This article is part of our four-part series “Forests, Fires, and People,” presented by the Institute for Science and Policy and the Center for Collaborative Conservation, with support from Gates Family Foundation and in partnership with the Denver Museum of Nature and Science, the Colorado Forest Restoration Institute, the Southern Rockies Fire Science Network, the Colorado State Forest Service, and the Climate Adaptation Partnership. Find all series episodes on our YouTube channel. 

Colorado’s three largest fires in recorded history all occurred in 2020, collectively burning more than 625,000 acres while damaging homes and costing lives. Our changing climate suggests that this devastating year may have been a glimpse into the future. Decades of population growth in the wildland-urban interface combined with changes in regulatory policies and forestry practices have left the region vulnerable to more destructive blazes, leaving policymakers and scientists with a challenging question: What have we learned, and what decisions might we consider in the future to protect ourselves and our forests?  

To continue our wide-ranging look at wildfires in the Western U.S., the Institute’s Kristan Uhlenbrock and the Center for Collaborative Conservation’s John Sanderson spoke with Jen Kovecses, Executive Director of the Coalition for Poudre River Watershed, Russ Schumacher, Colorado State Climatologist and Director of the Colorado Climate Center; and Monte Williams, Forest Supervisor for the Arapaho and Roosevelt National Forests and Pawnee National Grassland. 

Colorado is hotter and drier overall

RUSS SCHUMACHER: We can look at data from one weather station at Grand Lake, just outside Rocky Mountain National Park, right where the East Troublesome fire ended up. From July 1 through October 21, which is when that fire swept through there, it was by far the driest over this particular period in the late summer and fall. And what's interesting if we look in these higher elevation stations in Colorado, what we often see is a pretty narrow range of precipitation. Pretty much every year, it sits somewhere between four and 10 inches of rain over this period, with an average of about seven inches. This is much different than the Eastern Plains, where we have some years that are just extremely wet and some that are extremely dry. It's generally a narrower range up in the mountains.  

What we see from 2020 is about a six inch deficit in rainfall from July 1 up until when the fire came through there. That’s a couple inches drier than the previous driest year which was just the year before, in 2019. We can focus just on the month of August, which was when the most extreme conditions happened and kind of set the stage for what we saw with the wildfire season. It was the hottest August on record for western Colorado by about two degrees, warmer than any previous August, and then also the driest August on record for that part of the state.  

So, again, August is the time in western Colorado when we expect the North American monsoon to bring in at least somewhat frequent rain and cloudiness and more humidity. That all kind of works to keep the temperature down. But we didn't see any of that in 2020 and things heated up and dried out very quickly. 

One metric of drought is called the standardized precipitation index. Essentially, it's just a measure of how unusually wet or dry we are. We have reliable data across the state back to the late 1800s. We can see some of the historic droughts over the last century-plus:  the dustbowl in the 1930s and in the 1950s and the drought of the late 1970s, especially in the mountains, and then kind of a wet period through the 80s and 90s and then our three more recent droughts: 2002, 2003, and 2012 plus the one that we're currently in. Having three droughts within 20 years is somewhat more frequent than we see historically from this precipitation perspective. But it’s not that different from what we saw maybe in the 50s and 60s, and the lack of precipitation is certainly notable. 

We should also look at what happens when we also account for the effects of rising temperatures and a warmer atmosphere. All else being equal, a warmer atmosphere, especially in the summer, is more efficient at taking water out of the soil, the vegetation, forests, etc. This is what's known as SPE, the standardized precipitation evapotranspiration index. It tries to account for the evaporation part, that thirst of the atmosphere. And so now it's a pretty different picture over the last 20 years, where we see that it's essentially one long dry period with three extremely dry periods in there. That 2002 period was the most extreme, and that was of course a huge fire year as well. And then the ongoing drought, with no wet periods interspersed there. 

So when we were looking at just precipitation, it wasn't that unusual historically. But this is what we're kind of looking at as the climate warms: we get into what's been termed by others as “hot drought,” where the precipitation deficits aren't historic, but when you add in the effects of the temperature, everything is drying out. 

