LRA Legislation Factsheet - Flipbook combined - Flipbook - Page 5
FHSZ Frequently Asked Questions
General
What are the key elements of the Fire Hazard Severity Zone model?
The fire hazard severity model for wildland fire has two key elements: probability of an area
burning and expected fire behavior under extreme fuel and weather condi琀椀ons. The zones reflect
areas that have similar burn probabili琀椀es and fire behavior characteris琀椀cs. The factors considered
in determining fire hazard within wildland areas are fire history, flame length, terrain, local
weather, and poten琀椀al fuel over a 50-year period. Outside of wildlands, the model considers
factors that might lead to buildings being threatened, including terrain, weather, urban vegeta琀椀on
cover, blowing embers, proximity to wildland, fire history, and fire hazard in nearby wildlands.
FHSZs are not a structure loss model, as key informa琀椀on regarding structure igni琀椀on (such as roof
type, etc.) is not included.
Where do Fire Hazard Severity Zones apply?
Fire Hazard Severity Zones are found in areas where the state has financial responsibility for
wildfire protec琀椀on and preven琀椀on, called the State Responsibility Area. More than 31 million
acres are in this area. Under Senate Bill 63 (Stern, 2021) Government Code 51178 was amended to
also iden琀椀fy the Moderate and High Fire Hazard Severity Zones with the Very High in Local
Responsibility Area (LRA).
What are the uses of Fire Hazard Severity Zones?
The zones are used for several purposes including to designate areas where California’s defensible
space standards and wildland urban interface building codes are required. They can be a factor in
real estate disclosure, and local governments may consider them in their general plan.
When were the maps last updated?
In 2007, CAL FIRE updated the FHSZs for the en琀椀re State Responsibility Area (SRA). Between 20082011 the department worked with local governments to make recommenda琀椀ons of the Very High
Fire Hazard Severity Zones within Local Responsibility Area (LRA).
Why are fire hazard severity maps being updated?
The hazard maps are being updated to more accurately reflect the zones in California that are
suscep琀椀ble to wildfire. The hazard mapping process will incorporate new science in local climate
data and improved fire assessment modeling in determining hazard ra琀椀ngs.
