Archie Creek Fire Erosion Threat Assessment/Reduction Team (ETART) Extended Report December 2020 ETART Extended Report – Archie Creek Fire This page intentionally left blank. DR-4562-OR | EROSION THREAT ASSESSMENT/REDUCTION TEAM ETART Extended Report – Archie Creek Fire Table of Contents Executive Summary ................................................................................................................... 1 1. Overview .................................................................................................................................. 3 1.1. Burned Area Characterization ........................................................................................ 3 1.2. Post-fire Watershed Condition ........................................................................................ 8 2. Risk Assessment and Recommendations ............................................................................ 12 2.1. Human Life and Safety Summary ............................................................................... 12 2.2. Property Summary ........................................................................................................ 15 2.3. Natural Resources Summary ....................................................................................... 20 2.4. Cultural Resources Summary ...................................................................................... 26 3. Monitoring and Management Recommendations ............................................................... 27 3.1. Watershed Response and Hydrologic Analysis - Monitoring Recommendations ..... 27 3.2. Geologic Hazards - Management Recommendations................................................ 28 3.3. Road Management Recommendations ...................................................................... 28 3.4. Fish/Aquatic Habitat - Management Recommendations and Monitoring ................ 29 Resource Reports.................................................................................................................... 30 1. Weeds Specialist Report...................................................................................................... 30 1.1. Summary ....................................................................................................................... 30 1.2. Resource Condition and Setting .................................................................................. 30 1.3. Assessment Methodology - Field Evaluations and Modeling .................................... 32 1.4. Results of Field Work and Modeling ........................................................................... 32 1.5. Risk Assessment .......................................................................................................... 38 1.6. Recommended Response Actions .............................................................................. 39 1.7. Best Management Practices Recommendations ....................................................... 43 1.8. Recommended Monitoring .......................................................................................... 43 1.9. References .................................................................................................................... 44 2. Engineering Report .............................................................................................................. 45 2.1. Objectives ..................................................................................................................... 45 2.2. Values at Risk............................................................................................................... 45 DR-4562-OR – December 2020 i ETART Extended Report – Archie Creek Fire 2.3. Observations ................................................................................................................. 46 2.4. Reconnaissance Methodology and Results ............................................................... 46 2.5. Findings ........................................................................................................................ 47 2.6. Recommendations ...................................................................................................... 48 2.7. References ................................................................................................................... 50 3. Heritage and Cultural Resources ......................................................................................... 51 3.1. Setting ........................................................................................................................... 51 3.2. Background .................................................................................................................. 52 3.3. Critical Values and Proposed Treatment for Cultural Resources on NFS lands under BAER. ............................................................................................................................ 54 3.4. Assessment Methodology ........................................................................................... 54 4. Soil Resources ..................................................................................................................... 56 4.1. Summary ...................................................................................................................... 56 4.2. Resource Condition and Setting .................................................................................. 57 4.3. Assessment Methodology ........................................................................................... 59 4.4. Findings ........................................................................................................................ 60 4.5. Risk Assessment .......................................................................................................... 63 4.6. Recommendations ...................................................................................................... 63 5. Hydrology Resources ........................................................................................................... 65 5.1. Summary ...................................................................................................................... 65 5.2. Critical Values ............................................................................................................... 66 5.3. Resource Condition and Setting ................................................................................. 66 5.4. Risk Assessment .......................................................................................................... 68 5.5. Assessment Methodology – Field and Modeling ........................................................ 69 5.6. Findings ......................................................................................................................... 70 5.7. Recommendations ....................................................................................................... 74 5.8. References ................................................................................................................... 75 6. Geologic Hazards ................................................................................................................. 76 6.1. Introduction .................................................................................................................. 76 6.2. Assessment Methodology ........................................................................................... 79 6.3. Findings ........................................................................................................................ 80 DR-4562-OR – December 2020 ii ETART Extended Report – Archie Creek Fire 6.4. Recommendations ...................................................................................................... 81 6.5. Mitigation and Further Evaluation .............................................................................. 83 6.6. References ................................................................................................................... 84 7. Hazard Trees ........................................................................................................................ 87 7.1. Objectives ..................................................................................................................... 87 7.2. Danger/Hazard Trees Described ................................................................................ 87 7.3. Recommendations ...................................................................................................... 91 7.4. Danger Tree Guidelines ............................................................................................... 94 7.5. References ................................................................................................................. 101 8. Fish and Wildlife Resources .............................................................................................. 104 8.1. Objectives ................................................................................................................... 104 8.2. Assessment Methodology (field and modeling) ...................................................... 104 8.3. Resource Setting ........................................................................................................ 104 8.4. Critical Values, Results, Risk Assessment, and Recommended Response Actions