Steep Slope Forest Restoration
This project is a collaboration between Coconino County, the National Forest Foundation, the Arizona Department of Forestry & Fire Management, the Kaibab National Forest and private partners. The goal of the project is to reduce the threat of catastrophic wildfire and post-wildfire flooding while keeping communities safe.
The Bill Williams Mountain Watershed, located south and uphill from The City of Williams’ cultural, tourist, retail, residential and governmental core, is the watershed heavily used for outdoor recreation including a ski area, residential housing and summer camps. It is also unnaturally dense with ponderosa pine and mixed-conifer forests and characterized by steep slopes, making this area vulnerable to intense catastrophic wildfire and post-wildfire flooding.
A Northern Arizona Alliance Bank Economic Policy Institute Study commissioned in 2018 estimates that the economic impact from a catastrophic wildfire and the post-wildfire flooding in the Bill Williams Mountain watershed (City of Williams and downstream) is between $379 million and $694 million. A 2018 study conducted by J.E. Fuller Hydrology and Geomorphology, at the direction of the County’s Flood Control District concluded that the City of Williams will sustain severe damage from flooding and debris flows if Bill Williams Mountain burns and the report recommended the development of a pre-disaster plan, which will identify ways to reduce the impacts of the flooding on residences, businesses and infrastructure like roads and utilities. The Forest Service has identified the Bill Williams Mountain Restoration project as one of nine high priority partner projects in the 2021 4FRI Restoration Strategy.
Post-wildfire flooding models suggest that a moderate monsoon rain event following a wildfire would lead to flooding that could cover the City of Williams in up to six feet of floodwater and debris. Such an inundation would shut down Interstate-40 and the BNSF railroad, close the Grand Canyon Railway indefinitely, destroy infrastructure and cause irreparable damage to much of downtown Williams. Coconino County has identified fire and post-wildfire flooding to be the number one health and safety threat to the citizens of the County.
With a combined effort of the Forest Service and our partners, the Kaibab National Forest is collaboratively working on the Bill Williams Steep Slope project to protect communities, critical infrastructure, watersheds, habitats, and recreational areas.
Protecting our communities
If catastrophic wildfire does occur prior to significant restoration treatments being completed, the important opportunity would be lost to mitigate fire and post-fire impacts such as severe flooding that would devastate the City of Williams and its water supply. This project reduces the risk of unnaturally severe fire and post wildfire flooding. This significant investment in restoration will help reduce the chances of a costly, compound catastrophe of fire and flooding.
Continued treatment of the Bill Williams Mountain area is a top priority for the Kaibab National Forest, community and partners. These treatments will significantly alter fire behavior by removing the majority of small trees and downed material, or “ladder fuels,” thereby reducing the likelihood of crown fires. If a fire were to ignite in this area after treatment, then the Kaibab National Forest will have a significantly better chance of suppressing it and reducing potential severity.
We saw this on the Bill wildfire in 2022. Lightning struck and started this wildfire in a thinned steep slope area on the north aspect of Bill Williams Mountain. The restoration work that had been completed made it possible for firefighters to access the area quickly and with minimal risk. With the reduction of ladder fuels and improved access to the area, they were able to effectively build line around the fire and stop its growth at 3/10th of an acre. This fire was out within a couple of days.
Getting work done
Treatments are strategically placed to provide buffers from high-probability fire start zones, predominant wind directions, and areas that won’t be thinned, such as Mexican
spotted owl core habitat. Treating fuel accumulations will help abate fire risks on roughly 8,000 acres of Mexican spotted owl habitat. Nearly 100% of steep slope treatments occur within Mexican spotted owl habitat.
Hazardous fuels reduction on steep slopes requires technical operations with specialty equipment that is not commonly used nor readily accessible in the Southwest. Cost per acre is extremely high for this type of work.
To date, approximately 466 steep slope-acres have been treated at a cost of $5.7 million. Since the signing of the decision for the Bill Williams Restoration Project in December 2015, the Kaibab National Forest and its partners have completed several forest restoration efforts within the 15,200-acre project footprint. These efforts include, roughly, 2,500 acres of mechanical treatment off steep slopes with another 1,300 acres planned, 2,500 acres of hand thinning with 2,000 acres off steep slopes where piles can be accessed and burned subsequent to hand thinning, and 466 acres on steep slopes where material is yarded off the mountain by helicopter.
The Kaibab National Forest values our partners and their efforts to expand work to implement on the ground treatments and leverage funding to meet the needs of this important work.
For more photos & videos check out the Bill Williams Mountain restoration Flickr collection.