Water
Designing homes to use water efficiently, reduce costs and cope with more frequent droughts or storms.
Rainwater Systems: Uses of Rainwater
Collecting and storing rainwater can:
- reduce water costs for users on a metered water supply
- reduced demand on local authority water supplies and stormwater disposal systems
- provide an independent supply for watering the garden in times of drought
- provide an emergency supply
- be the sole source of supply to households not on piped supply
- reduce the rate of stormwater run-off.
Rainwater collection systems need to be designed and maintained properly to avoid contamination of potable water supply.
Uses of stored rainwater
Stored rainwater is most often used for homes that have no piped supply. It can also be used in addition to a piped supply (for irrigation, toilet flushing and other household uses).
For drinking water it is recommended that the water be treated or filtered.
- Simple rainwater storage tank for garden irrigation
A simple rainwater tank can supply water for a small garden. Purpose-built systems are available.
- Rainwater storage for all household purposes
The Ministry of Health recommends that where mains water supply is available, that it is used for drinking and food preparation.
Where no mains supply is available specifying a water filtration system for drinking water is recommended.
If main town supply is connected to a rainwater collection system, backflow must be prevented by an air gap or a backflow prevention device.