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Practical advice

Rainwater tank guides

Clear, independent guidance for planning a rainwater system, measuring your catchment and understanding installation requirements.

  • How to measure your roof catchment area Why you measure the footprint rather than the sloped surface, and which parts of the roof to count. Read guide →
  • What a first-flush diverter is and why the first rain is dirty How a first-flush diverter works, why the first rain off a roof is the dirtiest, and how to size and maintain one. Read guide →
  • How your roofing material affects collected rainwater How different roofing surfaces affect the quality of collected rainwater, and why testing is the only reliable way to know if it is safe to drink. Read guide →
  • Rural firefighting water supply requirements How a dedicated firefighting reserve works as a consent condition, and how it sits on top of your household rainwater storage. Read guide →
  • What carted water costs in New Zealand How much it costs to have water delivered by truck, and why that cost makes rainwater tank sizing concrete. Read guide →
  • Rainwater and drinking water rules in New Zealand Where private domestic rainwater supplies sit relative to registered water supply rules, and what Taumata Arowai's role is. Read guide →

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