Where can I find out the development costs?

So the street has been planned since around 2002. However, it could not be implemented because the city lacked a plot of land. They now have this, and the street is supposed to come this year.

Allegedly, the road construction costs will be distributed among all residents. How much that will be was not known last year, but it is supposed to be announced from March.
A statement from 2 years ago said that for something like this, you can expect about 24,000.

So I know there will also be additional costs, and so far I have estimated them at 25,000.
In March, I will probably know more about this and will also directly ask about water/sewage.

What exactly is included in the proportional costs for the street? Does the municipality also include the water supply? We had to connect our house ourselves and paid 12K for water, which depends on the length of the route. Sewage was another approx. 4K for KKA + infiltration. Electricity and telephone were almost a bargain in comparison. The question remains what the city wants for the street? Our general contractor took over most of it on our land, which made it overall cheaper.

What exactly is included in the proportional costs for the street? Does the municipality also include the water?

I don't know all that yet. I can only inquire about it starting from March (I will probably knock on the door already in mid-February ^^)

The fees of the utility providers are manageable in the sense of being predictable. You get the prices for empty conduits on your property from your service provider (for us, it was the civil engineer). The unpredictable costs have a lot to do with the coordination factor. The less digging you do, the cheaper it gets. We were able to schedule 3 out of 4 utility providers within a period of 5 days. This meant the street was only opened once at our expense; we also hired the civil engineer ourselves – he also took care of the sewage, knew the "electrician" and the "water man." Advantage of country living... Only Telekom was (apparently, even for themselves) uncoordinatable, but that didn’t matter since they have a fixed price. With €15,000, you should be very comfortably within budget for a new development area as long as you don’t have a rip-off utility provider.