Bauhaus concrete villa with core insulation - experiences

18 meters long and 76,000 liters. We switched to a smaller one because it fits better into the installation space in front of the pool. Originally we wanted 90m3. This gives us more options when designing the garden to the left of the pool.

Why so big? We have 15sqm and it is already completely uneconomical. For that money we probably could have paid for garden water for 20 years..

Last year there was already a ban on watering with fresh water. With a cistern like this, no problem. Depending on the garden and during the establishment phase, you can easily collect 10m3 per watering process. To operate larger sprinklers or circles, you also need an appropriate pump with sufficient volume and pressure. Otherwise, it would not be possible to complete a watering process in, for example, one night. You couldn't manage that from the tap, nor would you be able to keep up with refilling afterwards. Our pump would empty your cistern in half an hour. This way we can store enough water in between (from rain and well). The price jumps are not as extreme from a certain cistern size onwards. Our goal was to be able to bridge at least 4-6 weeks. Economically, a single-family home is not feasible anyway. We don't have this cistern to save money but to be able to water well. For what the pool costs, we could also go to a swimming pool for life. But we don't want to.

Google the amount of precipitation per m² per year in your region. Then multiply that by the m² you direct into the cistern and by approx. 4€/m³ fresh + wastewater price. I estimate the cistern pays off earliest in 30 years with rising water prices.

At the expense of the environment/freshwater quality, because if everyone collects their own seepage water, the nitrate concentration in the groundwater keeps increasing.

Irrigation ban with fresh water? Crazy, I haven't heard of that before.

Mottenhausen there are also regions where cisterns are part of the concept for preventing flooding after heavy rain. And heavy rain is on the rise. How cisterns will affect the groundwater time will tell. Basements underwater are also not exactly clean. I don’t want to know what kind of pollutants are being washed into streams and rivers there

As written by haydee, retention cisterns are required here in new development areas to buffer heavy rain. We would not have needed a cistern but wanted one. The water is also returned to the ground quite quickly in our case. Presumably, most of it then goes back into the source. Last year's watering ban was, I believe, only active for 4-6 weeks. Still sucks when you have invested a lot of money and work in the outdoor area and then sit in a brown desert.

Was in OWL last year and in (Middle) Franconia where there is generally little rain, this also happens more often in the summer. (Freshwater watering ban for lawn sprinkling). I find it annoying anyway, you can manage lawns and perennials again - bushes and trees sometimes need watering help.