Stream Stage Overview

Stream stage simply refers to the water depth in a stream or river.  The water depth is related to the flowrate and rating curves (plots of stage vs. flowrate) have been created for many streams and rivers.  Available data sources can give real-time (i.e., current to the moment) stream-stage data whereas other sources give historical figures along with statistical data such as median flowrates etc.  Some examples are given below for the Provo River in Utah.  Another important flow data type are flow-duration curves (also called reliability curves) which give engineers an idea of what flowrates can be expected a certain percentage of the time.  An annual hydrograph is required to create a flow-duration curve which is shown in the third figure.  Streamflow data used for forecasting is also available for specific streams or for regions in general.