Millions of Americans live in flood-prone areas. In 2012 alone, the cost of direct flood damage hit nearly half a billion dollars. However, because the factors contributing to flood risk are not fully understood, river basin management — and even the calculation of flood insurance premiums — may be misguided. A new study by UC Santa Barbara’s Michael Singer and colleagues presents a paradigm shift in flood hazard analysis that could change the way such risk is assessed in the future. The results are published in the journal Geophysical Research Letters.