Kat Demaree and Jason Quinn installing an in-situ water quality tool with multiple sensors providing near-continuous measurements of turbidity, chlorophyl-a, conductivity, and fluorescing dissolved organic matter (fDOM) along the Yampa River near Steamboat Springs. 

Using machine learning for better water quality

şÚÁĎÉçÇřÍř and Colorado State University researchers are teaming up to improve river water quality in the Rockies.

A team led by Environmental Engineering Professor Evan Thomas has received a $650,000 Convergence Accelerator grant from the National Science Foundation, to measure and mitigate pollution in the Cache la Poudre and Yampa Rivers in Colorado through new sensor technology, monitoring, and a voluntary carbon credits trading system with industry.

The Convergence Accelerator grant complements other Thomas-led initiatives also working to improve water quality. The work has also been funded by the Moore Foundation and the Walton Family Foundation. Thomas was influential in scoping the $160 million dollar NSF funded Colorado-Wyoming Regional Innovation Engine, and recently received a United States Congressional earmark directed-grant from NASA

Thomas has been working with Colorado State Senators Cleave Simpson and Jeff Bridges, and the Colorado Department of Public Health and Environment to advance legislation that could accelerate watershed restoration in Colorado by pairing wastewater utility water quality obligations under the Clean Water Act with restorative programs.

A central component of these projects is the use of ongoing, instream water quality measurements that will allow the team the ability to trace back negative changes, said Thomas, who also serves as director of the Mortenson Center in Global Engineering and Resilience.

“Typically, this work is done with point-in-time measurements when someone goes out and manually takes a sample, which is very expensive and infrequent. These new sensors we have are robust and durable and will allow us to do things continuously,” Thomas said.

The sensor data, enabled by a partnership with Fort Collins based sensor company In-Situ, will be fed into a machine learning system to develop predictive models that can track pollution and determine sources.

“Machine learning and AI aren’t new, but we’re applying these techniques in a place they haven’t been applied before – managing watersheds and enabling climate finance to pay for ongoing performance,” Thomas said.

Fernando Rosario-Ortiz, a professor of environmental engineering at şÚÁĎÉçÇřÍř and co-investigator on the project, said the grant builds on a wealth of earlier research.

"I am excited about taking all we have learned about wildfires and water quality and focusing now on how we can proactively work with communities to limit these impacts and the stresses they have on water infrastructure," Rosario-Ortiz said.

Being able to track back pollution sources has been a long-sought goal of environmental 

Evan Thomas

researchers. While it is simple to monitor pollution coming from fixed-point sources, like the outlet of a wastewater treatment plant, it is much harder to analyze diffuse sources, like runoff from industrial agriculture, mining, or forestry operations.

“It has been a technology barrier, and regulators have been reluctant to approve water quality projects that are hard to measure,” Thomas said. “We hope to change this. We’re working with landowners, stakeholders, and cities to make positive changes for restorative agriculture, irrigation, and wildfire management.”

In addition to water researchers at şÚÁĎÉçÇřÍř and CSU, the team has built a network of outside partners, including the cities of Steamboat Springs and Fort Collins, Friends of the Yampa, and Coalition for the Poudre River Watershed, as well as Virridy Inc., a şÚÁĎÉçÇřÍř spinout company that develops global water security programs.

A second key part of the project is a voluntary carbon market that aims to build industry investment in green infrastructure to improve water quality. Although the project is just getting underway, Mortenson Construction has already purchased $2 million in credits through it. Thomas said this market could generate as many as 1.6 billion carbon credits per year.

Thomas has been involved in large scale drinking water treatment carbon credit programs in Africa over the last 15 years, reaching over 5 million people with improved water security. This represents the first major effort in the United States.

“This is a way for industry and companies to demonstrate to shareholders and customers they’re committed to climate impact,” Thomas said. “It takes local water problems and brings them into the global market, creating business opportunities.”

In addition to Thomas and Rosario-Ortiz, the team at şÚÁĎÉçÇřÍř includes Kat Demaree, environmental engineer and doctoral student. At Colorado State University, the effort is being led by an assistant professor of ecosystem science and sustainability, and a professor of mechanical engineering. Also involved in the project is a sustainable development professor at Notre Dame who previously was a şÚÁĎÉçÇřÍř faculty member.

