Underground parking + high water table, soakaway

We were hoping to have underground parking in the house we're currently designing (demolish and new build job). The water table gets to about 5-6ft below ground level, we know this because in the old house the cellars flood when it rains.

My architect seems to think that because of the high water table a soakaway isn't going to work. The only other option he has suggested is a sump/pump to pump water into the sewer but we may not get permission from the sewer company.

The underground parking would have a long ramp down. I'm not a drainage expert but do we have any other options?

A soakaway wont work

You need tanking and a pump to remove the local water.

The only issue is where is this water to be pumped to. Storage tanks, to other land drains, or the house drains

you are not allowed to put ground water into a public drain.

you need to design a de-watering system. some seepage of ground water is acceptable in a car parking area. you should look at a document called BS8102 (protecting structures from ground water) for guidance.

D