Dimension Cistern - Building Plan Tips

At the moment, I am considering whether it might be more sensible to take a significantly smaller cistern and have a well drilled that fills the cistern when it is empty. That will probably be cheaper. The GU has estimated €4,200 for the 4,000 liter cistern.

So we also had a cistern installed. 7800L volume, it was full within 5 days after the last storms. House 45° roof; floor area 8.2*10.5. We also considered drilling a well. However, it would have had to be at least 30 meters deep and then a well becomes significantly more expensive. So it depends. And if you have to install a cistern anyway, I think a larger one would simply be more sensible and cheaper. We don’t have to have a cistern either, but we like to have water in the summer that we can simply use to regularly refill the paddling pool for the kids or water the plants really well, so you just don’t have to worry about it. Such a cistern probably won’t pay off, purely for garden irrigation.

We have an automatic pump in the cistern that starts independently as soon as water is drawn from a water outlet. Regards, Dirk

What kind of pump do you have? We are still searching and not sure whether to get an automatic pressure submersible pump or a simple one with an additional switch. Currently, water is pumped out with a simple garden pump, but that is not meant to be the permanent solution. How do you drain the hoses in winter? Compressed air?

The main contractor said that it would be best to install a cistern in the garden.

IMHO the mentioned size is sufficient. How is the infiltration supposed to take place then?

What kind of pump do you have? We are still searching and not sure whether an automatic pressure submersible pump or a simple one with an additional switch.?

We have an automatic pressure submersible pump from Gardena. It's quite a convenient thing when you just connect the hose and the pump starts running.

But it can also backfire...

At first, we just left the hose connected to the hose reel at the water outlet. Until that hot Sunday came when we were already wondering who had been watering their garden for 45 minutes – we were sitting inside with the shutters down (the awning wasn’t there yet :cool).

After 45 minutes, I wanted to check and was very surprised where the approximately 10 m high fountain in our garden came from...

In fact, the hose had come loose from the coupling, and the strong pump had completely distributed our full cistern in the garden, which looked more like a rice field...

Since then, the hose is disconnected – then something like that doesn’t happen anymore.

How do you drain the hoses in winter? Compressed air?

Our water outlet is lower than the pump in the cistern – so the pump is disconnected from the power, lifted out of the water, and then (with a short hose) suctioned at the water outlet to drain the line.

Regards,

Dirk

We have an automatic pump in the cistern that switches on independently as soon as water is drawn from a water outlet.

The world perishes comfortably.
We have the pump with the 20 m cable connected to the outdoor socket. Inside, we only need to operate the switch for the outdoor socket and the pump starts. When we no longer need the water - switch off.

Our water outlet is lower than the pump in the cistern - therefore, the pump is disconnected from the power, lifted out of the water, and then (with a short hose) suctioned at the water outlet and the line drained.

Our pump is lower than the sockets.
Last year we still had a "transparent" hose between the pump and the connection box. You could very well observe how the water completely ran back (even without a drainage valve).

At the moment, I'm considering whether it might be more sensible to take a significantly smaller cistern and have a well drilled that fills the cistern when it is empty. I will probably come out cheaper that way. The general contractor estimated €4,200 for the 4,000-liter cistern.

Just to illustrate, we needed about 30m³ of water last year (very dry) for a similarly sized garden. At about €6 for water + sewage costs (unless you can get exempted from sewage), that makes monthly costs of €15. If you have to finance the €4,200 at about 1.5%, then the cistern only pays off after 29 years at the earliest. (Provided the cistern never runs empty in those 29 years.) Taking into account electricity costs for the pump, possible repairs, etc., you’d probably be looking at a payback period of about 35-40 years.

For someone who doesn’t necessarily have to build a cistern, it probably will never be worth it.