According to the Natural Resources Defense Council, floods are the most common natural disasters in the United States. They account for 44 percent of natural disasters worldwide, with 1.81 billion people directly threatened by severe flooding. Global warming and the resulting rise in sea levels and extreme weather events are expected to make the problem worse.

An Australian-led study examined deaths associated with floods across 34 countries over a 10-year period. Researchers found that after a flood, the risk of dying increased by 2.6 percent from cardiovascular disease and 4.9 percent from respiratory diseases. The increased mortality risks persisted for up to 50 days for cardiovascular deaths and 60 days for respiratory deaths after the disaster. The researchers called on governments to monitor and protect citizens from the health impacts of flooding for weeks, not just days after the event.