[makedoandmend]

Folks,

Just wondering if anyone out there could give me some idea / rule of thumb for putting in land drains.

The garden is about 18 feet square, and I wonder how many feet of drainage pipe I should install / how close together they should be.

Beyond the top 6-8 inches of topsoil it is solid clay for as far down as it is safe to dig, and there used to be a sandstone quarry about 200 yards up the road, so I don't hold out any hope for penetrating the clay layer.

Thanks

[Amilo]

Where are you going to drain it to?

Are you going to dig a well?

For such a small area it might be easer to just to double dig with loads of grit and if you can get it manure/compost, if you have heavy clay don't let the lower levels of clay get lifted to the surface.

[makedoandmend]

I am using an inspection chamber as  a sump and then it's being pumped out.

I've already done the sharpsand and organic matter - simply not enough to soak up the moisture, plant roots are drowning!!!

[Plot74]

If all else fails try raised beds easier to maintain moisture levels you may loose a bit of growing space but at least things will grow..
John

[TerryB]

When we took over our plot we were told we would needed to put some drainage in, because it is halfway down a slop and always got water logged.
Spaced the drains 16ft apart and put 6in raised beds in between.
Dug down 18ins and lined the trench with some weed fabric, to stop the soil from getting in and blocking the drain.
Put in some 100mm drain pipe and and covered with stones.
Back filled and put down good layer of wood chip.
This now forms a path.
Works well as so far, as we have had no surface water and this was done 6 years ago.
As yours is 18ft square, just 1 drain down the middle should be fine. 

[makedoandmend]

Folks,

I have now completed this project and am in the process of restoring the lawn etc. The lawn wasn't great to start with so I've decided to let the repaired areas settle over the next 12 months and then rip it up and start again.

The pumps are wired in and come on automatically when required, so far we've had no repeats of the flooding and every time I've checked the inspection chamber it's been 'dry'. The pumps are connected via some simple flapper non-return valves and the pipe work under ground is pipe in pipe so it shouldn't freeze.

I followed some recommendations on a web-site (not sure if I can post the URL since it was a commercial site) And advice from John Davidson Pipes (Birtley branch) (JDP) who were really helpful and cost effective.

I used a total of 7 tonnes of gravel - although some of this has been decorative topping.

The trenches are quite deep at over three feet, but these taper upwards to produce a good fall. There is about 20m of 100mm pipe spread across the garden, which might seem a lot but it will provide a large 'buffer' capacity and I would rather have to water the garden than bail out!.

The clay is said to bulk up by 60% when you dig it out but I walked up and down on it to compact it into the skip! and we got the lot, including some iffy subsoil into an 8 cu yd skip.

I guess only time will tell garden wise, but it has given us some peace of mind - we no longer see the water creeping towards the French window everytime it rains.

I will post some pics when I get them organised.

make do