Watermain flushing moves water through sections of a water distribution system. The increased flow rate of the water scours the water pipe’s inner walls and helps to remove build-up.
The scouring action of water through the water pipe’s inner walls cleans the lines. Naturally-occurring debris and sediment are common culprits of build-up in the pipes! Biofilm is a thin layer of microorganisms which can also grow on the inside of piping.
Water must be at the appropriate velocity to remove these sediments and deposits. Without enough velocity, biofilm will not be removed. However when this is done correctly, flushing prevents discoloured water and improves the taste, odour, and colour of the water.
Flushing can also help maintain adequate chlorine residuals in the outer areas of a water distribution system. In areas with low water use, older water may be sitting in the distribution system with lower chlorine residuals. Flushing helps to balance this.
Water is discharged onto local roads or other surface areas through fire hydrants.
This process is critical for maintaining water quality. It also helps to maintain the distribution system for water. This is because it improves the carrying capacity of pipes and operation of hydrants and valves.
Flushing at a lower velocity also serves a purpose. It can be used to bring fresh water into parts of the distribution system where the water main ends.