Appendix D - Three Tier Analysis Criteria

El Dorado County Community Wildfire Protection Plan (CWPP)
 
 

DELINEATE THREAT ZONES

Threat Zones are Community Regions and Rural Centers within 1 1/ 4 miles of continuous wildland fuels equally threatened by a wildfire burning under average worst fire weather conditions. Examples would be Coloma & Lotus, Diamond Springs & El Dorado, the City of Placerville, Mosquito, the Sly Park Lake communities, etc.

ASSESS THE MAGNITUDE OF THE THREAT

Those Threat Zones within the Very High Fire Hazard Severity Zone constitute the top tier. Those within the High Hazard Severity Zone are placed within the second tier and those within the Moderate Fire Hazard Severity Zone are in the lowest tier.

Using historical fire records and current risk analyses, determine points where ignitions are likely. Utilizing weather parameters from Fire Planning Rerap Tables and a fire behavior prediction system ( i.e., BEHAVE, Spread Tables, etc.), calculate the rate of spread for fires burning under average worst ( 10% of the highest fire danger days per decade) weather and fuel conditions. Threat Zones in areas where Rates of Spread exceed 2 miles per hour rank in the top tier, 1 mile per hour or greater to the second tier and less than 1/2 mile per hour are in the lowest tier.

Determine the First Run Damage Potential expressed in numbers of structures to be defended (fire apparatus committed, etc.) or which are likely to be lost. 20 or more should be ranked in the first tier, 10 or more in the second, less than 10 in the third.

DETERMINE DEFENSIBILITY OF COMMUNITIES

Establish Community Defense Zones 1/ 4 mile from communities. Rank defense elements.

1. Access. Simultaneous egress of residents and ingress of fire suppression resources with through roads, two ways in and out, adequate passing and turnaround opportunities with roadside vegetation clearance shall be ranked in the lowest tier. Adequate access which allows resident evacuation and suppression resource with passing and turnaround opportunities but not necessarily through roads should be placed in the second tier. Narrow roads, dead end roads, poor passing and turnaround opportunities and inadequate or no roadside vegetation clearance shall be placed in the top tier.
    
   
2. Fire Support Infrastructure. Water supplies which meet NFPA 13 water flow requirements within 1/4 mile of threatened structures shall be placed in the lowest tier. Onsite water storage which meets NFPA 1142 requirements shall be in the second tier. Water which must be supplied via water tenders shall place the defenses in the top tier.
    
   
3. Defensible Space. AII elements of Defensible Space within a Community Defense Zone ( 1/4 mile ) from structures as described in SRA Fire Safe Regulations Title 14 are in place and are maintained ranks the community in the lowest tier.

Community Defense Zones where Defensible Space elements are only partially applied or are poorly maintained shall be in the second tier. Community Defense Zones where most structures fail to meet items in the Structural Assessment Checklist in the Incident Response Pocket Guide shall be placed in the top tier.

EVACUATION. SHELTERS AND STAGING

Evacuation. Communities with a well developed Evacuation Plan, established evacuation routes and has established shelters for evacuees shall be ranked in the lowest tier. Communities where evacuation is implemented upon immediate needs absent a formal plan but which has adequate egress and established staging areas (golf courses, athletic fields, etc.) shall be ranked in the second tier. Communities where evacuation would be difficult, with few or no staging areas shall be placed in the top tier.

IMPEDIMENTS TO DEFENSE

Vegetation. Communities with established and maintained fuel modification zones (fuelbreaks, fuel modification zones, etc.) roadside vegetation clearance and which have fuel modification at most or all structures shall be placed in the lowest tier. Communities with managed open space, roadside hazard reduction, and many, if not most, structures with adequate vegetation clearance should be placed in the second tier. Communities which have poor roadside hazard reduction, few structures with adequate vegetation clearance shall be placed in the top tier.

Fire Safe Plans. Communities with Fire Safe Plans prepared by qualified fire planning professionals under one or more WUI or National Fire Plan Grants should be placed in the lowest tier.

THE COMMUNITY PROTECTION PLAN

Each community should prepare an action plan which provides for resolving the inadequacies that have been identified. The what, where, why when and how of needed actions should be documented, costs identified and a Community Action Plan Grant application prepared and submitted to the Fire Safe Council who will assign priorities based upon the foregoing analysis. Those communities at greatest risk for losses from wildfire (in the highest tiers) shall be given the highest priority.

A committed representative administrative body which has wide community support places a community in the top tier for consideration for Community Protection Planning Grants.