Fort Collins is vulnerable to river and stream flooding, flash floods and urban street flooding.
Flooding along rivers is a natural and inevitable element of nature. Some floods occur seasonally when spring rains and melting snow fill river basins too quickly.
Most flash floods are caused by slow-moving thunderstorms or thunderstorms repeatedly moving over the same area.
Urban street flooding occurs when land is converted to roads or parking lots and loses its ability to absorb rainfall. Urbanization increases runoff two to six times over what would occur on natural terrain and can cause streets to become swift-moving rivers during rainfall.
To increase safety, the Fort Collins Utilities Flood Warning System provides information and emergency services. The Office of Emergency Management describes flood risk and preparation.