How do people use water judiciously in water scarce areas?

If its dry in an area, that means the water is scarce, therefore they need to conserve water in order to survive. They might get water from cactuses, low in the ground, or other plants. They might then drink just enough water to survive and still conserve the water.

In cities with low rainfall there may be restrictions on water use, for example, the use of sprinklers in gardens may be forbidden, or the use of hoses to wash cars.