FEBRUARY 2024
Prepared for:
SANCERRA MANAGEMENT
240 Newport Center Drive, Suite 200
Newport Beach, CA 92660
Contact: Suzanne Charnley, VP Entitlement and Development Prepared by:
605 Third Street
Encinitas, California 92024
__________________________
Noah Stamm
Fire Protection Planner III, Urban Forestry + Fire Protection
__________________________
Michael Huff
Discipline Director, Urban Forestry + Fire Protection
Fire Protection Plan
Whitewood I Residential Development
City of Murrieta, Riverside County
Printed on 30% post
-
consumer recycled material.
14499 i FEBRUARY 2024
Table of Contents
SECTION PAGE NO.
Acronyms and Abbreviations ............................................................................................................................................. v Executive Summary ........................................................................................................................................................... 1 1 Introduction .......................................................................................................................................................... 5
1.1 Applicable Codes and Existing Regulations .......................................................................................... 6
1.2 Project Summary .................................................................................................................................... 7
1.2.1 Project Overview ....................................................................................................................... 7
1.2.2 Project Location ........................................................................................................................ 7
1.2.3 Current Land Use ...................................................................................................................... 7
1.2.4 Project Description ................................................................................................................... 8 2 Project Site Risk Analysis .................................................................................................................................. 16
2.1 Environmental Setting and Field Assessment ................................................................................... 16
2.2 Site Characteristics and Fire Environment ........................................................................................ 16
2.2.1 Topography ............................................................................................................................. 17
2.2.2 Climate ................................................................................................................................... 17
2.2.3 Vegetation .............................................................................................................................. 18
2.2.4 Fire History ............................................................................................................................. 19
2.2.5 Analysis of Wildfire Risk from Adding New Residents ......................................................... 20
2.2.6 Fire Protection Features’ Beneficial Effect on Wildfire Ignition Risk Reduction ................ 23 3 Anticipated Fire Behavior ................................................................................................................................. 26
3.1 Fire Behavior Modeling ....................................................................................................................... 26
3.2 Fire Behavior Modeling Analysis ......................................................................................................... 26
3.3 Fire Behavior Modeling Results .......................................................................................................... 28
3.3.1 Existing Conditions................................................................................................................. 29
3.3.2 Post-Development Conditions ............................................................................................... 30
3.4 Project Area Fire Risk Assessment ..................................................................................................... 32 4 Emergency Response Service .......................................................................................................................... 37
4.1 Emergency Response Fire Facilities ................................................................................................... 37
4.2 Estimated Calls and Demand for Service from the Project .............................................................. 38
4.3 Cumulative Impact Analysis ................................................................................................................ 39 5 Fire Safety Requirements – Building Ignition Resistance, Infrastructure, and Defensible Space ............... 42
5.1 Fire Apparatus Access ......................................................................................................................... 42
5.1.1 Access Roads ......................................................................................................................... 42
5.1.2 Maximum Dead-End Road (cul-de-sac) Length .................................................................... 43
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
ii
FEBRUARY 2024
5.1.3 Gates
................................
................................
................................
................................
......
4 3
5.1.4 D
riveways
................................
................................
................................
...............................
44 5.1.
5 Surface
................................
................................
................................
................................
...
44 5.1.
6 Premise Identification
................................
................................
................................
............
4 4
5.1. 7
Ongoing Infrastructure Maintenance
................................
................................
....................
4 5
5.1. 8
P
re
-
Construction Requirements
................................
................................
............................
4 5
5.2 Ignition Resistant Construction and Fire Protection
Systems
................................
..........................
4 5
5.3 Infrastructure and Fire Protection System Requirements
................................
................................
47 5.3.1
Water Supply
................................
................................
................................
..........................
47 5.3.2
Fire Hydrants
................................
................................
................................
..........................
4 7
5.3.3 Automatic Fire Sprinkler Systems
................................
................................
.........................
4 7
5.4 Defensible Space and Vegetation Management
................................
................................
...............
48 5.4.1
Defensible Space and Fuel Modification Zone (FMZ) Requirements
................................
.
48 5.4.2
Vegetation Management
Maintenance
................................
................................
................
50 5.4.
3 Environmentally Sensitive Areas/Open Space
................................
................................
.....
51 5.4.
4 Prohibited Plants
................................
................................
................................
....................
51 5.4.
5 Construction Phase Vegetation Management
................................
................................
.....
51 6
Alternative Materials and Methods of Non
-
Conforming Fuel Modification
................................
...................
55 6.1
Additonal Structure Protection Measures
................................
................................
..........................
56 7
Justifications for Reduced FMZs
................................
................................
................................
......................
59 7.1
Strutcure Ignition
................................
................................
................................
................................
.
59 7.2
Fuel Separation
................................
................................
................................
................................
...
60 7.3
Heat Deflecting Walls
................................
................................
................................
..........................
61 8
Wildfire Education Program
................................
................................
................................
..............................
63 9
Conclusion
................................
................................
................................
................................
.........................
65 10
List of Preparers
................................
................................
................................
................................
................
67 1
1 References
................................
................................
................................
................................
........................
69 WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
iii
FEBRUARY 2024
APPENDICES
A
Representative Project
Photograph Log
B
Project Vicinity
Fire History
Map
C
BehavePlus
Fire Behavior Analysis
Summary
D
Ignition
-
Resistant Construction Requirements
E
MFR
Prohibited
Plant List
FIGURES
1 Project Location
Map
................................
................................
................................
................................
........
1 0
2 Fire Hazard Severity Zone
................................
................................
................................
................................
.
1 2
3 Proposed Site Plan
Map
................................
................................
................................
................................
...
1 4
4 Example Higher Density Development
................................
................................
................................
............
2 1
5 Example Moderate Density Development
................................
................................
................................
.......
22 6
Example Lower Density Development
................................
................................
................................
.............
22 7
BehavePlus Fire Behavior Analysis Map
................................
................................
................................
..........
3 5
8 Proposed Project Conceptual Fuel Modification Plan
................................
................................
.....................
53 TABLES
1 Fire Mod
els Used for Fire Beavior Modeling
................................
................................
................................
...
2 7
2 F
uel Moisture and Wind Inputs
................................
................................
................................
........................
27 3
RAWS BehavePlus
Fire
Behavior
Modeling Results
–
Existing Conditions
................................
....................
30 4
RAWS BehavePlus
Fire
Behavior
Modeling Results
–
Post
-
Project
Conditions
................................
.............
3 1
5 Fire
Suppression Interpretation
................................
................................
................................
.......................
3 2
6 Closest
MFR
Fire
Station Summary
................................
................................
................................
.................
3 7
7 Calculated Call Volume (Conceptual Based on
846
Persons)
................................
................................
.......
39 WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
iv
FEBRUARY 2024
INTENTIONALLY LEFT BLANK
14499 v FEBRUARY 2024
Acronyms and Abbreviations
AMSL Above Mean Sea Level
APN Assessor’s Parcel Number
BTU British Thermal Unit
CAL FIRE California Department of Forestry and Fire Protection CBC California Building Code
CC&Rs Covenants, Conditions and Restrictions
CFC California Fire Code
CCS Chaparral and Coastal Sage Scrub
EMWD Eastern Municipal Water District
FAHJ Fire Authority Having Jurisdiction
FMZ Fuel Modification Zone
FPP Fire Protection Plan
FRAP Fire and Resource Assessment Program
GIS Geographic Information Systems
I-15 Interstate 15
I-215 Interstate 215
IFC International Fire Code
ISO Insurance Service Office
MFR Murrieta Fire & Rescue
MPH Miles Per Hour
NFPA National Fire Protection Association
PRC Public Resource Code
Project The Whitewood I Residential Development Project RCFD Riverside County Fire Department
SRA State Responsibility Area
USGS United States Geological Survey
VHFHSZ Very High Fire Hazard Severity Zone
WRCC Western Regional Climate Center
WUI Wildland Urban Interface
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
vi
FEBRUARY 2024
INTENTIONALLY LEFT BLANK
14499 1 FEBRUARY 2024
Executive Summary
This Fire Protection Plan (FPP) has been prepared for the Whitewood I Residential Development Project (Project), which proposes the development of 243 multi-family residential two- and three-story townhomes and a recreational pool area with an approximately 900 square foot (SF) restroom and pool equipment building on the approximately
17.26-acre Project site located in the northeastern portion of the City of Murrieta (City), Riverside County, California.
Each townhouse unit is separated with its own fire-resistance rated common wall in accordance with the California Residential Code (CRC) Section R302.2.2. Furthermore, each townhouse will include the installation of its own National Fire Protection Association (NFPA) 13D automatic interior fire sprinkler system per CRC Section R313, meeting Item 1 of CRC Section R302.2.2. Access to the Project would be provided by two (2) full access driveways, one located on Arendt Lane, and the other located on Whitewood Road. The Project also proposes road improvements to Arendt Lane, an existing dirt road that connects to Clinton Keith Road and currently serves as an access road to the existing rural residential lots.
This FPP evaluates and identifies the potential fire risk associated with the P roject’s land uses and identifies requirements for water supply, fuel modification and defensible space, access, building ignition and fire resistance, and fire protection systems, among other pertinent fire protection criteria. The purpose of this plan is to generate and memorialize the fire safety requirements and standards of the Murrieta Fire and Rescue (MFR) Department along with Project-specific measures based on the Project site, its intended use, and its fire environment. This document provides analysis of the site’s fire environment and its potential impact on the proposed Project as well as the project’s potential impact on the existing fire protection service. The fire safety measures included herein are based on site-specific fire environment analysis, Project characteristics, while incorporating area fire planning documents, site risk analysis, and standard principles of fire protection planning.
As determined during the analysis of the site and its fire environment, the Project site, in its current condition, may include characteristics that, under favorable weather conditions, could have the potential to facilitate fire spread.
Under extreme conditions, wind-driven wildfires from the east/northeast are likely to cast embers onto the property.
Once the Project development is constructed, the on-site fire potential will be much lower than its current condition due to the conversion of the property to building footprints, parking areas, managed landscape areas, fuel modification zone implementation, improved accessibility for fire personnel, and structures built to the latest ignition and ember resistant fire codes.
It is important to note that the fire safety measures that will be implemented on this site, including ignition resistant construction standards, including each common wall separating townhouse units being assigned a fire-resistance rating according to CRC Section R302.2.2, water supply, fire apparatus access, fuel modification and defensible space, the installation of an NFPA 13D automatic interior fire sprinkler system within each townhouse unit per CRC Section 313, and fire response travel times were integrated into the model code requirements and local AHJ guidelines based on results of post-fire assessments, similar to the After-Action Reports that are now prepared after large fire events. When it became clear that specifics of how structures were built, how fire and embers contributed to ignition of structures, what effects fuel modification had on structure ignition, how fast firefighters could respond, and how much (and how reliable) water was available, were critically important to structure survivability, the Fire and Building codes were revised appropriately.
The proposed development of this property includes construction of 243 multi-family dwelling units. The entire site has been designed with fire protection as a key objective. The site improvements are designed to facilitate
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
2 FEBRUARY 2024
emergency apparatus and personnel access throughout the site. Driveway and road improvements with turnarounds provide access throughout the Project. Water availability and flow will be consistent with local
and
state code requirements
for
fire flow and hydrant distributio
n
. These features along with the ignition resistance of
all buildings, the
NFP
A
13D
automatic
interior
fire
sprinkler
s
ystems
, and the pre
-
planning, training and awareness
will assist responding firefighters through prevention, protection and suppression capabilities.
As detailed in this FPP, the project’s fire protection systems will include a redundant layering of protection methods that have proven to reduce overall fire risk. The fire safety measures included herein are performance based and site –
specific, consideri
ng the Project’s unique characteristics rather than a prescriptive, one -
size
-
fits
-
all approach. The fire
protection systems are designed to increase occupant and building safety, reduce the fire risk on site, to minimize risks associated with typical uses,
and aid the responding firefighters during an emergency. No singular measure is intended to be relied upon for the site’s fire protection, but rather, a system of fire protection measures, methods, and features combine to result in enhanced fire safety, r
educed fire potential, and improved safety in the development.
Early evacuation
for any type of wildfire emergency at
the Whitewood I Project site
is the preferred method of
providing for
occupant and business safety
, consistent with the
Owner’s and MFR curr
ent approach for
evacuation.
As such,
the Whitewood I Project’s
Owner and Property Management Company
will
formally adopt, practice, and
implement
this
approach to site evacuation
(see
www.rivcoready.org
for information)
.
Based on the results of this
FPP’
s analysis and findings, the
following FPP
implementation measures
will be
provided as part of the proposed development plan.
Based on the analysis conducted herein, the Project meets all fire and building code
requirements
and includes appropriate protections for the fire environment in which it is located.
These measures are discussed in m
ore detail throughout this FPP.
The
Project buildings will be constructed
of ignition resistant
1 construction materials
and e
ach
townho
use
unit
will be
separated with
i
ts own
fire
-
r
esistan
ce r
ated common wall in accordance with
the
CRC
Section
R302.2.2
.
Furthermore
,
e
ach to
wnh
ouse will include the installation of its own
NFPA
13D
automatic interior
fire sprink
ler system per
CRC Section R313
, meeting Item 1 of CRC Section R302.2.2
and
the latest
adopted Building and Fire Codes for occupancy types.
Fuel Modification will be provided around the perimeter of the site, as required by MFR and will be up to
2 00
feet wide
,
including off
-
site
equivalent fuel modification
along Clinton Keith Road to the south, along
Whitewood Road to the west, and along Arendt Lane to the east.
Should areas within the development not be
able to achieve a minimum
2 00 feet of onsite fuel modification,
then alternative materials and methods
shall
be proposed to provide the functional equivalency of
the MFR required 200
-
foot
-
wide
defensible space.
Alternative materials and methods will be to the satisfaction of the MFR
and may include structural
hardening enhancement
s or landscape features, like non
-
combustible walls
.
Paved roads are provided throughout the project, both on site and existing off site.
Landscape plantings will not utilize prohibited plants that have been found to be highly flammable ;
landscape materials must be drought tolerant, fire resistive plantings.
1 A
type of building material that resists ignition or sustained flaming combustion sufficiently to reduce losses from wildland -
urban
interface conflagrations under worst
-
case weather and fuel conditions with wildfire exposure of burning embers and small flam es,
as prescribed in
CBC, Chapter 7A
and State Fire Marshal Standard
12 -
7A
-
5,
Ignition
-
Resistant Materials.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
3 FEBRUARY 2024
FMZ Inspections.
HOA will hire a 3
rd
party,
MFR
-
approved, FMZ inspector and landscape plan reviewer to
provide
annual
certification
(written report submitted to MFR by May 1)
that the HOA maintained properties
including all FMZs and meet the requirements of this FPP.
Fire apparatus access roads
(i.e., public and private streets)
will be provided throughout the
development
and
will provide at least the minimum required unobstructed travel lanes, lengths, turnarounds
, and
clearances
required by applicable codes
. Primary
access and internal circulation
will comply with the
requirements
of the
MFR
.
E
ach to
wnh
ouse will include the installation of its own
NFPA
13D
automatic interior fire sprink
ler system
per
CRC Section R313
, meeting Item 1 of CRC Section R302.2.2
and
MFR
requirement
s
.
Water capacity and delivery provide for a reliable water source for operations and during emergencies requiring extended fire flow.
The
following
measures shall be established in the
Covenants, Conditions and Restrictions
(
CC&Rs
)
for the Project
and implemented by the Project’s Property Manager. Annual maintenance should occur before May 1 st
of each year
and inspected by
MFR
or an approved third party
.
1. On
-
going maintenance of all fuel modification will be managed by Owner’s, Project’s Property Manager, or another approved entity, at least annually or as needed.
2. The Project’s Property Manager will provide property owners informational brochures at time of occupancy, which will include an outreach and educational role to ensure fire safety measures detailed in this FPP have been implemented and development
-
wide “Re
ady, Set, Go!”
2 plans prepared
.
2 https://www.murrietaca.gov/DocumentCenter/View/342/Ready -
Set
-
Go
-
Brochure
-
PDF
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
4 FEBRUARY 2024
INTENTIONALLY LEFT BLANK
14499 5 FEBRUARY 2024
1 Introduction
The Fire Protection Plan (FPP) has been prepared for the proposed Whitewood I Residential Development Project (Project) in the northeastern portion of the City of Murrieta, Riverside County, California. The purpose of the FPP is to evaluate the potential impacts resulting from wildland fire hazards and identify/verify the proposed implementation measures adequately mitigate those risks to a level consistent with the City of Murrieta thresholds.
