Table : Summary of Alluvial Fan Analyses Drainage Date Area above Analysis Location Location Apex Model(s) was Flooding Source From (apex) To (toe) (sq mi) Used Completed Method Description Culvert Creek From apex Highway Geomorphic Data, Post Flood Hazard 24.2 N/A 2005 Fan of fan I-10 Verification, and Historical Information FLO-2D, Mountain Wash Apex of fan Stan Rd 54.5 version 2006 Risk-Based Analysis Fan 2006.07 FLO-2D From apex Tangerine Petal Creek fan 15.8 version 2009 Composite Methods of fan Road 2007.06 Areas identified with historical aerial photos. Apex of N. FAN FAN analysis used for 1% annual chance Fork Valley Creek Fan Maple Ln 44.7 Computer 1993 flood in active areas. HEC-2 4.6 was used in Inundation Program inactive areas, where incised networks and River Fan little risk of avulsion observed. Table : Results of Alluvial Fan Analyses 1% Annual Chance Location Location Peak Flow at Fan Flood Zones Minimum Maximum Flooding Source From (apex) To (toe) Apex (cfs) and Depths (ft) Velocity (fps) Velocity (fps) Culvert Creek Fan From apex of fan Highway I-10 1,750 AO 1-2', AE 1 6 Mountain Wash Fan From apex of fan Stan Rd 2,140 AO 1-3' 2 6 From apex of Petal Creek Fan Tangerine Rd 880 AO 1-3', A 1 7 Petal Creek fan
Table : Summary of Alluvial Fan Analyses Flooding Source Location From (apex) Location To (toe) Drainage Area above Apex (sq mi) Model(s) Used Date Analysis was Completed Method Description Culvert Creek Fan From apex of fan Highway I-10 24.2 N/A 2005 Geomorphic Data, Post Flood Hazard Verification, and Historical Information Mountain Wash Fan Apex of fan Stan Rd 54.5 FLO-2D, version 2006.07 2006 Risk-Based Analysis Petal Creek fan From apex of fan Tangerine Road 15.8 FLO-2D version 2007.06 2009 Composite Methods Valley Creek Fan Apex of N. Fork Inundation River Fan Maple Ln 44.7 FAN Computer Program 1993 Areas identified with historical aerial photos. FAN analysis used for 1% annual chance flood in active areas. HEC-2 4.6 was used in inactive areas, where incised networks and little risk of avulsion observed. Table : Results of Alluvial Fan Analyses Location From (apex) Location To (toe) 1% Annual Chance Peak Flow at Fan Apex (cfs) Flood Zones and Depths (ft) Minimum Velocity (fps) Maximum Velocity (fps) Flooding Source Culvert Creek Fan From apex of fan Highway I-10 1,750 AO 1-2', AE 1 6 Mountain Wash Fan From apex of fan Stan Rd 2,140 AO 1-3' 2 6 Petal Creek Fan From apex of Petal Creek fan Tangerine Rd 880 AO 1-3', A 1 7
FIS_Report_Template_May_2014.docx