A wildfire’s legacy can haunt rivers for years, putting drinking water at risk
(The Conversation is an independent and nonprofit source of news, analysis and commentary from academic experts.)
Ben Livneh, University of Colorado Boulder
(THE CONVERSATION) A wildfire rages across a forested mountainside. The smoke billows and the flames rise. An aircraft drops vibrant red flame retardant. It’s a dramatic, often dangerous scene. But the threat is only just beginning for downstream communtiies and the water they rely on.
After the smoke clears, the soil, which was once nestled beneath a canopy of trees and a spongy layer of leaves, is now exposed. Often, that soil is charred and sterile, with the heat making the ground almost water-repellent, like a freshly waxed car.
When the first rain arrives, the water rushes downhill. It carries with it a slurry of ash, soil and contaminants from the burned landscape. This torrent flows directly into streams and then rivers that provide drinking water for communities downstream.
As a new research paper my colleagues and I just published shows, this isn’t a short-term problem. The ghost of the fire can haunt these waterways for years.
This matters because forested watersheds are the primary water source for nearly...