City of Nanaimo Water Main Flushing Program

The 2023 Water Main Flushing Program begins on March 20 in the Harewood neighbourhood. Crews will continue north through Nanaimo and are expected to complete water main flushing in all neighbourhoods by the week of May 19, 2023. If you spot discoloured water, note it is temporary and not a health hazard, and you can flush it out by running the cold water tap until the water runs clear.

Regular water main flushing is an important component of a comprehensive water management program. The City of Nanaimo's Water Main Flushing Program flushes over 95 Kilometers of water supply mains and over 539 kilometers of distribution water mains. The City's Public Works Department annually flushes potable water at a high velocity through the water mains to ensure that all piping is refreshed and minor sediment within the pipe is removed. This is one of the methods that the City uses to help keep Nanaimo's drinking water safe and clean.

The annual water main flushing program begins in March with crews flushing water supply mains from South Forks dam into the City. Between March and May crews flush the in-town water distribution mains starting in the Cinnabar area then through town, finishing in the north end of Nanaimo.

For 2023, the program will begin on March 20. It is expected that there will be very little buildup of residue in the water mains. With high quality, treated water coming from our water treatment plant, there is very little sediment entering the system.

While this program is underway, short periods of low pressure and discoloured water may be expected. Any discolouration is temporary and not a health hazard. Residents are asked to minimize their water consumption if a change in water appearance is noticed. To clear water lines, residents are advised to turn on their cold water tap until the water runs clear. Anyone with a weakened immune system should reference information on Island Health's website.

Here is a look at our 2017 Water Main Flushing video:

We thank you for your cooperation and apologize for any inconvenience this program may cause.


Last updated: March 20, 2023

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