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REFERENCE

USGS River Gauge Glossary

Use this glossary as a quick reference for the most common river-gauge terms.

River gauge terms

Action stage
A local threshold where the NWS or partners may begin preparation or mitigation for possible significant hydrologic activity.
CFS
Cubic feet per second, a unit of streamflow. One CFS is about 7.48 gallons per second.
Discharge
Another name for streamflow: the volume of water passing a point over time.
Flood stage
A station-specific gauge height above which water begins creating a hazard to life, property or commerce.
Gauge / streamgage
A monitoring station used to measure river conditions such as stage and, through a site-specific relationship, streamflow.
Gauge height / stage
The height of the water surface above a local reference datum at a specific gauge.
Historical median
The middle historical value for a date or period. On Get Water Data, it is used to show how current flow compares with typical seasonal conditions when available.
River Pulse
Get Water Data's plain-English summary of current flow, historical context and recent direction.
Rating curve
A site-specific relationship used to convert measured stage into estimated discharge.
Streamflow
The volume of water moving down a river or stream over time, commonly reported in CFS.
Trend
The recent direction of change in a measurement, such as rising, falling or relatively steady.
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PRIMARY REFERENCES

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.