Help with idea for garden drainage

[Ste92]

Afternoon chaps

I’m after a bit of advice on a plan which I think will work.

We’ve a new build house which the garden slopes away from. At the lowest point, it gets boggy when it’s been raining heavy. There is a crate soakaway system in the garden but it isn’t at the lowest point. I’ve dug down and there’s about 300mm soil and the rest is thick heavy red clay and I’ve hit sandstone rock at about 1200mm which I can’t get through. I put some water in and it drained fairly quick.

My plan is to dig out a larger hole with a trench horizontal across the bottom of the garden, put some non woven Geo textile in it, fill it with ballast wrap the ballast in the Geo textile and have a perforated pipe in the trench going into the hole. Back fill the sides, top it up with soil and grass seed/turf over the top.

I think in theory this would work but I’d like a second opinion before I start breaking my back digging.

[lutonlagerlout]

late repsonse here but why use ballast?
10 mm pea shingle is preferred
cheers LLL