City Council Memorandum
TO: HONORABLE MAYOR AND CITY COUNCIL DATE: MAY 20, 2025 FROM: FIRE DEPARTMENT WARDS: ALL
SUBJECT: AMENDMENT OF ORDINANCE SECTION 16.32.365 OF THE RIVERSIDE MUNICIPAL CODE REGARDING THE ADOPTION OF MODERATE, HIGH, AND VERY HIGH FIRE HAZARD SEVERITY ZONES ISSUE:
Introduce and subsequently adopt an ordinance to amend section 16.32.365 of the Riverside Municipal Code regarding the adoption of the Moderate, High, and Very High Fire Hazard Severity Zones recommended by the Office of the State Fire Marshal.
RECOMMENDATIONS:
That the City Council:
Introduce and subsequently adopt an ordinance to amend section 16.32.365 of the Riverside Municipal Code to include the new Moderate, High, and Very High Fire Hazard Severity Zones.
LEGISLATIVE BACKGROUND
The foundation for Fire Hazard Severity Zone (FHSZ) classifications in Local Responsibility Areas (LRA) was established through Assembly Bill (AB) 337, also known as the "Bates Bill", enacted in response to the catastrophic 1991 Oakland Hills Fire. This landmark legislation directed the Office of the State Fire Marshal (OSFM) to identify Very High Fire Hazard Severity Zones (VHFHSZ) within LRAs and provide recommendations to local jurisdictions for formal adoption.
Between 2008 and 2011, CAL FIRE collaborated with local agencies to map and designate VHFHSZs across LRAs. Local governments were then required to adopt these designations by ordinance, while retaining the authority to implement stricter local fire safety standards as needed.
For many years, only Very High Fire Hazard Severity Zones were required to be designated within LRAs. However, with the passage of Senate Bill (SB) 63 in 2021, the State significantly expanded the scope of wildfire hazard planning by mandating the identification of Moderate and High Fire Hazard Severity Zones, in addition to the existing Very High designation. This marked a critical policy shift aimed at addressing wildfire risk in a broader range of environments, including areas not previously classified as high risk.
Subsequently, Assembly Bill (AB) 211 in 2022 and the resulting updates to Government Code section 51179 reinforced these requirements. Under current law, local jurisdictions must formally adopt all three FHSZ classifications—Moderate, High, and Very High—by ordinance within 120 days of receiving official recommendations from the Office of the State Fire Marshall (OSFM).
In the City of Riverside, Section 16.32.365 of the Riverside Municipal Code (RMC) currently addresses the designation, locations, and boundaries of VHFHSZs. These areas are reflected in the General Plan 2025, Public Safety Element, as part of the City's long-term hazard mitigation and land use planning efforts.
BACKGROUND:
The classification FHSZ in California has evolved over the past several decades as the State has responded to the growing threat of wildfires. Developed by the OSFM in collaboration with local jurisdictions, the FHSZ framework provides a standardized method for identifying and classifying areas based on their long-term wildfire hazard potential.
FHSZ designations are based on the probability of wildfire occurrence and the projected fire behavior over a 30- to 50-year period. These zones are determined using a combination of factors, including:
Vegetation and fuel loading
Topography and terrain
Fire weather patterns
Historical fire activity
Wind and ember transport dynamics
This scientific, data-driven approach supports consistent wildfire planning and mitigation efforts across the state.
On March 24, 2025, the OSFM released updated FHSZ maps impacting the City of Riverside. In accordance with Government Code section 51178.5, the City responded by publishing the maps on its website the following day, March 25, 2025. The maps were made available in an accessible, user-friendly format, enabling the public to search individual parcels to determine their designated fire hazard severity zone.
To promote community engagement and transparency, the City also launched an online public comment feature and hosted a Fire Hazard Severity Zone Public Review and Workshop during the City Council meeting on April 8, 2025. The workshop included a formal presentation of the updated maps and provided an opportunity for additional public input.
These efforts ensured the City remained in full compliance with Government Code section 51178.5, which requires local agencies to make updated FHSZ information available for public review and comment within 30 days of receiving the State’s transmittal.
