Water securityFire Today Will Impact Water Tomorrow
The effects of wildfire don’t end when the flames go out. There can be environmental consequences for years to come—and keeping an eye on water is key.
In 2020, Colorado battled the four largest wildfires in its history, leaving residents anxious for another intense wildfire season this year.
But last week, fires weren’t the issue—it was their aftermath. When heavy rains fell over the burn scar from the 2020 Cameron Peak fire, they triggered flash flooding and mudslides northwest of Fort Collins which destroyed homes, killed at least three people and damaged major roads. Flooding along the 2020 Grizzly Creek and East Troublesome burn scars also unleashed mudslides across Interstate 70 through Glenwood Canyon and in Grand County just west of Rocky Mountain National Park.
These tragic events make it clear that the effects of wildfire don’t end when the flames go out. There can be environmental consequences for years to come—and keeping an eye on water is key.
CU Boulder Today’s Kelsey Simpkins spoke with Professor Fernando Rosario-Ortiz, an environmental chemistry expert who studies how wildfires impact water quality; and Assistant Professor and CIRES Fellow Ben Livneh, a hydrologist who studies how climate change affects water supplies and how fires and rain influence landslide risk, about how fire may shape the future of water in the West.
Kelsey Simpkins: What happens to water in lakes, rivers and streams after a nearby wildfire?
Fernando Rosario-Ortiz: When you have open flames, a lot of gaseous reactions and solid phase reactions, it results in the transformation of chemicals and alterations to the soil, and we observe the effects once we look at the water quality. For example, we observe the enhancement in the concentration of nutrients in water, which is not necessarily a bad thing, but it can cause subsequent issues in the reservoirs like algae blooms. There can also be a mobilization of metals and enhanced concentration and activity of what we call organic carbon as well as turbidity, which can then impact water treatment production and formation of disinfection byproducts.
Simpkins: How do city water suppliers and treatment plants deal with these impacts?
Rosario-Ortiz: Ideally, you want to have a secondary water source. In Fort Collins, back in 2012 after the High Park fire, the river was impacted but the reservoir was not impacted. So they could draw from the reservoir and wait for the worst to pass.