The forests were primed for a big burn 

MONTE WILLIAMS: When I was starting out in my career, normally we didn't see snow come off around the ranger station until somewhere in late April or early May. And then one year we had a fire that started in early March and nobody can remember a fire actually burning in early March. We thought that was an anomaly in the 90s, and since that time, it's no longer an anomaly. 

I’ve spent about half of my career as a professional hydrologist with the Forest Service, and during that time, a lot of my efforts went into evaluating the impacts of wildfire and dealing with floods and erosion that happened afterwards. I want to talk a little bit about what conditions made the time right for the fires we saw last year. I'll focus on Cameron Peak fire, which became the largest wildfire in Colorado history. We all knew that this fire was going to happen someday up there. Three of the five largest fires in Colorado history burned on my forest at some point last year.  

The fireshed for the Cameron Peak fire goes from Wyoming all the way down to Estes Park, and it goes from the Continental Divide all the way to Fort Collins. You're talking about a huge area. All the trees, all the brush, even the needles you'll walk on on the forest floor, are all fuel for wildfires. Many of you have probably seen photos before from the late 1800s and you don't see a whole bunch of trees out there. That’s a landscape that can handle fire. Even a fire hits it, it's not running and gunning. But today in the same spot, with heavy lodgepole pine forest cover, and you add the weather conditions that Russ described, then all of a sudden you now have the recipe for disaster. We also started getting a bug epidemic that killed a large number of the trees in there, so we had a lot of standing dead that was ready to be burned. So next slide please.  

Work was started about 15 years ago, recognizing that there's going to be fires. We really didn't have a lot of thoughts about how it was all going to work, but they started working on prescribed fires and other types of thinning and things to give us a shot at stopping the fires. About five years ago, a group of partners formed the Northern Colorado Fireshed Collaborative, and it's a grassroots organization that’s stepping up efforts to make a difference with wildfire. What we're doing is constructing a one- to three-mile wide area from the Wyoming border all the way down south of the park where tree density is reduced and where prescribed fire has been used to consume other fuels. Wildfires usually burn west to east here, and so by stopping the fire at the start, we minimize their ability to continue to grow. We wanted to reduce the impact on the communities and damage to more wildlife habitat, drinking water, etc. This wasn't the final strategy, it just is what we could do to get started. 

The Cameron Peak fire made two runs at the strategic work that we did, and then a third run. Where we hadn't done work, that's where it blew out and doubled in size and most of the homes that burned were in that last run. We come up past Labor Day [on its first run] and folks thought the snowstorm stopped it but it actually hit the fire areas and was effectively stopped before the snow hit. At the second run, it's actually burning up in the canyon there, and it's gonna sit here for a little bit and then made a run towards Red Feather Lakes. Same thing: a series of prescribed burns and other work up there, we caught it.  

And so this fire sat on the landscape for a long time not doing much, but then as we got into mid-October, we had another run and we had a project planned in there. But we had not gotten started on it yet and were just finishing the analysis. A lot of this landscape looks like a whole bunch of the West. But where we work strategically and put treatments in place that that made sense and were designed to do something, they worked. Where we didn't, it pushed out and hopped out on this other side. 

The impacts of large fires are far-reaching in an ecosystem 

JEN KOVECSES: Why do we worry about these wildfires? What are those impacts that we are concerned about, and what does it look like for our communities moving forward to deal with those impacts? When the fire is active, when the flames are going, communities are evacuating... there's a lot of attention on those dramatic moments, but from the perspective of a watershed, it's really when the flames go out, that the problems really start to happen. 

Wildfires are a natural part of our ecosystems in the Rocky Mountain West. We have fire adapted forested ecosystems. So why do we have these big concerns?  It's really tied to how water moves through a watershed, and how the patterns of our wildfires have changed. So, in an unburned watershed, most of the water in the water cycle of the watershed isn't what you see in a river or a creek. Most of the water either slowly sinks into the ground, or as Russ alluded to earlier, it evapo-transpirates first through the plants and then into the atmosphere. It's that organic layer at the forest floor that creates like a watershed sponge basically and allows water to slowly infiltrate into the ground. 

