The Portland Water Bureau says the fire in the Columbia River Gorge has reached the Bull Run watershed, the primary source of water for much of the region.
But, in a Tuesday afternoon statement, the bureau said fire was not threatening the Bull Run Reservoir and or water distribution infrastructure.
The bureau says it is prepared to switch over the city's groundwater wells along the Columbia River if the need arises.
The bureau also says it has been working closely with all local, state and federal agencies fighting the fires since the Indian Creek fore started in July. It has authorrized water to be drawn from Blue Lake and other water sources in the water shed to fight the fires, but not the reservoir.
On Monday, Oregon Gov. Kate Brown briefed Mayor Ted Wheeler and Commissioner Nick Fish, who is in charge of the bureau, on the status of the fires.
"I am thankful for the close working relationship with our partner government agencies, said bureau director Michael Stuhr.
In fact, the announcement came at a time when the water level in the Bull Run reservoir drops so low that turbidity becomes a potential problem, prompting the bureau to consider blending it with Columbia South Shore Well Field water.
The announcement also comes a little over a month after the City Council voted to spend up to $500 million to build a filtration plant that can remove ash from wildfires and silt from landslides from Bull Run water. It will take around 10 years to complete, however.
The decision was prompted by the need to fight the cryptosporidium parasite in the Bull Run watershed. The council could have chosen a less expensive ultraviolet plant, but chose the filtration option in large part because it could remove so many more contaminants from the water.