the drains 2.5m from the edge and then 5m apart Might still use the straight drain rather than herringbone though as I'm not sure the herring bone would save much on drainage

caddy16

Large bottle small glass wrote: »

For longevity of land drains I'd be inclined to
*have bottom of drain clean and get stone and pipe in immediately after digging
*use a large stone
*have stone above and below the drainage pipe
*cover the top of stones with a sheet of plastic. A damaged roll of silage bale wrap is ideal.

I did that 20 year ago in a 9 acre field and it's still perfect.

The smaller the stone the better for drains. Pea gravel is the best but more expensive, smaller clean stone next best choice. Keeps the pipe clean.

I'd also use twin wall perforated pipe instead of the standard agricultural land drainage pipe, comes in 6 metre lengths.

macadam

Maybe you are sitting on the water table level after digging down or maybe its the run off of a spring.
I would tend to dig a drain away to the nearest storm outlet ditch or drain and dig a few herringbone drains into this main drain 32mm clean drainage stone with twin wall drainage pipe, use 6-10mm peagravel on the herringbone drains.Id also cap the main drain with a membrane like 1000g Terram.

randombar

Is there any advantage to doing herringbone over single straight drains?

Any recommendations for a place I could hire a trencher in cork? I don't even know if they'd have them in Ireland?

standardg60

GaryCocs wrote: »

Is there any advantage to doing herringbone over single straight drains?

Any recommendations for a place I could hire a trencher in cork? I don't even know if they'd have them in Ireland?

Herringbone is simply a less intrusive way of draining a large area as you're directing several smaller drains into one larger one. In your case (as seems from your pic), the water is congregating in a small area so one straight drain may suffice. You can then add some smaller herringbones (it is a great way of describing it!) if necessary.

macadam

I have looked at the picture again and I feel you may need to further investigate the area above the swing there seems to be a damp spot on the bank between the swing and the puzzle climber, is it possible there is a fork in the gripe above at the ditch? The wet area could just be a low spot on the lawn and the seepage is ponding here and the children are making it worse, a drain at the bottom pf the bank may be more benefical, where youd pick up the water earlier, depending on levels etc .

randombar

macadam wrote: »

I have looked at the picture again and I feel you may need to further investigate the area above the swing there seems to be a damp spot on the bank between the swing and the puzzle climber, is it possible there is a fork in the gripe above at the ditch? The wet area could just be a low spot on the lawn and the seepage is ponding here and the children are making it worse, a drain at the bottom pf the bank may be more benefical, where youd pick up the water earlier, depending on levels etc .

well spotted, I think that is a spring that has just appeared this year. I have land drainage at the bottom of the hill all right taking water away from the bottom section.


As part of whatever I'm doing I'll run some landrainage up to that spring and take it away too.

macadam

GaryCocs wrote: »

well spotted, I think that is a spring that has just appeared this year. I have land drainage at the bottom of the hill all right taking water away from the bottom section.


As part of whatever I'm doing I'll run some landrainage up to that spring and take it away too.

Maybe if you fork where the drain is along the bottom of the bank or better still, open it and fill with stone to the top again and let the grass take over it during the winter months, and let the Husky 450x have a rest.. Your drain could be just a bit too far own or the stone maybe not up enough.

randombar

macadam wrote: »

Maybe if you fork where the drain is along the bottom of the bank or better still, open it and fill with stone to the top again and let the grass take over it during the winter months, and let the Husky 450x have a rest.. Your drain could be just a bit too far own or the stone maybe not up enough.

That's true, will take a look at that too while I'm at it.