Wildfire, Rain and Floods: A case study of the June 2010 Schultz Wildfire, Flagstaff, Arizona

Ann Youberg, ARIZONA GEOLOGICAL SURVEY, Tucson
Karen Koestner and Dan Neary - Rocky Mountain Research Station, Flagstaff

Introduction

The summer of 2010 brought wildfires and near record monsoon rains to the San Francisco Peaks near Flagstaff, Arizona. The human-caused Schultz Fire on the Coconino National Forest northeast of Flagstaff (Figure 1) was the largest wildfire in Arizona during 2010 (www.inciweb.org). Ignited by an abandoned campfire on June 20th at Schultz Tank and Elden Trail, the Schultz Fire burned hot and fast (http://inciweb.org/incident/1996/). High winds quickly drove the blaze across the steep eastern slopes of the San Francisco Peaks: approximately 60% of the total 15,075 acres (23.5 sq mi) burned that first day (Figures 2 and 3; U.S. Forest Service, 2010). Over a thousand residents from nearby housing developments were evacuated, but no structures were directly impacted. By the time the fire was 100% contained on June 30th, the assessment of damages and preparation for monsoon rains was well underway. Following the fire, heavy rains from the 4th wettest monsoonon record in Flagstaff resulted in numerous debris flows, significant erosion, and substantial flooding of the residential areas below. While debris flows were confined to the forest upslope of residential neighborhoods, multiple sediment and ash-laden floods caused extensive damage to homes, property and infrastructure up to 4 miles from the burn. There were no fatalities from the fire itself, but a 12-year old girl was tragically killed in a flash flood in her neighborhood on the afternoon July 20th.

Figure 1. Location map of Schultz Fire (orange outline)
northeast of Flagstaff, Arizona.

Figure 2. Schultz Fire Progression Map.
Data from Coconino National Forest.

Figure 3. View of the Schultz Fire on June 24. The white almost horizontal line on the steep slopes
is FR146 (waterline). Timberline Estates in the foreground. Photo: D. Fleishman, USFS.

 

1 2 3 4 5 6

 

ARTICLE AUTHORS:
Ann Youberg, Research Geologist, Arizona Geological Survey
ann.youberg@azgs.az.gov

Karen Koestner, Research Hydrologic Technician, Rocky Mountain Research Station, Flagstaff
kkoestner@fs.fed.us

Dan Neary, Research Soil Scientist and Southwest Watershed Team Leader, Rocky Mountain Research Station, Flagstaff
dneary@fs.fed.us














Arizona Geology is published by the Arizona Geological Survey. | © The Arizona Geological Survey, 2011. All Rights Reserved.
Editor: Michael Conway