When burn scars become roaring earthen rivers
Debris flows are more powerful and dangerous than mudslides and slower-moving landslides: They can sweep away boulders, trees and cars and destroy everything in their path, including roads and homes and the people who live in them. Last year, in Washington’s Okanogan County, two residents were rescued from their home after a debris flow. Another flow destroyed a cabin and sent a foot of water and mud into more than 30 structures. And in 2018, 23 people were killed when heavy rains triggered a debris flow in the burn scar of Southern California’s Thomas Fire. … In the Northwest, for example, debris flows can occur several years after a fire, while in California, they usually happen in the first two rainy seasons that follow.