Additionally, this FPP establishes and memorialize the fire safety requirements of the Fire Authority Having Jurisdiction (FAHJ), which is the Murrieta Fire and Rescue (MFR) Department. Requirements and recommendations detailed in the FPP are based on Project site-specific characteristics, applicable code requirements, and input from the Project’s applicant, planners, engineers, and architects, as well as the FAHJ.
As part of the assessment, the FPP has considered the fire risk presented by the Project site including the property location and its topography, geology, surrounding combustible vegetation (fuel types), climatic conditions, fire history, and the proposed land use. The FPP addresses water supply, access, structural ignitability, and ignition resistive building features, fire protection systems, and equipment, impacts to existing emergency services, defensible space, and vegetation management. The FPP also identifies and prioritizes areas for hazardous fuel reduction treatments and recommends the types and methods of treatment that, when implemented and maintained, are designed to protect the Project community and essential infrastructures. The FPP also recommends measures that developer/builders, property owners, and the Property Manager will take to reduce the probability of structural and vegetation ignition.
The Project is located within the boundaries of the MFR and thus the FPP addresses MFR ’s response capabilities and response travel time within the Project area, along with projected funding for facility improvements and fire service maintenance.
The following tasks were performed toward completion of this FPP:
• Gather site-specific climate, terrain, and fuel data; • Collect site photographs3;
• Process and analyze the data using the latest geographic information system (GIS) technology; • Predict fire behavior using scientifically based fire behavior models, comparisons with actual wildfires in similar terrain and fuels, and experienced judgment;
• Analyze and guide the design of proposed infrastructure; • Analyze the existing emergency response capabilities; • Assess the risk associated with the Project site;
• Evaluate nearby firefighting and emergency medical response resources; and • Prepare the FPP detailing how fire risk will be mitigated through a system of fuel modification, structural ignition resistance enhancements, and fire protection delivery system upgrades.
3 Field observations were used to augment existing digital site data in generating the fire behavior models and formulating the recommendations presented in the FPP. Refer to Appendix A, Representative Site Photographs, for site photographs of existing site conditions.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
6 FEBRUARY 2024
1.1 Applicable Codes and Existing Regulations
The FPP demonstrates that the
Whitewood I
Project would comply with applicable portions of
the
MFR Fire Code
(Ordinance 584
-
22)
and Murrieta Municipal Code
–
Chapter 15.24,
which has adopted the 2022 edition of the
California Fire Code (CFC), based on the 2021 International Fire Code (IFC) including local amendments and additions. The project will also be consistent with applicable Murrieta Fire Prevention Standards
and
applicable
sections of
the
2022
edition of the California Building Code (CBC),
including
Chapter 7A as adopted and amended
by
the Murrieta
Municipal Code (Chapter 15.
08 California Building Standard
Code
s
)
an
d
applicable sections of the
California Residential Code (CRC), includ
ing
Sections 302
and 313
. Additionally,
MFR
references Fire Prevention
Standards for informational purposes in clarifying and interpreting provisions of the CFC, National Fire Protection Association (NFPA) and California Public Resources Code (PRC).
Finally, the project will be consistent with the MFR
Fuel Modification Guidelines (adopted December 2023) which provides Fuel Modification Plan requirements in conjunction with the 2022 CFC, Chapter 49, for all new single -
family homes, multi
-
family residen
tial, Accessory
Dwelling Units
(ADU), utility, and commercial structures built in, or adjacent to, a wildfire -
risk area or such areas
designated by the fire code official.
Chapter 7A of the CBC addresses
structural ignition resistance and
reducing ember penetration into homes, a
leading cause of structure loss from wildfires (California Building Standards Commission ,
2019). Thus, code
compliance is an important component of the requirements of the FPP, given the Project’s wildland -
urban interface
(WUI) location that is within an area statutorily designated as a Very High Fire Hazard Severity Zone (VHFHSZ) within
a
Local
Responsibility
Area
(
L
RA)
by the California Department o
f Forestry and Fire Protection (CAL FIRE) (
California
Office of the State Fire Marshal, 2010
).
Fire hazard designations are based on topography, vegetation, and weather, among other factors with more hazardous sites, including steep terrain, unmaintained fuels/vegetation, and WUI locations. Projects situated in VHFHSZ
’s
require fire hazard analysis and the application of fire protection measures to create ignition
-
resistant structures and defensible communities within these WUI locations. VHFHSZ designation s
do not, in and of themselves, indicate that it is unsafe to build in these areas.
As described in this FPP, the Project will meet all applicable fire and building code requirements for building in these higher fire hazard areas or meet the intent of the code through the application of Project
site
-
specific fire protection
measures. These codes have been developed through decades of after fire structure save and loss evaluations to determine what causes building loss during wildfires. The resulting fire codes now focus on mitigating former struc
tural vulnerabilities through construction t
echniques and materials so that the buildings are resistant to ignitions from direct flames, heat, and embers, as indicated in the 2022 CBC
(Chapter 7A, Section 701A Scope,
Purpose and Application)
(California Building Standards Commission 2019).
The Proposed Project will also be consistent with the following codes and regulations:
▪
–
Materials and Construction
Methods for Exterior Wildfire Exposure: minimum standards for a new building located in a WUI area to resist the intrusion of flame or burning embers projected by a vegetation fire.
▪
–
Requirements for Wildland
-
Urban Interface Fire Areas:
minimum standards to increase the ability of a building to resist the intrusion of flame or burning embers being projected by a vegetation fire.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
7 FEBRUARY 2024
▪
.
Requirements for
common walls separating townhouse units
shall be assigned
a fire
-
resistant rating in
accordance with Item
1 or 2 and shall be rated for fire exposure on both sides
(
Se
ction
R302.2.2)
. Further,
an automatic residential fire sprinkler system shall be installed in each townhouse
(
Section
R3
1 3).
▪
–
SRA/VHFHSZ Fire Safe
Regulations: minimum wildfire protection standards in conjunction with building, construction and development in the SRA and VHFHSZ.
▪
: minimum fire safety standards related
to defensible space in Hazardous Fire Areas;
: Defensible space maintenance on Mountainous,
Forest
-
, Brush
-
and Grass
-
Covered Lands.
▪
: Very High Fire Hazard
Severity Zones.
▪
: requirements for tentative map approval
in a very high fire hazard severity zone
.
1.2 Project Summary
1.2.1 Project Overview
The Project site comprises 17.26 acres of land designated by the City of Murrieta for Multiple -
Family Residential
land uses. The discretionary approval associated with the Project includes a Development Plan Permit and Tentative Tract Map. The Development
Plan Permit establishes the building layout and architecture proposed for the Project.
Approval of the Development Plan Permit and Tentative Tract Map would allow for development of the property with 243
multi
-
family residential dwelling units and
common
a
menity area
s
.
1.2.2 Project
Location
The Project site consists of approximately 17.26 acres in the northeastern portion of the City of Murrieta. From a regional perspective, the Project site is located 0.26 mile west of the French Valley area of unincorporated Riverside County. Interstate 215
(I
-
215) is located 0.6
mile west of the Project site. Specifically, the Project site is located east of Whitewood Road
and
north of Clinton Keith Road
(Figure 1. Project Location Map
).
The Project site
encompasses Assessor’s Parcel Numbers (APNs) 392
-
330
-
003,
-
007,
-
020, and
-
021
. Primary
Access to the Project
would be provided by two (2) full access driveways, one located on Arendt Lane, and the other located on Whitewood Road
.
The site is located in Section 2, Township 7 South, Range 3 West, SBM as found on the USGS –
Murrieta
Quadrangle, 7.5
Minute Series topographic
.
The entirety of the proposed property lies within the
local
responsibility area (
L
RA) VHFHSZ, as statutorily designated
by CAL FIRE (20
07 ) and the
MFR
(
Figure 2, Fire Hazard Severity Zone Map
).
1.2.3 Current Land Use
The Project site contains two existing residences in the eastern half of site and the western half of the site is undeveloped. Elevations range between approximately 1,385 feet above mean sea level (amsl) in the southeast corner to 1,480 feet amsl along th
e western boundary.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
8 FEBRUARY 2024
The overall setting is that of a transitional area with urbanized areas to the west and moderately developed and rural area
directly
to the
north and
east.
Surrounding
l
and uses that lie adjacent to the Proposed Project site include Clinton Keith Road to the
South
, which is a multi
-
lane
primary
thoroughfare through the city of Murietta
;
Whitewood
Road to the west, and Arendt Lane to east, which currently is a two -
lane dirt access road.
To the west of the Project
site is an existing residential development
;
directly to the
n
orth and east of the Project site are several existing
rural
homes
; and
s
outh of the Project site is undeveloped land designated for multiple -
family residential land uses
. The
Vista Murietta High
School campus exists southwest of the Project site, across the intersection of Clinton Keith Road and Whitewood Road
.
The Project area, like all of Southern California and
Riverside
County, is subject to
seasonal weather conditions that can heighten the likelihood of fire ignition and
spread, and, considering the site’s
terrain and vegetation, may result in a fast
-
moving and intense wildfire
.
1.2.4 Project Description
The Project consists of a Development Plan Permit and Tentative Tract Map for a 17.26 -
acre site. The Project would
provide for the development of 243 multi
-
family residential homes at a density of 15.1 dwelling units per acre. The Project also includes con
struction of a recreational pool area with a
±
900sf restroom and pool equipment building,
tot lot and 65,120 SF of total common open space areas throughout the site.
The proposed 243 dwelling units comprise 2
-
and 3
-
story townhomes.
Each
townho
use
unit
is
separated with
i
ts
own
fire
-
r
esistan
ce r
ated common wall in accordance with
the
Cal
ifornia
Residential Code (CRC)
Section
R302.2.2
and shall be rated for fire exposure on both sides
.
Furthermore
,
e
ach to
wnh
ouse will include the installation of its
own National
Fire Protection
Association
(NFPA)
13D
automatic interior fire sprink
ler system per
CRC Section R313
,
meeting Item 1 of CRC Section R302.2.2
.
A total of 629 parking spaces would be provided with 10% of spaces designated as future electric vehicle (EV) spaces. Access to the Project would be provided by two (2) full access driveways, one located on Arendt Lane, and the other located on Whitewood R oad.
Grading proposed by the Project would result in disturbance to 16.64 acres of the Project with the balance of the site remaining undisturbed. The project will preserve 0.62 acres of sensitive area including 33 mature Oaks and
0.35 acres of County of Rivers
ide riparian/riverine features.
The project will construct a
±
12 -
inch
offsite EMWD master plan sewer line within Arendt Lane, continuing easterly within Clinton Keith Road and terminating near the northwest corner of Clinton Keith Road and Menifee Road
(Figure 3, Project Site Plan Map)
.
.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
9 FEBRUARY 2024
INTENTIONALLY LEFT BLANK
79 215
Project Location
Fire Protection Plan for the Whitewood I Project
SOURCE: USGS 7.5-Minute Series Murrieta Quadrangle
Date: 10/11/2022 - Last saved by: lterry - Path: Z:\Projects\j1449900\MAPDOC\DOCUMENT\Fire Protection\FIG 1 Project Location.mxd Project Site
FIGURE 1
Banning
Beaumont
Brea
Calimesa
Canyon Lake
Carlsbad
Cathedral City
Claremont
Colton
Corona
Dana Point
Del Mar
Desert
Hot Springs
Eastvale
Encinitas
Escondido
Fontana Grand Terrace
Hemet
Highland
Indian Wells
Irvine
Jurupa Valley
Laguna Niguel
Laguna Woods
Lake
Elsinore Menifee
Monrovia
Moreno
Valley
MurrietaNewport Beach
Norco
Oceanside
Ontario
Orange Palm Desert
Palm
SpringsPerris
Poway
Rancho
Mirage
Rancho
Santa Margarita
Rialto
San Bernardino
San Clemente
San Dimas
San Jacinto
San Marcos
Santee
Solana
Beach
Temecula
Villa Park
Vista
Wildomar
Yucaipa
Yucca ValleyS a n
B e r n a r d i n o C o u n t yL o s A n g e l e s
C o u n t y
S a n D i e g o
C o u n t y
71 57
60 74
91 55
73 241
39 206 330
72 56
22 90
111
67 243
66 60
38 78
74 76 79
5 605
10 215
15 210
405
0 2,0001,000
Feet
Project Site
Project Site
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
11 FEBRUARY 2024
INTENTIONALLY LEFT BLANK
Murrieta
Murrieta
79 215
Document Path: Z:\Projects\j1449900\MAPDOC\DOCUMENT\Fire Protection\FIG 3 Fire Hazard Severity Zone.mxd 0 2,0001,000
Feet
FIGURE 2
Very High Fire Hazard Severity Zones
Fire Protection Plan for the Whitewood I Project
SOURCE: PARCELS- RIVERSIDE COUNTY GIS; FIRE DATA- CALFIRE Project Boundary
City Limits
Local Responsibility Area
LRA, Very High
LRA, High
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
13 FEBRUARY 2024
INTENTIONALLY LEFT BLANK
WR RW WR WR WR RW RW WR WR WR RW
S S S S S S
W W W W W W W
S
C
C
A
A
B
B
CC
B
B
A
A
25'
TYP.
12'
TYP.
R=12'
TYP.
25'
TYP.
R=12'
TYP. R=12'
TYP.
R=12'
TYP.
R=12'
TYP.
R=25'
R/W
R/W
R/W
PL
25'
TYP. 25'
TYP.
R=35'
R=35'
TELEPHONE EASEMENT
(EXISTING)
ELECTRIC EASEMENT
(EXISTING)
ROAD EASEMENT
ROAD EASEMENT
(EXISTING)
SLOPE EASEMENT
(EXISTING)
SLOPE EASEMENT
(EXISTING)
SLOPE EASEMENT
(EXISTING)
SLOPE EASEMENT
(EXISTING)
SLOPE EASEMENT
(EXISTING)R/W
R/W
R/W
R/W
EXISTING BUILDING
EXISTING BUILDING
EXI
ST
IN
G
BUILDING
EXISTING BUILDING
EXISTING
BUILDING
EXIST
ING
BU
ILD
ING
EX
ISTINGBUI
LD
ING
PL
RW
PL
R=35'
EV CHARGING
STORM DRAIN
EASEMENT
STORM DRAIN
EASEMENT
STORM DRAIN
EASEMENT
AC BERM
R/W
R=35'
R/W
UTILITY POLE
(EXISTING)
UTILITY POLE
(EXISTING)
UTILITY POLE
(EXISTING)
UTILITY POLE
(EXISTING) UTILITY POLE
(EXISTING)
UTILITY POLE
(EXISTING)
UTILITY POLE
(EXISTING)
UTILITY POLE
(PROPOSED)
UTILITY POLE
(PROPOSED)
100'
'04
10'
100'
100'
10'
10 '
10'
40'
'01
FUEL MODIFICATION
ZONE
FUEL MODIFICATION
ZONE
FUEL MODIFICATION
ZONE
FUEL MOD
ZONE
FUEL MOD
ZONE
'32'8
24'
26'
'6226''6226'
'62
'42'4224'24''4224' 18'
24'
26'
26 '
24'
26'
26' 18'
26'
9'
26' 26'
26'
18 '
9'
9'
9'
9'
9'
26'
26'
24'
'42
8'
4'
8'
5'5'
5'
6'
4'10'
5'9'
5'
9'
4'
4'8'
5'9'
5'9' 5' 7'
9'9'9'
28 ' 18'
5' 5'
22' '22 22'
'02
22'22'
22'22'
27'
8'
23'
22'
29'
22'42'
32' 4'
'72
'22
SD
S
W
DEVELOPMENT STANDARDS TABLE
PRODUCT 1 (2-STORY TOWNHOME)
PLAN TYPE PROGRAM UNIT SIZE UNIT COUNT TOTAL
PLAN 1 2 BD/2.5 BA 1,588 SF 43 68,284 SF
PLAN 2 3 BD/2.5 BA 1,676 SF 46 77,096 SF
PLAN 3 3+LOFT/BD-4 BD/2.5 BA 1,875 SF 46 86,250 SF
TOTAL 135 233,630 SF
PRODUCT 2 (3-STORY TOWNS)
PLAN TYPE PROGRAM UNIT SIZE UNIT COUNT TOTAL
PLAN 1 2 BD/2.5 BA 1,351 SF 36 48,636 SF
PLAN 2 3 BD/2.5 BA 1,704 SF 36 61,344 SF
PLAN 2X 3 BD/2.5 BA 1,807 SF 36 65,052 SF
TOTAL 108 175,032 SF
Project Site Plan
FIGURE 3
Fire Protection Plan for the Whitewood I Project
SOURCE: WILSON MIKAMI CORPORATION 2023
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
15 FEBRUARY 2024
INTENTIONALLY LEFT BLANK
14499 16 FEBRUARY 2024
2 Project Site Risk Analysis
2.1 Environmental Setting and Field Assessment
After review of available digital Study Area information, including topography, vegetation types, fire history, and the Project’s Development Footprint, a Dudek Fire Protection Planner conducted a field assessment of the Whitewood I Residential Project site in July 2022, in order to confirm/acquire site information, document existing site conditions, and to determine potential actions for addressing the protection of the Project’s structures. While on - site, Dudek’s Fire Planner assessed the area’s topography, natural vegetation, and fuel loading, surrounding land use, and general susceptibility to wildfire. Among the field tasks that were completed included:
• Topography evaluation;
• Vegetation/fuel assessments;
• Photograph documentation of the existing condition;
• Confirmation/verification of hazard assumptions;
• Off-site, adjacent property fuel and topography conditions; • Surrounding land use confirmations;
• Necessary fire behavior modeling data collection;
• Ingress/egress documentation;
• Nearby Fire Station reconnaissance.
