New Mexico’s Largest Fire Wrecked This City’s Water Source
Era of megafires endangers water supplies in American West.
By Brett Walton, Circle of Blue – October 25, 2023
LAS VEGAS, New Mexico — The largest fire in New Mexico history began with a disastrous government agency blunder. Its consequences for land and a small northern New Mexico city’s water were magnified by man-made climate change.
In the first week of April 2022, the U.S. Forest Service was setting a controlled burn in Santa Fe National Forest near the rocky promontory of Hermit’s Peak. A tool to thin overgrown forests, prescribed fires are intended to reduce the risk of hundred-thousand-acre megafires that have recently incinerated the American West.
Fanned by shifting winds blowing across dry timber, the deliberately ignited flames jumped containment lines. Then a dormant fire in nearby Calf Canyon reignited and merged with the blaze beneath Hermit’s Peak. Combined, the fire grew into an uncontrolled juggernaut that burned 341,735 acres of public and private land over four months.
But the collision between government error and climate change that produced a colossal fire disaster in the forests of northern New Mexico didn’t end once the flames were extinguished. The fire was a prelude to a water supply emergency that the city of Las Vegas still reckons with.
The fire burned the upper reaches of the Gallinas River watershed, the drinking water source for more than 17,000 people in and around Las Vegas. The fire had plenty of fuel — the watershed hadn’t had a major burn in more than a century. Ash and sediment flushed into the river from the bald slopes of the burn scar are undeniable threats to the city’s water treatment system.
By the end of August 2022, amid heavy monsoon rains, Las Vegas had a full-blown menace: a deteriorating river and just 21 days of water remaining in storage.
The trials of Las Vegas in the last year and a half are a sharp illustration of climate vulnerability in the American West, the domino effect of climate disasters, and the cost to taxpayers of repairing the damage. Similar cautionary tales dot the region’s map. Fires in recent years have destroyed water systems in Superior, Colorado; Detroit, Oregon; Malden, Washington; and in the California locales of Paradise, Santa Rosa, and the San Lorenzo Valley.
The risk of high-severity fire is growing due to decades of fire suppression combined with a warming planet. A fuels buildup is being conditioned to burn. As the number of burned acres trends upwards, the U.S. Forest Service expects one-third of western U.S. watersheds to experience a doubling of post-fire sediment flows in rivers by mid-century. Towns downstream of flammable terrain are a lightning strike or undoused campfire away from being unable to provide reliable water service.
The seat of San Miguel County, Las Vegas is one of the poorest municipalities in one of the country’s poorest states. The city’s poverty rate is more than 30 percent. The Hermit’s Peak/Calf Canyon fire so damaged the Gallinas watershed – charring the soil and increasing the sediment load in streams – that the drinking water treatment system cannot keep up. It must be replaced.
Unable to afford such a large expense on its own, Las Vegas turned to Congress. Lawmakers were willing to open the public purse due to the federal government’s role in causing the disaster. The Hermit’s Peak/Calf Canyon Fire Assistance Act was included in a short-term budget extension that President Biden signed on September 30, 2022. It offered $2.5 billion to compensate property owners for fire damage. The final 2023 budget bill added $1.45 billion to the pot, bringing the total federal assistance for injuries and property losses to $3.95 billion. That includes $140 million to replace water treatment facilities damaged by the fire.
Las Vegas intends a complete overhaul: a new water treatment plant, equipment to remove sediment from river water before it enters the treatment facility, and a system to purify wastewater to reuse as drinking water. Full build-out might take seven years, but when all the pieces are in place it will be the largest capital project in the city’s history.
“It’s huge,” Mayor Louie Trujillo told Circle of Blue about the federal assistance. “We could have never done it. We don’t have the budget.”
A Chaotic Period
As soon as the fire started, Maria Gilvarry knew that her city’s water supply was in jeopardy.
“The watershed is our water system,” Gilvarry, the Las Vegas Utilities Department director, told Circle of Blue. “So the more of the watershed that burns, the more that impacts our ability to treat and provide water.”
Even as the forests above Las Vegas smoldered, monsoon rains pummeled the burn scar last summer, delivering huge slugs of soil and debris into the Gallinas River. “It was just day after day of brown and black water,” Gilvarry recalled. The sediment load was too thick for the 1970s-era treatment facility. Two of the city’s three reservoirs were incapacitated by the muck.
Forests are on the frontlines of climate disasters. Hotter temperatures are a hair dryer pointed at mountain slopes that bristle with dense stands of trees and understory growth.
Because forests provide a disproportionately large share of the nation’s drinking water, what happens in the woods doesn’t stay in the woods. Though forests are water sources in eastern ranges like the Appalachians and Catskills, the water-forest-fire relationship is especially acute in the drying American West.
