Water logging in garden - Replaced pond with seating area

[martinT]

I have created a seating area where an active pond existed, I drained the pond and levelled it out using permeable materials, and this level sits 400mm below the garden level. All went well, until I noticed water sitting back in the area. I have dug down to approx 700mm and found compacted clay. Because of the low level, I feel a drainage system with a soak-away may not sort the problem , my immediate option would be to hire an auger and drill holes beyond the clay and back fill with aggregate, is this the correct approach or is there any other solutions.

[darrenba]

Have you tried digging the clay to see how deep it goes? I had a similar issue with a client but we were lucky and found the clay was only about a foot or so thick and we had nice free draining gravel below.

[Tony McC]

When you say you "drained the pond", do you mean you punctured the pond lining (whether it was placky, concrete or puddle clay) and allowed it to drain to earth, or do you mean you baled out the pond prior to backfilling?

If the liner was left intact, that could explain why you're having waterlogging issues now.