Study Area photographs were collected (refer to Appendix A, Representative Site Photographs), and fuel conditions were mapped using aerial images. Field observations were utilized to augment existing site data in generating the fire behavior models and formulating the requirements and recommendations detailed in the FPP.
2.2 Site Characteristics and Fire Environment
Fire environments are dynamic systems and include many types of environmental factors and Project site characteristics. Fires can occur in any environment where conditions are conducive to ignition and fire movement.
Areas of naturally vegetated open space are typically comprised of conditions that may be favorable to wildfire spread. The three major components of the fire environment are topography, vegetation (fuels), and climate. The state of each of these components and their interactions with each other determines the potential characteristics and behavior of a fire at any given moment. It is important to note that wildland fire may transition to urban fire if structures are receptive to ignition. Structure ignition depends on a variety of factors and can be prevented through a layered system of protective features including fire-resistive landscapes directly adjacent to the structure(s), application of known ignition resistive materials and methods, and suitable infrastructure for firefighting purposes.
Understanding the existing wildland vegetation and urban fuel conditions on and adjacent to the site is necessary to understand the potential for fire within and around the Project site.
The following sections discuss the characteristics of the Project area and the surrounding region, local climate, and fire history within and surrounding the Project site. The Whitewood I Residential Development Project is similar concerning topography, vegetative cover, and proximity to adjacent residential areas, available access, and planned use. The following sections discuss the characteristics of the Project site at a regional scale. The intent
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
17 FEBRUARY 2024
of evaluating conditions at a macro
-
scale provides a better understanding of the regional fire environment, which is not constrained by property boundary delineations.
2.2.1 Topography
Topography influences fire risk by affecting fire spread rates. Typically, steep terrain results in faster fire spread up -
slope and slower spread down
-
slope
in the absence of wind
. Terrain that forms a funneling effect, such as chimneys, chutes, or saddles on the landscape can result in especially intense fire behavior. Conversely, flat terrain tends to have little effect on fire spread, resulting in fires that are driven by vegeta tion and wind.
The Proposed Project is situated
along the northeast corner of the intersection of Clinton Keith Road and Whitewood Road. The site is fairly flat
with elevations that range from approximately 1,385 amsl in the southeast corner to 1,480 feet amsl along the western boundary.
2.2.2 Climate
The Project
s
ite, like much of Southern California, is influenced by the Pacific Ocean and a seasonal, migratory subtropical high
-
pressure cell known as the “Pacific High.” Wet winters and dry summers with mild seasonal changes characterize the Southern California clim
ate. This climate pattern is occasionally interrupted by extreme periods of hot weather, winter storms, or dry, easterly Santa Ana winds.
The climate of
Murietta and
western
Riverside County
is typical of a Mediterranean area, with warm, dry s
ummers
and cold, wet winters. Temperatures
average (average annual) around 61
°F and reach up to 100°F
during the summer
. Precipitation has been
averaging
about
14 inches and typically occurs between December and March. The prevailing wind is an on -
shore
flow between 7 and 11 mph from the Pacific Ocean.
4 From a regional perspective, the fire risk in southern California can be divided into three distinct “seasons” (Nichols et al. 2011, Baltar et al 2014). The first season, the most active season and covering the summer months, extends from late May to late
September. This is followed by an intense fall season characterized by fewer but larger fires.
This season begins in late September and continues until early November. The remaining months, November to late May cover the mostly dormant, winter season. Mens
ing et al. (1999) and Keeley and Zedler (2009) found that large fires in the region consistently occur at the end of wet periods and the beginning of droughts.
Fires can be a
significant issue during summer and fall, before the rainy period, especially during dry Santa Ana wind events. The seasonal Santa Ana winds can be particularly strong in the Project area as warm and dry air is channeled through the San Gorg
onio Pass from the dry, desert land to the east. Although Santa Ana events can occur anytime of the
year, they generally occur during the autumn months, although the last few years have resulted in spring (April -
May) and summer events. Santa Ana winds may gust up to 75 miles per hour (mph) or higher. This phenomenon markedly increases the wildfire
danger and intensity in the
P
roject area by drying out and preheating vegetation
(fuel moisture of less than 5% for 1
-
hour fuels is possible) as well as accelerating oxygen supply, and thereby, making possible the burning of fuels that otherwise might not burn under cooler, moister conditions
.
The prevailing wind pattern is from the west (on
-
shore), but the presence of the Pacific Ocean causes a diurnal wind pattern known as the land/sea breeze system. During the day, winds are from the west –
southwest (sea), and at
4 Climate
-
data.org:
https://en.climate
-
data.org/north
-
america/united
-
states
-
of
-
america/california/murrieta
-
5928/
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
18 FEBRUARY 2024
night winds are from the northeast (land). The highest wind velocities are associated with downslope, canyon, and Santa Ana winds.
2.2.3 Vegetation
2.2.3.1 Fuels (Vegetation)
The Proposed Project site and surrounding
areas primarily support chamise chapparal, coastal sage scrub and non -
native grassland plant communities.
Native and non
-
native trees are also observed throughout the project site including willows, oaks, and eucalyptus.
Vegetation
types were derived from an on
-
site field assessment of the
project site
. The adjacent lands have similar vegetation types, with non -
native grasslands as well.
Th
e
vegetation
cover
types were
assigned a
corresponding
fuel model for use dur
ing site fire behavior modelin
g. Section 3.0
describes the fire modeling conducted for the Project Area.
2.2.3.2 V
egetation Dynamics
The vegetation characteristics described above are used to model fire behavior, discussed in Section 3.0 of this FPP. Variations in vegetative cover type and species composition have a direct effect on fire behavior. Some plant communities and their associ
ated plant species have increased flammability based on plant physiology (resin content), biological function (flowering, retention of dead plant material), physical structure (bark thickness, leaf size, branching patterns), and overall fuel loading. For e xample, non
-
native grass dominated plant communities
become seasonally prone to ignition and produce lower intensity, higher spread rate fires. In comparison, sage scrub can produce higher heat intensity and higher flame lengths under strong
, dry wind patterns, but does not
typically ignite or spread as quickly as light, flashy grass fuels.
As described, vegetation plays a significant role in fire behavior, and is an important component to the fire behavior models discussed in this report. A critical factor to consider is the dynamic nature of vegetation communities. Fire presence and absence
at varying cycles or regimes disrupts plant succession, setting plant communities to an earlier state where less fuel is present for a period of time as the plant community begins its succession again. In summary, high frequency fires tend to convert shru
blands to grasslands or maintain grasslands, while fire exclusion tends to convert grasslands to shrublands, over time. In general, biomass and associated fuel loading will increase over time, assuming that disturbance (fire, or grading) or fuel reduction efforts are not diligently
implemented
. It is
possible to alter successional pathways for varying plant communities through manual alteration. This concept is a key component in the overall establishment and maintenance of the proposed fuel modification zo nes on site. The
fuel modification zones on this site will consist of irrigated and maintained landscapes as well as thinned native fuel zones that will be subject to regular “disturbance” in the form of maintenance and will not be allowed to accumulate ex
cessive biomass over time, which results in reduced fire ignition, spread rates, and intensity.
Conditions adjacent the project
’
s footprint (outside the fuel modification zones), where the wildfire threat will exist post
-
development, are classified as low
to medium fuel loads due to the dominance of sage scrub -
grass fuels.
As described, vegetation plays a significant role in fire behavior, and is an important component of the fire behavior models discussed in the report. A critical factor to consider is the dynamic nature of vegetation communities. Fire presence and absence
at varying cycles or regimes disrupts plant succession, setting plant communities to an earlier state where less fuel is present for a period of time as the plant community begins its succession again.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
19 FEBRUARY 2024
In summary, high
-
frequency fires tend to convert shrublands to grasslands or maintain grasslands, and fire exclusion tends to convert grasslands to shrublands over time as shrubs sprout back or establish and are not disturbed by repeated fires. In general,
biomass and associated fuel loading will increase over time, assuming that disturbance (e.g., fire) or fuel reduction efforts are not diligently implemented. It is possible to alter successional pathways for varying plant communities through manual altera tion. This concept is a key component in the overall
establishment and maintenance of the proposed FMZs for the Project s
ite. The FMZs will consist of irrigated and
maintained landscapes that will be subject to regular “disturbance” in the form of maintenance and will not be allowed to accumulate excessive biomass over time, which results in reduced fire ignition, spread rat es, and
intensity.
Conditions adjacent
to
the
P
roject’s footprint (outside the fuel modification zones), where the wildfire threat will
exist post
-
development, are classified as low to medium fuel loads due to the dominance of sage scrub -
grass fuels
.
2.2.4 Fire History
Fire history is an important component of a site
-
specific FPP. Fire history data provides valuable information regarding fire spread, fire frequency, ignition sources, and vegetation/fuel mosaics across a given landscape. One important use for this informa
tion is as a tool for pre
-
planning. It is advantageous to know which areas may have burned recently and therefore may provide a tactical defense position, what type of fire burned on the
Project
site,
and how a fire may spread.
Fire history represented in the FPP uses the California Department of Forestry and Fire Protection (CAL FIRE) Fire and Resource Assessment Program (FRAP) database. FRAP summarizes fire perimeter data dating to the late 1800s, but which is incomplete due to
the fact that it only includes fires over 10 acres in size and has incomplete perimeter data, especially for the first half of the 20th century (Syphard and Keeley 2016). However, the data does provide a summary of recorded fires and can be used to show w hether large fires have occurred in the Project area,
which indicates whether they may be possible in the future.
According to available data from the CAL FIRE in the FRAP database, nineteen (19)
fires
have burned within 5 miles
of the Project
s
ite since the beginning of the historical fire data record
(1956 was the first year recorded in the
area)
.
Recorded wildfires within 5 miles range from
approximately
4 .
3 acres to
approximately
24,434
acres (
1993
California
Fire) and the average fire size is approximately
3,400
acres
.
The
2012 Scott
Fire
(approximately
4.3 acres)
is
the most recent fire
; before the
2012 Scott
Fire, the next most recent fire that occurred within 5 miles of the Project site
was
the
2011 Keller
Fire and burned approximately
450
acres
.
There is one
fire
on record that
ha
s
burned on the Project
s
ite
; the
1959 Yoder
Fire burned approximately
153.9
acres
in the
eastern
portion of the
Project site
.
MFR or Riverside County
may have data rega
rding smaller fires (
other fires
less than 10 acres) that
have occurred on
-
site that have not been included herein. Fire history for the general vicinity of the Project s
ite is
illustrated
in Appendix B, Fire History Map
.
Based on an analysis of the fire history data set, specifically, the years in which the fires burned, the average interval between wildfires within 5 miles of the Project
s
ite was calculated to be
approximately
three
years
with intervals
ranging between 0 (multiple fires in the same year) to
1 1
years. Based on the analysis,
it is expected that wildfire
that could
burn in available unmaintained landscapes
may occur, if weather conditions coincide,
possibly
every two
to three years
,
with the realistic possibility of longer interval occurrences, as observed in the fire history records
and
considering the recent past and ongoing development of the region . Based on fire history, wildfire risk for the Project
site is associated pr
imarily with a
n
on
-
shore
more typical
wildfire burning or spotting on
-
site from the
south
or
we
st,
although a fire approaching from the
north and east
during
a Santa Ana
wind
-
driven fire weather pa
tterns is
also
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
20 FEBRUARY 2024
very
possible. The proximity of the Project to
o
pen space to the
north and
northeast
, has the potential to funnel
Santa Ana winds, thereby increasing local wind speeds and increasing wildfire hazard in the Project vicinity.
2.2.5 Analysis of Wildfire Risk from Adding New Residents
Humans (i.e., human related activities or human created features, services, or processes) are responsible for the majority of California wildfires (Syphard et al. 2007, 2008; Romero -
Calcerrada et al. 2008). Certain human activities
result in sparks, flames
, or heat that may ignite vegetative fuels without proper prevention measures in place. These ignitions predominantly occur as accidents, but may also be purposeful, such as in the case of arson. Roadways are a particularly high source for wildfire ignitio
ns due to high usage and vehicle caused fires (catalytic converter failure, overheated brakes, dragging chains, tossed cigarette, and others) (Harris 2019; Dudek 2008). In Southern California, and
Riverside
County, the population living at, working in, or traveling through the wildland urban interface is vast and provides a significant opportunity for ignitions every day. However, it is a relatively rare event when a wildfire occurs, and an even rarer event
when a wildfire escapes initial containment effort
s. Approximately
90 to 95 percent of wildfires are controlled below 10 acres (CAL FIRE 2019; Santa Barbara County Fire Department 2019).
Research indicates that the type of dense, master planned developments, like the
Whitewood I
Residential
Development
, are not associated with increased vegetation ignitions. Syphard and Keeley (2015) summarize all wildfire ignitions included in the CAL FIRE Fire and Resource Assessment Program (FRAP) database –
dating back
over 100 years. They found, in the case of one
Southern California county (San Diego County), equipment -
caused
fires were by far the most numerous, and these also accounted for most of th e area burned, followed closely by the
area burned by power line fires. This pattern is consistent beyond San Diego County and is applicable in Los Angeles County. Ignitions classified as equipment caused frequently resulted from exhaust or sparks from po wer saws or
other equipment with gas or electrical motors, such as lawn mowers, trimmers or tractors and associated with lower density housing. In San Diego County, and in areas like the open space areas near the Project site in
Murrieta
in
Riverside
Count
y, ignitions were more likely to occur close to roads and structures, and at intermediate structure densities.
As
F
igures
4 through
6 illustrate
, housing density directly influences susceptibility to fire because in higher density developments, there is one interface (the community perimeter) with the wildlands whereas lower density development creates more structural exposure to wildlands, less o r no ongoing landscape maintenance (an intermix
rather than interface), and consequently more difficulty for limited fire resources to protect well -
spaced homes. The
intermix includes housing amongst the unmaintained fuels whereas the proposed project converts all fuels within
the footprint and provides a wide, managed fuel modification zone separating homes from unmaintained fuel and creating a condition that makes defense easier. Syphard and Keeley go on to state that “The
WUI, where housing
density is low to intermediate is an apparent influence in most ignition maps ”further enforcing the conclusion that lower density housing poses a higher ignition risk than higher density communities. They also state that “Development o
f low
-
density, exurban housing may also lead to more homes being destroyed by fire” (Syphard et al. 2013). A vast wildland urban interface already exists in the area s
adjacent to
the
Whitewood I
Residential
Development
Project site
, with
some
older, more fire
-
vulnerable structures, constructed before stringent fire code requirements were imposed on residential development, with varying levels of maintained fuel modification buffers in the area. As discussed in detail throughout this FPP, the Residential Development Project site
is a
planned
ignition
resistant community designed to include professionally managed and maintained fire protection components, modern fire code compliant safety features and specific measures provided where ignitions ar e most likely to occur
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
21 FEBRUARY 2024
(such as roadways). Therefore, the development of the Project would not be expected to materially increase the risk of vegetation ignitions.
Figure
4 . Example higher density development. Homes are ignition resistant and excludes readily ignitable vegetative fuels throughout
and provides a perimeter fuel modification zone. This type of new development requires fewer fire resources to defend and can
mini
mize the likelihood of on
-
site fires spreading off
-
site.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
22 FEBRUARY 2024
F
igure
5 . Example of
“
moderate density
”
development. Homes are located on larger properties and include varying levels of ignition resistance and landscape / fuel modification provision and maintenance. This type of development results in a higher wildland
exposure level for all homes and does
not provide the same buffers from wildfire encroaching onto the site, or starting at a structure and moving into the wildlands as a higher density project.
Figure
6 . Example of “lower density” development
.