According to U.S. Forest Service research, national forests in the western states account for just 19 percent of the land area. But they contribute 46 percent of the surface water supply.
Amanda Hohner, an assistant professor at Montana State University, has spent a decade studying the effect of wildfire on municipal water systems. She says the places most vulnerable to wildfire contamination of drinking water sources share several characteristics. They are small systems with a single, surface water source — usually a river or lake. Who fits that description? The city of Las Vegas, for one.
Las Vegas has a backup groundwater well for emergencies. But Gilvarry said that mechanical problems kept it offline last summer. When the fire started, the Gallinas River was the only option.
It was a chaotic, high-stress period. Evacuated from her property, Gilvarry was running the utility department while staying in a trailer on a co-worker’s property. Her husband volunteered to fight the fire.
The utility crew shifted to round-the-clock operations at the water treatment plant, watching nervously as the fire approached — but never overran — the facility.
“Young staff members could look out and see flames,” Gilvarry said. “And, you know, they wanted to go home with their families at night. So part of my job was to counsel them and keep them safe, while also keeping water flowing for the community. And they did it — those employees were awesome.”
After the fire threat subsided, the task did not get easier. The Army Corps of Engineers installed 10-foot-tall steel Geobrugg netting across side canyons to catch large trees and boulders. The U.S. Geological Survey ramped up its stream monitoring. Straw-filled wattles, rock-filled gabions, berms, and barricades were deployed to prevent ash and sediment from entering the Gallinas. And yet it was not enough. Monsoon rains were severe, and sediment spiked.
Trujillo and Gilvarry said that Las Vegas made it through the emergency period by focusing on conservation until a temporary state-funded sediment removal system could be installed at Storrie Lake, one of the storage reservoirs. Water department staff talked with restaurants and laundries. They asked car washes to voluntarily shut down. They identified pipe leaks and sealed them. Water was brought in via truck and bottle. Trujillo made frequent appearances on radio, in town hall meetings, at the senior center, at the community college.
“The citizens were ready to help us and they did,” Trujillo said.
‘A Marathon, Not a Sprint’
High-intensity fires do more than scorch trees and destroy homes. They upend the ecological function of entire watersheds. Burned forests become riddled with impairments. Shorn of trees, the land sheds more water than before. Though more water flows downstream, the costs of megafire outweigh this benefit. Without the forest buffer, floods are more destructive and more common. The land erodes easily. More nutrients are flushed downstream.
For these reasons, the conservation groups American Rivers named the Gallinas one of the country’s most endangered rivers for 2023.
“The recovery of wildfire can be a little bit different from other natural disasters, in that the impacts can be cascading,” explained Madelene McDonald, a water scientist with Denver’s drinking water utility, which has also contended with the ripple effects of wildfires. “They’re not necessarily all at once, but it’s those repetitive storm events that can cause the greatest impact.”
It happens again and again in the western states. Nitrogen levels in Colorado streams spiked immediately after the 2002 Hayman fire and remained elevated for more than a decade. Nitrogen is a plant vitamin that feeds lake-befouling algal blooms. And that’s not the only contaminant. Carbon, organic matter, heavy metals, and sediment — all accumulate in post-fire streams.
These chemical and physical changes to land and water are impairments that Gilvarry and her staff will face for years. More organic matter in the river can interfere with drinking water treatment. Disinfection chemicals like chlorine can produce toxic byproducts when too much carbon is in the source water. Sediment also clogs reservoirs and reduces water storage capacity.
The risks for Las Vegas were not unknown. The 1994 Gallinas River Watershed Plan, a joint effort with the city, U.S. Forest Service, and Tierra y Montes Soil and Water Conservation District, noted the need to reduce the fuel load in the watershed. The Viveash fire, in year 2000, burned mostly in the adjacent Cow Creek drainage. But some 820 acres of high-intensity fire did creep into the Gallinas watershed.
“A fire of Viveash’s magnitude occurring completely in the Gallinas Watershed would be disastrous for those who depend on Las Vegas’ water quality,” according to a March 2006 environmental assessment of prescribed fire that was prepared by the Santa Fe National Forest. That is exactly what happened with Hermit’s Peak/Calf Canyon.
Though the summer of 2022 was a nightmare, the summer of 2023, in terms of water quality, was much better. Monsoon rains were a trickle, not a flood. Sediment levels have been manageable. All three reservoirs are functioning again.
A bright spot for Gilvarry is that Las Vegas itself did not burn. That means there are no contaminants to flush from drinking water pipes. Cities in California, Colorado, and Oregon had to deal with benzene and other volatile chemicals in their water distribution systems after fires burned within city limits.