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Hundreds of thousands of Puerto Ricans are still without electricity nearly two weeks after Hurricane Fiona hit the island on Sept. 18, initially knocking out power for almost all 3.3 million U.S. citizens. The island's aging power infrastructure had not fully recovered since Hurricane Maria five years ago, leaving residents with high electricity bills and rolling blackouts even before last week’s storm. 

And when the power goes out, so does access to clean water. 

Fernando Rosario-Ortiz, professor of environmental engineering and associate dean for faculty at the College of Engineering and Applied Sciences, specializes in environmental chemistry and water treatment. He has analyzed the impact of natural disasters on water quality and treatment, including the aftermath of Hurricane Maria on Puerto Rico’s water supply. 

şÚÁĎÉçÇřÍř Today spoke with Rosario-Ortiz, a native of Puerto Rico, about what threats the island faces in providing safe drinking water to its residents after Hurricane Fiona.

Fernando Rosario-Ortiz, professor of environmental engineering and associate dean for faculty at the College of Engineering and Applied Sciences

What is happening right now in Puerto Rico? 

When Hurricane Fiona hit Puerto Rico on Sept. 18, there was a significant amount of rain that fell, with a lot of impacts to the power infrastructure that also impacted water supply production. Right now, the island is working toward recovery, and there has partial restoration to power and water supply. However, there are still challenges with the water system, which include the lack of power to run the pumps and the fact that there is debris stuck in the water intake structures that pull water into the treatment plants.

How much has Hurricane Maria impacted what’s happening now?  

Hurricane Maria had catastrophic impacts on the infrastructure in Puerto Rico in 2017. The power grid essentially collapsed and there were impacts to the water infrastructure. Since Maria, extensive work has been done to repair Puerto Rico’s power grid.

The reality is, though, the work to improve the grid over the last five years wasn't complete before Hurricane Fiona hit. Even before Fiona, a lot of people in Puerto Rico were struggling with outages—and the hurricane just exacerbated those effects. The system in Puerto Rico is quite fragile. We’re hopefully days away from recovery after Fiona, but it could be longer than that. 

What else does a hurricane like Fiona do to affect water access? 

Growing up in Puerto Rico, it was always kind of comical that when it rains a lot, your water will turn off. With major rain comes a lot of sediment and turbidity in the water, and most of the systems on the island cannot deal with that. They have to shut down and wait for the high turbidity events and high sediment events to pass. 

Hurricane Fiona overflowed the rivers in Puerto Rico, and it will take some time for the flows to go back to normal. In addition, there's a lot of debris in what is called the intake structures, where the water comes into the treatment plant. That debris needs to be manually removed and all the pumps and parts need to be tested to ensure they are operational. However, that work can’t be done until the conditions are safe and the river levels aren’t too high.

What are the next steps right now for residents?

In the aftermath of an event like this, the first priority is to make sure people are safe and taken care of and get access to power and water. For those people who have lost homes, there will be a long, long road toward recovery. In the southern portion of Puerto Rico, Salinas, for example, there will be a major cleanup effort because these communities were underwater for a long time. That's on top of restoring the power supply and water access to Salinas. 

How can the rest of us help our fellow citizens? 

Puerto Ricans are indeed U.S. citizens, and we should rally to help—just like we do when natural hazards occur in California or Florida. We also know it’s not a matter of if, but a matter of when this type of event will happen again. And it is not out of the question that it could occur again in the near future. We should be thinking about looking into the future and making investments that will result in long term resilience for the residents in Puerto Rico.

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The three largest wildfires in Colorado’s known history all occurred in 2020. More than 600,000 acres burned, with the Cameron Peak Fire alone causing $6 million in property damage.

Fernando Rosario-Ortiz
Professor, Environmental Engineering

While the last embers of the Cameron Peak Fire are long since extinguished, researchers are increasingly worried about how the remnants of those burns — and future fires — may threaten water supplies across the West.

Environmental engineering Professor Fernando Rosario-Ortiz said the chemical reactions that occur during a wildfire can lead to health and safety concerns when contaminants are released into water, in addition to the more visible and immediate effect on air quality.

