To ensure South-East Asias’s growing population has enough water to drink, we need to collect more rain, says Crispin Maslog. The world’s next major crisis will be a lack of water for home use, including drinking water, many scientists predict. Humans can survive around 40 days without food, but much less than that without water to drink. The scarcity of water for domestic use is becoming a critical problem, especially in rural parts of developing countries. Surface water in rivers, streams or lakes, and groundwater, are increasingly becoming contaminated with pollutants from factories, households, farms and mines. Wells dug deeper to extract groundwater are drying up.