Drainage in a pan flat clay lawn?
glasgowdan
Posts: 632
I have a lawn of around 200m2 which is really pan flat, no discernible fall to it that I can see. It's clay and gets very wet during periods of heavy rain. I'd really like this to be a firmer all-year type of lawn that allows you to walk on it without getting soaking wet.
Reading up on all sorts of drainage advice there's always talk of a water outlet area, and a fall on the pipes/drains. Both of these would prove difficult for me as I can't find a way to get water to fall towards the house where there might be a way to break into a drain. There also isn't an area I'd like to make a pond.
Would it work if I dug a large sump right in the middle, say 1mx1mx0.75m, filled it with rough large gravel, then dug 'spokes' going out from it? I could slope these spokes from 0.7m deep at the middle to 0.5m, say, which over a length of 5-7metres each should be workable, and allow me to lay perforated pipes.
Can anyone see any problems with doing this? I'd probably do a couple of years of sand applications after this to try and create a dry top zone.
Thanks
Posts
Have you ever scarified it, to start with? That's a lot of clay filled lawn to deal with - having only 30sqm of almost solid clay, I sympathise - in the end, I abandoned grass altogether as it was always getting too wet, and went with raised borders, plum slate and different types of hard and soft paving.
It's definitely installed drains that are needed, scarifying won't help the soil drain better sadly.
No - scarifying will do nothing to improve it, not with the amount of stuff that falls out the sky here, eh Dan?
I think if you're determined to have lawn, you'll have to take extreme measures and put in drains and new topsoil. I'm not so sure about a sump in the middle though. Is there any way you could put it to one side, or in a corner? My Dad did that with the front garden, placing it where the lowest natural spot was. That might give you more scope. it depends what else you wnat in the garden too. Other, more substantial, planting helps a little with soaking up wet from surrounding areas.
A pic of the site and surroundings would help too if you can manage it, just to give a better idea. Start with the camera icon at the top right of the posting 'window'.
I live in west central Scotland - not where that photo is...
Just remembered this and I'm starting to make plans. There really isn't a low spot that I can identify. I'd like it all to be revamped with some new beds, sunken trampoline for the kids, ivy planted to cover that horrid brick wall and a few other things.
Maybe an open sump area at the side somewhere would work, filled with bog loving plants