So when we have these really big, large footprint, high intensity fires, the difference is that the spongy layer gets burnt up, and there's no more vegetation, or less vegetation to put water into the atmosphere. And so the net result of that, in these high severity burn areas, is that you have way more volume of water moving over the surface of the slopes. That excess volume of water moves at a higher velocity, has more energy in it. And as more of that water is moving over the slopes, it's going to pull all of that ash, sediment, debris, and rock down into the water.  

In 2012, the Hyde Park fire was the largest wildfire in Larimer County's history. And we got black water coming down the drainage pretty much any time we had a large rain event, or even a moderate sized rain event, in the watershed over the burn area. All of that material eventually made its way into the Poudre itself. It's just one example of what our concerns are moving forward. These types of impacts after a large wildfire can vary greatly, and really depend on a lot of different factors. We don't know yet what all of the impacts are from the Cameron Peak fire, we're waiting for that first set of rain storm events to happen to see what that will look like. But we've been working very closely with many people to try and understand and predict what those impacts will be.  

Watersheds like the Cache de Poudre watershed -- which is, you know, pretty similar to many of the watershed and headwaters across Colorado and throughout the west -- supports drinking water for over 300,000 people. It supports irrigation water for at least 200,000 irrigated acres  fully or in part. This watershed also supplies the industrial water for a really important manufacturing industry locally and a really important drilling industry, in addition to a multimillion dollar recreational industry. Arapaho-Roosevelt, which Monty manages, is the third or fourth most visited National Forest in the country. We have a really important whitewater industry and really important recreational fishing industry. The Poudre is also the only Wild and Scenic River designated in the state of Colorado. So there's a lot of value at risk from these types of events.  

And these types of post-fire impacts across the West can last anywhere from three years to more than 10 years. So it's not a small change in our landscape, and then you combine the footprint of a high profile fire, that's a huge amount of our landscape and our watershed that has radically changed in the past 10 years. 

Recovery is a complicated process 

JK: Given the degree and the sheer size of the Cameron peak footprint, the number of land owners, the different land ownership, the different cross jurisdictional issues, the number of different government agencies that have different jurisdictions in in or downstream from that footprint...dealing with the recovery from this type of event takes a lot of collaboration. It takes a lot of work to bring all of those different agencies together and really think through strategically all of the needs over 200,000 acres. We can't treat every single piece of burn acreage in the burn footprint, we have to make choices. And so we work really carefully together to use the best available science to plan and prioritize those needs.  

One thing that's specific or maybe a little bit unique about the Cameron Peak fire and some of the other fires that happened in 2020 is the importance of this watershed for our drinking water supply. Not only did it burn around the Poudre and the Big Thompson watershed itself - rivers that supply drinking water for about 50% of the needs of both Greeley and Fort Collins -  but it also encompassed at least five of the most important water storage reservoirs in our watershed. So, the compounding effect of this type of event on our water supply is particularly concerning for our local municipal water suppliers. Big Thompson was affected by the East Troublesome fire in 2020 as well. We're in a situation where there's a lot of concern about what this means for how well our watersheds can continue to support water supply, without risk. Moving forward, there's a lot of work going into trying to mitigate those impacts. 

2021’s fire conditions are shaping up to be similar   

RS: It's probably still a little bit too early to say for sure - there's a lot of things that can happen between now and the summer. But that being said, in most places we're not going into it in great shape. The soils were very dry after last summer. The snowpack has gotten back up to closer to average in most places in in Colorado from some storms here in February and March, but the drought certainly persists. The outlooks for the spring and summer don't look great, the odds are tilted towards warm and dry.  

Here along the northern Front Range, we had this massive snowstorm a few weeks ago and there was a lot of moisture there and that helped a lot in our specific area, in Denver, Fort Collins and in the mountains west of us. But if you go further west, they didn't get nearly as much snow from that. And last summer was even more extreme in those areas. If we look at the US Drought Monitor map right now, it still looks very bad once you get west of the immediate Front Range. It's not exactly where we want to be going into summer, but at the same time, there's a lot of things that can happen between now and June that could mitigate that. But that's not what the outlooks are pointing to at this point. 

