Is a cistern economically viable through pumping?

Who thinks they can save the world with the cistern and can afford it, great. However, those who currently have to watch every penny because of high prices and high interest rates should do without a cistern because it is not worth it. But coming here with "saving the environment" and keeping your lawn green all year round. Honestly, is that satire? ;)

That depends on a few more factors, such as cistern size (most have only about half of yours), the type and number or area of plants and lawn, shading of the same. Soil conditions (märklischer sandy soil is quite ungrateful). I would say your area/cistern volume is quite favorable. Some have a similar area (rather larger) but only half the cistern volume.

And of course, watering your garden from the cistern is more environmentally friendly than watering with drinking water or creating a gravel garden instead of plants.

Our architect also found a cistern unnecessary, as uneconomical, and although he is not entirely wrong with that, we still installed one. Not because money doesn’t matter or because I want to save the world, but because watering bans will more likely be the rule rather than the exception in the future, and rightly so. It’s no longer about the perpetually green lawn, but about whether any plants (including vegetables) can survive prolonged heat periods at all. I’m still struggling with myself why we didn’t at least make toilet flushing usable with rainwater. Drinking water is actually far too precious to be used that way.

And you want to water the 1200sqm twice a week with treated drinking water, in an area complaining about drought and water shortage. Excellent

No, I have a well. But this was about economic efficiency, not moral questions.

I am still struggling with myself why we didn’t at least make toilet flushing usable with rainwater. Drinking water is actually way too precious to be used like that.

Generally yes. But the question is how much technology you want to bring into the house, and a second water circuit is quite a commitment. For me, there were too many sources of error, and I have already experienced several times firsthand what it is like when the system fails. So far, I only know people who have regretted having it installed.

I would like to ask for your opinion on the initial offers: (each including delivery, earthworks, installation, but excluding accessories) (1) 5000l plastic cistern: €2,150-2,450 (depending on the offer) (2) 5000l concrete cistern: €3,000 (3) 10000l plastic cistern: €4,000 As I said, I am receiving a 40% subsidy (limited to €3,750 purchase costs), I am unsure whether to go for option 1 (probably the most economical) or directly upgrade to 10,000l so that I don’t run empty in really dry periods (the actual purpose of a cistern). Concrete vs. plastic is probably more or less a matter of belief or price, right?