ᐅ Is a rainwater tank worth it for garden irrigation?

Hello,

I wanted to ask if a rainwater cistern is worth it at all if it is only used for garden irrigation.

About our house: All the rainwater is directed through pipes into the garden to the soakaways (from both sides of the roof and from the garage driveway).

My idea was to install a cistern before the soakaways with an overflow that flows into the soakaways.

We would then use the water for garden irrigation (possibly with an automatic irrigation system).

Is it possible to install the cistern yourself?

Financially, it only becomes worthwhile after many years or even decades – but this depends on the specific wastewater fees and the regulations of the local water authorities or network operators.

Installing it yourself depends on the available space and ground conditions.
If there is plenty of space and the soil is not too sandy, it is probably possible to do it yourself with a rented excavator (excavating gently).
If space is limited and/or the soil is sandy, I would not recommend doing it yourself, as the risk of cave-ins (which can be life-threatening) is too high.

I don’t think it’s worth it for us, at least. The problem is that, for example, in summers like this one, you won’t have any water in the cistern when you need it. Even during average summers, a cistern can run dry in a few days, depending on its size and the size of your garden.

However, here we can let the water infiltrate into the ground and don’t pay any fees. If you have to pay those fees, the situation might be different.

Whether you can install it yourself depends on whether you’re able to dig a sufficiently large hole and remove the excavated soil. It also depends on how large you want the cistern to be. If you have plenty of space, you can install several 1 m³ (35 cubic feet) units connected in a row. That can also be done by hand.

We have no wastewater fees because everything flows into soakaways and infiltrates on our property.

The only saving is that we do not need to use drinking water for garden irrigation.

Taitv789 schrieb:

We don’t have any wastewater fees since everything flows into the soakaway system and infiltrates on our property.

The only savings are that we don’t have to use drinking water for garden irrigation.

Then you can calculate when it pays off. For example, we have a separate water meter for garden water and pay €1.60 per cubic meter. Compare that with the costs of the cistern and the electricity for the pump. Keep in mind that even in summers like this one, you still need water for the house. The most economical solution is always having your own well, if it can be drilled at a reasonable depth.

A cistern can also be worthwhile for other reasons, as some plants do not tolerate hard water well, and tap water or groundwater is usually harder than rainwater.
My wife keeps nagging me to finally connect the cistern (it’s already buried) or at least set up a rain barrel.
But before we moved in, she also wanted a fence and trees.