In pre-incident planning, an estimate of the fire flow for the building should be developed to detect any deficiency in the water supply.

• A. Residual
• B. Reliable
• C. Average
• D. Probable

Answer: (B)

This question tests whether you focus on the water supply’s ability to sustain the needed flow during firefighting. In pre-incident planning, you estimate the required fire flow and then check whether the water system can deliver that flow consistently without dropping below an acceptable pressure. The best term to describe the supply in this context is reliable—meaning the system can be depended on to meet or exceed the estimated fire flow when needed. Residual refers to the pressure remaining after water has moved through the system, which is about the outcome of flow rather than the system’s ability to deliver it. Average and probable don’t capture the ongoing capability of the water supply to meet demand; they describe typical values or likelihood, not dependable performance during a fire.