Rain water use: Halve your costs - save drinking water
Higher costs for treating drinking and waste water, further new and increased duties lead to continually rising costs. Think, for example about fuel prices.
Efficient rain water harvesting systems helps the environment as well as your wallet. It pays off year after year.
Water for different purposes
About half of your drinking water can be easily subsituted by using rain water. For personal consumption in the bath or shower, for washing dishes or for cooking or drinking you should use public drinking water.
For any other purposes like flushing the toilet, for your laundry, for the garden irrigation or for cleaning purposes (indoor, outdoor, car etc) rain water is certainly more than sufficient.
Rainwater for industrial or private purposes
Example of a Domestic System with automated drinking water feed
This system for domestic supply is backed by tried and tested module technology. When an extraction point (toilet..) is opened in the rainwater pipework system, the circuit breaker switches on the domestic water works and vice versa.
If there is no rainwater in the tank due to a long period of drought, a float switch in the cistern automatically switches the solenoid valve of the mains water on, thus ensuring that the extraction point turned on in the rainwater pipeworks is supplied with drinking water (with no deviation in the tank). When the tank fills up again, the float switch automatically closes the solenoid valve and the supply of rainwater is once again assured.

- 1. Earth tank; 2. Dome; 3. Tank filter; 4. Siphon 5. Outflow to rainwater drain; 6. Overflow; 7. Floatswitch for solenoid valve; 8. Siphon pipe with swimming filter; 9. rainwater inflow; 10. Underground drainage; 11. Through the wall connection; 12. Wall holder; 13. Drinking water pressure pipe; 14. Circuit breaker ; 15. Solenoid valve; 16. Drinking water feed; 17. Emergency overflow; 18. Drinking water pressure pipe; 19. Rainwater pressure pipe; 20. Double socket; 21. Water tap
Main components of a rain water system
- Storage tank
- Water filter
- Overflow siphon
- Calmed inlet
- Connections
- Drinking water feed in line
- Pumps
- Electronic controls
Example: Automatic drinking water feed

- 1. Drinking water feed 2. Float gauge 3. Inflow valve 4. Possible connection for drinking water pipe 6. Connection set for pump 8. Double socket for automated control of valve 9. Float switch
How to keep the rainwater clean?
A number of features in a professional rainwater harvesting systems keeps the rainwater clean:
Outside rain water filter holding back larger particles
Other optional filter before the tank
Calmed inlet
Overflow siphon cleaning swimming particles during required overflow
Float switch
In order to help you to provide the most cost efficient rainwater harvesting solution please download the DWC Rainwater Questionnaire (1 page, pdf)
Choosing the tank capacity - Rule of thumb
Per person and year you need a tank capacity of at least 1,000 liters.
For a tank capacity of 1,000 litres you need 25m² of roofed-over surface.










