Create slight slope on lawn

[jaimeobeirne]

Hi all I paid some money a few years ago to have my lawn levelled with retaining sleepers at the back of the lawn and then the pre existing stone retaining wall at the front of the lawn was left in place. Roughly speaking steps up to first level are about 4 feet high, sleepers at the back probably another 5 feet then it’s allotments behind. The bit they levelled used to be a slope that was 5 feet high at the back (hence sleeper height).

Anyway, soil is heavy clay as far as I’ve dug down (2 feet). I was going to put in a land drain or french drain but I’ve heard clay soils might not be good for this as water will sit whenever it is not pretty much directly above the drain pipe/channel.

I had the lawn levelled for the kids to play so we have a trampoline etc on it. I’ve now ripped up the decking that was covering maybe 1/3 and thinking that while I’m turning the soil and trying to grow a lawn from seed (the kids will destroy whatever I put down so reluctant to turf) I could maybe introduce a very slight (hopefully almost imperceptible) slope towards the front, it’s never waterlogged at the front only ever the back.

Is there a way to know how much of a slope to introduce and how to measure it when you are putting it in? I’m a novice gardener but quite enjoy the manual labour of it as I’m an office worker so sometimes it’s good to unplug from the matrix, put some music on and grab a shovel!

The deck previously was on left hand side from top of stairs almost to the back. The back left corner has always been “grass” and has always had the worst drainage. I’m hoping removing the decking and the slabs under it will help the situation a bit too.

Any advice gratefully received. I want to try to get away with minimal cost as the garden gets heavy heavy use with 3 kids, water slide in the summer, pets etc. so anything beautiful or expensive gets hammered. Sweat equity is my preferred investment!

 

[Blokky27]

I have no idea how much of a slope you should put in and doubt there's much of a science to it other than, the more the slope the better the run off so I guess for you its a trade off between levelness for activities and run-off for drainage (if indeed this will work on a clay lawn - others may know better).

As for the process of levelling you'll need to find your current level in the middle and then try and keep this there, but take soil from where you want it lowered (the front presumably) and take this to the back. In terms of measuring it, if you only have basic diy/garden tools then you could do a quick calculation of drop, say 5cm per metre, which doesn't sound like a lot but 1:20 is way more than you would do for e.g. a patio - my guess would be that more would be needed for a permeable surface. Then you can work on this level with a long straight piece of timber and a block of the right height under the lower end along with a spirit level to get yourself the slope.

Just my idea, I'm sure someone else with more experience will have an alternative. Good luck.

 

[jaimeobeirne]

Thank you mate much appreciated