“This is especially true in the context of fires at the wildland-urban interface, where if a home burns, we are talking about combusting everything inside those homes — from cleaning chemicals to, potentially, electric vehicle car batteries,” he said. “Better understanding all of those reactions with exposure to water is something that we will definitely need to explore further over the next few years.”

A researcher from Rosario-Ortiz’s lab collect water samples from a creek running through a burn area. 

Wildfires are becoming increasingly common in Colorado and the West, thanks to climate change and land management processes over the last 30 years, which sought to suppress wildfires as quickly as possible. That combination has resulted in longer, more intense wildfire seasons that lead to larger, more intense burns due to dense vegetation growth.

When it comes to water and wildfire, though, Rosario-Ortiz and his colleagues are increasingly interested in the “burn scars” fires leave behind. Wildfires destroy the vegetation that holds soil in place. Without it, heavy rains can push mud and sediment onto interstate highways. Or carry bacteria and freshly formed toxic compounds from the fire into freshwater supplies — causing headaches for treatment facilities. Meanwhile, water contamination from burns could also limit freshwater sources during tight drought seasons.

Rosario-Ortiz and colleagues have been going into the field to collect samples from burn scars in California, Colorado, Kansas and Alberta, Canada, for analysis in the lab. They hope to better understand how ash can affect watersheds as it creates and spreads a wide range of potentially harmful organic compounds.

“Our results from that work show the complexity of how a wildfire can impact water quality,” Rosario-Ortiz said. “(Our recent study in Science of the Total Environment) is the first of its kind to identify a specific suite of aromatic acids in wildfire ash and surface water samples. And it will help with the broader discussion and understanding around the nature of dissolved organic matter and the impacts of wildfire on water quality and drinking water sources.”

While Rosario-Ortiz and others are focused on water quality and chemistry, Assistant Professor Ben Livneh is studying these kinds of issues from another direction. As a physical hydrologist, he and his research group explore how climate and landscape changes affect how much water is available in an area — and when. His work also examines how fires and rain can influence landslide risk.

His team is working on NASA-funded research that studies 5,000 landslide sites around the world. So far, they found that sites that had a fire in the past three years required less precipitation to cause a landslide.

Soil and water samples from Bennett Creek in the Rio Grande National Forest.

“But there’s also a lot of local variability that really matters,” said Livneh, who was also recently appointed director of Western Water Assessment. “We now have a lot of people who have built structures on steep slopes in these areas, so there’s a human element there, too. And the time of the year that it happens can be crucial. For example, when a fire occurs right before a large storm can be critical, like we saw in Glenwood Springs, Colorado, this past summer.”

Livneh added that as rain becomes more prevalent due to climate change, leaders, researchers and communities affected by slides and other interrelated problems will have to keep an open mind and work together to solve them.

“Management is a policy problem, and in the next 10 years we’re going to continue to have these big fires and see their impacts,” he said. “But the more open-minded we can be about managing for these things, the better. I’m kind of an optimist. As humans, we’ve overcome so many technical challenges, and I think we can continue to do so here and in the future.”

Up close at the wildland-urban interface

The effects of wildland fires hit close to home for the şÚÁĎÉçÇřÍř community in late December.

, which spread through Superior, Louisville and unincorporated areas of Boulder County, became the most destructive fire in Colorado’s history. More than 1,000 homes and businesses were lost, and approximately 6,000 acres burned. More than 60 CU Engineering faculty and staff were affected, as well as many undergrads, graduate students and alumni.

Researchers watch a drone take off from the Spanish Hills neighborhood.

şÚÁĎÉçÇřÍř researchers — including those from engineering — immediately swung into action to learn all they could to help in future disasters.   

In February, Assistant Research Professor Brad Wham and colleagues from Oregon State and Purdue universities used drones to survey the damage as part of an initiative funded by the National Science Foundation that deploys researchers to disaster sites around the world.

Wham and his team hope to better understand the disaster from a uniquely engineering perspective: Why did some houses burn, for example, while neighboring homes survived? How did critical services like water, gas and electricity hold up during one of the worst disasters in Boulder County’s history?

“I think what we’re doing here is going to be beneficial in the future, especially with other communities that are going to have fires,” said Jessica Ramos, a senior civil engineering major who’s working on Wham’s research team.

