GPM (Gallons Per Minute)

GPM and PSI together define the water system's performance on a hydrovac truck. While PSI determines the cutting force of the water jet, GPM determines the volume of water being applied to the soil per unit time. Higher GPM means more water is being used, which can speed up excavation but also depletes the water tank faster.

Typical GPM ratings for hydrovac truck water systems range from 5 to 18 gallons per minute. The operator can adjust GPM independently of PSI on most trucks, allowing fine-tuned control of the water application. For potholing near utilities, operators often use lower GPM and moderate PSI to maintain precision without excessive water usage.

Water consumption directly impacts operational costs and productivity. At 10 GPM, a 1,000-gallon water tank lasts 100 minutes of continuous digging. At 18 GPM, the same tank lasts only 55 minutes. Operators who manage their water usage efficiently can complete more potholes per tank load, reducing the time and cost associated with water refills.