‘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.”

This article was supported by The Water Desk, an independent journalism initiative based at the University of Colorado Boulder’s Center for Environmental Journalism.