Water saving tips for living with rainwater tanks

Water saving tips for living with rainwater tanks

Water use – living off the ‘water supply grid’ in New Zealand

Water saving when you rely on rain water tanks


Living rurally in New Zealand, my family relies on using rain water that we collect from our roof, rather than being connected to a town water supply. When we moved to our place, we had to change our water use habits to water saving habits.

After years of living with a town water supply in both NZ and the UK, it needed a change of mindset to rely on water tanks. Previously, I took water for granted, as I could always turn on a tap and there it was! I did not have as many water saving habits as I do now.

Our rain water harvesting set-up


My house and garage have a combined roof area of 260 square metres. The average rain harvest in my area is estimated to be:

Average Monthly Potential Catchment – 22,382 Litres

Average Annual Potential Catchment – 268,580 Litres

Source: https://www.devan.co.nz/rainwater-calculator/

In my area, the local council has calculated that people use on average 240 litres per day (source: Smartwater website).

As a family of four people, if we use 240 litres a day, that’s 960 litres a day. In a year, the total water use would be 350,400 litres.

We can’t use that large amount of water, as we just don’t collect it as rainwater. The last two summers have seen drought conditions, meaning we collected even less water. This trend is likely to continue, as we have more droughts (https://niwa.co.nz/news/drought-hits-hard-far-and-wide).

We can get a water tanker to deliver a load of water. We have had to do a few times over the years, usually at the end of summer to get us through until a decent rainfall.


At our place, we have a large vegetable garden, fruit trees, and paddocks with animals that need water. So we need to have enough water for us, and also for the produce we are growing and animals we care for.

Water saving tips and ideas

We have become very aware of water saving measures, and the many ways we can all save water. For us, these include:

  • Having two minute showers (we have an egg timer in the shower – low tech works best).
  • Having ‘navy showers’ – this is where you turn the water when you are soaping / shampooing, and turn it on again to rinse.
  • Rarely having baths. My husband has installed two baths in the course of our complete house renovation, and hasn’t used either of them!
  • We have a pump that boosts the hot water to the taps, so we don’t have to run the cold water until it goes hot.
  • Turning the tap off when cleaning our teeth.
  • We have ‘half flush’ and ‘full flush’ option on the toilet. Most NZ toilets have this, I think it should be introduced everywhere. For wees, you generally only need a half flush.
  • I only run the dishwasher or washing machine on a full load.
  • I use a washing up bowl in the sink, and tip this water on the garden in summer. No waste disposal unit in the kitchen either as they use a lot of water, food scraps go in the compost.
  • We always keep water in Soda Stream bottles in the fridge, so that we have cold water and don’t have to run a tap for a while to get colder water in summer.
  • I fill the kettle with just enough water for the hot drinks I am making, instead of filling it up completely.

Some additional information:

We use a two filter system for the house water (UV and Charcoal filters), but we don’t filter the water for the garden or the toilets. We don’t add chlorine or fluoride to the water. This is great, as the water can be used for making home brew beer without having to filter it first! I’ve checked with our dentists, and they say we get enough fluoride from shop bought toothpaste.


One huge benefit of being on tank water is that the water tastes amazing! When you drink chlorinated town water again, you can really taste the difference.


We collect rainwater from one of the shed roofs, around 1,000 litres – this is only for garden use. This will last for a few weeks, without being topped up by a decent downpour of rain.


Having rainwater tanks involves some extra plumbing and pumps, so you need to consider that if you add water tanks to your house.

Water tanks for collecting rain for watering the garden

Interested in your views – do you have rainwater tanks? Do you have water saving tips?

Would you consider getting water tanks? Would you need to take on some water saving habits to make it work for you?

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Water saving habits are just one of my self sufficiency challenges – check out this post for more of my Eco friendly living challenges.