Is a cistern economically viable through pumping?

So we all agree that a cistern is not economical today.

No, we absolutely do NOT agree. For new construction, it certainly takes about 10-20 years to pay off – unless water prices rise. Since there are subsidies in many places, it can be profitable (as here) already after 5-10 years.

And again: My cistern has never been empty. So nothing with "shorter to medium dry periods." I don't know what is unclear about "always."

That is why I wrote today. I could also have written at short notice. I have deliberately ignored subsidies. They are just the exception that one has to be locally aware of. What I actually wanted to say but probably did not phrase clearly enough for you: A cistern, beyond the (financial) economic aspect, is also a sensible purchase.

But exactly then, in the height of summer when a watering ban is imposed, the cistern is of absolutely no use to you. That’s the joke of the story. Watering bans are imposed when it hasn’t rained a drop for a long time, sometimes weeks. By then the cistern is long empty. And even if it then rains a little, the water evaporates from the dark roof tiles before it has found its long way into the cistern.

A major problem, by the way, is also the enormously outdated irrigation technology of the farmers. Of the water that is sprayed onto the fields for hours via huge sprinklers, the plants effectively receive less than half. You can learn from the Israelis, if you want.

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And again: My cistern has never been empty. So nothing with "shorter to medium dry periods". I don't know what's unclear about "always".

Then you don't have a garden that really needs water ;)

With intelligent irrigation, it can supply plants so that they sprout again in autumn and do not have to be completely written off for the year. As I said, I am not talking about the golf lawn that needs 20l/m² per day or something like that. The garden is still brown during the drought. But the difference is that it recovers faster in autumn. You just shouldn’t water in the middle of the day, and anyway it doesn’t have to be watered daily. My cistern wasn’t even half empty, but there was no significant dry period this summer anyway. I am curious about next year.

A cistern is, beyond the (financial) economic aspect, also a sensible purchase.

Absolutely.

And I water, of course sensibly and with minimal losses, my lawn quite well with it, and because I do it properly, it is by no means "so that it can be revived again in autumn" but "so that it remains beautifully green and unrestrictedly barefoot-friendly all year round." Of course, the right (!) irrigation is only one aspect of this, but a quite important one. And yes, if watering from the tap and well is prohibited, I run my sprinkler with a clear conscience.

If the garden is brown in summer despite cistern water, the fault clearly lies with the operator, not the tool.