Whether you are in the US or Africa or anywhere that has potential water supply issues, harvest the rain and store it in rain water tanks. As the article below mentions, it need not be complex but the sky is the limit! Rainwater is free – harvest it!
Rainwater harvesting can be as simple as a small inexpensive drum or rain barrel positioned to catch runoff from a valley on the roof, or as complex as a 5000 gallon reservoir or underground water tank with a sophisticated filtration system to provide indoor water. Regardless of the level of complexity you are comfortable with; all rainwater harvesting systems have the same basic components.