Wildfires scorch soils and create ash and debris that can clog rivers and reservoirs, increasing the cost of water treatment for years to come.

When trees and underbrush burn, there is less organic material left to absorb moisture when it rains. In addition, many plants release a waxy substance when they are incinerated; creating a water-repellent coating on burn areas that heightens the risk of flash floods and contributes to erosion. Storms flush silt and other debris from the fires into rivers, reservoirs, and ultimately into municipal water-treatment facilities, slowing the treatment process.

Western water managers learned a harsh lesson ten years ago when the devastating Hayman Fire ripped through Colorado’s forests, severely impacting the extensive forested watersheds that protect rivers and water sources for more than 75 percent of the state’s residents, according to the U.S. Forest Service. The Hayman Fire—the most destructive in the state’s history, possibly until now—destroyed nearly 140,000 acres and 600 structures in 20 days.