H
omes are
interspersed amongst wildland fuels, are of varying ages, and include varying levels of fuel modification zone setbacks. Homes are exposed on most or all sides by flammable vegetation and propert ies
rely solely on owners for maintenance, are often far dist ances from the nearest fire station, and have minimal buffer from on -
site fire
spreading to wildlands.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
23 FEBRUARY 2024
Moreover, frequent fires and lower density housing growth may lead to the expansion of highly flammable exotic grasses that can further increase the probability of ignitions (Keeley et al. 2012). This is not the case with the proposed project as the landsc
apes are managed and maintained to remove exotic fuels that may establish over time.
As discussed above, research indicates that it is less likely for higher density developments to be impacted by wildfires than lower density developments. The same protections that starve wildfire of fuels and minimize or prevent wildfire from transitionin
g into a higher density community or moderate density with high maintenance levels, such as
the
Whitewood I
Project
also serve to minimize or prevent on
-
site fires from transitioning into the
wildlands. Further, the requirement that
each
of the townho
use units
will include
the installation of
their
own
NFPA
13D
automatic resid
ential
interior fire sprinkler
s
ystem
significantly reduces the likelihood that a building fire spreads to the point of flashover, where a structure
or unit
will burn beyond control and produce embers. Interior
fire
sprinkler
s
ystems
are very efficient, keeping fires to the room of origin, or extinguishing the fire before the responding firefighters arrive. Similarly, the
comb
ination of
irrigated
/drought
-
tolerant
and non
-
c
ombustible
roadways and parking
areas inc
luded in the
fuel modification zones
positioned throughout the development areas
as well as the first zones on the perimeter of the
structures within the
P
roject. Irrigated zones include plants with
high internal moisture and spacing between plants and plant groups that 1) make it difficult to ignite and 2) make it difficult for fire to spread plant to plant. Lastly, the nearby
fire station
results
in fast detection of fires and fast
firefighter response, a key in limiting the growth of fires beyond the incipient stage.
Various recreational opportunities, both legal and illegal exist today.
If a wildfire were to ignite from human activity
today, fire detection and response could be delayed due to the remoteness of the area not directly visible from populated areas. Delayed detection would contribute to delayed response to the scene due to the
lack of site
access. Fire size up (determining the needed firefighting resources) and requests for additional resources, including aerial support, also are delayed in comparison to po
st
-
construction of the Project
structures
. If a hiker or mountain
biker
in the area
was to start a fire, detection and response would be anticipated on a fast timeline due to the residents that would be living within the community with the ability to detect fires throughout the property. The quick detection and call to 911 would result i
n faster response from the
nearby
fire stations, which can reach anywhere
within the project quickly. If a fire is detected and cannot be accessed by a responding fire engin e, it can be sized
up and additional aerial and other support requested quickly.
2.2.6 Fire Protection Features’ Beneficial Effect on Wildfire Ignition Risk Reduction
Each of the fire protection features provided as part of the code requirements or customized for this Project are based on the FPP’s evaluation work to protect the
Project
site,
the
proposed
townhouse
structures and
each
individual unit
,
and their occupants from wildfires.
These features also have a similar positive impact on the potential for wildfire ignitions caused by the Project and its inhabitants.
As mentioned previously, the ignition resistant landscapes and structures /individual
to
wnhouse
units
and the
numerous specific requirements would minimize the ability for an on -
site fire to spread to off
-
site fuels, as follows:
1. –
all site landscaping of common areas and fuel
modification zones will be subject to strict plant types that are lower ignition plants with those closest to structures requiring irrigation to maintain high plant moistures which equates to difficult ignit ion. These
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
24 FEBRUARY 2024
areas are closest to structures, where ignitions would be expected to be highest, but will be prevented through these ongoing maintenance efforts.
2. –
the wide FMZ (
extends up to
200
feet wide)
includes specifically selected plant species, very low fuel densities (only 5 0% retention of native plants in
outer zone and irrigated inner zones), and ongoing
Property Management
funded and applied maintenance,
resulting in a wide buffer between the developed areas and the off -
site native fuels.
3. –
all structures
, including
each individual townhouse unit,
will be built to the Chapter 7A
of the Cal
ifornia Building Code
ignition
resistant requirements that have been developed and codified as a direct result of after fire save and loss assessments.
Additionally
,
e
ach
townho
use
unit
will be
separated with
i
ts own
fire
-
r
esistan
ce r
ated
common wall in accordance with
the
Cal
ifornia
Residential Code
Section
R302.2.2
and shall be rated for
fire exposure on both sides
.
These measures result in homes that are designed, built and maintained to withstand fire and embers associated with wildfires. It must be noted that the FMZs would not result in wildfire directly next to these structures. Homes and buildings can be built i n the VHFHSZs and WUI areas
when they are part of an overall approach that contemplates wildfire and provides design features that address the related risk. A structure within a VHFHSZ that is built to these specifications can be at lower risk than an olde
r structure in a non
-
fire hazard severity zone. The ignition resistance of on -
site structures
and
the
ind
ividual townhouse units
would result in a low incidence of structural fires, further minimizing potential for project
-
related wildfires.
4. –
E
ach to
wnh
ouse will include the
installation of its own
NFPA
13D
automatic interior fire sprink
ler system per
CRC Section R313
, meeting
Item 1 of CRC Section R302.2.2
.
Automatic fire
sprinklers in
eac
h
residential
unity
are designed to provide
additional time for occupants to escape the home. Sprinklers in multi -
family and commercial structures are
designed to provide structural protection. The common benefit of fire sprinklers is that they are very successful at assisti
ng responding firefighters by either extinguishing a structural fire or at least, containing the fire to the room of origin and delaying flash over. This benefit also reduces the potential for an open space vegetation ignition by minimizing the possibility
for structure fires to grow large and uncontrollable,
resulting in embers that are blown into wildland areas. This is not the case with older existing homes in the area that do not include interior sprinklers.
5. –
roads provide access for firefighting apparatus. Project roads provide code -
consistent
access throughout the community. Better access to wildland areas may result in faster wildfire response and continuation of the fire agencies’ successful control of w ildfires at small sizes.
6. –
providing firefighting water throughout the Project with fire hydrants accessible by fire engines is a critical component of both structural and vegetation fires. The Project provides firefighting water volume, availability and sustained pressures to the
satisfaction of
MFR
. Water accessibility helps firefighters control
structural fires and helps protect structures from and extinguish wildfires.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
25 FEBRUARY 2024
INTENTIONALLY LEFT
BLANK
14499 26 DECEMBER 2023
3 Anticipated Fire Behavior
3.1 Fire Behavior Modeling
Following field data collection efforts and available data analysis, fire behavior modeling was conducted to document the type and intensity of the fire that would be expected adjacent to the Project site given characteristic features such as topography, vegetation, and weather. Dudek utilized BehavePlus software package version 6 (Andrews, Bevins, and Seli 2008) to analyze potential fire behavior5.
3.2 Fire Behavior Modeling Analysis
An analysis was conducted to evaluate fire behavior variables and to objectively predict flame lengths, intensities, and spread rates for four fire scenarios, including one summer, onshore weather condition (southwest of the Project Site) and three extreme fall, offshore weather condition (north/northeast, and east of the Project Site). These fire scenarios incorporated observed fuel types representing the dominant vegetation representative of the site and adjacent land, in addition to slope gradients, wind, and fuel moisture values. Modeling scenario locations were selected to better understand different fire behavior that may be experienced on or adjacent to the site.
To support the fire behavior modeling efforts conducted for the Project’s Fuel Modification Plan (see Figure 8), a Dudek Fire Protection Planner analyzed the different vegetation types observed on and adjacent to the site and were classified into the aforementioned numeric fuel models. As is customary for this type of analysis, the terrain and fuels directly adjacent to the Project site and fuel modification zones (FMZ) are used for determining flame lengths and fire spread. Vegetation types, which were derived from the field assessment for the Project site, were classified into a fuel model. Fuel models are selected by their vegetation type, fuel stratum most likely to carry the fire, and depth and compactness of the fuels. Fire behavior modeling was conducted for vegetative types that are both on and adjacent to the proposed development. Fuel models were also assigned to illustrate post-Project fire behavior changes. Fuel models were selected from Standard Fire Behavior Fuel Models: a Comprehensive Set for Use with Rothermel’s Surface Fire Spread Model (Scott and Burgan 2005).
Based on the anticipated pre- and post- Project vegetation conditions, three different fuel models were used in the current conditions of the fire behavior modeling effort and one additional fuel model was used to depict a fire post construction, as presented herein. Modeled areas including the moderate- to- high-load shrub and grass-shrub fuels (Fuel Models Gs2, Sh2, and Sh5) found throughout the interior portion of the Project site, as well as in the adjacent areas to the north, south, and east. These fuel types can produce flying embers that may affect the project, but defenses have been built into the structures to prevent ember penetration. Table 1 provides a description of the fuel models observed that were subsequently used in the analysis for the Project. For modeling the post- development condition, fuel model assignments were re-classified to Gr1 representing an irrigated landscape up to 100 feet from the structures.
5 A discussion of fire behavior modeling is presented in Appendix C, Fire Behavior Modeling.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
27 FEBRUARY 2024
Table
1 .
Fuel Models Used for Fire Behavior Modeling
Gs2
Moderate
-
load, Dry
climate grass
-
shrubs
Represents the grass
-
shrub vegetation located
throughout and adjacent to the Project without
maintenance.
<2.0 ft.
Sh2
Moderate
-
load, Dry
Climate Shrubs
Represents the
shrubs/chaparral vegetation
located throughout and adjacent to the Project
without maintenance.
<2.0 ft.
Sh5
High
-
load, Dry Climate
Shrubs
Represents the shrubs/chaparral vegetation
located throughout and adjacent to the Project
without
maintenance.
>4.0 ft.
Gr1
Short, sparse, dry climate
grasses
Fuel Modification Zones 0 and 1: irrigated
landscape throughout the Project site
<1.0 ft.
A total of
four
fire modeling scenarios were completed for the Project area. These modeling scenario locations
were
selected based on the
probability
of
a
fire approaching from these directions during a Santa Ana wind -
driven fire
event (fire scenario
s 1, 2, and 3
) and an on
-
shore weather pattern (fire scenario
4 )
.
Fuel modification includes
the
establishment of
fully
-
irrigated zones on the periphery of the
new residential structure
.
Table
2 summarizes the weather and wind input variables used in the BehavePlus modeling process.
Table
2 .
Fuel Moisture and Wind Inputs
Fuel Models
Gr1 (Post)
;
Gs2, Sh2, and Sh5 (Pre)
Gr1 (Post)
;
Gs2, Sh2, and Sh5
(Pre)
1 hr. Moisture
7%
1%
10 hr. Moisture
8%
2%
100 hr. Moisture
13%
5%
Live Herbaceous Moisture
52%
30%
Live Woody Moisture
104%
60%
20 -
foot Wind Speed (mph)
16 mph (sustained winds)
18 mph (sustained winds); wind
gusts of 50
mph
Wind Directions from north
(degrees)
210
40, 80, and 120
Wind adjustment factor
0.4 0.4
Slope (uphill)
3%
4% to 7%
14499 28 DECEMBER 2023
3.3 Fire Behavior Modeling Results
The results of fire behavior modeling analysis for pre- and post-Project conditions are presented in Table 3 and Table 4, respectively. Identification of modeling run (fire scenarios) locations is presented graphically in Figure 7, BehavePlus Fire Behavior Analysis Map.
As presented, in the Fire Behavior Analysis Summary (Appendix C), wildfire behavior on the Project site is expected to be primarily of moderate to high intensity through the non-maintained surface grass-shrub/shrub-chaparral dominated fuels directly adjacent to the Project site. As mentioned, the BehavePlus fire behavior modeling software package was utilized in evaluating anticipated fire behavior adjacent to the Proposed Project site. Four focused analyses were completed for both the existing project site conditions and the post project conditions, each assuming worst-case fire weather conditions for a fire approaching the project site from the north/northeast, east, and south/southwest. The results of the modeling effort included anticipated values for surface fires flame length (feet), rate of spread (mph), fireline intensity (Btu/ft/s), and spotting distance (miles). The aforementioned fire behavior variables are an important component in understanding fire risk and fire agency response capabilities.
Flame length, the length of the flame of a spreading surface fire within the flaming front, is measured from midway in the active flaming combustion zone to the average tip of the flames (Andrews, Bevins, and Seli 2008). Fireline intensity is a measure of heat output from the flaming front, and also affects the potential for a surface fire to transition to a crown fire. Fire spread rate represents the speed at which the fire progresses through surface fuels and is another important variable in initial attack and fire suppression efforts (Rothermel and Rinehart 1983).
Spotting distance is the distance a firebrand or ember can travel down wind and ignite receptive fuel beds. Four fire modeling scenario locations were selected to better understand the different fire behavior that may be experienced on or adjacent the site based on slope and fuel conditions; these fire scenarios are explained in more detail below:
▪ A fall, extreme off-shore fire (97 th percentile weather condition) burning through moderate- load grass shrub/shrub and chaparral dominated vegetation directly north of the property. The terrain is flat (approximately 5% slope) with potential ignition sources from a car and/or structure fire originating within the existing rural residential homes to the north Project site. This type of fire would typically spread through the grass shrub/shrub and chaparral dominated vegetation relatively slow towards the northern portions of the residential development site, pre-development. ▪ A fall, extreme off-shore fire (97 th percentile weather condition) burning through moderate- load grass shrub/shrub and chaparral dominated vegetation northeast of the property. The terrain is flat (approximately 7% slope) with potential ignition sources from a car and/or structure fire originating within the existing rural residential homes to the northeast or within the naturally-vegetated areas farther to the east/northeast of the Project site. This type of fire would typically spread relatively slow towards the eastern portions of the residential development site, pre-development. ▪ A fall, extreme off-shore fire (97 th percentile weather condition) burning through high-load grass shrub and chaparral dominated vegetation east of the property. The terrain is flat (approximately 4% slope) with potential ignition sources from a car and/or structure fire originating within the existing rural residential homes to the east, from a car fire along Clinton Keith Road, or within the naturally-vegetated
WHITEWOOD I RESIDENTIAL DEVELOPMENT PROJECT - FIRE PROTECTION PLAN
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
29 FEBRUARY 2024
areas farther to the east/south of the Project site
. This type of fire would typically spread
relatively slow
towards the eastern and southern portions of the residential development site, pre -
development.
▪
A
summer
, o
n
-
shore fire (
50 th
percentile weather condition)
burning
through high
-
l
oad
grass
shrub and chaparral dominat
ed vegetation
south of the property and across Clinton Keith Road
. The terrain
is
flat
(approximately
3 % slope) with potential ignition sources from
car fire along Clinton Keith Road or
within the naturally
-
vegetated areas farther to the south of the Project site . This type of fire would typically
spread
relatively slow towards the eastern and southern portions of the residential development site, pre -
development
.
The results presented in
Tables
3 and
4 depict values based on inputs to the BehavePlus software and are not intended to capture changing fire behavior as it moves across a landscape. Changes in slope, weather, or pockets of different fuel types are not accounted for in this analysis. For planni ng purposes, the averaged worst
-
case fire
behavior is the most useful information for conservative fuel modification design. Model results should be used as a basis for planning only, as actual fire behavior for a gi ven location will be affected by many factors, including unique weather patterns, small
-
scale topographic variations, or changing vegetation patterns.
3.3.1 Existing Conditions
Based on the BehavePlus analysis result presented
below
and in Table
s
3 and
4 ,
w
ildfire
behavior
through the non
-
maintained
shrub
-
chaparral dominated
fuels
farther to the south being fanned by 16 mph sustained winds,
from
the
west/northwest
and pushed by
on
-
shore
ocean breezes typically exhibit less severe fire behavior due to lower wind speeds and higher humidity. Under typical onshore weather conditions,
a surface vegetation
fire could have
flame lengths
approaching
15 feet in height and spread rates
of approximately 0.8
mph. Spotting distances, where
airborne embers can ignite new fires downwind of the initial fire, can originate approximately 0.5
miles
aw
ay
.
A worst
-
case
fire behavior under
p
eak weather conditions (represented by Fall Weather, Scenario
3 ) is anticipated
to be a wind
-
driven fire from the
east/northeast
during the fall. Under such conditions, expected surface flame length
are
expected to
r
each
approximately
21 feet with wind speeds of 50+ mph. Under this scenario, fireline intensities reach
4,041
BTU/feet/second with moderate spread rates of
4.2 mph and could have a spotting
distance up to 2.