The team planned to publish its initial findings through a publicly available report in March.

— Dan Strain contributed to this report.

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Nearly one month after the Marshall Fire became the most destructive and one of the most unique wildfires in Colorado history, şÚÁĎÉçÇřÍř researchers from across campus—many of them personally affected by the fire—have pivoted and applied their expertise to the aftermath, hoping to learn from a tragedy in their own backyard and help prepare the country for the next “climate fire.”

“What makes this fire really unique is that it happened in a community that is full of researchers that study this exact topic,” said Natasha Stavros, director of the Earth Lab Analytics Hub at the Cooperative Institute for Research in Environmental Sciences (CIRES) at şÚÁĎÉçÇřÍř. “We are going to have measurements unlike anywhere else.”

What makes this fire really unique is that it happened in a community that is full of researchers that study this exact topic. We are going to have measurements unlike anywhere else.”
–Natasha Stavros

 

As a grass-fueled December wildfire in a crowded suburb, the fire was quite different than the state’s massive forest fires of 2020, resulting in many novel impacts on the environment and human health. More than a dozen research projects are already underway, investigating everything from its impact on air and water quality, to the fire speeds that drove it, and how changes in infrastructure and insurance could limit damage from future fires like it. Researchers hope the findings can help inform homeowners, local governments and communities today and shape policies for tomorrow.

“In between all of us, there is so much expertise to address the causes and the impacts of this fire,” said Joost de Gouw, CIRES fellow and professor of chemistry. “If we come together to produce and publish research, we can really change the future of how we think about wildfire.”

Recipe for a winter wildfire

Three ingredients contribute to fire on the landscape: fuel, climate and ignition, said Stavros.

Due to higher-than-normal snowpack levels in late winter of 2021, a wet spring and a rainier than normal July, grasses grew abundantly in the Front Range throughout the year. By the time December rolled around, fuel accumulation was up 60% to 70% compared with a normal year. These plentiful dry grasses, combined with a 3-foot snow deficit and fierce Chinook winds, set the perfect stage that day for a spark to spiral out of control.

Avery Hatch, a şÚÁĎÉçÇřÍř doctoral student in environmental engineering, monitors indoor air quality in a spared home after the Marshall wildfire. (Photo by Casey A. Cass/şÚÁĎÉçÇřÍř)

Environmental engineering faculty Julie Korak and Cresten Mansfeldt collect water samples. (Credit: Fernando Rosario-Ortiz)

This abundant fuel would not have existed without increases in precipitation and snowmelt in the first half of 2021, followed by a drastic lack of moisture in the second half of the year—both of which point to climate as the driving cause.

“It’s the first time in my career I have felt comfortable saying this is a climate fire,” said Stavros.

Climate change will continue to have a hand in the future of wildfire, increasing the length and intensity of fire seasons as well as changing how, when and where water is distributed, said Stavros.  

In addition to analyzing the impacts of fuel growth, researchers in the Earth Lab are also examining the role of another major factor in the Marshall Fiire: speed.

The Marshall Fire only burned 6,000 acres, less than half the size of Colorado’s second most destructive fire in state history, the Black Forest Fire. Yet it tore through twice as much infrastructure, accounting for 39% of all homes lost to wildfire disasters in the state since 1999, according to Maxwell Cook, doctoral student in the Department of Geography and the Earth Lab.

The fire also now ranks in the top 15 most destructive wildfire events in the western United States, only one of two grassland fires in that list.

Cook is currently working with Jennifer Balch, director of the Earth Lab, to conduct research on the factors which make a fire most likely to burn down homes.

So far, their data shows speed matters most. This may seem obvious, but Cook, Balch and their colleagues have developed new data that now allows them to track and quantify that impact.

“The speed of the fire is also really what makes it difficult for emergency management personnel to respond, to get evacuation orders out in time,” said Cook. “Management strategies that are aimed at reducing the speed of wildfires could be critically important for communities.”

This could include creating fire/fuel breaks around suburban neighborhoods and removing vegetation next to homes—strategies already broadly in use in foothills communities around Colorado. Early detection systems and quick emergency responses are also key, especially in densely populated neighborhoods.

is also involved in helping develop better maps of where homes are at risk of wildfire across the West, which can help communities and insurances companies better plan for and mitigate that risk.

