It is common to hear things like it takes one gallon of water to create a single almond, or watering a lawn can take X gallons per month/year, or it takes X gallons to make one pound of beef or yield X pounds of alfalfa.
My question is, is that water “gone forever”? Or does the water thats used return to the water table/cycle in some other form. When you water the lawn does a large amount of that seep into the ground, evaporate, and return to the atmosphere?
Or is the water used in these ways truly gone forever (in terms of humans being able to use it again)?
The question is a bit like “If I spend all my money, is it truely gone forever or did it just return to the global financial streams?”
Like with the money, water exists in very different states of usefulness. Sea water, for example, is incredibly abundant, but using it requires desalination, which requires enormous amounts of energy.
Ground water is really useful, because it’s where you need it and it’s usually pretty clean.
Rain clouds mostly pull their water from the sea. Hence using water e.g. in agriculture will not increase the amount of rain by any significant amount.
Ground water replenishment thus doesn’t depend on the amount of ground water spent for e.g. lawns. Similar as your wages usually don’t depend on how much money you spend on a holliday.
So if you waste ground water, it’s mostly just gone, while you wait for rain to refill it. Sadly, in most regions that happens far slower than people are spending their precious water resources on useless nonsense like a green lawn.
Depends. Sometimes the water gets dirty and needs to be treated, sometimes it evaporates and needs to rain, sometimes it could be reused as is
In very rare cases (nuclear fusion) the water is destroyed into its primitive elements
You can’t destroy it and it doesn’t go anywhere. It just gets moved around and used for different things at different times.
Water lawn > Grass uses water to grow more grass > humans mow lawn > grass clippings dry out > water returns to atmosphere
What about something like electrolysis where it’s separated?
If you keep them separate sure, but the moment you burn hydrogen it just turns back into water.
So then the truth of the matter is that we can create water from hydrogen and oxygen and we can also destroy water by reducing it to its elemental compounds. As such, water can be created and can be destroyed, meaning that the overall level of water available on earth can change over time, however our commonest uses for water have it not be destroyed and eventually return to the water cycle.
Technically, yes.
Realistically, any amount we split/convert is so small as to not matter to anything. The amount of water on the planet is absolutely ridiculous. 1233.91 quintillion liters to be more specific.
Water is a bit more complicated than ordinary ressources, watershed are mostly local and it’s hard to transport water over large distances. To make-it simple, saving water in Scotland won’t bring more water to the Sahara.
All the water we use comes from rain (snow), and it would either go to the ground where it could be pumped, or join stream them rivers and flow downstream. A part of the water you use upstream will evaporate, and therefore won’t flow downstream, which is the cause of big geopolitical conflict, especially in dry regions. This water will still evaporate and at a point fall back on the ground as rain, but you don’t really control where (and when) the rain falls, moreover, with global warming, a hot atmosphere can store water than a cold one, leading to “less rain”.
Another issue is ground pollution. If you keep the ground clean, you can pump water, people have stuff to drink, farmer can water their crop and so on, but if there is any pollution you might have non drink water in the ground or even contaminate the plant you water with it, meaning that water is lost… forever
While the water most likely returns to the cycle, in many places replenishing the aquifer can actually take years, even decades. In those places using too much water means the aquifer keeps depleting and causes a bunch of other problems such as salt water intrusion.
