LARIMER COUNTY — For such important infrastructure, this section of the Michigan Ditch on the east side of Cameron Pass near a culvert that saved Fort Collins’ water supply seems pretty vulnerable.
It’s relatively shallow, although the exact depth is unstated. It lies at around 10,000 feet alongside a service road in State Forest State Park where hikers, runners, mountain bikers and backpackers frequent. It’s a smallish part of the 5.2-mile-long transmountain diversion system originally constructed in the 1900s that transports water from the western side of Cameron Pass at Lake Agnes to the Cache la Poudre watershed on the east and now provides up to 11% of the Fort Collins water supply.
But unlike stretches of the ditch that are protected from the elements and other dangers by wood or concrete pipe, the stretch in question is uncovered. That means it’s at the mercy of all kinds of things, including landslides that rip loose from the steep mountainside above it. And that’s why a couple dozen water, fire, land, parks and city officials were gathered around it one day in early August.
They represented the various agencies involved in the Michigan Ditch Fire Mitigation Project to reduce hazardous fuels above and below the ditch, which is owned by the city of Fort Collins. It’s projected to cost in the ballpark of $3 million and unfold in three phases that will run into the next decade. And if this summer is any indication of fire seasons to come, it’s high time the work is getting done. Because wildfire and its associated impacts are the greatest risks to this part of Fort Collins’ water supply worth $430 million and “it’s not if a fire starts but when,” a common refrain during the field trip.
A very valuable water supply
Fort Collins first vetted the idea for a fire mitigation project in 2021.
It was six years after a catastrophic landslide buried a portion of the ditch; however Richard Thorp, the city’s watershed program manager, said “implementation of water conservation methods by the Fort Collins’ Water Resources Department meant no residents lost their supply.”
Slope instability above the ditch has plagued it from the time it was constructed in the early 1900s. The city of Fort Collins purchased the ditch and Joe Wright Reservoir from the North Poudre Irrigation Company in 1971 to address increasing demands on the city’s water supply. It has maintained the ditch ever since, placing a $430 million value on the collected water it provides. But in 2015 a landslide buried a section in an area appropriately named “the mudslide.”
Fixing it took two years, $8.5 million and an 800-foot-long culvert that now protects the water from that particularly unstable region. But in the past decade-plus, wildfire, and its effects on the area’s water supply, has become an increasing concern for city and state officials.
The High Park fire burned more than 87,000 acres above the Poudre River in 2012, for instance. Colorado’s second-largest fire in history, East Troublesome, ripped through 194,000 acres about a dozen miles away from the ditch in 2020. And the state’s largest fire, the Cameron Peak fire, burned just down the road in 2020.
The Cameron Peak burn was “a close call, to say the least,” and the city became “very concerned another big fire that gets up on the ditch could destabilize (the steep slopes above it),” Thorp said during the field trip. And that could lead to another blowout like the one in 2015 “that could interrupt our water supply. It likely would degrade our water supply. It could impact the infrastructure up here, taking out sections of the ditch.”
Enter the multiagency partnership and cost-share funding collaborative created to assess the impacts of post-wildfire hazards on critical water infrastructure and to identify strategies to minimize these impacts before and after fires.
Partners on fire
Partners include the Colorado State Forest Service, Colorado Parks and Wildlife, the Department of Natural Resources, the Colorado State Land Board, the Colorado Water Conservation board and the city of Greeley.
The project consists of creating a wildfire action ready plan for the area (due May 2026) and three phases of on-the-ground work including erosion prevention through helicopter and tethered logging (in motion), wildfire risk reduction through the creation of fuel breaks and wetland enhancement (2027-29) and treating additional fuels adjacent to the ditch (date TBD).
Funding for phase one includes $210,000 from the water conservation board, with matches totaling around $61,000 from Fort Collins, Water Supply & Storage Company and Greeley. Phase two funding includes $500,000 from the state Forest Restoration & Wildfire Risk Mitigation Grant Program and $1 million from the Colorado Strategic Wildfire Action Program, with matching grants of $500,000 for each from the city of Fort Collins.