“We may need to think hard about what we define as the wildland urban interface (WUI). There's a lot of flammable landscape and development out there that's maybe not accounted for,” said Cook. “Building smarter, both in terms of where we build and how we build, that's going to be a big thing moving forward.”

Clearing the air

Three weeks after the fire, homeowners and renters who did not lose their residences still face an important unknown: Is it safe to go home?

Buildings were inundated with smoke, full of unhealthy compounds created as the blaze burned paint, fried refrigerators and melted metals in nearby homes. These chemicals, absorbed by surviving structures like a sponge, now pose a previously unquantified problem.

Air quality scientists from şÚÁĎÉçÇřÍř, CIRES and NOAA quickly compiled an about the impacts of post-fire smoke cleanup in homes. Led by de Gouw, they next installed instruments in several surviving homes to measure levels of harmful gases and understand the lingering effects of smoke on indoor air quality. Another team of scientists have also been driving through affected neighborhoods with a mobile laboratory to measure what the remains of buildings emit into the immediate atmosphere.

An interdisciplinary team including engineers, social scientists and chemists from across campus will continue to collect data indoors over the coming months to and learn more about lingering human health concerns that wildfires in urban areas can present.

Downstream effects

Meanwhile, Fernando Rosario-Ortiz and his colleagues are studying water.

For years, the associate dean for faculty advancement at the College of Engineering and his colleagues in the Environmental Engineering Program have worked to understand the implications of wildfire on water. But they usually study forests.

“Combusting homes is a whole different ball game,” said Rosario-Ortiz.

It’s not just wood that’s burning in a suburban fire: It’s homes, vehicles and all the stuff in them: fabric, plastics, electronics, batteries, you name it. Those remains and the compounds created can find their way into local water systems. When a fire is quickly followed by rain or snow, as was the case with the Marshall Fire, concerns about contamination are even higher, he said.

Julie Korak and Cresten Mansfeldt, assistant professors of environmental engineering, have partnered with colleagues across campus, local community organizations and municipalities, to collect surface water samples in the area, test for concerning chemicals and address questions of watershed safety posed by residents. In the next month or so, the team will have initial results to share with stakeholders.

“Everyone here takes their water very seriously,” said Mansfeldt. “This work provides a first fingerprint of how a fire like this impacts a community, and how we can assist recovery.”

Building back better

Now that we know a fire like this is possible, the big question the Front Range faces is: How do we keep this from happening again?

A first step in answering: To get a comprehensive, birds-eye view of the damage.

Read more

• After the fire: A look at the Marshall Fire’s community impact
•  (CIRES)
• If you really listen, survivors and emergency responders will tell you what they need
• (Earth Lab blog)

To that end, Brad Wham, assistant research professor in the Center for Infrastructure, Energy and Space Testing, will join a national team of colleagues this week to fly drones over the burn sites before cleanup begins, gathering valuable clues about what happened that day. The work is part of a larger collaborative research effort, supported by the Resilient Infrastructure with Sustainability and Equity IRT (RISE) within the College of Engineering and Applied Science, formed in the wake of the fire to connect environmental engineers, social scientists, first responders, and policy experts conducting work on natural disasters.

And once rebuilding begins?

“It is entirely practical to build back better,” said Keith Porter, adjoint professor of civil, architecture and environmental engineering.

Porter explains that using fire resistant materials to build a home doesn’t only make it less likely to burn, but they’re a relatively cheap upgrade (less than $10,000 compared to replacing a home worth $600,000) and due to their longevity, can lead to immense savings over the life of the home.

The International Wildland Urban Interface Code, for example—adopted in parts of Boulder County—requires that fire resistant materials be used in new construction. Porter points out, however, that unless cities and counties mandate this kind of fire code, homebuilders aren’t required to swap wood shingles for a non-combustible roof or to replace vinyl siding with stucco in new developments. When rebuilding, insurance companies may mandate that a house be replaced “like for like,” potentially inhibiting homeowners from replacing flammable building materials with fire resistant ones—even if it could save insurance companies money to let people do so, according to Porter.

