Which actions are used to assess the adequacy of water supply at a fixed fire scene?

• A. Compare static and residual pressures to expected values; evaluate available GPM; determine if additional sources are required.
• B. Only monitor flow meters.
• C. Increase pump discharge to maximum regardless of readings.
• D. Ignore hydrant metering.

Answer: (A)

The key idea is to verify that the water source can sustain the needed attack flow by looking at both pressure and volume. Static pressure tells you the available pressure in the system when nothing is flowing, while residual pressure shows what remains once water is flowing to the attack lines. By comparing these pressures to what you expect based on your pump settings and the demands of the hoses and appliances, you can judge whether the supply is adequate. At the same time, you evaluate the available GPM from the current sources (hydrants, tankers, or other feeds) to know how much water you actually have coming into the system and for how long it can be sustained. If either the pressures are too low or the GPM is insufficient, you determine that additional sources are required to maintain a safe, steady water supply for firefighting operations.

Relying only on flow meters ignores the pressure side of the equation, which can lead to under- or over-estimating supply capability. Pushing the pump to maximum without regard to readings can cause pressure surges or exhaust the system unnecessarily, and ignoring hydrant metering prevents understanding of actual usage and availability. The combination of comparing static and residual pressures to expected values, evaluating available GPM, and determining the need for extra sources gives a complete, actionable picture of water supply at the scene.