When incident flow rates exceed 300 gpm, which setup should be used?

• A. One portable tank
• B. Two or more portable tanks
• C. Three portable tanks
• D. Four portable tanks

Answer: (B)

When the water demand at the incident is high, you need a continuous source that won’t run dry or cause the pump to lose its prime. A single portable tank can’t reliably sustain that higher flow because as the pump draws water, the tank level drops and suction conditions can deteriorate, risking air entrainment and a drop in discharge. Using two or more portable tanks creates a relay system: one tank feeds the pump while the other refills or is prepared to take over, keeping the pump fed and the flow steady. This minimal two-tank arrangement is the practical way to meet higher flows without interruption, and adding more tanks isn’t usually necessary for this purpose.