MW: One of the things that was fascinating about last year and terrifying all at the same time was that we still had active fires on Thanksgiving week and if the fire teams had not been able to put that out, we that may have drawn clear in January. I'm not sure we have ever seen anything like that. What was happening was the big heavy fuels, the logs that are standing or laying down on the ground, hey came into that drier than the timber that you buy at Home Depot. It was that dry, and it takes a long time for moisture to be in contact with that wood for it to get wet again and not want to burn as well.  

We have a measurement called the energy release component, or ERC, and when it gets up above around the 97th percentile, then you got all sorts of crazy behavior. Well, we kept having those high numbers all through the year.  On Labor Day, we had snow, but it melted and didn't do anything for those big logs. This is a game of how long do we get moisture that will slowly soak into those logs and make them wetter and wetter and get them where they don't burn with the explosive energy that he did that year. So, I don't know where our heavies are at right now, but from what I've been hearing, they haven't recovered as much as we would like to.  

And then another thing that happened last year is: where did the monsoons go? Normally we start to warm up and we start to dry out and all that happens, but then we get a period where there's clouds and there's rain storms and all of that, and it's not as hot, not as dry, and maybe even adding moisture to the system. And so we get a break in the middle of the summer and then it really takes a while for the fires to take off. Not last year. It just builds and builds and builds until August.  

I'm listening to Russ very carefully because he's previewing what the summer looks like, what it's going to depend upon. Do we keep getting moisture, does it dry out, do we lose what we've gotten with the recent storms? Are those monsoons coming, and what are they going to do when they're here? They make all the difference in the world in terms of what our fire outlook looks like later in the summer. 

Mitigation strategies will vary depending on the specific area of the forest  

MW: That [proactive firebreak line] is a line that is the combination of a lot of folks putting their brains around and saying, where would we have the best place to make a stand, and where do we invest first? Like I said, there’s a lot of work that needs to go in that watershed and we're evaluating now where we're going to go in the future...maybe going more up the center of the canyon and making kind of a cross just instead of a strike to break down even more of the landscape into a smaller area. Each of those types of strategies are really specific to the site that you're in and asking what you are trying to protect. Where do you have a chance to do something? Where do you think you've got the ability to actually to get in there and treat if you've got a whole bunch of homeowners? 

If you look at how ponderosa pine interacts with fire, which is different than lodgepole pine, it loves fire. There are fires in there every so many years, and it's a place that once you build something like that strike, you can maintain it in that state. Lodgepole pine just to the west of there doesn't burn that way. It burns more catastrophically becaus it goes up all at once. And so it's a harder place to try to create something that creates a barrier for fire. 

JK: Monte referenced the Northern Colorado Fireshed Collaborative and that collaborative effort to do that planning and really bring in those cross-jurisdictional elements to think strategically about how we get those treatments on the ground, how do we use the best available science, and how do we work with our agencies and our communities to think beyond the defensible space. How do we bring communities into that process of planning and get more community buy in for this type of work so that we really are planning where the work needs to happen and not just where we have permission from the federal government to work. And that process takes a long time.  

The scope of the wildland-urban interface (WUI) is changing  

MW: The WUI is an idea that came out 15 years ago or so and I'll make two arguments. First, I think our concept of WUI has changed, and it’s maybe not as effective of a way of talking about prior treatments. But the second part is this idea that WUI is something special, at least if you think about the places in and around homes. Cameron Peak covered 17 miles one day. How far away do you need to be to say that the fire is right next to the house? Is one day's worth of burning close enough? The East Troublesome burned over the Continental Divide and made a run in Estes Park. How far away do you have to be to say now you're in the WUI? So I think you have to think about separating that from a definition standpoint. I 

I'm not going to advise anybody to live out in the woods or not to. That's the place I want to be all the time, myself. But what I'm going to say is that it's not as simple as just going around your house and looking and saying, what do I do here. I think as you look at where homes burn, the ability to have firefighters be able to shelter in place and stay in those sites often made some of the biggest differences to whether homes were standing or not. This gets into a complex discussion but as a neighborhood, you need to look at what you've got going on, and you need to do some work to make sure not only have you reduced the risk, but you have the ability to actually to hold fire crews in there as that fire is burning over so on that bad day, people can hang in and maybe protect your house. 

