Guides · Understanding the Data
How to Read a River Gauge: Stage, Flow, Flood Stage & Generation Explained
Gauge numbers look cryptic until someone explains them once. Here is what stage, flow, flood stage, pool elevation, and generation actually mean — so the readings on any map make sense.
Stage (gauge height)
Stage, or gauge height, is how high the water is at a gauge, measured in feet. It is a relative reading tied to that gauge’s zero point, not depth of the whole river. Rising stage means more water; falling stage means less. It is the single most useful number for "is the water coming up?"
Flow (discharge, CFS)
Flow, or discharge, is the volume of water moving past a point, measured in cubic feet per second (CFS). A small creek might run a few dozen CFS; a big river in flood, tens of thousands. Flow and stage rise and fall together, but flow better captures how much water is actually moving.
Flood stage
Flood stage is the stage at which a river begins to cause problems — water out of its banks, roads and low property affected. Gauges are often described relative to flood stage, and a rising river approaching it is the classic early-warning signal.
Pool elevation (lakes)
On a reservoir, the equivalent of stage is pool elevation — the water surface height above sea level. It is managed between the conservation (normal) pool and the top of flood pool. Above conservation pool, the lake is storing flood water.
Generation and tailwater
At a hydropower dam, generation means the turbines are running and releasing water downstream, which raises the tailwater stage below the dam quickly. That is why generation status is a safety-critical reading for anyone below a dam.
Where the numbers come from
These readings come from official networks — the U.S. Geological Survey, the National Weather Service, and the U.S. Army Corps of Engineers, which transmit gauge data by satellite. GaugeKeep reads that same telemetry, decodes it, and updates within minutes of each report so the numbers you see are current.
Need this data for work?
Utilities, engineers, insurers, and industrial operators use the same live gauge data to make decisions. GaugeKeep can deliver monitoring and alerting for the specific dams and reaches your team depends on.
Frequently asked
What does river stage mean?
Stage (gauge height) is how high the water is at a gauge, in feet, relative to that gauge’s zero point. Rising stage means the river is coming up. It is the most useful number for tracking a rise.
What does CFS mean on a river gauge?
CFS is cubic feet per second — the volume of water moving past the gauge. It rises and falls with stage and captures how much water is actually flowing.
What is flood stage?
The stage at which a river starts to cause problems, such as water leaving its banks. A river rising toward flood stage is the standard early warning to watch.
Where does GaugeKeep get its data?
From official USGS, National Weather Service, and U.S. Army Corps of Engineers telemetry, decoded and updated within minutes of each satellite report.
Get the alert before the water moves
Track any Arkansas gauge with a free GaugeKeep account and get an email the moment the level crosses the line you care about. No card needed.
Data: official USGS, National Weather Service, and U.S. Army Corps of Engineers telemetry, decoded by GaugeKeep. Educational information only — not a substitute for official navigation, flood, or safety guidance. Conditions below dams change without warning.