The financial impacts of a catastrophic wildfire and post-fire flooding on Bill Williams Mountain could dwarf those of the 2010 Schultz wildfire and subsequent flooding.
That’s according to a new study out of Northern Arizona University that estimated potential damages of between $379 million and $694 million if both fire and flooding hit the mountain just south of the city of Williams.
The total financial impact of the 15,000-acre Schultz fire and post-fire flooding was estimated to be between $133 million and $147 million.
The NAU study, which was presented to the Coconino County Board of Supervisors Tuesday, analyzed how floodwaters racing down the burned slopes of Bill Williams Mountain would threaten the city of Williams, including retail shops, government buildings, schools, residential neighborhoods, critical infrastructure, hotels and the Grand Canyon Railway. Its scope also covered potential impacts to the city’s water supplies, its tourism industry and sales tax revenues.
In drawing its conclusions, the study assumed that a wildfire with similar size and intensity to the Schultz Fire burned through Bill Williams watershed. If even a smaller storm dropped rain on the mountain after a blaze like that, the study found it would produce flows through Williams similar to those of a 100-year flood under current forest conditions.
Nearly 950 structures would be at risk in the flood zone, the study found.
Among its other findings:
- Flood damages could cost $93 million to $124 million in repairs
- Tourism revenue losses due to reduced demand could total $85 million to $170 million
- The impact of freight delays on Interstate 40 due to post-fire flooding could total $27 million to $53 million
- Fire damage to communications towers and structures at the top of Bill Williams Mountain could cost $39 million to $94 million
- If the mountain burned, flows through the city of Williams would be up to five times greater than if the same amount of rain fell on the mountain in its current, unburned state.
Wade Rousse, interim director of NAU’s Alliance Bank Economic Policy Institute and one of the study’s authors, said its conclusions are likely very conservative. They didn’t include, for example, loss of employee income if businesses have to close due to fire or flooding, health problems from those events or the potential negative impacts to outdoor recreation, Rousse told Coconino County supervisors on Tuesday.
Also telling was the estimate of what it would cost to thin trees that blanket the slopes of Bill Williams Mountain in order to reduce the threat of catastrophic wildfire.
That cost, according to the Kaibab National Forest, would be $8 million to $10 million, spokeswoman Jackie Banks said in an email. Most of the mountain and its lower slopes are on Forest Service lands.
She noted that other prescribed fire and thinning work has already occurred or is planned around the base of the mountain.
The thought that the forest could be thinned for $8 million to avoid $379 million or more in damage is telling, Rousse said.
Going through a data-driven process to assess the potential impacts of severe wildfire helps the county prioritize future projects and validates its focus on forest restoration, Supervisor Matt Ryan said.
The study is a “poster child” for why the county needs to expand its own capacity to support forest restoration and the cultivation and development of a local forest products industry, Coconino County Supervisor Art Babbott said. The county made a significant move to do that last month when it hired its first forest restoration director.
For the county itself, the study also provides a foundation to say “Alright how are we going to invest to mitigate long term risk?” Babbott said.