From May to October, the City conducts unidirectional watermain (hydrant) flushing as part of its ongoing efforts to maintain safe, high-quality drinking water. Flushing removes mineral deposits and sediment from watermains, helping improve water quality and the reliability of the distribution system.

Flushing typically takes place on weekdays between 8 a.m. and 4 p.m., and each hydrant usually takes 30 to 60 minutes to flush.

Unidirectional flushing involves opening hydrants and operating valves in a specific sequence to move water through the pipes in one direction at a higher flow rate. This creates a scouring action that removes sediment. Flushing begins near clean water sources, such as water treatment plants, and moves toward the outer areas of the system to ensure clean water is used throughout the process.

During Flushing

When flushing is scheduled in an area, the City will post advisories on the website and notify email subscribers. Digital signs will also be placed in the neighbourhood during operations.

While flushing is taking place on your street, avoid using water for activities that require clean water, such as preparing food or beverages, doing laundry, or using hot water. You may notice a temporary drop in water pressure or discoloured water as sediment is flushed from the system. Water service should not be interrupted.

After Flushing

After flushing, water may appear cloudy, milky, or have a chlorine smell for a short time. These effects are temporary and usually clear within a few hours. Cloudiness is often caused by tiny air bubbles that disappear if the water is left to stand.

If Your Water Is Discoloured

If your water appears discoloured, run a cold water tap—preferably a bathtub faucet—for several minutes until the water clears. Avoid using hot water or taps connected to filters, as sediment may enter your hot water tank or clog the filter. If the water does not clear after several hours, contact Access St. John’s.