Who determines the risk of flood in various locations across the United States?

The Federal Emergency Management Agency (FEMA) is responsible for determining flood risk in various locations across the United States. This agency creates Flood Insurance Rate Maps (FIRMs), which identify areas at risk of flooding based on historical data, rainfall patterns, and topographical information. These maps are crucial for informing land use planning, development regulations, and insurance requirements.

FEMA's role includes assessing flood zones and updating maps to reflect changes in flood risk over time, particularly after significant weather events or as a result of implementing flood control measures. By establishing these flood zones, FEMA also helps inform property owners about their risk level and the need for flood insurance, which is a requirement for properties located in high-risk areas.

While other agencies, such as the National Oceanic and Atmospheric Administration (NOAA) and the Environmental Protection Agency (EPA), are involved in various aspects of environmental monitoring and regulation, their primary functions do not specifically include assessing flood risk across the nation in the systematic manner that FEMA does. The Department of Commerce has a broader economic focus and does not directly handle flood risk assessments.