Although potable fresh water may seem like an endless resource, it is becoming scarcer as the population continues to grow and as the climate continues to change. 

According to FreshWater Watch, an Earthwatch research project that investigates the health of global freshwater ecosystems, water scarcity occurs when the amount of water withdrawn from lakes, rivers or groundwater is so great that water supplies are no longer adequate to satisfy all human or ecosystem requirements, resulting in increased competition between water users and other demands. The group’s research shows that about 40% of the world’s population lives in water-stressed areas, and this is projected to be 50% to 65% by 2025. By 2050, nearly half of the world’s population will be living in areas where water is scarce, yet 90% of all population growth will occur in those regions.