No, you can take care of it beforehand, but I’m not exactly sure how important it is for you since the development looks relatively simple in your case. Usually, site plans need to be submitted. It must be clear where the house is located and where the house connection is. For the applications, we sometimes already needed a house number.
We also don’t have a construction company yet, but for example, we have already had the sewage canal and electricity laid up to the "Baugebiet". I had also already applied for fresh water. However, nothing will be done for now because the canal is already on the property. The installation on our property and the house connection will be done when the house is ready.
Construction electricity and construction water will be installed as soon as I give the "Go" for it and provide a responsible craftsman.
I would simply call the utility providers and ask. They can usually see in their system where the lines run and give you appropriate advice.