4 miles away
.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
30 FEBRUARY 2024
Moderate
-
load grass
-
shrub (Gs2)
10.5 (20.5)
3 933 (4,041)
1.0 (4.2)
3 1.0 (
2.4 )
3 Moderate
-
load shrubs (Sh2)
8.5 (15.9)
588 (2,334)
0.2 (1.0)
0.2 (1.0)
Moderate
-
load grass
-
shrub (Gs2)
10.4 (20.5)
3 932 (4,040)
1.0 (4.2)
3 1.0 (
2.4 )
3 Moderate
-
load shrubs (Sh2)
8.4 (15.9)
587 (2,333)
0.2 (1.0)
0.2 (1.0)
Moderate
-
load shrubs (Sh2)
0.2 (1.0)
3 568 (2,314)
8.3 (15.9)
0.4 (1.2)
Moderate
-
load grass
-
shrub (Gs2)
0.9 (4.2)
905 (4,014)
10.3 (20.5)
0.4 (1.4)
Note:
1. W
ind
-
driven
surface
fire.
2. MPH=miles per hour.
3. Flame length, spread rate, and s
potting distance from a wind driven surface fire; it should be noted that the wind mph in parenthesis represent peak gusts of 50 mph
3.3.2 Post
-
Development
Conditions
As previously mentioned, Dudek conducted modeling of the site for post -
fuel modification zones.
MFR
Fuel
Modification Guidelines
require
the
establishment of
a
minimum
2 00
-
foot wide
fuel modification zones that
includes irrigated and thinning zones, however, this project proposes project -
specific
fully
-
irrigated
fuel
modification
zone
s
(Zones
0 and
1 ) beginning at the structure
and extending outward towards the property
line
. For modeling the post
-
FMZ treatment condition, the fuel model assignment for non -
n
ative grass
-
shrub
lands was re
-
classified according to the specific fuels management (e.g., irrigated, fire resistive landscaping) treatment.
Based on the BehavePlus analysis,
post development fire behavior expected in
the
non
-
burnable roadways and
hardscapes and
irrigated
FMZs that are
replanted with plants that are acceptable with the
MFR Approved Plant List
(FMZ Zones 0 and 1
–
Gr1)
under peak weather conditions
experience a significant reduction in flame length and
intensity.
Fuel modification would result in a reduction to
approximately
4.0 feet by the time the
interior irrigated landscapes
of the FMZ (Zone
s 0 and 1
) are reached. During on
-
shore weather conditions, a fire ap
proaching from the
west/southwest
towards the development footprint would
have
low fire intensity and spotting distances due to the higher live and dead fuel moisture contents. These reduction of flame lengths and intensities are assumed to occur within the proposed on
-
site
fuel
modification
.
Therefore, the FMZs proposed for the Project are approximately 4 -
times the flame length of the worst
-
case fire scenario under peak weather conditions in the hillsides east/northeast of the Project site and approximately 8
-
times the flame lengths within the development footprint and would provide
adequate defensible
space to augment a wildfire approaching the perimeter of the Project site .
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
31 FEBRUARY 2024
Fuel Model NB1
N/A
N/A
N/A
N/A
Fuel modification zone
s
0 and
1 (
Gr1
)
4.0 (
4.0 )
3 115 (115)
0.7 (0.7)
3 0.
2 (
0.5 )
3 Fuel Model NB1
N/A
N/A
N/A
N/A
Fuel modification zone
s
0 and
1 (
Gr1
)
4.0 (
4.0 )
115 (115)
0.7 (0.7)
0. 2
(
0.5 )
Fuel Model NB1
N/A
N/A
N/A
N/A
Fuel modification zone
s
0 and
1 (
Gr1
)
4.0 (
4.0 )
115 (115)
0.7 (0.7)
0. 2
(
0.5 )
Fuel Model NB1
N/A
N/A
N/A
N/A
Fuel modification zone
s
0 and
1 (
Gr1
)
1.9 22
0.2 0.1
Note:
1. W
ind
-
driven
surface
fire.
2. MPH=miles per hour.
3. Flame length, spread rate, and s
potting distance from a wind driven surface fire; it should be noted that the wind mph in parenthesis represent peak gusts of 50 mph
The following describes the fire behavior variables (Heisch and Andrews 2010) as presented in Tables 3 and 4
:
▪
Flame Length (feet):
The flame length of a spreading surface fire within the flaming front is measured from midway in the active flaming combustion zone to the average tip of the flames.
▪
Fireline Intensity (Btu/ft/s):
Fireline intensity is the heat energy release per unit time from a one -
foot wide
section of the fuel bed extending from the front to the rear of the flaming zone. Fireline intensity is a function of rate of spread and heat per unit area, and is directly r elated to flame length. Fireline intensity and the
flame length are related to the heat felt by a person standing next to the flames.
▪
Surface Rate of Spread (mph):
Surface rate of spread is the "speed" the fire travels through the surface fuels. Surface fuels include the litter, grass, brush and other dead and live vegetation within about 6 feet of the ground.
The information in Table
5 presents an interpretation of the outputs for
five
fire behavior variables as related to fire
suppression efforts. The results of fire behavior modeling efforts are presented in Table s
3 and
4 . Identification of
modeling run locations is presented graphically
in
Figure
7 of this FPP.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
32 FEBRUARY 2024
Table
5 . Fire Suppression Interpretation
Under 4 feet
Under 100 BTU/ft/s
Fires can generally be attacked at the head or flanks by persons using hand tools. Hand line should hold the fire.
4 to 8 feet
100
-
500 BTU/ft/s
Fires are too intense for direct attack on the head by
persons using hand tools. Hand line cannot be relied on to hold the fire. Equipment such as dozers, pumpers, and retardant aircraft can be effective.
8 to 11 feet
500
-
1000 BTU/ft/s
Fires may present serious control problems
--
torching
out, crowning, and spotting. Control efforts at the fire head will probably be ineffective.
Over 11 feet
Over 1000 BTU/ft/s
Crowning, spotting, and major fire runs are probable.
Control efforts at head of fire are ineffective.
3.4 Project Area Fire Risk Assessment
Wildland fires are a common natural hazard in most of southern California with a long and extensive history.
Southern California landscapes include a diverse range of plant communities, including vast tracts of shrublands and grasslands, like those found o
n and adjacent to the
Whitewood I
Residential Development s
ite. Wildfire in this
Mediterranean
-
type ecosystem ultimately affects the structure and functions of vegetation communities (Keeley 1984) and will continue to have a substantial and recurring role (Keeley and Fotheringham 2003). Supporting this
are the facts that 1) native landscapes, from forest to grasslands, become highly flammable each fall and 2) the climate of southern California has been characterized by fire climatologists as the worst fire climate in the United
States (Keeley 2004) with high winds (Santa Ana) occurring during autumn after a six -
month drought period each
year. Based on this research, the anticipated growing population expanding into WUI areas, and the regions’ fire history, i
t can be anticipated that periodic wildfires may start on, burn onto, or spot into the site. The most common type of fire anticipated in the vicinity of the Project Area is a wind -
driven fire from the north/northeast, moving
through the chaparral and sage
scrub on the adjacent lands.
With the conversion of the landscape to ignition
-
resistant development, wildfires may still encroach upon and drop embers on the site but would not be expected to burn through the site or produce sustainable spot fires
due to the
lack of available fuels. Studies indicate that even with older developments that lacked the fire protections provided in the Project, wildfires declined steadily over time (Syphard, et. al., 2007 and 2013) and further, the acreage burned remaine
d relatively constant, even though th
e number of ignitions temporarily increased. This is due to the conversion of landscapes to ignition resistant, maintained areas, more humans monitoring areas resulting in early fire detection and discouragement of arson, and fast response from the fire su ppression resources that are located
within these developing areas.
Therefore, it will be important that the latest fire protection technologies, developed through intensive research and real
-
world wildfire observations and findings by fire professionals, for both ignition resistant construction and for creating defensible
space in the ever
-
expanding WUI areas, are implemented and enforced. The Project, once developed, would not facilitate wildfire spread and would reduce projected flame lengths to levels that would be
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
33 FEBRUARY 2024
manageable by firefighting resources for protecting the site’s structures, especially given the ignition resistance of the structures and the planned ongoing maintenance of the entire site landscape. The Project will implement the latest fire protection me
asures, including fuel modification along the perimeter edges of the development.
In
addition, the
Project’s
FMZs
(100
-
foot
FMZ widths
)
would be
between 2 and
8 times
wider than the longest
calculated flame length conditions for portions of the proposed de veloped area that abut chamise chaparral and
sage scrub plant communities
(ref
e
rence
Table 4)
.
Given the climatic, vegetative, topographic characteristics, and local fire history of the area, the Project Site, once developed, is determined to be subject to periodic wildfires that may start on, burn toward
, or spot into the site. The
potential for off
-
site wildfire encroaching on, or showering embers on the site is considered moderate
to high
, but
the risk of ignition from such encroachments or ember showers is considered low based on the type of ignition
resistant landscapes and
construction and fire
protection features that will be provided for the structures.
While it is true that humans are the cause of most fires in California, there is no data available that links increases in wildfires with the development of ignition
-
resistant communities. The Project will include a robust fire protection system, as detail
ed in the Project’s FPP. This same robust fire protection system provides protections from on -
site
fire spreading to off
-
site vegetation. Accidental fires within the landscape or structures in the Project will have limited ability to spread. The landscape
throughout the Project and on its perimeter will be highly maintained and much of it irrigated, which further reduces its ignition potential. Structures will be highly ignition resistant on the exterior and the interiors will be protected with automatic sp rinkler systems, which have a very high success rate
for confining fires or extinguishing them. The Project will be a fire -
adapted community with a strong resident
outreach program that raises fire awareness among its residents.
14499 34 DECEMBER 2023
INTENTIONALLY LEFT BLANK
WHITEWOOD I RESIDENTIAL DEVELOPMENT PROJECT - FIRE PROTECTION PLAN Document Path: Z:\Projects\j1449900\MAPDOC\DOCUMENT\Fire Protection\FIG 4 BehavePlusAnalysisMap.mxd 0 500 1,000250
Feet
FIGURE 7
BehavePlus Analysis Map
Fire Protection Plan for the Whitewood I Project
SOURCE: AERIAL- BING MAPPING SERVICE
Project Boundary
SCENARIO RUN #2
SCENARIO RUN #3
SCENARIO RUN #1
SCENARIO RUN #4
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
36 FEBRUARY 2024
INTENTIONALLY LEFT BLAN
K
14499 37 DECEMBER 2023
4 Emergency Response and Service
The following sections analyze the Project in terms of current Murrieta Fire and Rescue (MFR) Fire Service capabilities and resources to provide Fire Protection and Emergency Services to the Project. The analysis that follows examines the ability of the existing nearby MFR fire stations to adequately serve the Proposed Project.
Response times were evaluated using Project build-out conditions. It was assumed that phased construction would include access roads to the newly constructed structures and that the shortest access route to those structures would be utilized.
4.1 Emergency Response Fire Facilities
The project site is located within the Murietta Fire and Rescue (MFR) response area, which includes the corporate limits of the city of Murietta. Table 6 presents a summary of the location, equipment, staffing levels, maximum travel distance, and travel time for the two closest, existing MFR stations responding to the Project. The MFR’s primary service area is approximately 33.6 square miles with an estimated population of 116,000 residents within the City of Murrieta (Murrieta Fire & Rescue 2021-2025 Strategic Plan) 6. The MFR is a career fire service organization consisting of 76 professionals that provide services from five strategically located fire stations, two of which could respond to the Project site in a timely manner (MFR Station Nos. 2 and 4); all MFR stations could respond to the Project site within 20 minutes to an incident. Travel distances are derived from Google road data while travel times are calculated applying the nationally recognized Insurance Services Office (ISO) Public Protection Classification Program’s Response Time Standard formula (T=0.65 + 1.7 D, where T= time and D = distance). The ISO response travel time formula discounts speed for intersections, vehicle deceleration and acceleration, and does not include turnout time. Automatic and/or Mutual Aid agreements with surrounding fire departments are in place and would potentially result in additional resources that are not analyzed in this FPP.
Table 6. Closest Responding MFR Fire Stations Summary
4 28155 Baxter Road
Murietta, California
Engine Company, Brush
Engine
NA 1.3 mi. 2 min. 52
sec.
2 40060 California Oaks Road
Murietta, California
Truck Company, Medic
Patrol Unit
NA 3.1 mi. 6 min.
* Assumes travel distance and time to the project site from either Station 4 or 2. Travel Time is one portion of the “total reflex time”, which also includes call processing, dispatch, arrival and set up times MFR Station 4, located at 28155 Baxter Road, is staffed 24/7 with career firefighters and would provide initial response. It is equipped with one engine company, a brush engine and Battalion Chief. Station 4 will be capable of responding within 3.2 minutes to the proposed entrance of the Whitewood Condo/Apartment Project. Secondary response would be provided from MFR Station 2, which is located at 40060 California Oaks Road, and can respond
6 https://www.murrietaca.gov/DocumentCenter/View/6107/Murrieta-Fire-2021---2025-Strategic-Plan-PDF?bidId=
WHITEWOOD I RESIDENTIAL DEVELOPMENT PROJECT - FIRE PROTECTION PLAN
14499 38 FEBRUARY 2024
within 6 minutes to the proposed entrance. Station 2 is staffed 24-hours per day and houses a Truck and Medic Patrol unit.
Within the area’s emergency services system, fire and emergency medical services are also provided by other agencies. Generally, each agency is responsible for structural fire protection and wildland fire protection within their area of responsibility. However, mutual aid agreements enable non-lead fire agencies to respond to fire emergencies outside their district boundaries. In the project area, fire agencies cooperate under a statewide master mutual aid agreement for wildland fires. There are also mutual aid agreements in place with neighboring fire agencies and typically include interdependencies that exist among the region’s fire protection agencies for structural and medical responses, but are primarily associated with the peripheral “edges” of each agency’s boundary.
4.2 Estimated Calls and Demand for Service from the
Project
Determining the potential impact associated with the Project’s estimated population increase is required in order to compare how many additional calls may be realized and determine what effects they may have on the available response resources. The estimated incident call volume of the Project is based on a conservatively calculated estimate from the maximum potential number of additional persons that would be expected on site. Emergency call volumes related to typical projects, such as new residential developments, can be reliably estimated based on the historical per-capita call volume from a particular fire jurisdiction.
The following estimated annual emergency call volume generated by the Project is based upon per capita data for 2022 from MFR calls within their jurisdiction (MFR 2022 Annual Report). ▪ Total population served: approximately 116,000
▪ 2022 annual calls:11,6167 Per capita call generation: 0.10 ▪ 2022 annual fire calls, including structure, vegetation, vehicle fires, and other fire calls (approximately 5% of calls): 595. Per capita call generation: 0.005.
▪ 2022 annual Emergency Medical Services, traffic accidents and technical rescue (approximately 75% of total calls): 8,634. Per capita call generation: 0.074
▪ 2022 annual other calls (Explosion, Hazardous Materials, Good Intent, Public Service, etc.; approximately 21% of total calls): 2,387. Per capita call generation: 0.021 Using the data above, the estimated annual emergency call volume for the Project site was calculated. In order to provide this conceptual estimate, Dudek made assumptions regarding the estimated population within the Whitewood I Project (257 units x 3.29 persons per unit). Based on this information, the estimated total population of the Project site is projected to be 846 persons. The calculated call volumes by type of call are provided in Table
7. 7 Based on Murrieta Fire & Rescue 2022 Annual Report; https://issuu.com/cityofmurrieta/docs/2022_mfr_annual_report_final_reduced
WHITEWOOD I RESIDENTIAL DEVELOPMENT PROJECT - FIRE PROTECTION PLAN
14499 39 FEBRUARY 2024
Table 7. Calculated Call Volume (Conceptual Based on 846 Persons) Total Other Calls 0.021 18
Total Fires 0.005 4
Total EMS Calls 0.074 63
Total Calls 0.10 85
As mentioned, the Project will increase the call volume at a rate of a conservatively calculated (the actual number of calls may be lower than this estimate) 85 calls per year (1.6 calls per week or 7 to 8 calls per month). Fire Stations 4 and 2 combined incident calls for 2022 is approximately 5,899 calls (approximately 16 calls per day combined). The level of service demand for the Project raises overall call volume, but is not anticipated to impact the existing fire stations to a point that they cannot meet the demand. When the Whitewood I Project site is built out, Fire Stations 2 and 4 could potentially respond to an additional 1.6 calls per week combined.
4.3 Cumulative Impact Analysis
Cumulative impacts from multiple projects within a fire agency’s jurisdiction, like MFR can cause fire response service decline and must be analyzed. The Proposed Project represents a development that would increase the existing call volume by 1.6 calls per week, on average. The resulting impact on fire services has been analyzed within this report and despite the population increase and anticipated call volume increase, the existing fire service delivery system is considered to have capacity to serve the Proposed Project. When compared to standard utilization rates for busy (10 calls per day for an urban station) fire stations (Hunt 2010), it is clear there is capacity to serve the Proposed Project.
Despite the relatively low increase in number of calls per year from the Proposed Project, it contributes to the cumulative impact on fire services, when considered with other anticipated projects within the MFR’s primary response area.
