ᐅ Can rainwater from a cistern also be used for laundry and toilet flushing?
Created on: 29 Apr 2020 08:09
A
Andreas94A
Andreas9429 Apr 2020 08:09Hello everyone,
we are currently in the planning phase of our new build.
We also want to include a cistern to use rainwater for garden irrigation.
Now we're wondering if the rainwater can also be used for other purposes,
for example, toilet flushing or laundry.
The water collected from the roof will be filtered through several screens to keep it clean.
Our question is whether this makes sense or if there are any experiences with this.
Of course, we hope to save costs over the years on rainwater disposal, water supply, and so on.
The cistern will have a capacity of about 15,000 liters (3,960 gallons).
We would appreciate your experiences or opinions.
Best regards, Andreas94
we are currently in the planning phase of our new build.
We also want to include a cistern to use rainwater for garden irrigation.
Now we're wondering if the rainwater can also be used for other purposes,
for example, toilet flushing or laundry.
The water collected from the roof will be filtered through several screens to keep it clean.
Our question is whether this makes sense or if there are any experiences with this.
Of course, we hope to save costs over the years on rainwater disposal, water supply, and so on.
The cistern will have a capacity of about 15,000 liters (3,960 gallons).
We would appreciate your experiences or opinions.
Best regards, Andreas94
I think this is very sensible from an ecological perspective, since you hardly need the water from the cistern for the garden during half the year (autumn, winter). However, I have no idea how much the additional piping would cost or how much water and fees could be saved as a result.
N
nordanney29 Apr 2020 08:30Andreas94 schrieb:
We are now wondering if we can use the rainwater for other purposes as well, for example for flushing toilets or for doing laundry.Yes, you definitely can. However, you will need to install separate piping and keep the cistern water completely separate from the potable water supply. Additionally, you will need a second water meter, since you still have to pay for wastewater discharge (at least officially). The system must also allow for quick switching, as the cistern will likely run dry regularly (during dry periods like the recent weeks or in summer). Also, if the water in the cistern becomes a bit musty (for example, if it hasn’t been replenished for a long time), it might not be ideal for laundry.
I would need to look up the exact figures for the additional costs of the extra piping in our case.
By using rainwater for the washing machine and toilets, we had some (minor) savings over about 10 years because the wastewater fees were calculated based on fresh water consumption. For the past approximately 5 years, we have also been paying for the rainwater discharged into the sewer, calculated based on the roof area of the house rather than by a separate meter. However, municipalities handle this differently.
It doesn’t seem possible to save a significant amount, but I simply feel good about using less fresh water, even though Germany is not, or at least has not been, a water-scarce region.
My laundry does not smell musty, even though I only use fragrance-free detergent. I also save detergent because our fresh water is very hard, and I have to use at least twice the usual amount when the cistern is empty and I switch to fresh water.
By using rainwater for the washing machine and toilets, we had some (minor) savings over about 10 years because the wastewater fees were calculated based on fresh water consumption. For the past approximately 5 years, we have also been paying for the rainwater discharged into the sewer, calculated based on the roof area of the house rather than by a separate meter. However, municipalities handle this differently.
It doesn’t seem possible to save a significant amount, but I simply feel good about using less fresh water, even though Germany is not, or at least has not been, a water-scarce region.
My laundry does not smell musty, even though I only use fragrance-free detergent. I also save detergent because our fresh water is very hard, and I have to use at least twice the usual amount when the cistern is empty and I switch to fresh water.
Definitely do not do this. You will only end up with problems such as dirty filters and dirty toilets. I hardly know anyone who would do it again or is satisfied with the result.
Additionally, it is not economically viable. The installation is more complex, and the potential savings are very small.
Another argument against it: My 8,000-liter (2,113-gallon) rainwater tank has been empty for two weeks due to the drought. In Germany, you will likely need a 15,000-liter (3,962-gallon) tank in the future to keep your garden plants and lawn alive.
Additionally, it is not economically viable. The installation is more complex, and the potential savings are very small.
Another argument against it: My 8,000-liter (2,113-gallon) rainwater tank has been empty for two weeks due to the drought. In Germany, you will likely need a 15,000-liter (3,962-gallon) tank in the future to keep your garden plants and lawn alive.
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