Water Sources
Hydrant Flow Test
A hydrant flow test measures what a hydrant can actually deliver by flowing it and reading the pressures, rather than trusting its static reading. It records the static pressure, a flowing pressure, and the flow to estimate available water.
The test puts numbers on a hydrant's real strength. One hydrant is flowed while its pressure is read, a nearby hydrant gives the static and residual readings, and the drop between them — together with the measured flow — estimates how much water is available.
Crews use the results to pre-plan which hydrants can feed which demands. Knowing ahead of time that a hydrant tests strong or weak turns a fireground guess into a planned supply, well before an engine ever connects to it.
Where this shows up
Calculator
Hydrant Available Water