The City responded to approximately 11,616 calls for the 12 month period ending in December 2022.8 This equates to an average of 6.4 calls per day per station. Stations 2 and 4 respond to higher call volumes than this average and the other stations respond to fewer. The increase in additional calls per year, depending on where those calls originate, could result in a significant impact and negatively affect MFR’s response capability. The addition of a sixth fire station, which is currently being explored by MFR, would mitigate this additional call volume, but would need to be situated where it could respond to the most new calls, or reduce the load for otherwise busy fire stations.
The Proposed Projects’ as well as other area projects that may be approved, provide revenue for fire resources through funding via tax allocations and fire impact fees. This revenue source is expected to fund capital improvements to enhance MFR’s response capabilities and at least maintain the current standards for firefighting and emergency response. The City is contemplating constructing a sixth fire station and contributions from the Proposed Project and other City projects could be allocated toward ongoing maintenance of that station. Over the
8 Based on Murrieta Fire & Rescue 2022 Annual Report;
https://issuu.com/cityofmurrieta/docs/2022_mfr_annual_report_final_reduced
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
40 FEBRUARY 2024
long term, it is anticipated that MFR will be able to perform its mission into the future at levels consistent with its’ internal response time goals
.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
41 FEBRUARY 2024
INTENTIONALLY LEFT BLAN
K
14499 42 DECEMBER 2023
5 Fire Safety Requirements – Building
Ignition Resistance, Infrastructure, And
Defensible Space
The MFR Fire Code (Ordinance 584-22) and Murrieta Municipal Code – Chapter 15.24, which has adopted the 2022 edition of the California Fire Code (CFC), based on the 2021 International Fire Code (IFC) including local amendments and additions, 2022 CBC (adopted by reference with several modifications), and 2022 CRC, Title 24, Part 2.5, including applicable portions of Sections R302 and R313, governs the building, infrastructure, and defensible space measures detailed in this FPP; the project will meet applicable codes. The following summaries highlight important fire protection features.
Prior to bringing combustible materials onto the site, utilities shall be in place, fire hydrants operational, an approved all-weather roadway, or an approved road surface alternative in place, and interim fuel modification zones established and approved.
A response map update, including roads and fire hydrant locations, in a format compatible with current mapping standards shall be provided to MFR.
5.1 Fire Apparatus Access
5.1.1 Access Roads
Site access, including road widths and connectivity, must comply with the requirements of the MFR and will include:
▪ Primary access to the Project site will be provided by Whitewood Road and Arendt Lane; proposed interior streets will facilitate access throughout the site. Other interior roads will be provided to meet fire department access requirements to each structure (as amended by Section 503.2.1 of the MFR Fire Code).
The dimensions of fire apparatus access roads shall be in accordance with the following:
• The width of an approved fire apparatus access road is measured flow-line to flow-line. All fire apparatus access roads shall have and maintain an unobstructed vertical clearance of not less than 13 feet 6 inches.
• Fire apparatus access roads shall have an unobstructed improved width of not less than 24 feet, except for single-family residential driveways serving no more than two single-family dwellings, which shall have a minimum of 14 feet of unobstructed improved width. Any of the following, which have separated lanes of one-way traffic: gated entrances with card readers, guard stations, or center medians, are allowed, provided that each lane is not less than 16 feet wide. • Fire apparatus access roads serving multi-family structures shall have an unobstructed improved width of not less than 24 feet. The fire code official may require additional access road improvements, including 26 feet of roadway width when necessary to accommodate an Aerial Fire Apparatus. • Fire apparatus access roads serving commercial, industrial, or buildings greater than two stories shall have an unobstructed improved width of not less than 26 feet to accommodate an Aerial Fire
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
43 FEBRUARY 2024
Apparatus. The fire code official may require additional access road improvements necessary to accommodate an Aerial Fire Apparatus.
▪
Interior circulation streets include all roadways that are considered common or primary roadways for traffic flow through the site and for fire department access serving all proposed structures.
▪
Private and public streets for each phase will meet all fire code requirements, paving, and fuel management prior to combustibles being brought to the site.
▪
Vertical clearance of vegetation (lowest
-
hanging tree limbs), along roadways will be maintained at clearances of 13 feet, 6 inches to allow fire engines passage. Unobstructed vertical clearance must be clear to the sky to allow aerial ladder truck operatio
n.
▪
Roads with a median or center divider will have 20 feet unobstructed width on both sides of the center median or divider. Maximum road grade will not exceed 10%.
▪
F
ire apparatus turnarounds will meet
req
ui
rements
and
MFR
Fire Prevention Standards.
▪
Roadway design features (e.g., speed bumps, humps, speed control dips, planters, and fountains) that could interfere with emergency apparatus response speeds and required unobstructed access road widths will not be installed or allowed to remain on roadway
s. Traffic Calming features may be allowed following
review and approval of the fire code official.
▪
Access roads shall be completed and paved prior to issuance of building permits and prior to the occurrence of combustible construction.
5.1.2 Maximum Dead
-
End Road (cul
-
de
-
sac) Length
▪
According to Section 503.2.5 of the Murrieta Municipal Code, all dead -
end roads in excess of 150 feet in length
shall be provided with approved provisions for turning around emergency access. There are no dead -
end roads
or driveways within the Whitewood I
Development that exceed 150 feet in length.
▪
The
Whitewood I
Project
includes two full access
driveways, one located on Whitewood Road and the other
located on Arendt Lane, providing primary and secondary access to and from the Project Development.
▪
Fire apparatus turnarounds to include turning radius widths approved by MFR.
5.1.3 Gates
No gates are currently proposed
for the Whitewood I Development, however, g
ates on private roads and/or private
driveways are permitted, but subject to Fire Code requirements and standards, including:
•
Gates will be equipped with conforming sensors for detecting emergency vehicle “opticom” strobe lights from any direction of approach, if required.
•
All automatic gates will be equipped with a Knox, emergency key -
operated switch overriding all command
functions and opening the gate(s). Gate activation devices will be equipped with a battery backup or manual mechanical disconnect in case of power failur
e.
•
Further, gates will be:
o
Minimum 20 feet wide of clearance for one
-
way traffic when fully open at entrance.
o
Minimum of two feet wider than road width at exit.
o
Constructed from non
-
combustible or exterior fire
-
rated treated wood materials.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
44 FEBRUARY 2024
o
Inclusive of provisions for manual operation from both sides, if power fails. Gates will have the capability of manual activation from the development side or a vehicle (including a vehicle detection loop).
5.1.4 Driveways
All driveway
grades shall be 10% or less with surfacing and sub
-
base consistent with MFR requirements.
5.1.5 Surface (as amended by Section 503.2.3)
Fire apparatus access roads shall be designed and maintained to support the imposed loads of fire apparatus at 75,000 pounds and shall be hard
-
surfaced, paved, or concrete and suitable for fire apparatus. Pervious pavers may be used when designed, installe
d, and maintained to hold the imposed loads of fire apparatus at 75,000 pounds and are approved by the fire code official. In rural areas, all -
weather surfaces may be utilized for fire apparatus
access roads where slopes permit. All
-
weather surfaces must b
e maintained to engineered standards, failure to do
so will result in violations as outlined in
in the Murrieta Fire Code (Chapter 15.24.120)
.
5.1.6 Premises Identification
Identification of roads and structures will comply with MFR Fire Prevention Standards, as follows:
▪
Approved numbers and/or addresses shall be placed on all new and existing buildings and at appropriate additional locations, plainly visible and legible from the street or roadway fronting the property when approaching from either direction. All commercial addressing shall be illuminated to be visible from the street at all hours. Single
-
family residential
numbers shall contrast with their background and shall meet the following minimum size standards: 4" high with a ½” stroke. For buildings up to 25 feet in height, address numbers shall be a minimum of 12” high with a minimum 2” stroke. For building(s) exce eding 25
feet in height, address numbers shall be a minimum of 24” in height with a minimum 4” stroke and be placed on all sides of a structure. Additional numbers shall be required where deemed necessary by the fire code official, such as rear access door
s, building corners, and entrances to commercial centers. Where access is by means of a private road and the building cannot be viewed from the public way, an approved monument, pole, or other approved sign or means shall be used to identify the structure.
Address
identification shall be maintained
(as amended by Section 505.1)
.
▪
Multiple structures located off common driveways or roadways will include posting addresses on structures and on the entrance to individual driveway/road or at the entrance to the common driveway/ road for faster emergency response.
▪
Roof addresses are required, shall be a minimum of three feet in height, installed on a contrasting background, be durable enough for the weather conditions exposed, and face the street in which it is addressed.
▪
Lighted directory maps will be installed at the two driveway entrances.
▪
Proposed private and public streets within the development will be named, with the proper signage installed at intersections to satisfaction of the Department of Public Works.
▪
Streets will have street names posted on non
-
combustible street signposts. Letters/numbers will be
per MFR standards.
WHITEWOOD I RESIDENTIAL DEVELOPMENT PROJECT - FIRE PROTECTION PLAN
14499 45 FEBRUARY 2024
▪ Temporary street signs shall be installed on all street corners within the Whitewood I Project site prior to the placing of combustible materials on site. Permanent signs shall be installed prior to occupancy of buildings.
5.1.7 Ongoing Infrastructure Maintenance
The Project ’s Owner/HOA/Property Management Company shall be responsible for long term funding and maintenance of FMZs, fire protection systems (including automatic interior fire sprinklers), and internal private roads through annual HOA fees or similar measures.
5.1.8 Pre-Construction Requirements
Prior to bringing lumber or combustible materials onto the site, site improvements within the active development area shall be in place, including utilities, operable fire hydrants, an approved roadway surface, and fuel modification zones established.
These features will be approved by the fire department their designee prior to combustibles being brought on site.9
5.2 Ignition Resistant Construction and Fire Protection Systems
All new structures within Whitewood I Residential Development Project site will be constructed to meet all applicable Building Code standards. Each of the proposed townhouse structures will comply with the enhanced ignition- resistant construction standards of the 2022 CBC (Chapter 7A). These requirements address roofs, eaves, exterior walls, vents, appendages, windows and doors, and result in hardened structures that have been proven to perform at high levels (resist ignition) during the typically short duration of exposure to the flaming-front of burning vegetation from wildfires. Appendix D provides a summary of the requirements for ignition resistant construction.
Furthermore, each individual townhouse unit is separated with its own fire-resistance rated common wall in accordance with the California Residential Code Section R302.2.2 and shall be rated for fire exposure on both sides. Each townhouse unit will also include the installation of its own NFPA 13D automatic interior fire sprinkler system per CRC Section R313, meeting Item 1 of CRC Section R302.2.2.
While these standards will provide a high level of protection to structures in this development, there is no guarantee that compliance with these standards will prevent damage or destruction of structures by fire in all cases.
There are three primary concerns for structure ignition: 1) radiant and/or convective heat, 2) burning embers, and 3) direct flame contact (NFPA 1144 2008, Ventura County Fire Protection District 2011, IBHS 2008, and others).
Burning embers have been a focus of building code updates for at least the last decade, and new structures in the Wildland Urban Interface (WUI) built to these codes have proven to be very ignition resistant. Likewise, radiant and convective heat impacts on structures have been minimized through the Chapter 7A exterior fire ratings for walls, windows and doors. As such, most of the primary components of the layered fire protection system provided the project are required by the MFR, but are worth listing because they have been proven effective for minimizing structural vulnerability to wildfire and, with the inclusion of required interior sprinklers, of extinguishing interior fires, should embers succeed in entering a structure. Even though these measures are now required by the latest Building and Fire Codes, at one time, they were used as mitigation measures for buildings in WUI areas, because they were known to reduce structure vulnerability to wildfire. These measures performed so well they were adopted into the
9 Ordinance 555-20 requires all roadways and fire protection to be installed, tested and accepted prior to combustible construction; MFR will allow the first lift of asphalt as long as it will hod the imposed load of fire apparatus at 75,000 pounds.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
46 FEBRUARY 2024
code. The following project features are required for new development in WUI areas and form the basis of the system of protection necessary to minimize structural ignitions as well as providing adequate access by emergency responders:
1. The
Chapter
7A Materials and
Construction Methods for Exterior Wildfire Exposure (CBC) chapter details the ignition resistant requirements for the following key components of building safely in wildland urban interface and fire hazard severity zones:
a.
Roofing Assemblies (covering, valleys and gutters)
b.
Vents and Openings
c.
Exterior wall covering
d.
Open Roof Eaves
e.
Closed Roof Eaves and Soffits
f.
Exterior Porch Ceilings
g.
Floor projections and underfloor protection
h.
Underfloor appendices
i.
Windows, Skylights and Doors
j.
Decking
k.
Accessory structures
2. New class
-
A fire rated roof and associated assembly. With the proposed class -
A fire rated roof, areas where
there will be attic or void spaces requiring ventilation to the outside environment, the attic spaces will require either ember
-
resistant roof vents
or a minimum 1/16
-
inch mesh (smaller sizes restrict air flow) and
shall not exceed 1/8
-
inch mesh for side ventilation (recommend BrandGuard, O’Hagin or similar vents). All vents used for this project will be approved by
MFR
.
3. Per Chapter 7A of the CBC, m
ulti
-
pane glazing with a minimum of one tempered pane, fire
-
resistance rating
of not less than 20 minutes when tested according to NFPA 257 (such as SaftiFirst, SuperLite 20 -
minute
rated glass product), or be tested to meet the performance requirements of
State Fire Marshal Standard
12 -
7A
-
2 .
Code
-
exceedi
ng
dual pane dual tempered glass
windows (and sliding glass doors, garage doors,
or decorative or leaded glass doors)
will be installed
facing the open space and naturally vegetated areas
to
the north
and the Preservation Area
where
t
he project as reduced fuel
modification
zones
.
4. Per
2022
CRC
,
Tit
le 2
4, Part 2.5,
Sect
ion R302
,
subsection 302.2.2,
the common walls se
parating
townhouse units shall be assigned a fire
-
resista
nce rating in accordanc
e
with Item 1 or 2 (listed below) a
nd
sha
ll be rated for
fir
e exposure from both sides.
Common walls shall extend to and be tight
against the
ex
terior sheathing of the exterior walls, or the inside face of exterior walls without stud cavities, and the
underside of the roof sheathing. The common wall shared by two townhouse units s hall be constructed
without
plumbing
or mechanical equipment, ducts, or vents, or other than water -
fille
d fire sprinkler piping
in the cavity of the common wall. Electrical
installations
shall be in accordance with the California
Electrical
Code (CEC)
. Penetra
tions of the membrane
of
common walls for electrical outlet boxes shall be in
accordance with Section R302.
4 .
a)
Item 1
.
Where an automatic sprin
kler system in accordance with Section R313 is provided , the
common wall shall be not less than 1
-
hour fire
-
resistan
ce
-
rated
wall assembly tested
in accordanc
e
with ASTM E119, UL
263 or Section 703.2.2 of the California Building
Code.
WHITEWOOD I RESIDENTIAL DEVELOPMENT PROJECT - FIRE PROTECTION PLAN
14499 47 FEBRUARY 2024
b) Item 2. Where an automatic sprinkler system in accordance with Section R313 is not provided, the common wall shall be not less than 2-hour fire-resistance-rated assembly tested in accordance with ASTM E119, UL 263 or Section 703.2.2 of the California Building Code. • Exception: Common walls are permitted to extend to and be tight against the inside of the exterior walls if the cavity between the end of the common wall and exterior sheathing is filled with a minimum 2-inch nominal thickness wood studs.
5. As part of this Project, each individual townhouse unit will include the installation of its own NFPA 13D automatic interior fire sprinkler system per CRC Section R313, meeting Item 1 of CRC Section R302.2.2.
6. The proposed pool equipment building shall be constructed of non-combustible concrete masonry unit (CMU) construction with a metal or concrete roof.
7. Modern infrastructure, access roads, and water delivery system.
5.3 Infrastructure and Fire Protection System
Requirements
5.3.1 Water Supply
The Whitewood I Project site is not currently served by a local water district (outside of district boundaries); the Eastern Municipal Water District (EWD) provides service for the areas surrounding the project site. There is currently a 12-inch water main within the Whitewood Road right-of-way. Water service arrangement will need to be made to supply sufficient fire flows and pressure to meet the demands for required on site fire hydrants and interior fire sprinkler systems for all structures. This shall include two points of water connection; one from Whitewood Road and one from Arendt Lane.
5.3.2 Fire Hydrants
Fire Hydrants shall be located along fire access roadways and adjacent to each structure, as determined by the MFR and current fire code requirements to meet operational needs. Fire Hydrants will be consistent with applicable Design Standards.
