In some parts of the world, water use has far exceeded what nature can replenish. This gallery ranks the 30 most water-stressed countries, where freshwater withdrawals outpace renewable supplies. The number beside each country shows its water stress percentage, meaning how much water is used compared to what is naturally available. In extreme cases, nations are using 10 to nearly 40 times more water than they can sustainably replace.
Click on through to see where shortages are most severe and why it matters.