What streamflow measures
Streamflow is commonly reported as a volume per unit of time, such as cubic feet per second. The reading belongs to a particular monitoring station and reflects conditions at that location.
Why flow changes
Rainfall, snowmelt, groundwater, dams, withdrawals, and seasonal conditions can all change flow. A storm can raise a river quickly, while a dry period can lower it over days or weeks.
Why flow helps explain other readings
Flow affects dilution, sediment movement, temperature, and how quickly a substance travels. Compare flow with the date, station, recent weather, and other measurements rather than treating it as a standalone river-health score.