A Smoke Alert has been issued for Mandurah, Dwellingup, North Dandalup, Waroona, Preston Beach and surrounding suburbs on Saturday.
The smoke is the result of a significant prescribed burn being carried out east of North Dandalup, near the dam.
The large smoke plume could be seen from Mandurah’s coastline more than 20 kilometres away.
It’s one of several prescribed burns being carried out across the region.
The Parks and Wildlife Service said the smoke is expected to clear overnight but have issued the followning advice for residents.
If the smoke is unusually thick, it is recommended people shut doors and windows and turn off air-conditioners.
Smoke may reduce visibility on some roads and motorists should take care, turn on headlights and travel at appropriate speeds when travelling in these areas.
People with asthma and pre-existing respiratory or cardiovascular illnesses should follow their pre-prepared treatment plan.
People with conditions exacerbated by smoke should take precautions in line with their medical advice for these circumstances.
For updates, visit http://www.emergency.wa.gov.au or call 13 DFES (13 3337).