National Weather Service United States Department of Commerce
Graphic depicting a hydrograph
A hydrograph is a way of displaying water level information over time. A hydrograph plot may display stage, streamflow, and sometimes both. Hydrographs can be a helpful way to show water level observations and forecasts visually on a single graphic.
The NWS provides hydrographs of water level forecasts on the Advanced Hydrologic Prediction Center (AHPS) web page.

Understanding Hydrographs


Learn more about how to use NWS hydrographs by viewing the example below (left) with the explanations of each hydrograph part (right).

  • Example hydrograph from AHPS
  • Example hydrograph from AHPS with annotations

More information about hydrograph terms: Stage, Flow, Datum, Action Stage, Minor Flood Stage, Moderate Flood Stage, Major Flood Stage.


More Information

Icon pointing left or backward Icon linking to educational information about river forecasting   Icon linking to educational information about National Weather Service flood products Icon pointing right or forward