Water scarcity is becoming a challenge in arid and semi-arid climates across the world. Rainwater harvesting systems can help make every drop go a little further.

Massive storms over a few weeks have led to extreme flooding, yet California remains in an historic drought, which has prompted experts to explore ways to better manage floodwaters.

Today's question: Is urban runoff treated before being discharged into drinking water sources?

A few days ago The New York Times published an article about Los Angeles redoing its alleys to capture stormwater.