It makes up 60% of the human body, 73% of the human brain, and 71% of the world's surface is covered with it - so it goes without saying that water is pretty important.
Water underlines almost every aspect of our lives and keeps us alive, so it's perhaps as understandable as it is unwise that we take it for granted.
A 2019 survey found the average Brit underestimates their water usage by 55%, while 38% admitted giving little or no thought to water economies.
In reality, the average UK household runs through 330 litres of water per day, putting a strain on one of our planet's most precious resources.
And not everyone realises that it often impacts gas bills too. It's estimated that roughly 20% of a typical gas bill is from heating water for taps and showers - corresponding to around £135 a year, according to the Energy Saving Trust.
Here's how to save water and help the environment by reducing water waste at home...
Estimates suggest that a single dripping tap haemorrhages up to 5,300 litres of water a year, so stemming the flow is essential.
The fault will usually lie with the washer, which experienced DIY-ers can replace themselves. Start by turning off the water at the stopcock and double check your replacement washer is the right fit for your tap (most will take standard size).
Remove the handle and cover before unscrewing the main nut, while holding the body of the tap in place. Pull the old washer off the pin with a pair of pliers and put the new one in place the same way, using petroleum jelly to slide it down it if gets stuck.
If this all sounds a bit technical, or you have a modern, washerless tap, do not attempt to do it yourself. When plumbing goes wrong, it goes really wrong, so unless you want to enjoy a long soak in rooms besides your bathroom, call in the pros.
Showers are traditionally known as more efficient than baths, however this is not always true.
Exact estimates vary, but showers that last 10 minutes or more are very likely to use more water than a bath overall, while power showers, which use more water, can cut the tipping point to five or six minutes.
Having a shower is not in itself a virtue, but having a short shower works wonders when it comes to curbing water usage.
Consider showering while you are listening to music and try to condense your shower into a single song.
For next-level optimisation, employ a so-called 'navy shower' by temporarily switching the water off while lathering.
There's a whole host of appliances that can help you save water too. If you're wedded to washing by bathtub, consider a reduced capacity bath, as regular 80 litres tubs need a hefty volume to get even half full. Old-fashioned, cistern toilets use up to 13 litres a flush, while modern units are required by law to at least cut that number in half.
Consider installing 'aerated' taps and shower heads, which simulate higher water pressure by injecting the flow with air, or at least eschew the high turnover of the modern power shower.
To help you identify water-efficient facilities, check for a European Water Label (yes, they'll still be there), which categorises products into one of five coloured-coded brands, or check for the Waterwise Recommended Checkmark.
Not every water-saving hack has to involve spanners and pipework, and there's a whole reservoir of simple, small-scale lifestyle changes that can have a noteworthy effect on your usage.
Halt unnecessary boil-off (and energy costs) by only filling the kettle with what you need; wash vegetables in a bowl, rather than under the tap; wait until you have a full load before starting a cycle on your dishwasher and washing machine - you get the idea.
A running tap wastes more than six litres every minute, so turn the tap off while brushing your teeth. Instead of waiting for the water to run cold when you're thirsty, put a bottle of tap water in the fridge and replenish as necessary, and garden with a watering can, not a hosepipe.
Day to day, conserving water is often about mindset, and if you're on the lookout for opportunities to save, you'll find them.