How much water do we really need?
How many litres of water do we use every day?
It’s a question you probably ponder each time you brush your teeth. “Should I leave the tap running or turn it off?” The true answer to how much water is used (and much of it wasted) on average every day is likely to surprise and shock you!
Firstly, let’s look at why it’s such an important question. How much water is there on planet earth? Any guesses…?
Roughly 1,260,000,000,000,000,000,000 litres.
That’s a LOT of zeros, so let’s cut it down to 1,260 million trillion litres. “Million trillion”, yes that’s a real number!
BUT… only around 3% of that is fresh water (sorry, you’ll have to do the maths for yourself there, our calculator just exploded.) And only 1% is actually available for drinking.
How much do we NEED to use?
The World Health Organisation has estimated that the basic amount needed for minimum impact on health is 50-100 litres a day. At the lower end, this covers ‘basic needs’ such as hand washing and general sanitation but NOT laundry and bathing.
As you get up to the 100 litre mark, you have enough water available to cover all drinking, laundry and hygiene needs.
Interestingly, ‘access’ to water and ‘availability’ of water aren’t always the same thing. Latin America, for example, has the world’s highest level of drinking water per head. It has over 30% of the world’s water resources – but 300 million people (half of the country’s population), have access to poor quality water or lack a regular supply.
So how do things shape up in our more fortunate society? Do we use 100 litres per person per day? Prepare to be shocked…
- A bath: 150-300 litres
- Shower: 50-100 litres
- Flushing a toilet: 10 litres
- Washing dishes by hand: 23 litres
- Dishwasher: 20-40 litres
- Washing machine: 40-80 litres
- Leaving the water running for 1.5 minutes while you brush your teeth can use more than 18 litres
- Washing your car with a hose: 200-500 litres
Even assuming you rarely wash the car, it’s clear that we are, on average, vastly over the minimum required level. Which raises the question of how much of this water is wasted every day and how we can try to ensure the future availability of clean, usable water by cutting down how much we waste?
We don’t pretend to have an answer to that, but it’s obvious that we can all do our bit by turning off the tap when brushing our teeth, taking shorter showers instead of baths, getting an extra wear out of clothes that don’t need washing just yet, or washing a few more dishes by hand (using a bowl, not running water) rather than putting the dishwasher on again.
What are your thoughts? How else can we conserve one of the most precious and vital commodities we have on our planet?