5.3.3 Automatic Fire Sprinkler Systems
As part of this Project, each individual townhouse unit will include the installation of its own NFPA 13D automatic interior fire sprinkler system per CRC Section R313, meeting Item 1 of CRC Section R302.2.2. CRC Section R313.1 states that an automatic residential interior fire sprinkler system shall be installed in townhouses. The automatic residential fire sprinkler systems for townhouses shall be designed and installed in accordance with CRC Section R313.3 or NFPA 13D (Section R313.1.1).
• CRC Section R313.3 outlines the design and installation of the residential automatic sprinkler systems shall be in accordance with NFPA 13D or Section R313.3, which shall be considered equivalent to NFPA 13D. Partial residential sprinkler systems shall be permitted to be installed only in buildings not required to be equipped with a residential sprinkler system. Section R313.3 shall apply to stand- alone and multipurpose wet-pipe sprinkler systems that do not include the use of antifreeze. A multipurpose
WHITEWOOD I RESIDENTIAL DEVELOPMENT PROJECT - FIRE PROTECTION PLAN
14499 48 FEBRUARY 2024
automatic sprinkler system shall supply domestic water to both fire sprinklers and plumbing fixtures. A stand-alone sprinkler system shall be separate and independent from the water distribution system. • Fire sprinkler plans for each individual townhouse unit will be submitted and reviewed by MFR for compliance with the applicable fire and life safety regulations, codes, and ordinances as well as the MFR Fire Prevention Standards for fire protection systems.
5.4 Defensible Space and Vegetation Management
5.4.1 Defensible Space and Fuel Modification Zone (FMZ) Requirements
WUI fire protection requires a systems approach, which includes the components of infrastructure and water, structural safeguards (addressed in the FPP), and adequate defensible space setbacks. This section provides defensible space details for the Whitewood I Residential Development Project.
A fuel modification zone (FMZ) is a strip of land where combustible vegetation has been removed and/or modified and partially or totally replaced with more adequately spaced, drought-tolerant, fire resistant plants in order to provide a reasonable level of protection to structures from wildland fire. According to MFR’s Fuel Modification Guidelines, a typical landscape/fuel modification installation consists of three Zones. Zone A, extends 30 feet from the structure and is fully irrigated. Zone B extends 100 feet from the structure and consists of thinning by a minimum of 50% so that the maximum coverage does not exceed 50%. Land within this zone must be free of debris, deadwood, branches touching the ground, and other dry or dead vegetation. Zone C extends 200 feet from the structure and consists of thinning by a minimum 30%. However, based on the Project’s site plan, the southern, western, and eastern portions of the Project site achieve 200 feet of FMZ, through a combination of onsite and offsite equivalent FMZ (Whitewood Road and existing residential community to the west, Clinton Keith Road to the south, and the road improvements to Arendt Lane and existing rural single-family residential lots to the east. Due to property boundary restraints along the northern property boundary and the Preservation Areas in the north-center portion and northwestern corner of the project site, a full 200 feet of on-site fuel modification is not achievable; instead, the Project Owner will either need to pursue an off-site interim easement from the existing adjacent single-family residential lots to the north. If that is not achievable, then alternative methods and materials of construction (i.e., the installation of a six-foot masonry fire wall along the northern edge where 200 feet is not achievable and exterior building hardening on the exposed side of the structures (upgraded dual pane dual tempered windows and Type X gypsum drywall)) will be proposed to mitigate for the reduced fuel modification along the northern property boundary and around the Preservation Areas. The Project’s Conceptual Fuel Modification Plan (Figure 8) conceptually illustrates the minimum FMZ Plan proposed for the Project site which consists of two fully-irrigated zones; a 5-foot Ember-Resistant Zone 0 and up to a 100-foot fully irrigated Zone A (where achievable) landscaped area with MFR approved plant species. Within Zone A is an Ember-Resistant Zone extending from the exterior wall surface of the building to 5-feet on a horizontal plane. Within this zone, all combustible material shall be removed. Landscape within the remaining portion of the Zone A FMZ area of the Development Footprint will minimally meet Zone A standards and will include a combination of irrigated landscapes and non-combustible road and hardscape surface areas that will be maintained by the Project’s Property Manager and by the private property owners , as detailed below. Due to the footprint of the proposed development, the Project will no include Zone B or C FMZ areas.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
49 FEBRUARY 2024
Cohen (1995) performed structure ignition fire research studies that suggest, as a rule -
of
-
thumb, larger flame
lengths and widths require wider fuel modification zones to reduce structure ignition. For example, valid Structure Ignition Assessment Modeling
results indicate that a 20
-
foot
-
high flame has minimal radiant heat to ignite a
structure (bare wood) beyond 33 feet (horizontal distance). Whereas, a 70 -
foot
-
high flame requires about 130 feet
of clearance to prevent structure ignitions from radiant heat (Cohen and Butler 1996). For this fire study example,
bare wood was used, which is
considerably
more combustible
than the non
-
combustible exterior materials for the
proposed project.
Although FMZs are very important for setting back structures from adjacent unmaintained fuels, the highest concern is considered to be from firebrands or embers as a principal ignition factor. To that end, the Project site, based on its location and ember
potential, is required to include the latest ignition and ember resistant construction materials and methods for roof assemblies, walls, vents, windows, and appendages, as mandated by the MFR
and
City
’s Fire
and Building Codes (e.g., Chapter 7A)
.
5.4.1.1 Fuel Modification
Zone
Description
(0
-
10 0 feet wide)
All
of the interior landscaped areas will meet
FMZ
standards. All highly flammable native vegetation shall be remove
d
. Th
e FMZ
will be planted with drought
-
tolerant, less flammable plants. The
Proposed Project’
s plant palette
will be approved by the
fire department
. A permanent, automatic irrigation system will be installed the FMZ
to
maintain hydrated plants.
T
he Ember
-
Resistant Zone is applicable site
-
wide and is measured from the exterior wall of the structure outward to 5
-
feet (horizontal)
and falls within the irrigated Zone
A
FMZ
.
The ember
-
resistant zone is designed to keep fire or
embers from igniting materials that can spread the fire to your home .
The
Immediate
Zone includes the following key components:
•
The use of hardscaping like gravel, pavers, concrete, and other non -
combustible mulch materials. No
combustible bark or mulch.
•
Remove all dead and dying weeds, grass, plants, shrubs, trees, branches, and vegetative debris (leaves, needles, cones, bark, etc.); check the roofs gutters, decks, porches, and stairways.
•
Remove all branches within 10 feet of any chimney or stovepipe outlet.
•
Limit plants in this area to low growing, nonwoody, properly watered and maintained plants.
•
Relocate firewood and lumber to be a minimum 30 feet or more from the structure.
•
Vegetation limited to no more than 6” to 18” in height
.
•
Vegetation shall be irrigated
.
Zone
A
e
xtends
100
feet
from buildings, structures, decks, or to your property line, whichever is closer. Zone A
includes the following key components:
•
Irrigated by the automatic or manual system to maintain healthy vegetation and fire resistance .
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
50 FEBRUARY 2024
•
Remove all dead plants, grass, and weeds.
•
Remove dead or dry leaves and pine needles from yard, roof, and rain gutters.
•
Remove branches that hang over your roof and keep dead branches 10 feet away from chimneys.
•
Trim trees regularly to keep branches a minimum of 10 feet from other trees.
•
Remove or prune flammable plants and shrubs near windows.
•
Remove vegetation and items that could catch fire from around and under decks, balconies, and stairs.
•
Create separation between trees, shrubs, and items that could catch fire such as patio furniture, wood piles, and swing sets.
•
Landscaping and vegetation in this zone shall consist primarily of green lawns, ground covers (not exceeding
4 inches in height), and spaced shrubs.
•
Plants in Zone
A
shall be inherently highly fire
-
resistant and spaced approximately,
Plants shall be on the
approved fuel modification plant list
.
•
Trees are not recommended for Zone
A
unless they are dwarf varieties or mature trees of small stature.
•
Prohibited plant species
(Appendix E
)
shall not be within 30 feet or more of the structures.
•
Vines and climbing plants shall not be allowed on any structure.
5.4.2 Vegetation Management
Maintenance
Vegetation management, i.e., assessment of fuel modification zone condition and removal of dead and dying
material,
shall be completed annually by May 1 of each year and more often as needed for fire safety, as determined by the MFR. Whitewood
I Project site
shall be responsible for all vegetation management throughout the Project, in compliance with the project FPP.
The permanent FMZ required for Whitewood I Project will be maintained by the property owner who will be responsible for FMZ vegetation management once the project is built out and the adjacent areas are developed.
The Owner or Property Manager will be resp
onsible for vegetation management in perpetuity. A third -
party
consultant shall be hired annually to perform an inspection and provide a written report of compliance to MFR (filed on or before May 1 each year). This
requirement
shall be a disclosure docume
nt if the property is sold and is
required of future owners as well.
O
n
-
going/as
-
needed fuel modification zone maintenance
during the interim period while
the
Whitewood
I
Project is
built out and adjacent parcels are developed, which may be one or more years, will include
necessary measures for
consistency with the FPP, including
:
▪
Removal or thinning of undesirable combustible vegetation and replacement of dead or dying landscaping.
▪
Maintaining ground cover
at a height not to exceed 18 inches. Annual grasses and weeds shall be maintained at a height not to exceed
three
inches.
▪
Removing a
ccumulated plant litter and dead wood. Debris and trimmings produced by thinning and pruning should be removed from the site or chipped and evenly dispersed in the same area to a maximum depth of
four inches
.
▪
Maintaining manual and automatic irrigation systems for operational integrity and programming.
Effectiveness should be regularly evaluated to avoid over or under -
watering.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
51 FEBRUARY 2024
▪
Compl
ying
with the
se
FPP
measures
on a
year
-
round
basis
. Annual inspections are conducted following the
natural drying of grasses and fine fuels, between the months of May
and June
, depending on precipitation
during the winter and spring months.
5.4.3 Environmentally Sensitive Areas/Open Space
Once the FMZs are in place, there will not be a need to expand them as they have been planned to meet the fire code. However, if unforeseen circumstances were to arise that required hazard reduction within an area considered environmentally sensitive or pa
rt of the Multispecies Conservation Plan, it may require approval from the County and the appropriate resource agencies (California Department of Fish and Game, U.S. Fish and Wildlife Service, U.S. Army Corps of Engineers) prior to any vegetation managemen t activities occurring within those areas.
5.4.4 Prohibited
Plants
Certain plants are considered
prohibited
in the landscape due to characteristics that make them highly flammable.
These characteristics can be physical (structure promotes ignition or combustion) or chemical (volatile chemicals increase flammability or combustion characteristics). The plants inc luded in the
Prohibited Plant List
(Appendix
E
)
are
unacceptable from a fire safety standpoint, and will not be planted on the site or allowed to establish opportunistically within fuel modification zones or landscap ed areas.
5.4.5 Construction Phase Vegetation Management
Vegetation management
measures
shall be
implemented
at commencement and throughout the construction
phase. Vegetation management shall be performed pursuant to the FAHJ on all building locations prior to the start of work and prior to any import of combustible construction materials. Adequate fuel breaks s hall be created around
all grading, site work, and other construction activities in areas where there is flammable vegetation .
14499 52 DECEMBER 2023
INTENTIONALLY LEFT BLANK
WHITEWOOD I RESIDENTIAL DEVELOPMENT PROJECT - FIRE PROTECTION PLAN Date: 12/20/2023 - Last saved by: mmcginnis - Path: \\dudek.int\data\GISData\Projects\j1449900\MAPDOC\DOCUMENT\Fire Protect ion\Fig 8 Fuel Mod Plan - 20231219.mxd Preservation
Area
Preservation
Area
9 1818
2020
28 33
33 33
35 39
39 40
41 42
59 60
61 65
67 67
72 8080
82 82
86 88
91 Proposed Project Fuel Modification Plan
Fire Protection Plan for the Whitewood I Project
SOURCE: AERIAL-ESRI MAPPING SERVICE 2022; DEVELOPMENT-WILSON MIKAMI CORPORATION 2023 0 12060
Feet
FIGURE 8
Project Boundary
Retaining Wall
FMZ Dimension
Fuel Modification Zone
On-site Fuel Modification Zone (irrigated
landscape/hardscape)
Interim Off-site Fuel Modification Easement or
a Free Standing Wall along Project Boundary
where 100 feet is no achieveable
FMZ Equivalent
6-foot Non-Combustible Fire Wall
Structures requiring mitigation measures
Exposed side of structures requiring mitigation
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
54 FEBRUARY 2024
INTENTIONALLY LEFT BLAN
K
14499 55 DECEMBER 2023
6 Alternative Materials and Methods for
Non-Conforming Fuel Modification
As previously mentioned, due to property boundary constraints and the preservation of on-site wetland areas in the north-center portion and northwest portion of the Project site (Preservation Areas), the Project is unable to fully achieve the standard FMZ width along the northern boundary or in the northwest portion of the Project site. As such, this FPP describes additional measures options that will be implemented to mitigate the non-conforming fire-related threats and reduced fuel modification zone. These measures are customized for this site based on the analysis results and focus on providing functional equivalency as a County-defined, full fuel modification zone.
As experienced in numerous wildfires homes in the WUI are potential fuel. The distance between the wildland fire that is consuming wildland fuel, and the home (“urban fuel”) is the primary factor for structure ignition (not including burning embers). The closer a fire is to a structure, the higher the level of heat exposure (Cohen 2000). However, studies indicate that given certain assumptions (e.g., 10 meters (roughly 32 feet) of low fuel landscape, no open windows), wildfire does not spread to homes unless the fuel and heat requirements (of the home) are sufficient for ignition and continued combustion (Cohen 1995, Alexander et al. 1998). Construction materials and methods can prevent or minimize ignitions. Similar case studies indicate that with nonflammable roofs and vegetation modification from 10–18 meters (roughly 32–60 feet) in southern California fires, 85–95% of the homes survived (Howard et al. 1973, Foote and Gilless 1996). Similarly, San Diego County after fire assessments indicates strongly that the building codes are working in preventing home loss: of 15,000 structures within the 2003 fire perimeter, 17% (1,050) were damaged or destroyed. However, of the 400 structures built to the 2001 codes (the most recent at the time), only 4% (16) were damaged or destroyed. Further, of the 8,300 homes that were within the 2007 fire perimeter, 17% were damaged or destroyed. A much smaller percentage (3%) of the 789 homes that were built to 2001 codes were impacted and an even smaller percentage (2%) of the 1,218 structures built to the 2004 Codes were impacted (IBHS 2008). Damage to the structures built to the latest codes is likely from flammable landscape plantings or objects next to structures or open windows or doors (Hunter 2007).
These results support Cohen’s (2000) findings that if a community’s homes have sufficiently low home ignitability, the community can survive exposure to wildfire without major fire destruction. This provides the option of mitigating the wildland fire threat to homes/structures at the residential location without extensive wildland fuel reduction. Cohen’s (1995) studies suggest as a rule-of-thumb, larger flame lengths, and widths require wider fuel modification zones to reduce structure ignition. For example, valid SIAM results indicate that a 20-foot-high flame has minimal radiant heat to ignite a structure (bare wood) beyond 33 feet (horizontal distance). Whereas, a 70-foot-high flame may require about 130 feet of clearance to prevent structure ignitions from radiant heat (Cohen and Butler 1996). This study utilized bare wood, which is more combustible than the ignition-resistant exterior walls for structures built today. The proposed FMZ is approximately four times the length of the predicted flame length. Additionally, the Project site is adjacent to existing properties with existing defensible space, creating a reciprocal FMZ.
As indicated in this report, the FMZs and additional fire protection measures proposed for the Project provide equivalent wildfire buffer but are not standard zones. Rather, they are based on a variety of analysis criteria including predicted flame length, fire intensity (Btu), site topography and vegetation, extreme and typical weather, the position of structures on pads, position of roadways, adjacent fuels, fire history, current vs. proposed land use, neighboring communities relative to the proposed Project, and type of construction. The fire intensity research conducted by Cohen (1995), Cohen
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
56 FEBRUARY 2024
and Butler (1996), and Cohen and Saveland (1997)
,
and Tran et al. (1992) supports the fuel modification alternatives proposed for this
P
roject.
6.1 Additional Structure Protection Measures
The following additional measures
will be implemented to “mitigate” potential structure fire exposure related to the northern
and northwestern portions
of the Project. These measures are customized for this site, its unique topographical and vegetative conditions, and focus on providing functional equivalency as a full fuel modification zone. In order to provide compensating structural protection in the absence of a
2 00
-
foot
-
wide FMZ all around the
entire
site, and in addition to the residences being built
to the latest ignition resistant codes
, the Project site will
incl
ude
the following features for additional fire prevention, protection, and suppression:
1. Pursue obtaining
an interim
off
-
site FMZ
eas
e
ment
from the property owner to the north, allowing the
Whitewood I Project to maintain the approximately 20 feet of off -
site fuel modification needed to
achieve a full
2 00 feet of fuel modification along the northern property boundary.
