Description: The data are derived from the following sources:CalFire Watershed Emergency Response Team (WERT) “Values At Risk” report for the Holy Fire burn area and ongoing communication with team members. California Geological Survey (CGS) identification of hazard areas based on field review, peer review of this exhibit and communications regarding findings of their ongoing assessments of debris runout potential.United States Forest Service’s (USFS’s) Burn Area Emergency Response (BAER) team report and ongoing communication with team members.State of California Department of Water Resources (DWR) Awareness Floodplain Map:These 1%-annual chance floodplains were developed using approximate methods. Base flood elevations, depths, and velocities are not available. Flood insurance is available by FEMA through the National Flood Insurance Rate program. These are not FEMA flood hazard areas, therefore, flood insurance is not mandatory in DWR floodplains. FEMA Mapped Floodplain Zones: The referenced zones utilized for risk mapping are Zones A, AE, AE Floodway (1 percent annual chance flood) and X (0.2 percent annual chance flood) to determine the limits of potential inundations. These risk zones are shown on Flood Insurance Rate Map (FIRM) databases published by the Federal Emergency Management Agency (FEMA), and any Letters Of Map Revision (LOMRs) that have been issued against those databases since their publication date. The FIRM Database is the digital, geospatial version of the flood hazard information shown on the published paper FIRMs. The FIRM Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual-chance flood event, and areas of minimal flood risk. The FIRM Database is derived from Flood Insurance Studies (FISs), previously published FIRMs, flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by FEMA. Each State or Territory data set consists of all FIRM Databases and corresponding LOMRs available on the publication date of the data set. Coordination with CalTrans hydraulic and geology staff regarding their assessment of debris flow hazards impacting state highways.Communications with Riverside County Sheriff, CalFire, Emergency Management Department staff regarding historic flooding and debris issues that they have observed.Rapid assessments by the Riverside County Flood Control and Water Conservation District, Riverside County Geologist, Riverside County Transportation Department, City of Lake Elsinore and other local agencies using available models, topography, field assessments, historic records, historic photography, review of available reports and consultation with expert teams referenced above, and other tools to delineate approximate debris and mud flow hazards downstream of the burn areas. Hazards were broadly characterized as follows:High risk– These areas are also at risk for flooding and debris flows from waterways, as well as localized falling rocks, mud flows, debris flows and landslides. Properties facing the greatest threat are those near creek channels or steep slopes. Even if not directly impacted, properties in the high-risk areas experience significant impacts, including road closures and disruptions to utilities.Extreme risk: - These areas are within known floodplains, flood risk zones or debris risk zones. Properties within these areas are at extreme threat of damage or destruction should a flood, mud or debris flow start in the local streams.
Definition Expression: N/A
Copyright Text: RCFC&WCD, County of Riverside, City of Lake Elsinore, State of California – CalTrans, Department of Water Resources, FEMA, United States Forest Service (USFS), California Geological Survey (CGS), CalFire Watershed Emergency Response Team (WERT)