PORTLAND, Ore. (KOIN) – Rain is helping firefighters protect Portland’s water supply at the Bull Run Reservoir as the Camp Creek Fire burns less than two miles away and spans nearly 2,000 acres outside of Sandy.

The Camp Creek Fire started by lightning on Aug. 24 near the junction of Forest Road 1210 and Forest Road 12, 10 miles east of Sandy, according to InciWeb.

As of Thursday, Aug. 31, the fire spans 1,969 acres and with cooler, moist air coming from the west this week, firefighters are able to expand and construct better containment lines to protect the reservoir.

Some wildfires in the Pacific Northwest are being allowed to burn as part of the natural cycle of the forest, but with drinking water so close to the Camp Creek Fire, those containment lines are a priority for United States Forest Service firefighters.

U.S. Forest Service Public Information Officer Niki Carpenter said, “it allows them to contain the fire more tightly than they had planned when fire activity was more intense.”

National Weather Service Incident Meteorologist Chuck Redman told KOIN 6 News there isn’t enough rain to fully extinguish the fire.

The blaze is burning in forest duff — a mix of pine needles, downed trees and fallen leaves — and in some areas it’s six to eight feet deep, meaning the rain is barely breaking through the surface.

“If it’s just the top layer that’s wet, that’s still a lot of dry stuff to smolder, creep around until we start to warm things up, dry things out and the fire could get active again,” Redman explained.

Carpenter added, “you get flames on the surface…and it works its way down into the bottom of the duff and it has an insulating layer that can keep it there for a long time.”

With more than 400 personnel fighting the fire, incident commanders are going to monitor the fire closely over the next few days as it warms up and dries out.

Record high fire danger hit the region in August, and while the rain has tempered some of that, there’s still up to two months of the fire season to go.

“We’re calling this a fire season pausing event,” said John Saltenburger, fire weather program manager with the Northwest Interagency Coordination Center. “I’d like to see two to three inches of rain over and extend over three or four days followed by a spell of cool weather to really put things to bed and we’re just not there at this point.”

With warm weather in the forecast over Labor Day weekend, fire officials are warning people to be careful and follow the fire restrictions in place.

“If we can reduce the number of human caused ignitions, we can free up firefighters to deal with the larger fires we already got on the landscape,” Saltenburger said.