What is the minimum desired water flow velocity when flushing a distribution system?

The minimum desired water flow velocity when flushing a distribution system is set to 2.5 feet per second, which is essential for effectively removing sediment and biofilm that may accumulate in the pipes. Maintaining this velocity helps ensure that the flushing process is effective in cleaning the system, as it generates sufficient turbulence to dislodge particulates without causing issues such as pipe erosion or water hammer, which can occur at higher velocities.

A flow velocity of 1 foot per second is typically too low to achieve effective flushing, as it may not generate sufficient force to remove deposits effectively. Higher velocities, such as 10 feet per second or 25 feet per second, may be excessive and could lead to potential damage to the distribution system due to increased friction and hydraulic stresses. Therefore, 2.5 feet per second strikes a balance between sufficient cleaning power and safety for the infrastructure.