How much water does one person need?
You think you’re pretty solid, but seven tenths of your body weight is water. If you lose one percent of that water, you feel thirsty. Lose 10 percent or more, and you risk death. Humans can only survive three days without water.
We need to drink two to five litres of water per day to survive, depending on the climate and our level of activity. But not everyone has the water they need.
50 litres - It takes a recommended 50 litres per day to meet one person’s basic water needs.
95 litres - Half the world’s population uses 95 litres per person per day.
More than 200 litres - People in industrial countries like New Zealand use more than 200 litres per person per day.
Less than 10 litres - People in water-stressed countries like Niger use less than 10 litres per person per day.
Basic water needs
In New Zealand, the average person uses 227 litres of water per day:
- Toilet = 86 litres per day
- Bathing and hygiene = 68 litres per day
- Laundry = 36 litres per day
- Kitchen = 32 litres per day
- Housekeeping = 5 litres per day
More than 70% of this water is used in the bathroom. More than 20% is used in the kitchen and laundry.
How much water do you think you would need to have stored to survive for three days if there was a disaster such as an earthquake that cut the water supply?
Do New Zealanders use a lot of water?
Yes, we use a relatively large amount of water when compared to people in most other countries.
Measuring water use
Every litre of tap water produced and distributed uses resources and energy. We all need to try and conserve water. It is helpful if we know how much water we use. Water is measured in cubic metres (m³), litres (L), or millilitres (mL). 1000mL equals one litre and 1000L = one cubic metre.
Using the following measures, you could estimate your water use:
- Flushing toilet = 6L full flush
- Using taps = 10L per minute
- Washing dishes (by hand) = 6L
- Drinking water = 3L per person perday
- Shower = 15L per minute
- Bath = about 90L
- Garden hose = 15L per minute
- Washing machine = 100L per full load
- Cooking = about 1.5L per pot
Having enough water for everyone in New Zealand in the future will rely on more water efficient appliances, water conservation and fair distribution between households, industry, agriculture and the environment.