Drainage application - which form of rainwater retention?

Hello, according to the city drainage department, "rainwater retention for all sealed areas connected to the rainwater sewer system must be provided. A 10-year rain event with 3l/s*ha is assumed. A hydraulic proof must be attached to the application."
Upon inquiry with the city drainage department, a retention cistern, soakaways, a storage sewer, or basins on the property would be possible. How does a layperson make a decision here? Who can help with this, possibly also to get an overview of costs? Which system did you decide on and why?

Here are some more details about the rear property:
Size: 890 sqm
Roof area house and garage: 186 sqm
Driveway: approx. 200 sqm
Terrace: approx. 45 sqm

How the driveway should be designed has not yet been firmly planned. Permeable paving might be an alternative here.

I am looking forward to your opinions and experiences!

Hopefully, the decision is not made by the layman but by the specialist. There are specialized companies for such civil engineering measures. Keyword: civil engineer or also hydraulic engineer

I have the feeling that we are required to choose a system, and then the experts would prepare the application.

I would find that somewhat inappropriate. Therefore: find a professional, get advice about the pros and cons, and THEN decide. I believe there is even such an expert hanging around in the [green forum].

After the annual costs for rainwater disposal were too high for me, I installed a cistern that is not connected to the rainwater drain. The advantage is that several hundred euros are saved every year. Additionally, the rainwater can also be used for the garden. By the way, [Terrasse mit Gefälle zum Garten] and therefore it does not have to be connected either.