Clay Lawn drainage help

Need help! suggestions or advice please, I landscaped my garden 2 years ago and dropped the old sloping lawn to the patio level.
I knew it was clay so I dug down 30cm and refilled with sand/soil. I was really happy but now for 5 months it floods and the grass dies and becomes a permanent bog, it's pretty much ruined unfortunately. I dug out in the centre about 1x1 & 2m down and still didn't break the clay layer, it's full of water which I drain with a pump but it still doesn't save the lawn. I really don't know what to do from here and any help would be appreciated.
The tiled patio is set on a concrete slab encircling the lawn.

 

Hi,

Is that center hole the lowest part of the lawn or is it almost all the same level ?

If you do have a low point towards an edge that would be the better place for a sump which, if you do not already have such a pump, use one like this with a float switch which you can leave to automatically drain the sump, though you will have to connect it properly to the mains.

https://www.machinemart.co.uk/p/051016044/

We used a very large plastic box/sump with a lid so we could cover it over with soil and plants or in your case turf.

Not sure whats on the market today but you could use the same idea as farmers do in their fields and use some similar domestic type perforated drainage pipes etc between the clay and top soil directing the water towards the sump.

 

Maybe you just have a high water table.
If you have I doubt there is any way of rectifying it.

All the raised areas will be draining into the lawn.

 

Before you attempt to drain, consider where it could drain to.You need to consider the topography, assess whether you would cause flooding of a neighbour property etc. Unless your plot is literally the bottom of a pond, it will have drained naturally before it was built upon, but possibly not to well!
What you must not do (legally) is pump your groundwater into the surface drainage, or sewer of the properties.It appears that the fall of the land shown is towards the house. The question you need to answer , is it possible to find a route past the house so that you can access a position on your property where you can provide a soak-away ,to drain through pipes or french drains. Both your local authority Building control and the Environment agency will have interests in what you propose, and potentally could fine you if you transgress their guidelines.

 

The money you'll probably plough into this project, and more than likely fail, would be better off spent extending that lovely tiled patio. Job jobbed.

It seems every man and his dog at this time of year, myself included, have miserable swamp problems due to clay just under the top soil.

The wife and I keep saying we're going to get ours sorted out, but the lawn looks so beautiful during the summer we temporarily forget about our winter woes.

Just going out picking up dog crap at this time of year is a health hazard.