As affected residents navigate their insurance policies, find temporary housing in a tight market and try to stay healthy during the omicron surge, fighting for fire resistant materials may not be able to be a top priority. This is why, Porter points out, the real power to protect public safety is not on the individual, but in the hands of local officials.

“Everybody else is affected by somebody else's house burning,” said Porter. “Both in an economic sense and in a moral sense, we really are all in this together.”

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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. 

şÚÁĎÉçÇřÍř Today spoke with Professor Fernando Rosario-Ortiz, an environmental chemistry expert who studies how wildfires impact water quality; and Assistant Professor and 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.

Fernando Rosario-Ortiz, professor of civil, environmental and architectural engineering, is an expert in environmental chemistry who has been studying the natural processes that impact water quality since his arrival at şÚÁĎÉçÇřÍř in 2008, and how wildfires impact water quality since the High Park fire in Fort Collins in 2012. (Credit: şÚÁĎÉçÇřÍř) 

What happens to water in lakes, rivers and streams after a nearby wildfire? 

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. 

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. 

If you don't have that option, some of the challenges after wildfire and rain events include increased sediment mobilization, which is very challenging for water treatment operations. Those are short-term effects that might give you a headache, but they can also become long-term challenges. Never mind the fact that you may have issues with infrastructure. 

Ben Livneh, assistant professor in civil, environmental and architectural engineering and a fellow at the Cooperative Institute for Research in Environmental Sciences (CIRES), is a physical hydrologist who researches how climate change and landscape changes can affect where and how much water is available in an area—and when. His work also examines how fires and rain can influence landslide risk. (Credit: şÚÁĎÉçÇřÍř) 

How can wildfire affect water quantity and timing in a landscape? 

Livneh: In the western U.S. we really rely on water that flows in rivers and streams, and that fills the reservoirs for our supply. So when we think about even small changes to the amount of water that comes off of the hill slope, or across the landscape, that can have a big impact on the total availability of water. 

One of the most notable things that happens in a fire is that the texture of the soil changes. Initially, less rain will soak into the soil, and more rain will become surface runoff. There's a lot of reason to think that you will get more total water—but it'll be much more “flashy” when it comes. 

On one hand, that can be good if you have a reservoir to collect it. But we've heard of water utilities actually turning off their intakes after a fire if the quality of the water is too low. And that's tricky, because often drought is involved in some fashion. So there's often this competing need for more water, and yet the quality is low. 

What are the factors that affect the likelihood of floods or mudslides after wildfire?

Livneh: When water carries enough stuff with it, we call it a debris flow, which is a type of landslide. The bigger and bigger it gets, the more impactful it is. We have research funded by NASA where we looked at 5,000 landslide sites around the world. We found that sites that had a fire in the past three years required less precipitation to cause a landslide. 

But there's also a lot of local variability that really matters. Moderately steep, heavily vegetated areas, types of soils—especially sandier soils—increase risk. Also we now have a lot of people who have built structures on steep slopes in these areas, so there's a human element there, too. And the time of the year that it happens can matter. A fire right before your rainy season is an important factor. 

What does this all mean for the future of Colorado and the western U.S.?

Rosario-Ortiz: When homes burn, you’re not just combusting houses, you're combusting everything inside those homes. You might now be combusting electric vehicles, for example, with a large battery. 

Then what are some of the other potential concerns with exposure to air? Water? That's going to be something that we will need to explore further over the next few years. 

Livneh: Some estimates say the amount of forest area being burned each year in the western U.S. has doubled in the last 25 years. And it really poses risks to communities, especially in the wildland-urban interface (WUI). Managing it is largely a kind of a policy problem, but in the next 10 years or so we're going to continue to have these big fires. 

First and foremost, people need to be paying attention to these flood watches and to local guidance on evacuation. The most important thing is saving lives. 

What can we do to prepare for the future? 

Rosario-Ortiz: Utilities might have to be thinking about potential upgrades in facilities. That means we may have to also consider financing of these projects and how to improve overall resiliency. 

Livneh: One of the most robust features of climate change is warming, right? As rain becomes more prevalent, we're just going to have to continue expanding our portfolio of things we do to keep up. The more open-minded we can be about managing for these things is important. I'm kind of an optimist. As humans, we've overcome so many technical challenges; it's not going to be something we can't solve our way out of. 

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