Ross Valley Fire
Fire Hazard Severity Zones
The following presentation will cover:
• California Government Code Requirements
• State and Local Map History
• How Fire Hazard Severity Zones (FHSZ) Are
Determined
• How Does This Affect Your Town?
Fire Hazard Severity Zone Remap Fire Hazard Severity Zones California Government Code Requirements
• California Government Code Section 51179 (a)
mandates that local agencies “shall designate, by
ordinance moderate, high, very high fire hazard severity zones in their jurisdiction within 120 days of receiving recommendations from the State Fire Marshall pursuant
to Section 51178”.
*All required Marin Agencies are currently in this process State and Local Map History
CAL Fire FHSZ Map History
• 1992: CAL Fire published maps that only included Very High Fire Severity Zones in Local responsibility Areas
• 2021: CAL Fire was required to publish maps that not
only includes Very High Severity area but also areas of Moderate and High hazard
State and Local Map History
Local Fire Map History
• 2007: Fairfax Town Council adopted the Wildland-Urban Interface (WUI) map identifying wildfire-prone areas.
Both Maps Side By Side
Fairfax WUI Map New FHSZ Map
Differences from FHSZ and WUI Maps
• The new FHSZ maps include most of the downtown
area, as the WUI maps adopted in 2007 did NOT.
• The new FHSZ maps exclude the Taylor and Rocca
area where the WUI maps included them.
• The new FHSZ maps cover more area than the WUI
maps.
• CAL FIRE used the best available science and data to
develop, and field test a model that served as the basis of zone assignments. The model evaluated the probability of the area burning and potential fire behavior in the area. • There are multiple determining factors to designate a Fire Hazard Severity Zone.
How are FHS Zones Determined? Fire Hazard Severity Zo
New Updates
• Fire History - Burn probabilities based on past fires in the area up to 2020
• Vegetation/Fuel Levels - Intensity/heat produced by available type of vegetation
• Predicted flame length - Length of flame from fuels
• Blowing embers - New firebrand production and transport model using discrete local wind vector distributions
• Localized fire weather - Wind patterns and local weather patterns • Terrain - Lay of the land (hills, valleys, canyons)
What Factors are considered?
Moderate, High, Very High Zones
Results of the scoring factors determine the severity of the hazard zones.
• Very High - Highest hazard area based on consistent statewide criteria and the severity that is expected to prevail in those areas. • High - 40-60% reduction in severity score of Very High criteria. • Moderate - 40-60% reduction in severity score of High criteria.
Fairfax FHSZ Map
● Moderate: Forrest, Meernaa,
parts of Cascade
● High: Scenic, Tamalpais,
Olema
● Very High: No areas
identified
Compared to Neighboring Counties
What do these maps mean to Fairfax?
• Fairfax took a proactive approach in adopting
requirements (fire/building) back in 2007 when the WUI
maps were adopted.
• The new FHSZ map includes additional areas previously not identifies on the WUI maps
• Existing 2007 requirements are now applicable to both the WUI maps and the new FHSZ maps.
• Building standards for new construction in the Fire
Hazard Severity Zones beyond the WUI Zone
(California Building Code Chapter 7A)
• Defensible Space Requirements (Government Code
51182)
• Vegetation Management Plans (California Fire Code
Chapter 49)
• Natural hazard real estate disclosure (High Hazard)
Fire Hazard Severity Zone Remap Fairfax Requirements
Fire Insurance Effects
Ricardo Laura, Insurance Commissioner (California Department Of Insurance):
“CAL FIRE’s maps are intended to drive local planning decisions, not insurance decisions. Under Commissioner Lara’s new regulation finalized in October 2022, insurance companies must provide discounts for wildfire safety actions such as community mitigation and home-hardening, which CAL FIRE’s maps do not assess. In addition, insurance companies are already using risk analysis tools and models that go beyond CAL FIRE’s proposed maps in determining what properties they will
underwrite.”
Help us help YOU!
• Defensible Space/Zone 0
• Home Hardening
• Evacuation Ready
It’s time for YOU to adapt to living in a Wildfire Environment! Firesafemarin.org
Questions?
osfm.fire.ca.gov/fhsz