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Coconino County Assessment of Post-Wildfire Debris-Flow and Flood Hazards JOE LOVERICH, PE, CFM JE FULLER/HYDROLOGY & GEOMORPHOLOGY, INC.
Coconino CountyAssessment of Post-Wildfire Debris-Flow and Flood Hazards
JOE LOVER I CH, PE , CFM
JE FULLER /HYDROLOGY & GEOM OR PHOLOGY, I N C.
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS2
Acknowledgements
Coconino County
JE Fuller
Arizona Geological Survey
City of Williams
Kaibab National Forest
Cooperating Technical Partner
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS3
Post Fire Risk1. What?
2. Where?
3. How Bad?
4. WHAT NOW?
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS4
What?
Debris-Flows
HyperconcentratedFlows / Flooding
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS5
Schultz Fire
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS6
Where?
Debris Flow Initiation ZoneSlopes 15o to 40o
Debris Flow Deposition Zone
Slopes >5o
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS7
Debris-Flow Risk Corridors
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS8
Pilot Area Debris Flow & Flood Risk
Pilot Areas • Fort Valley•Williams
1. Field investigation
2. Debris flow modeling
3. 2-Dimensional flow modeling• Existing Conditions
• Post-Fire with Forest in its Current Condition
• Post-Fire with Forest in Healthy (Treated) Condition
Williams Fort Valley
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS9
Williams Flood
Results
1200 1200400
6100
3400 340031002500
2000
Cataract at Oak Cataract at Sewer Plant Cataract Downstream City Dam
Williams 100-Year Discharge (CFS)Pre Fire Post Fire (Non Treated) Post Fire (All Treated)
8X3X5X
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS10
Williams Flood
Results Downtown Buildings Impacted with >1' Flooding
Event Pre-FirePost-fire No
Treatment
Post-fire All
Treated
2-Year 26 117 34
10-Year 41 268 105
100-Year 147 515 318
Critical Facilities Impacted with >1' Flooding
Event Pre-FirePost-fire No
Treatment
Post-fire
Treated
2-Year 1 4 1
10-Year 1 7 4
100-Year 4 14 8
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS11
Williams 100-Year
Risk Zones
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS 12
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS 13
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS14
Mitigation Strategies
Mitigation
Forest Health
Infrastructure
Emergency Planning
Flood Warning
Collaboration is Key!
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS15
Emergency Action Plan
No Significant Warning Time
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS16
Reservoir Management Plan
Joe Loverich, PE, CFM
JE Fuller/Hydrology & Geomorphology, Inc.
www.jefuller.com
6/21/2018COCONINO COUNTY ASSESSMENT OF POST-WILDFIRE FLOOD AND
DEBRIS-FLOW HAZARDS17
Questions?
