Unidirectional Flushing Program
Every summer, our crews carry out Unidirectional Flushing — UDF for short — across Bathurst's water distribution system. It's a thorough deep clean of the water mains that keeps your drinking water clear and the system running well.
Track this summer's UDF work
Our public map shows which areas have already been done, which are coming up next, and where crews are working today.
How UDF works
UDF is a standard industry technique for cleaning the inside of water mains. Crews isolate one section of pipe at a time, then push high-velocity water through it in a single direction and out through a fire hydrant. That one-way, high-speed flow scours the inside of the pipe more effectively than regular flushing, pulling out sediment that has settled over the years.
The hydrant stays open until the water runs clear — usually 30 to 60 minutes per section. Once one section is done, crews move on to the next.
UDF is a multi-year program. The distribution system is divided into strategic zones, and crews work through them in a planned sequence. Over time, every part of the system gets covered.
When and how it affects you
UDF runs weekdays from 8 a.m. to 4 p.m., except statutory holidays. Your water service won't be interrupted while crews are working, but you may notice a slight drop in pressure or some cloudy or discoloured water in your taps. This is the sediment we're flushing out — it's temporary and isn't a sign of a water quality problem.
If your water looks cloudy or discoloured, run cold water only for about 10 to 15 minutes, or until it runs clear. UDF can take a bit longer than regular flushing to fully clear from your line, so if it's still discoloured after the first try, wait a few hours and run cold water again.
Stay informed
We send alerts through Voyent Alert! when UDF work is coming to your area. If you haven't already, sign up for Voyent Alert! so you get a heads-up before crews arrive.
Common questions about UDF
Isn't UDF a waste of water?
No. UDF is a normal and necessary part of maintaining a safe, reliable drinking water supply, and it actually uses less water than older flushing methods. After the water passes through the main, we dechlorinate it and return it to the environment.
Why don't you do this at night when traffic is lighter?
Two reasons: it's safer for our crews to work in daylight, and they need to see the discharged water clearly to know when the sediment has been fully flushed out and the water is running clean.
Are there other benefits beyond cleaning the pipes?
Yes. As crews work through the system, the UDF process also exercises and maintains the valves and hydrants along the way, which keeps them in good working order.
Other types of flushing
UDF is one of several flushing programs we run throughout the year.
Regular dead-end flushing
Routine flushing of hydrants at dead-ends to maintain water quality. Runs on a four-week rotation, year-round.
Reactive flushing
Done in response to a specific event, like a watermain break, when crews need to flush part of the system to restore normal conditions.
Unidirectional Flushing (UDF)
The annual summer deep clean — a multi-year program that moves through the distribution system in planned, strategic zones.
Questions?
If you have questions about UDF or water quality in your area, give City Hall reception a call at (506) 548-0400.