Scientific research and tools to support management and protection of water supplies from the effects of wildfires

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Scientific research and tools to support management and protection of water supplies from the effects of wildfires Deborah A., Martin, U.S. Geological Survey

1 Scientific research and tools to support management and protection of water supplies from the effects of wildfires Deborah A., Martin, U.S. Geological Survey Managing for Uncertainty and Climatic Variability: Post-fire Flooding and Extreme Precipitation Workshop Las Vegas, Nevada September 22-23, 2014 Photo: John Moody, USGS

2 Strontia Springs Reservoir near Denver, Colorado July 1996 Photo: John Moody, USGS

3 Why are we here? What is the scope of the issue? GIS analysis: Ann Youberg AZ Geological Survey

4 Review of key concepts presented by Chi Ho: Fire or burn severity: organic matter loss Magnitude of the effects of severity on soil a function of: Fuel properties Fire behavior Soil moisture Soil texture and properties Timing, magnitude, duration and location of storms after wildfire Landscape susceptibility

5 Burn Severity Mapping

6 GROUND COVER Burn Severity: Surface and Soil Parsons et al., 2010 Low severity: Little change <50% litter consumption Needles and leaves intact Soil structure unchanged SOIL STRUCTURE Moderate severity: Up to 80% litter consumption Needles and leaves recognizable or leaf/ needle fall Soil structure slightly altered High severity: <20% remaining ground cover Nearly all litter and duff consumed Little to no leaf or needle fall to shield ground Soil structure reduced or destroyed

7 Sequence of rainstorms is important! Colorado 1996 Buffalo Creek Fire First large storm New Mexico 2000 Cerro Grande Fire First large storm

8 Rainfall intensity is key! (in western United States) Threshold at ~0.5 inch/hr I 30 Source: Moody, An analytical method for predicting post-fire peak discharge.

9 Hydrologic response depends on footprint of storm over burned area 13 July August Buffalo Creek Fire

10 Landscape susceptibility 2005 Harvard Fire near Burbank, CA Photo: John Moody, USGS

11 Research, Tools and Planning Pre-Fire Fire Post-Fire

12 Research, Tools and Planning Pre-Fire Fire Post-Fire Establish communication and collaborations Identify Values at Risk and threats e.g. WFDSS, SWAP, Contingency planning e.g. CDPHE recommendations Identify potential for post-fire response (Cont.)

13 Identify Values at Risk e.g. WFDSS: Wildland Fire Decision Support System Where are your intakes and diversion? Where are critical watersheds or infrastructure? What are your access routes? Are there other values at risk?

14 Guidance from CDPHE

16 Wildfire Impacts on Water Supplies and the Potential for Mitigation Source: Emelko and Sham, 2014.

17 Wildfire Impacts on Water Supplies and the Potential for Mitigation Source: Emelko and Sham, 2014.

18 Identify potential for post-fire response Grand Lake, CO Tree mortality, high-risk slopes, and structure locations

19 USGS Colorado Water Science Center

20 Research, Tools and Planning Pre-Fire Fire Post-Fire (Continued) Identify legacies of previous land use e.g. mining Fuel management Plan for new infrastructure, extreme weather, and climate change: resiliency and redundancy

21 Identify legacies of previous land use: e.g. mining Photo: Claire DeLeo

22 Plan fuel management based on research! Source: Ager et al., 2013; Figure 10

23 Plan for new infrastructure, extreme weather, and climate change: resiliency and redundancy

24 Research, Tools and Planning Pre-Fire Fire Post-Fire Communicate with Incident Command Team Monitor intakes, diversions, infrastructure

25 Research, Tools and Planning Pre-Fire Fire Post-Fire Participate on BAER Teams Apply post-fire stabilization measures Monitor rain predictions Be prepared to shut intakes and diversions After careful analysis, install sediment retention basins etc.

26 Most common post-fire stabilization technique: Mulching

Scientific basis for mulching: Restore surface cover Source: Ebel, 2012 Changes Interception - Canopy - Litter Storage - Canopy/litter - Soil Infiltration

27 Scientific basis for mulching: Restore surface cover Source: Ebel, 2012 Changes Interception - Canopy - Litter Storage - Canopy/litter - Soil Infiltration rates - Clogging (fines) - Structure loss - Roughness Before fire Before fire After fire After fire litter organic rich soil mineral soil ash ash/soil mineral soil

28 Sediment Yield Post-fire Action:? Install sediment basins? Sediment Yield after Wildfire Fire-Induced Accelerated Sediment Yield Baseflow Sediment Yield FIRE TIME After Swanson, 1981

29 Sediment Yield Punctuated Sediment Supply (Benda and Dunne, 1997 a,b) Also called pulsed disturbance FIRE FIRE FIRE TIME After Swanson, 1981

30 Fire-Flood Frequency Buffalo Creek Watershed in Colorado ~100 years BP ~950 years BP ~1,020 years BP ~1,030 years BP ~1,970 years BP ~2,900 years BP Photo by Bob Meade Elliott and Parker, 2001

31 Research, Tools and Planning Pre-Fire Fire Post-Fire Establish communication and collaborations Identify Values at Risk e.g. WFDSS, SWAP Contingency planning e.g. CDPHE recommendations Identify potential for post-fire response Etc. Communicate with Incident Command Team Monitor intakes, diversions, infrastructure Participate on BAER Teams Monitor rain predictions Be prepared to shut intakes and diversions After careful analysis, install sediment retention basins etc.

32 A few more thoughts..

33 A few more thoughts..

36 ALWAYS!

37 Questions? Many thanks!

38 References Ager, A.A., Vaillant, N.M., McMahan, A Restoration of fire in managed forests a model to prioritize landscapes and analyze tradeoffs. Ecosphere 4(2)29. http//dx.doi.org/ /es Ebel, B.A., 2012, Impacts of wildfire and slope aspect on soil temperature in a mountainous environment Vadose Zone Journal, v. 11, vzj Emelko, M., Sham, C.H., Wildfire Impacts on Water Supplies and the Potential for Mitigation Workshop Report. Canadian Water Network and Water Research Foundation, 25 p. Available at http// rce.ca/assets/resources/pdf/wildfire-impacts-on-water-supplies-and-the- Potential-for-Mitigation_Workshop-Report.pdf Milly, P.C.D., Betancourt, J., Falkenmark, M., Hirsch, R.M., Kundzewicz, Z.W., Lettenmaier, D.P., and Stouffer, R.J., 2008, Stationarity is dead Whither water management? Science, v. 319, p DOI /science

39 References Moody, J.A., An analytical method for predicting postwildfire peak discharges U.S. Geological Survey Scientific Investigations Report , 36 p. Available at http//pubs.er.usgs.gov/publication/sir Parsons, A., Robichaud, P.R., Lewis, S.A., Napper, C., Clark, J.T., Field guide for mapping post-fire soil burn severity. General Technical Report RMRS-GTR-243. Fort Collins, CO U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 49 p. Available at http//

40 Resources

Landslide Hazards: A Stealth Threat to the Nation

Landslide Hazards: A Stealth Threat to the Nation Sponsored by the Geological Society of America Association of Environmental & Engineering Geologists American Society of Civil Engineers In Cooperation