COLORADO – 2020 was a record-breaking year for wildfires across Colorado. The Cameron Peak Fire, just west of Fort Collins, now holds the title as the state’s largest wildfire in recorded history.
Over the course of 112 days, the Cameron Peak Fire burned more than 208,000 acres, impacting several reservoirs and watersheds that provide water to Colorado communities. A group of researchers is studying how water quality and supplies are impacted from the historic wildfire.
“Where we’re standing right now would have been really densely forested so you’d just kind of fight your way through trees to get through here,” said Stephanie Kampf.
Kampf is a professor of Ecosystem and Wetlands Science at Colorado State University. She’s blazing the trail to understand how the region’s watersheds are changing after the fire.
“For this fire to come and burn the rest of the main corridor of the Poudre River, it was pretty devastating. So you can see, it’s opened up a lot of the space here,” said Kampf as she’s standing in the heart of the burn scar.
She and a team of researchers have nearly a dozen data and weather stations around the forest. They’re set up everywhere from areas completely burned to lightly charred. The data stations sit across different elevations as well to get a good range of measurements around the burned forest.
When there’s a fire, it produces big changes in streamflow and changes in snowpack. Researchers are looking into how water quality and supplies are impacted during snowmelt and rainfall. They studying the same streams and rivers that provide the water Coloradans drink, shower and irrigate with.
“Whenever the water is filled with ash and fine sediments, it’s not easy to treat that water. It will clog up the filter really quickly. So they will have to turn off their water supply intakes any time that sediment pulses into the river,” said Kampf.
“We’re just seeing water flow into the channels and through them much more rapidly. And that leads to erosion and the ability to carry the sediment downstream,” said Kira Puntenney-Desmond, a research associate working with Kampf.
Cities, like Fort Collins and Greeley, can’t treat the water when it’s filled with ash and sediments. They’ll turn to backup water storage, including Horsetooth Reservoir, when that happens.
“Wildfires are a major gamechanger in which the soil, vegetation, and how much water makes it into the stream changes dramatically,” said Puntenney-Desmond.
This team has been observing changes in this area since winter.
“What we saw is the snow melted out a lot more quickly in the places that were burned because there was more ash falling down from the trees and covering the snow and making it darker,” said Kampf.
She adds, “And then as the snow started melting, we saw new flow paths or new little streams where we’ve never seen them before. So there was a lot more water moving through, creating new streams that started pushing some of the ash from the fire out into the river.”
Without tree cover, more snow accumulates but melts off faster with more direct sun. That’s the same snowpack that melts off during spring to fill reservoirs for our water.
The area is also prone to flash floods and debris mudslides when summer rains hit the unstable ground left in the wake of a wildfire. You can still find piles of debris near the Poudre River from The Black Hollow Flood in July 2021. Heavy rains triggered a mudslide in the burn scar that rushed over homes near Rustic, Colorado.
It was a similar scene in Manitou Springs after The Waldo Canyon Fire of 2012. Several months after the fire was put out, flooding and mudslides wreaked havoc on Highway 24 due to the nearby burn scar.
“So as the rain falls, it just hits this bare soil and it doesn’t have anything there to slow it down. So it starts accumulating into overland flow paths, so it’s sort of flowing along the ground. The water just stays on the soil and as it’s flowing over the surface, it gets to the streams really quickly so they rise really quickly.”
The area is also likely to see faster erosion and soil gets carried into the water and water run-off carves new streams along the way. That soil might be getting into nearby rivers and filling up the streams. Or it might even flow all the way into the Poudre River and be carried farther downstream.
Kampf and her team hope this research can limit the impact on water supplies and gain insight into what kind of conditions create hazards downstream.
They’re learning from the largest burn scar in Colorado, planning to shift perspectives in how we manage the water resources we depend upon.
While there are burned trees and dead forests as far as the eye can see where the team is taking measurements, there is a glimmer of hope for how this area will recover. There’s new life springing up, little aspen trees everywhere, and Kamf tells me all this growth has happened just over the last few months.