DISCUSSION:
The adoption of an ordinance designating Moderate, High, and Very High FHSZ within the City of Riverside is a required step to ensure compliance with Government Code section 51179. Per Section 51179(a), "A local agency shall designate, by ordinance, moderate, high, and very high fire hazard severity zones in its jurisdiction within 120 days of receiving recommendations from the State Fire Marshal pursuant to Section 51178." The OSFM released updated FHSZ maps affecting the City of Riverside on March 24, 2025, triggering the City’s 120-day deadline to adopt the ordinance.
In accordance with Government Code section 51179 and the scientific methodology employed by CAL FIRE and the OSFM, the City has limited authority to modify the State’s designations. Specifically, local agencies may not decrease the level of fire hazard severity assigned by the State Fire Marshal. However, they may choose to elevate severity zones or include additional areas not identified by the State, provided such changes are supported by substantial evidence. This provision ensures alignment with the State’s data-driven wildfire risk assessments.
The latest FHSZ maps incorporate enhanced scientific modeling, updated climate data, and modern wildfire behavior analysis to provide a more accurate depiction of risk—particularly in wildland-urban interface (WUI) areas where ember cast, topography, and vegetation density heighten fire hazards.
For local governments, these classifications have several important implications:
Building Code Requirements: New construction within High and Very High FHSZs must comply with California Building Code Chapter 7A, which outlines wildfire-resistant building standards.
Defensible Space: Property owners in the Very High Severity Zone must maintain 100 feet of defensible space around structures, per Government Code section 51182.
Land Use and Planning: Cities are required to integrate FHSZ designations into General Plans, zoning ordinances, and emergency response frameworks.
Real Estate Disclosures: Sellers of properties located within designated zones must disclose wildfire hazard classifications during real estate transactions.
In addition to land use and regulatory impacts, emergency response agencies will utilize the updated FHSZ maps to enhance evacuation planning, prioritize resource allocation, and refine wildfire response strategies. These updated designations are essential in safeguarding life and property and improving long-term wildfire resilience for the City of Riverside.
STRATEGIC PLAN ALIGNMENT:
Items contributing to the Strategic Priority No. 2 Community Well-Being and Goal No. 2.6 -Strengthen community preparedness for emergencies to ensure effective response and recovery.
This project aligns with the Cross-Cutting Threads of the City’s Strategic Plan as follows:
Community Trust – By adopting the ordinance in compliance with Government Code section 51178, the City reinforces its commitment to public safety and transparency. The formal designation of Moderate, High, and Very High Fire Hazard Severity Zones (FHSZ) through this ordinance ensures that residents have access to accurate, science-based wildfire hazard information.
Equity – The Fire Department is committed to providing equitable fire and life safety services for all Riverside residents. By formally adopting the FHSZ ordinance, the City ensures that all communities have access to vital wildfire hazard data, enabling informed decision-making, proactive fire prevention efforts, and emergency preparedness across diverse neighborhoods.
Fiscal Responsibility – The City remains committed to financial transparency and accountability in public safety investments. By adopting the FHSZ ordinance, the City aligns with state mandates to ensure wildfire hazard mapping is conducted systematically and efficiently, preventing unnecessary expenditures on redundant assessments.
Innovation – The adoption of this ordinance is guided by cutting-edge wildfire modeling, climate data, and GIS-based hazard mapping technologies. The OSFM’s updated hazard maps incorporate advanced fire behavior modeling, wind and ember transport analysis, and climate-based risk assessments to provide the most accurate and predictive wildfire hazard classifications to date.
Sustainability & Resiliency – The formal adoption of Moderate, High, and Very High Fire Hazard Severity Zones strengthens the City’s ability to mitigate wildfire risks, promote defensible space initiatives, and encourage fire-resilient building practices.
FISCAL IMPACT:
There is no fiscal impact associated with amending section 16.32.365 of the Riverside Municipal Code.
Prepared by: Brian Guzzetta, Deputy Fire Chief
Approved by: Steve McKinster, Fire Chief
Certified as to
availability of funds: Kristie Thomas, Finance Director/ Assistant Chief Financial Officer Approved by: Mike Futrell, City Manager Approved as to form: Rebecca McKee-Reimbold, Interim City Attorney Attachment:
Presentation
Redline Ordinance – Section 16.32.365
Local Responsibility Area Fire Hazard Severity Zones – City of Riverside Fire Hazard Severity Zone Ordinance Adoption ● Page 2