Action Stage vs. Flood Stage
Action stage and flood stage are not interchangeable. They are different local thresholds used to describe increasing river risk at a specific forecast point.
Action stage
The National Weather Service defines action stage as the level where the NWS or a partner may need to begin mitigation or preparation for significant hydrologic activity.
Reaching action stage does not automatically mean damaging flooding has begun. It is an earlier threshold intended to prompt attention or preparation.
Flood stage
Flood stage is an established gauge height above which rising water begins to create a hazard to life, property or commerce at that location.
Flood stage is not necessarily the same as bankfull stage, and flood impacts can vary along the river even when the gauge reading is unchanged.
Why the numbers are local
A flood stage of 18 feet at one gauge has no direct meaning at another gauge. Channel geometry, nearby roads, levees, structures and the gauge datum all differ by location.
Keep learning
These guides summarize public technical information in plain English. Measurements and official thresholds should always be checked at their original source when making safety or flood decisions.