Unidirectional Flushing Program

Unidirectional Flushing is a method of cleaning the water mainlines through a network of flushing specific sequences of pipes with the water moving in one direction and being discharged from a fire hydrant.

The UDF technique allows higher water flow velocities by isolating sections of water mains. These higher water velocities allow for better scouring of pipes and will use 40% less water in the flushing process than traditional flushing.

For more detailed information about the program try our UDF Information Sheet.


  • Improving water quality in water mains
  • Reduce bacterial growth
  • Restore disinfectant residual
  • Improve colour and turbidity
  • Control corrosion
  • Help restore flow and pressures in system

Details and Specifications

For an up to date progress of the UDF program try our current UDF Map 2016. 

Flushing for the 2016 UDF program will start on July 18th 2016.