Phase three currently has no funding, but phase two has begun in earnest.
Weston Toll, watershed program specialist for the Colorado State Forest Service, said after the partners had “treated a lot of low-hanging fruit, we needed to start treating the right acre in the right location.”
In the Michigan Ditch’s case, that’s actually 150 acres on either side of the ditch where the average slope is 40% to 60% (think black-diamond ski run). It’s an area of the forest “displaying the heaviest spruce bark beetle mortality” that was never treated, said Blair Rynearson, Colorado State Forest manager. Approximately 30 to 35 of the acres burned sometime in the last 100 to 150 years. And the remaining acreage was likely treated sometime between 1950 and 1965, he said.
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All of those factors point to a big risk of wildfire that “would generate an incredible amount of heat, with the potential to increase soil burn severity,” Weston said. And that would create the increased risk of erosion that could harm water quality in the Poudre River.
The material the road along the ditch is made of is also highly erodible and susceptible to future washouts, so another goal of the project is to mitigate the risk of hazards in protecting the infrastructure. And Rynearson said the area gets a ton of users.
“We can’t keep people out of the ditch. It’s e-bikers. It’s bikers. Also city of Fort Collins’ employees,” he said. “And these trees have been dead, they’re more frequently falling down. So that also presents a safety risk to firefighters that could potentially use this infrastructure, if there ever were wildfires in the area.”
Tree removal on steroids
Matt McCombs is the Colorado State Forest Service’s state forester and director. And he knows that spending years using big machines to remove thousands of trees from a park visited by 300,000 passionate hikers, walkers, bird watchers, backcountry skiers annually may not make them particularly happy.
But Rynearson says the work has to be done due to the density of the trees, their diameter and the amount of highly flammable understory lying on the forest floor.
He also emphasized that the treatment currently underway, which involves half-million-dollar Finnish feller-buncher machines grinding around those steep slopes and cutting trees at their bases, “isn’t intended to stop a fire,” but “to mitigate the impact if a fire occurs” which, again, is “when it will occur.”
Taking out standing dead trees is good, because as those start to come down, “you get surface loading, with large-diameter heavy fuels on the forest floor. A lot of times they’re Jack Straw on top of each other and you get jackpots of fuels when fire moves through,” he added.
That’s what creates the highest soil burn severity, and “places where embers can land and a fire can get going,” he continued. “And in this forest site, spot fires are the primary mechanism of fire spread, so being able to remove some of this dead material before it falls on the ground is a priority. It’s a lot easier to move it when it’s standing. And, in fact, it still has some commercial value.”
That word, “commercial,” denotes logging for profit to groups like Eco-Integrity Alliance, which insists countless independent, peer-reviewed studies show state and federal agencies are wasting billions of dollars on fuel reduction that not only doesn’t reduce fire impacts but could lead to hotter, faster-moving fires.
But on the Michigan Ditch trip, Rynearson said “I want to emphasize this is not a project that is focused on producing wood. Wood is a byproduct of fire mitigation.”
“If we did not have markets for these larger logs, we would have to figure out a way to burn them or a way to chip them,” he added, “and it would be incredibly expensive and incredibly difficult. So the local wood markets that northwest Colorado is fortunate to have really make this project possible. They’ve lowered the cost per acre significantly, and they’ve allowed us to have a larger project size, which will increase the effectiveness of the treatment.”
McCombs says people should prepare themselves for more projects like the Michigan Ditch, because “this kind of sustained engagement with the landscape” where we’re “building out the architecture of resilience and resistance,” is going to go on for the better part of every Coloradan’s life, as we answer our responsibility to steward landscapes for current and future generations.
And while part of that responsibility is trying to moderate the intensity and the frequency of mega fire, somewhere down the line, it could also include “creating opportunities for us to use fire in appropriate ways, to reconnect with ancient historic practices that humans have been conducting with applied fire, and using prescribed fire,” he said.