[Sam85]

HI, struggling to get water to flow over flat land. There is a lower drain but I am struggling to get water flowing from the flat area to the drain. Any suggestions?
Thanks

[Bywaters]

It's certainly impossible to get water to flow up hill and very difficult to get it to flow if it's flat

Have you considered soakaways ? or is it not appropriate in this case?

[Kiran]

French drsins through flat land work well and moving a decent volume if water. If the  wet spots are localised you can create vertical french drains which take wayer from the wet soil below the hard pan and allow it to soak away

[Sam85]

French drain sounds good. How deep and wide do you think would be needed?
Thanks

[Sam85]

Would a soakaway not just fill up with water? Clay/Gley subsoil here.

[Bywaters]

You would have to do a test pit

Basically, dig a hole of a known volume and deeper than your lowest point , pour a known quantity of water into it (in as near to one go as you can)  and time it as it drains away. That will give you an indication of how efficient (if at all) it would be

How think is the clay ?

[Sam85]

Top 20cm is soil, then your down to the clay/grey subsoil at least the next 2 feet. Don't know beyond that.

[Kiran]

French drain sounds good. How deep and wide do you think would be needed?
Thanks

It depends on how much water you are looking to move and over what distance. At the bottom of one of our fields which has a gentle slope, the ground rises up before the edge of the field and ultimately the ditch that runs along the bottom. I should re profile the ground, but I have temporarily put 6m long feench drains to clear the water passed the raised area, they were dug with a 1ft bucket on the excavator and are 12-18" deep filled with clean stone and a perforated pipe.

[Lambic]

The very old stone drains and the old clay tile drains, are very effective on my gley / clay soil

They knew what they doing.

In fact they are too effective if you are creating  ponds, proving very difficult to severe and block.

With a large area, I would be inclined to dig a pond / seasonal pond, fed by some open ditches.  Or covered perforated pipe, french drain style.

Based on this summer, we should try and attenuate it as much as possible on the land
.