The Brew Cabin

I have a property on built up land … Railways filled in a valley to create a railway sidings, and to get track to level of bridges over the nearby toads.
So in the 50’s they filled it in with around 25’ depth of … to give it a technical name - crap.
A combination of material from the local main road that was being constructed … and the more problematic material, slag from local steelworks.

The issue is the land does not drain.
I tried French drains to suds crates, once rain starts it just delays ‘saturation’ but once crates fill, it’s weeks before they empty … they were on gravel /terram base, but no real answer.

My problem is the lawn … it gets sodden, and lawn dies in patches.

It has several runs of French drains and new 150mm of top soil …. But it gets saturated.
To give a clue the earth rod inspection hole is 200 depth when dry, when it rains water table comes up to within 50mm of surface.
I can’t remove the 25’ depth not practical.

Thought was if I drill a number of vertical holes … maybe 1.5m deep, and fill with clean stone or maybe sharp sand … create enough drainage points to improve the plot.

Can you hire a mini-digger with 150mm or 200mm auger … needs weight to stand any chance of drilling. I tried 2 man powered auger, just went off at tangent as soon as it hit stones, and threw us about a bit.
Seen 450mm auger but that is too big.

Alternatively anybody know of companies that can do this for me,

You can hire mini digger and auger. Ive got a 200mm and 100mm wide auger for my digger.
Your idear is worth a try. Can you get rid of the water any where else

Thinking of holes every 2m to help get water to drain away.
No way to drain it anywhere, the French drains & crates go nowhere to drain … other 5han down.

Where's the sewer go? How old is the property. Maybe do a few holes and see what happens. But i don't think this will solve the problem. Can you pump it any where. Any pictures

I have surface water and foul drains, but Building Control have said land drainage cannot go into the drains.

When I dug out foundations .. just over a metre deep, and put in hardcore, Had some serious storms, ground level was a swamp, but the foundations drained away fine.
Thinking that if I can get a series of holes, it will increase drainage of overall plot, enough to let it cope with rain.

It would also be least impactful to laid lawns.

Are there any companies you are aware of that rent digger & auger.