Is rainwater automatically safe to drink?
No. Official health guidance warns that rainwater is not necessarily safe without removing germs and chemicals. Potable use needs local health advice, appropriate treatment, testing and compliance.
How much water does a roof collect?
In metric units, 1 mm of rain over 1 m² equals 1 litre before losses. Apply a conservative runoff factor and then account for first flush and tank overflow.
Should I buy the largest tank that fits?
Not automatically. Storage should match rainfall timing, actual demand, turnover, site support, access, overflow and budget.
Can a tank prevent flooding?
A water-supply tank may be full before a storm. Flood or stormwater credit requires local hydrologic design and often controlled available volume.
Can I connect rainwater to toilets or laundry?
Only where allowed and with required treatment, backflow protection, labelling, permits and qualified plumbing work.
Do calculators send my entries to the site?
No. The tools calculate in the browser and do not intentionally transmit or save the entries.
How often should a system be maintained?
Frequency depends on debris, climate, water use and equipment. Inspect after storms, clean screens seasonally or more often, and follow product and health guidance.
Does a first-flush diverter make water potable?
No. It can reduce some initial roof debris but does not reliably remove all germs or chemicals.
Can I bury any plastic tank?
No. Use a tank rated for burial and actual groundwater, soil and loading conditions, following the manufacturer and local requirements.
Where should overflow go?
To a lawful, stable route away from foundations, neighbours, septic systems, unsafe slopes and public paths, with erosion and icing considered.