Water demand garden/year --> Is a cistern worthwhile?

But if you only have one extraction point (with system separator), you don’t have an external drinking water pipe. If you only use it for irrigation, that’s not bad but you have to be aware of it. That’s why I have two extraction points. Automatically switching to irrigation is of course not possible that way.

If you only have one outlet (with a system separator), you don't have a drinking water pipe outside. If you only use it for irrigation, that's not a problem, but you have to be aware of it. That's why I have two outlets. Automatic switching for irrigation obviously doesn't work that way.

But the thing with drinking water is difficult anyway. As far as I know, all branch lines that are not flushed at least every 72 hours no longer supply drinking water by definition.

I would never drink from outdoor faucets.

From a certain standing volume, I believe that's the definition. Otherwise, a circulation pump is required. But who does something like that outside... Therefore, a system separator is required. Let's be honest, who didn't drink from the garden hose as a child... we survived that too. Now theoretically a sign saying "no drinking water" has to be posted. In a single-family house, you are quite free (until something happens).

I'm not concerned with the legal definition or according to DIN or dvgw.

Everyone can do as they please. But as already wrote, the children from the garden hose. Or the small basin for the toddler. How do you preferably fill that in the garden? Cistern water? Pure fresh water line? Tap with both coming from a system separator?

I don't want to judge anything as right or wrong, I'm just of the opinion that one should be aware of it and then decide for themselves.

I believe we are talking past each other. The freshwater line at the outdoor faucet requires a backflow preventer. Regardless of whether I also want to feed cistern water there. For the refill, no additional backflow preventer would be necessary since there is already one in front of the outdoor faucet.

I think we are talking past each other.

...could be! Probably I'm having a brain freeze right now and don't exactly understand how you mean the setup.

System separator before the outdoor faucet to make a branch for refilling the cistern before the outdoor faucet? Sure, then you have a pure fresh water outdoor faucet (ignoring the length of the pipe and standing times). But then you also need a second faucet for withdrawal from the cistern.

Maybe I still misunderstood it.

Of course, you can also have a domestic water system with automatic refill. That costs, though.

Actually, I just want to say that no matter the setup, you should think about the "problematic" (if you see one there) fresh water/cistern water, and what kind of withdrawal options you want to have in the garden.