What are some things that put stress on water resources?
The answer is a complicated Geo-econo-political battle that cannot be answered in one sentence. But read below to begin the understanding.
I will begin my answer with an analogy.
Water Apple Analogy
Pretend that an apple is planet Earth, round, beautiful, and full of good things. Notice its skin, hugging and protecting the surface. Water covers approximately 70% of its surface.
Right away, cut the apple into quarters. Toss one quarter (25%) away. This one quarter you just removed represents dry land. What is left (75%) represents how much of the earth is covered with water – oceans, lakes, rivers, and streams.
Remove the peel from one of the three remaining quarters. This represents 3% of water on earth that is freshwater. The remaining pieces represent the saltwater of the oceans. Cut the peel into three equal pieces. Set two pieces aside. The remaining piece
represents 1% of the freshwater not frozen in the polar ice caps (2%)
Of this remaining 1%, not all of it is potable – some is contaminated by pollution.
Now the problem becomes not only do we have limited potable water on the Earth, but that water is privatized and owned by companies like Suez, Vivendi, Coca-Cola and Nestle. This water becomes so expensive under thee multinational corporations that it becomes unattainable for much of the population.
I would also suggest that you watch the documentaries "Flow", "Blue Gold" and "Tapped" to fully understand the limits placed upon our universal water supply.