Hello everyone,
Here is the situation:
- Single-family house in the southern Hamburg area; 545 m² (5,856 ft²) plot; 110 m² (1,184 ft²) house footprint; approximately 150 m² (1,615 ft²) roof area (rough estimate)
- Cost for a cistern according to the earthworks contractor’s offer, 5 m³ (1,320 gallons), including delivery and installation, excluding the "interior components" (What does that mean???): €2,150
- Funding from IFB Hamburg: 40%, up to €1,500 --> Net cost: €1,290
Questions:
- Does such a cistern make sense under these conditions?
- At which planning stage should the decision be made? Before construction or possibly only afterwards?
- Does it make sense (also in terms of cost-effectiveness) to supply the toilet flush and washing machine with water from the cistern?
Best regards!
Here is the situation:
- Single-family house in the southern Hamburg area; 545 m² (5,856 ft²) plot; 110 m² (1,184 ft²) house footprint; approximately 150 m² (1,615 ft²) roof area (rough estimate)
- Cost for a cistern according to the earthworks contractor’s offer, 5 m³ (1,320 gallons), including delivery and installation, excluding the "interior components" (What does that mean???): €2,150
- Funding from IFB Hamburg: 40%, up to €1,500 --> Net cost: €1,290
Questions:
- Does such a cistern make sense under these conditions?
- At which planning stage should the decision be made? Before construction or possibly only afterwards?
- Does it make sense (also in terms of cost-effectiveness) to supply the toilet flush and washing machine with water from the cistern?
Best regards!
H
HeimatBauer5 Dec 2023 09:14Tolentino schrieb:
So we all agree that installing a cistern isn't economically viable nowadays.No, we absolutely do NOT agree on that. For new constructions, the payback period is certainly around 10-20 years—unless water prices increase. Since there are subsidies in many areas, it can sometimes pay off (as in this case) within 5-10 years.
And again: My cistern has never run dry. So much for "short to medium dry periods." I don’t know what’s unclear about "always."
That’s why I wrote today. I could have also written at short notice.
I deliberately ignored subsidies. They are just exceptions that you need to be locally aware of.
What I actually wanted to say, but probably didn’t express clearly enough for you, is that a rainwater tank is a sensible investment beyond just the (financial) aspect.
I deliberately ignored subsidies. They are just exceptions that you need to be locally aware of.
What I actually wanted to say, but probably didn’t express clearly enough for you, is that a rainwater tank is a sensible investment beyond just the (financial) aspect.
X
xMisterDx5 Dec 2023 09:17But precisely in midsummer, when a watering ban is imposed, the cistern is of no use at all.
That's the crux of the matter. Watering bans are issued after an extended period, sometimes weeks, without a drop of rain. By then, the cistern is already empty.
And even if it rains a little, the water evaporates from the dark roof tiles before it makes its long way into the cistern.
Another major issue is the extremely outdated irrigation technology used by farmers. Of the water sprayed for hours over the fields by large sprinklers, less than half actually reaches the plants effectively. There is a lot to learn from the Israelis in this regard, if one is willing.
That's the crux of the matter. Watering bans are issued after an extended period, sometimes weeks, without a drop of rain. By then, the cistern is already empty.
And even if it rains a little, the water evaporates from the dark roof tiles before it makes its long way into the cistern.
Another major issue is the extremely outdated irrigation technology used by farmers. Of the water sprayed for hours over the fields by large sprinklers, less than half actually reaches the plants effectively. There is a lot to learn from the Israelis in this regard, if one is willing.
X
xMisterDx5 Dec 2023 09:19HeimatBauer schrieb:
(...)
And once again: My cistern has never run dry. So no such thing as "short to medium dry periods." I don’t understand what is unclear about "always."Then you don’t have a garden that actually needs regular watering 😉
With smart irrigation, plants can be watered in a way that allows them to sprout again in autumn instead of being completely lost for the year.
As I mentioned, I’m not talking about golf turf that requires 20 liters per square meter (0.5 gallons per square foot) per day or something like that.
During drought, the garden will still turn brown, but the difference is that it recovers more quickly in the autumn.
You just shouldn’t water in the middle of the day, and it doesn’t need to be watered daily anyway.
My rainwater harvesting tank wasn’t even half empty, but this summer there wasn’t any significant dry period.
I’m curious to see how it goes next year.
As I mentioned, I’m not talking about golf turf that requires 20 liters per square meter (0.5 gallons per square foot) per day or something like that.
During drought, the garden will still turn brown, but the difference is that it recovers more quickly in the autumn.
You just shouldn’t water in the middle of the day, and it doesn’t need to be watered daily anyway.
My rainwater harvesting tank wasn’t even half empty, but this summer there wasn’t any significant dry period.
I’m curious to see how it goes next year.
H
HeimatBauer5 Dec 2023 09:33Tolentino schrieb:
A rainwater harvesting tank is a sensible investment, even beyond financial reasons. Absolutely.
And I do water my lawn with it, of course efficiently and with minimal losses. Since I do it properly, it's by no means just "so it can be revived again in autumn," but rather "so it stays beautifully green and fully comfortable to walk on barefoot all year round." Proper irrigation is just one aspect of this, but definitely an important one. And yes, if watering from the mains water supply or well is prohibited, I run my sprinkler with a clear conscience.
If the garden turns brown in summer despite having rainwater tank water, the fault clearly lies with the user, not the tool.
Similar topics