Fuels Treatment Effectiveness 2008 Grass Valley Fire
Executive Summary
The Grass Valley Fire started at approximately 0508 on October 22, 2007 in the mountains of the San Bernardino National Forest in Southern California about 60 miles east of Los Angeles. Weather conditions were warm and dry. Santa Ana winds (strong, dry winds) had been blowing for two days. Live vegetation and dead fuels were very dry.
The fire spread to the south through wildland fuels and then transitioned to urban structural fuels where it destroyed or damaged approximately 199 structures. U.S. Forest Service, state, and local firefighters responded immediately after the initial report. Most of the final fire area burned on the first day. The fire was contained on the 26th of October. According to firefighters, suppression actions were substantially enhanced by fuel treatments in and adjacent to the fire.
A team was formed to assess effects of fuel treatments on:
• Fire behavior • Fire effects • Structure ignition • Fire suppression • Public safety and egress • Fire behavior in fuel treatment areas was less rapid and less intense than in adja¬cent untreated wildland fuel and urban-structural fuel. The reduced spread rate and intensity allowed suppression forces to concentrate on protecting structures and on preventing additional fire spread to the south. • Fuel treatments improved visibility enabling firefighters to engage the fire directly in places and to protect homes without jeopardizing their safety. • The Mountain Area Safety Task Force coordinates hazard reduction efforts of all the organizations and agencies manag¬ing land, infrastructure, and emergency response in the Lake Arrowhead area. Their efforts greatly enhanced the safe evacuation of thousands of people due to previous dead tree removal. Removal of these dead trees reduced the amount of tree fall in roadways along main routes and also reduced ember production and associated spot fires. • The Grass Valley Fire burned more in¬tensely within the residential area than in adjacent wildland fuels. Mass ember pro¬duction from structures ignited adjacent and downwind structures in many cases.