Denver’s experience with wildfire is a template for Las Vegas’s future. Both the Hayman fire and the 1996 Buffalo Creek fire burned the watersheds above Strontia Springs reservoir, a storage facility through which 80 percent of Denver’s drinking water passes. Denver Water is still planting trees in the burn scar. Even today, more than two decades after the fires, McDonald sees sediment levels in the reservoir climb after heavy rain.
“Recovery really is a marathon and not a sprint,” McDonald said.
How can communities like Las Vegas better prepare for the race? McDonald is part of the Wildland Fire Mitigation and Management Commission, a group of more than 50 national and regional fire experts tasked by Congress to recommend policy solutions to the wildfire crisis.
In September the commission submitted its report. Among its many recommendations are five specific to drinking water. In essence, they focus on prevention and response. Before a fire, utilities need to map their vulnerabilities and reduce fire risk in their watersheds by thinning and incorporating low-intensity burns. Risk assessments could identify utilities in need of water infrastructure upgrades – those like Las Vegas that have a sole surface water source or do not have the equipment to handle higher sediment levels. Portland, Oregon, for instance, is building a $1.48 billion water filtration plant, scheduled for completion in 2027, that will filter sediment from post-wildfire erosion in its forested Bull Run watershed.
Congress also has a role, the commission argues. Lawmakers could authorize grant funding for these assessments and amend existing forest restoration programs so that they explicitly target funds to areas with critical sources of drinking water, even though those areas may be far from where people live. Lawmakers could expand the timeline for disaster-relief funding, acknowledging that fire can harm water quality for years.
Gilvarry points to funding as a major obstacle to protecting water for smaller, low-income areas. Even if they are aware of the risks, can they bear the adaptation costs? “For the community to have built a top-of-the-line system ten, twenty, thirty, forty years ago to plan for this would have been multi-million dollars, but it would have come from the residents here,” Gilvarry said. “And I don’t think the residents could have afforded that.”
There are targeted research approaches, too. The Wildfire and Water Security project is investigating how drinking water systems can become more resilient to wildfire. Led by the U.S. Forest Service’s Pacific Northwest Research Station along with academic partners at Montana State, Oregon State, and Washington State, the initiative is considering water treatment options, water quality after fires, and the economic implications of fire damage and risk-reduction costs.
At the state level, the Colorado Water Conservation Board assessed the vulnerability of drinking water infrastructure in the state to wildfire damage. Called Wildfire Ready Watersheds, the program is intended to enable community-level preparation before a fire.
Critical to the effort is the U.S. Forest Service. Armed with $3.5 billion from the two-year-old Infrastructure Investment and Jobs Act to prepare communities for wildfire, the land management agency has adopted a “fireshed” approach in responding to the wildfire crisis. Firesheds are forest and rangeland units of roughly 250,000 acres that, if wildfire erupted, could damage homes, watersheds, water supplies, utility lines, and other critical infrastructure.
The U.S. Forest Service did not make any staff available for an interview. “The agency collaborates in the development and implementation of source water protection plans,” the press office wrote to Circle of Blue in an email. “In many places, we have agreements with local municipalities on how activities in the municipal watershed will be carried out to ensure the drinking water supply is protected; some of these agreements go back decades.”
A year after being pushed to the brink, Las Vegas residents celebrated the return of the People’s Faire, a community arts festival held on August 26 that had been absent for three years due to Covid and the fire.
Food and crafts vendors lined the sun-dappled lawn in front of the Monticello-inspired Carnegie Library, while children plotted their moves on a giant chess board.
Trujillo, in sunglasses and a stylish floral shirt, acted as unofficial host, greeting nearly everyone who passed by. For a moment, on a warm late-summer day, the water emergency was a memory and all was right in Las Vegas.
“It’s nice that we have all this,” an older woman told him.
Her friend, who was shopping for Christmas presents, agreed. “When I lived in Oregon, we didn’t have the parades,” she said. “We didn’t have all this stuff that we have here. So it is nice. This little town does a lot.”
Brett writes about agriculture, energy, infrastructure, and the politics and economics of water in the United States. He also writes the Federal Water Tap, Circle of Blue’s weekly digest of U.S. government water news. He is the winner of two Society of Environmental Journalists reporting awards, one of the top honors in American environmental journalism: first place for explanatory reporting for a series on septic system pollution in the United States(2016) and third place for beat reporting in a small market (2014). He received the Sierra Club’s Distinguished Service Award in 2018. Brett lives in Seattle, where he hikes the mountains and bakes pies. Contact Brett Walton