Rainwater cistern: Useful? Necessary? Costs?

that sounds like a solution (who does it, what it is called (and must be approved) and what it will approximately cost. today in the new development area, two builders enthusiastically joined in. both reported major problems with the subsequent change to the original building application. why the construction company Mulde chose infiltration, I do not know. I will ask when I include the "Regenwassersickerschacht" as drainage...

Swales are installed by the municipality between the property and the street. They then catch the rainwater from the surfaces. The swales are then sown with grass. The rainwater infiltration shaft is only intended to collect rainwater from the roof. I think later on, you could also put a pump in there... I believe two neighbors have alternatives and giant swales with stones under the terrace or wherever. These apparently also collect the rainwater from the roof and let it infiltrate.

what use is a pump in a soakaway pit? the water has to be pumped somewhere, right? if into the normal sewer system, then an overflow protection would also suffice (additionally: then why the infiltration?!). if only upwards, then it just goes in circles and comes back.

the builders definitely drove me crazy with the topic. both said they should lower about 15% of their property by 30cm. and that's nonsense. i would then take the edge and the water would run to the neighbor. that can't possibly be the point...
and now both somehow got approval for a pit.

On our property, water must also infiltrate into the ground, which is done through a soakaway. According to the architect and civil engineer, it is not worth installing a cistern in addition because you still need the soakaway and you don't really get a lot of usable water that way. They recommended that we drill a well for half the price instead.

, what was the cistern supposed to cost? Have you obtained a concrete offer for drilling a well (costs)?

Unfortunately, I don't have any concrete numbers. We will take care of the well only after we have moved. We simply trusted the experts and didn't follow up much further. The cost of the cistern depends a lot on its size, while for the well it depends on how deep it needs to be drilled. So, everything can vary greatly.