Understanding Flood Stages and Warnings

2026-04-28

Flood stages are critical thresholds that the National Weather Service uses to warn communities about impending flooding. Action stage is the level where the NWS begins monitoring more closely. Flood stage is when water begins to overflow banks and affect structures. Major flood stage indicates significant threat to life and property

. These stages are determined locally based on topography, infrastructure, and historical flood data. The relationship between river flow (cfs) and stage (feet) varies dramatically by location. A narrow canyon might see stage rise 10 feet from a modest flow increase, while a wide floodplain might spread the same water over miles with minimal stage change. Understanding your local river gauge and its flood stages is one of the most important things you can do for personal safety..