 Water, we all need it. But how well do we really understand its effects of society? Or is its behavior too unpredictable? Floods, droughts and other water-related disasters can cost loss of lives and billions of dollars in damage. And climate change is making it harder to predict water's behavior. So, how can we know what water will do tomorrow if the data and hydrological models of the past no longer reflect our reality? In their Encouraged Water Series lecture, scientists Dave Gauches and David Yates discussed, divided waters, weathering or changing, flood and drought extremes.