JK: We can think of planning like the Russian nesting doll, right. The smallest, more central part of that is where communities or homeowners have the most agency and that's immediately around their house or immediately in their communities. There’s a lot of responsibility and agency for people to do work to protect themselves from fire in that space. And that's traditionally where we really focus this conversation. 

But Monte’s right that the current trends in our wildfires is that that's not enough. So that's why we're working at that next level, from the neighborhood to the watershed to the full landscape, so that we can bring more of those layers of protection. Communities have historically focused in that innermost space. And what we're trying to do is reach across those lines and really trying to pull and link those types of planning together so that as local volunteer fire departments and their individual homeowners are focusing on that near space stuff, we're building out from that with our planning and integrating across that.  

I think one of the conversations that has been changing in in the wildfire and forest and fire community is just this notion of WUI in the first place. The focus historically has been on those residential structures that are in the forests, close to where we would expect fires to happen. But as I alluded to earlier, we have so many assets and infrastructure interwoven throughout all of our watersheds. So how do you really separate water supply infrastructure or recreational infrastructure or transportation infrastructure? And if you really look at the WUI from the perspective of what's at risk from these wildfires, there's an ongoing conversation that has been shaping up to consider more than just like, you shouldn't have wood shingles on your roof. 

MW: My argument is, you got to do both. The technical landscape level solutions can work, the individual efforts can work. You can't do one at the exclusion of the other, and I think that's an important thing for folks to recognize. It’s not just, if I treat around my house I'm going to be protected. 

2020 may have been a preview of the future   

RS: There's plenty of history of drought in Colorado and throughout the West. Our climate is prone to that. Within the last 20 years, there's been a pretty strong connection between the drought years and the big fire years. The scientific research that's been done on this all really points to increased acreage burning and more intense fires in the West as the climate continues to warm, basically for the same reasons. It's not going to be every year, necessarily, but the number of years where you have these hot dry conditions in the summer will be more frequent. 

Having looked at what we've seen here in Colorado, this year opened a lot of eyes as to what was even possible. It may not be next year or five years from now, but we're gonna have even hotter summers than we had last year as we continue to go forward. At some point there will be conditions that are that are even more favorable than what we saw last summer. 

Prevention efforts are more cost-effective than response measures 

MW: You think about the money that we've spent from a suppression standpoint just on that one fire and now the damages, which are almost as much as we spent on it – it's unbelievable how much money that is. Hundreds of millions of dollars. And yet the work and the investment of the amount of money that we spent to create [the firebreaks] we did was a small fraction of that. 

One of the things is having strategic vision, creating a direct connection between things happening on the ground and evaluating the pros and the cons. The second thing is, this is not being done in a back room. You don’t just get a letter one day saying oh by the way, we’re going to burn all your wood. The conversation is starting in the community and when the local VFB Captain comes and participates, he goes back to his community and he talks to Bob and Joe, his neighbors, about the whys and the whats. It makes a difference. They understand what we're doing and why we're doing it. So I think the strategic vision piece is really critical because you've got to be able to lay it out in ways that people see what's happening and why.  

JK: We each have agency and space to act, and there's a really important conversation to have about what kind of outcomes we prefer to manage. Are we worried about the risk of a prescribed fire, or are we worried about the risk from a Cameron Peak fire? Are you more willing to have your neighborhood have prescribed fires? There's still a lot of fear from communities around that, but really, the risk is never eliminated. 2020 is maybe going to be the springboard for us to have a more fulsome conversation with our communities about what the outcomes that we want to see on our landscape and downstream of these forested areas.