Rainwater dripping off a ridged roof and collecting in a metal gutter.

If you're building a rural home and need a safe water supply or if you just want to collect rainwater on a urban property for garden use, rainwater harvesting is a good investment. Not only are water bills becoming more and more expensive, but climate change is making our water supply here in New Zealand even more precarious.

Water is a precious natural resource, and it's becoming more precious. Whether you need household supply or emergency supply in case of a natural disasters, rainwater harvesting can be a simple and cost-effective answer for many people.

It’s also a great source of water for the garden in dryer months, for washing clothes, for showers, and – if it’s properly treated – for drinking and cooking.

Consider these questions when you are thinking about harvesting rainwater:

  • Do you need an above ground tank?
  • Does water need to be plumbed into the house?
  • Do you need consent from your local council?
  • Do you require on-site emergency supply?
  • Do you have fire sprinklers in the house?

For emergency preparation, Civil Defence and Emergency Management in Nelson Tasman recommends everyone keep on hand water for at least three days, which includes water for drinking, washing, and feeding pets. Plan on three litres of water per person for each day. Add one litre per day for pets (more if you have more pets than average).

In addition, you need about one litre for each of the following:

  • Washing food and cooking for each meal
  • Washing dishes after each meal
  • Washing yourself (one litre per day per person)

If you’re doing maths, a family of four with two pets should keep 81 litres on hand. Rainwater that is harvested can potentially help with almost half of that supply.

If your emergency kit includes what’s required to treat rainwater, such as our TankSafe product, it can also be used for the drinking and cooking stock you should keep on hand.

Allflow can help you work out what size tank and equipment you need and hook you up with the right gear for the job. Shop our rainwater tank selection now, we have tanks in sizes from 425L up to 30,000L.

Once you've collected rainwater, you'll need to filter it for household consumption. We carry high quality UV filtration products that will turn rainwater into drinking water, available at every tap in the house.