ᐅ Rainwater Harvesting Tank: Yes or No, and Which Material?

I would have a well flushed, which costs between 150 and 500 EUR here, depending on the service provider and the invoice requirements.

Wallyfan schrieb:
I would have a well flushed, and that costs between 150 and 500 EUR here, depending on the service provider and invoicing preferences.

That is inexpensive. For nearly 10 m (33 feet) of drilling plus pump and pressure switch, it was about 1,000 EUR for us.

kernm23 schrieb:
How is the water drawn? Can the cistern be connected to the outdoor faucet?

The cistern water may be connected to its own outdoor faucet, but not to an existing faucet that supplies drinking water.

Otherwise, municipalities nowadays often regulate the methods for water use through local ordinances, so you can’t simply rely on eco-friendly gardening.

If the excavator will dig the hole for a small fee, it’s better to proceed independently: have the cistern delivered and installed, and consider handling the supply line and, if necessary, an overflow yourself (or ask the excavator again).

Ellie schrieb:
Municipalities nowadays often regulate the type of money-spending method through local ordinances

No one is really forced to install a rainwater cistern (any counterexamples?). In my opinion, it’s important to distinguish between infiltration systems (soakaway, infiltration trench, etc.) and cisterns for rainwater harvesting. And regarding usage, there is a difference between garden irrigation and household use (washing machine, toilet flushing, etc.). Usually, only infiltration is mandated.

For us, I’ve calculated a required cistern volume between 7 m³ and 25 m³ (only for garden irrigation). The range depends on assumptions about irrigation demand (100, 150, or 250 L/m²/year). The large size is due to the big plot (about 1200 m² (13000 sq ft) of unsealed area), although it’s likely that irrigation demand won’t increase linearly with plot size, as less intensive gardening would probably be done in that case (just my guess). A concrete cistern of 5.4 m³ (190 ft³) adds around 1500 euros to the price (somehow incorporated in the contract with the developer). This is about as cost-effective as the concrete stairs or the mechanical ventilation system with heat recovery... In my opinion, these 1500 euros should be considered relative to the green plastic tanks people often buy later from DIY stores (or don’t buy at all).

I know someone with a well that delivers highly iron-containing water. Even washing the car is borderline with that water. It really depends on the individual case… Rainwater is a quality of its own.

I believe my father has about 7,000 liters (1,850 gallons), plus an above-ground tank of 1,500 liters (400 gallons).
In summer, he often completely runs out, even though the property is only about 650 square meters (7,000 square feet), including the house and terrace.
However, the garden is mostly a kitchen garden, with only about 80 square meters (860 square feet) of lawn at most. I’m not sure how much more water vegetables and flowers need compared to grass.

Bieber0815 schrieb:
Well, no one is really forced to install a cistern (counterexample?). ).

Actually, in our area it is required by the development plan. A retention cistern with a throttled outlet into a retention basin.