Emergency services were called to Lake Joondalup in the early hours of this morning after a fire started burning through swampland.
The fire started on Scenic Drive in Wanneroo near the intersection of San Rosa Road just before 1am.
It took career and volunteer firefighters about five hours to get the blaze under control.
The size and cause of the fire is not yet known.
A Department of Fire and Emergency Services spokesman said crews would continue to monitor the area today.
"Being a lake area, once the fire gets in there it is hard to extinguish," he said.