2. If it is not possible to obtain the off
-
site interim FMZ easement, then the property owner
will be required
to
provide the following code exceeding
mitigations to the structures along the northern property boundary and in the northwestern portion of the property adjacent to the Preservation Area s
:
a.
P
rovide
(and sliding glass doors, garage
doors, or decorative or leaded glass doors)
facing the open space and naturally vegetated areas to
the north
and the Preservation Area
. Dual pane, one pane tempered glass has been shown during testing and after
a
fire
,
assessments to significantly decrease the risk of breakage and ember entry into structures. Therefore, requiring code
-
exceeding dual
-
pane, both panes tempered is anticipated
to be an important safety measure that provides enhanced structure protection and provides mitigation for reduced fuel modification zones and limited setbacks from
adjacent structures.
The
window upgrade also exceeds the requirements of Chapter 7A of the CBC and provid es
additional
protection for the structure’s most vulnerable, exterior side ;
AND
b.
On the wildland exposed sides
/Preservation Area sides
of the structures along the northern side
and in the northwestern portion
of the development shall also include
one layer of
5/8
-
inch Type X
fire rated gypsum sheathing applied behind the exterior covering or cladding (stucco or exterior siding) on the exterior side of the framing, from the foundation to the roof for a facade facing the open space and naturally vegetated areas
. 5/8
-
inch Type X fire rated gypsum sheathing is required
to be manufactured in accordance with established ASTM standards defining type X wallboard sheathing as that which provides not less than one
-
hour fire resistance when tested in specified
building a
ss
emblies and has been tested and certified as acceptable for use in a one -
hour fire
rated system.
CertainTeed Type X Gypsum Board has a Flame Spread rating of 15 and Smoke Developed rating of 0, in accordance with ASTM E 84, (UL 723, UBC 8 -
1, NFPA 255, CAN/ULC
-
S102)
; UL classified for Fire Resistance (ANSL/UL 263; ASTM E119) and listed under UL File No.
CKNX.R3660 (Certainteed, 2021).
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
57 FEBRUARY 2024
3. In addition, the applicant shall p
rovide a noncombustible,
6 -
foot
-
high
concrete masonry unit (CMU)
fire
wall a
long the
northern edge where 100 feet of FMZ is not achievable
, making sure the wall extends
20 feet be
yond the footprint of the buildings
.
These walls will be installed to function as heat
-
deflecting
walls.
The
northern boundary provides
an opportunity to place a non
-
combustible, six
-
foot tall, heat
-
deflecting wall (lower 1 to 2 feet block wall and upper 4 to 5 feet dual pane, one pane tempered glazing or a six
-
foot
high CMU block wall) to provide additional deflection for these lots to compensate for the reduced fuel modification zones.
Walls like these have proven to deflect heat and airborne embers on numerous wildfires in San Diego, Orange
, Los Angeles, Ventura, and Santa Barbara County. Rancho Santa Fe Fire Protection District, Laguna Beach Fire Department, Orange County Fire Authority, and others utilize these walls as Alternative methods based on observed performance during wildfires. Th is
has led to these agencies approving use of non
-
combustible landscape walls as mitigations for reduced
fuel modification zones and reduced setbacks at top of slope. These walls are consistent with NFPA 1144 Standard for Reducing Structure Ignition Hazard
s from Wildland Fire
–
2008 Edition, Section
5.1.3.3 and A.5.1.3.3 and International Urban Wildland Interface Code (ICC 2012). NFPA 1144, A.5.1.3.3 states: “Noncombustible walls and barriers are effective for deflecting radiant heat and windblown embers fr
om structures.” These walls and barriers are usually constructed of noncombustible materials (concrete block, bricks, stone, stucco) or earth
and the open cells
of the
CMU fire wall shall be filled
.
The information provided herein supports the ability of the proposed structures throughout the development
and
FMZs to withstand the predicted short duration, moderate to high -
intensity wildfire
,
and ember shower that would
be expected from
a
wildfire burning in the vicinity of the site or within the site’s landscape .
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
58 FEBRUARY 2024
INTENTIONALLY LEFT BLAN
K
14499 59 FEBRUARY 2024
7 Justification for Reduced Fuel
Modification Zones
As presented in this FPP, the FMZs provided for the proposed Whitewood I Project are not standard FMZs. Rather, the structures along the northern portion of the project site cannot achieve the required 200 feet of FMZ through a combination of on-site and off-site equivalent FMZs due to lot constraints and Project boundary limitations. An important component of a fire protection system for this Project is the provision for ignition-resistant construction and modified vegetation buffers. The structure ignition resistance standards detailed in the 2022 California Fire Code, Chapter 7A of the 2022 California Building Code, and applicable sections of the 2022 California Residential Code, will enable the new multi-family residential townhouse structures to withstand the type of wildfire that may occur in the fuels outside the development footprint. Fuel modification zone requirements will provide a reasonable level of wildfire protection to the ignition resistant structure. Additionally, undesirable, highly flammable plant species shall not be planted in fuel modification zones. For all structures along the northern portion of the property that are unable to achieve the full 200-foot FMZ, windows (and sliding glass doors, garage doors, or decorative or leaded glass doors) facing the open space and naturally vegetated areas will be required to include the installation of code-exceeding dual pane with both panes tempered glass. Additionally, the exposed sides of structures shall also include the installation of one (1) layer of code-exceeding 5/8-inch Type X fire rated gypsum sheathing applied behind the exterior covering or cladding (stucco or exterior siding) on the exterior side of the framing, from the foundation to the roof for a facade facing the open space and naturally vegetated areas. The installation of one (1) layer of 5/8-inch Type X fire rated gypsum sheathing increases a wall's fire rating to a minimum of 1-hour, from the 30-minute rating for standard ½-inch drywall. Also, yearly fuel modification maintenance shall be required for all portions of the development by the Project’s HOA and each individual property owner. The communities HOA as well as individual property owners, shall be responsible for obtaining an FMZ inspection and report from a qualified MFR- approved 3rd party inspector in May of each year. In addition to the code-exceeding building enhancements, the project also proposes the construction of a 6-foot-high CMU fire wall along the northern property boundary, and will function as heat-deflecting wall and stop the progression of a ground fire from advancing into the development.
Dudek has found that the code exceeding mitigation measures provided have been used for many other similar successful projects and demonstrate that they meet or exceed the code required 200 feet fuel modification zone.
Fire behavior modeling, as previously presented, was used to predict flame lengths and was not intended to determine sufficient fuel modification zone widths. However, the results of the fire modeling provide important fire behavior projections, which is key supporting information for determining buffer widths that would minimize structure ignition and provide “defensible space” for firefighters. With that said, it is anticipated that the proposed structures will be able to withstand the short duration, low to moderate intensity fire and ember shower that is projected from off-site, adjacent fuels based on several factors, as discussed below.
7.1 Structure Ignition
There are three primary concerns for structure ignition: 1) radiant and/or convective heat, 2) burning embers, and 3) direct flame contact (NFPA 1144 2008, IBHS 2008, and others). Burning embers have been a focus of building code updates for at least the last decade, and new structures in the WUI built to these codes have proven to be very ignition resistant. Likewise, radiant and convective heat impacts on structures have been minimized through the Chapter 7A exterior fire ratings for walls, windows and doors. Further, per the 2022 CRC, Title 24,
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
60 FEBRUARY 2024
Part 2.5,
Sect
ion R302
,
subsection 302.2.2,
the common walls se
parating
townhouse units shall be assigned a
fire
-
resista
nce rating in accordanc
e
with Item 1 or 2 (listed below) a
nd sha
ll be rated for
fir
e exposure from both
sides.
P
rovisions for modified fuel areas separating wildland fuels from structures have reduced the number of fuel
-
related structure losses. As such, most of the primary components of the layered fire protection system provided
for
the
development
are required by
the
City
of
Murrieta
and
S
tate codes but are worth listing because
they have been proven effective for minimizing structural vulnerability to wildfire and, with the inclusion of required
NFP
A 13D automatic
interior
fire
sprinkler
s
ystems
(required in the 2013 Building/Fire Code update)
for each townhouse unit
, of extinguishing interior fires, should embers succeed in entering a structure.
Even
though these measures are now required by the latest Building and Fire Codes, at one time, they were used as mitigation measures for buildings in WUI areas, because they were known to reduce structure vulnerability to wildfire. These measures performe
d so well, they were adopted into the code. The following project features are required for
this new
development in WUI areas and form the basis of the system of protection n
ecessary to
minimize structural ignitions as well as providing adequate access by emergency responders:
1. Application of Chapter 7A
of the CBC
, ignition resistant building requirements
, along with applicable
s
ections of the 2022 CRC, including Section
R
302, subsection
302.2.2
.
2. Minimum 1
-
hour rated exterior walls and doors
.
3. Multi
-
pane glazing with a minimum of one tempered pane, fire
-
resistance rating of not less than 20 minutes
when tested according to NFPA 257, or be tested to meet the performance requirements of State Fire Marshal Standard 12
-
7A
-
2 .
.
Dual pane, one pane tempered glass has been shown
during testing and in after fire assessments to significantly decrease the risk of breakage and ember entry into structures. Therefore, requiring code
-
exceeding dual pane, both panes tempered is anticipated
to be
an important safety measure that provides enhanced structure protection and provides mitigation for reduced fuel modification zones and limited setbacks from adjacent structures.
The window upgrade also
exceeds the requirements of Chapter 7A of th
e CBC and providing additional protection for the structure’s most vulnerable, exterior side.
4. Ember resistant vents (recommend BrandGuard or similar vents) .
5. Installation of
an
NFPA 13D, a
utomatic
residential
interior fire sprinkler system
within each
individual
to
wnhouse unit
to code for occupancy type.
7.2 Fuel Separation
As experienced in numerous wildfires, including the most recent fire storms in San Diego County (2003 and 2007), homes in the WUI are potential fuel. The distance between the wildland fire that is consuming wildland fuel s
and
the home (“urban fuel”) is the primary factor for structure ignition (not including burning embers). The closer a fire is to a structure, the higher the level of heat exposure (Cohen 2000). However, studies indicate that given certain assumptions (e.g
., 10 meters of low fuel landscape,
no open windows), wildfire does not spread to homes unless the fuel and heat requirements (of the home) are sufficient for ignition and continued combustion (Cohen 1995, Alexander et al. 1998). Construction materials and methods can prevent or minimize ig nitions. Similar case studies
indicate that with nonflammable roofs and vegetation modification from 10 to 18 meters (roughly 32 to 60 feet) in
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
61 FEBRUARY 2024
southern California fires, 85% to 95% of the homes survived (Howard et al. 1973, Foote and Gilless 1996). Similarly, San Diego County after fire assessments indicate strongly that the building codes are working in preventing home loss: of 15,000 structures
within the 2003 fire perimeter, 17% (1,050) were damaged or destroyed. However, of the 400 structures built to the 2001 codes (the most recent at the time), only 4% (16) were damaged or destroyed.
Further, of the 8,300 homes that were within the 2007 fire
perimeter, 17% were damaged or destroyed. A much
smaller percentage (3%) of the 789 homes that were built to 2001 codes were impacted and an even smaller percentage (2%) of the 1,218 structures built to the 2004 Codes were impacted (IBHS 2008). Damage to the
structures built to the latest codes is likely from flammable landscape plantings or objects next to structures or open windows or doors (Hunter 2008).
These results support Cohen’s (2000) findings that if a community’s homes have a sufficiently low home ignitability, the community can survive exposure to wildfire without major fire destruction. This provides the option of mitigating the wildland fire thr
eat to homes/structures at the residential location without extensive wildland fuel reduction.
Cohen’s (1995) studies suggest, as a rule
-
of
-
thumb, larger flame lengths and widths require wider fuel modification zones to reduce structure ignition. For examp
le, valid SIAM results indicate that a 20
-
foot
-
high flame has minimal
radiant heat to ignite a structure (bare wood) beyond 33 feet (horizontal distance). Whereas, a 70 -
foot
-
high flame
requires about 130 feet of clearance to prevent structure ignitions fro m radiant heat (Cohen and Butler 1996). This
study utilized bare wood, which is more combustible than the ignition resistant exterior walls for structures built today. Obstacles, including steep terrain and non
-
combustible
fire
walls can block or deflect a
ll or part of the
radiation and heat, thus making narrower fuel modification distances possible. Fires in ravines, chutes, coves, v -
drainages, and steep
-
sided canyons can, under specific conditions, result in an upward draft, similar to a fireplace chimney
. Chimneys on the landscape are created when air is drawn in from lower elevations, creating strong upslope drafts. The result can be acceleration of radiant and convective heat as well as actual fire spread, similar to opening the damper in a fireplace ch
imney. Areas where the terrain includes a restriction or narrowing can result in this type of acceleration. The terrain features adjacent the Project
site include few mild examples of these
“chimneys” that are not expected to significantly alter fire behavior.
7.3 Heat Deflecting Walls
The reduced
fuel modification
areas
along the northern property boundary
provide
s
an opportunity to place a non
-
combustible, six
-
foot tall, heat
-
deflecting wall (lower 2 feet block wall and upper 4 feet dual pane, one pane tempered glazing or a six
-
foot
high CMU block wall)
that
extends 20 feet beyond the footprint of the buildings where a m
in
imum 100 feet of FMZ is not achievable,
to provide additional deflection for these lots to compensate for the reduced fuel modification zones.
Walls like these have proven to deflect heat and airborne embers on numerous wildfires in San Diego, Orange, Los Angeles, Ventura, and Santa Barbara County. Rancho Santa Fe Fire Protection District, Laguna Beach Fire Department, Orange County Fire Authorit y, and others utilize these walls as Alternative
methods based on observed performance during wildfires. This has led to these agencies approving use of non
-
combustible landscape walls as mitigations for reduced fuel modification zones and reduced setbacks at top of slope. These walls are consistent with NFPA 1144 Standard for Reducing Structure Ignition Hazards from Wildland Fire
–
2008 Edition, Section 5
.1.3.3 and A.5.1.3.3 and International Urban Wildland Interface Code (ICC 2012).
NFPA 1144, A.5.1.3.3 states: “Noncombustible walls and barriers are effective for deflecting radiant heat and windblown embers from structures.” These walls and barriers are u sually constructed of noncombustible materials
(concrete block, bricks, stone, stucco) or earth with emergency access openings built around a development where 30 feet
(9 meters) of defensible space is not available
and
the open cells
filled
.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
62 FEBRUARY 2024
I
N
TENTIONALLY LEFT BLAN
K
14499 63 FEBRUARY 2024
8 Wildfire Education Program
Early evacuation for any type of wildfire emergency at the Project site is the preferred method of providing for resident safety, consistent with the MFR’s current approach within Riverside County. As such, the Project’s Property Manager would formally adopt, practice, and implement a “Ready, Set, Go!” approach to evacuation10. The “Ready, Set, Go!” concept is widely known and encouraged by the State of California and most fire agencies. Pre -planning for emergencies, including wildfire emergencies, focuses on being prepared, having a well-defined plan, minimizing the potential for errors, maintaining the Project site’s fire protection systems, and implementing a conservative (evacuate as early as possible) approach to evacuation and Project area activities during periods of fire weather extremes.
Project residents and occupants would be provided ongoing education regarding wildfires and the FPP’s requirements. The educational information must include maintaining the landscape and structural components according to the appropriate standards designed for the community. Informational handouts, community website pages, mailers, fire-safe council participation, inspections, and seasonal reminders are some methods that would be used to disseminate wildfire and relocation awareness information. MFR would review and approve all wildfire educational material/programs before printing and distribution.
10 https://www.readyforwildfire.org/
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
64 FEBRUARY 2024
INTENTIONALLY LEFT BLAN
K
14499 65 FEBRUARY 2024
9 Conclusion
This FPP for the Whitewood I Residential Project provides guidance for vegetation maintenance for the proposed FMZ and landscaped areas on the site. As described, vegetation maintenance measures will be provided on all sides of the proposed development. The fire safety measures provided in this FPP have been designed specifically for the Whitewood I Project. This analysis and its fire protection justifications are supported by fire science research, results from previous wildfire incidents, and fire agencies that have approved these concepts.
The Proposed Project design features, asphalt roads and parking stalls, and a fully irrigated landscape, along with the proposed fire protection measures, would provide a level of safety equal to a 200-foot wide FMZ. This FPP and project components required and recommended are compliant and include alternative materials and methods to meet the intent of the code in limited areas.
Ultimately, it is the intent of this FPP to guide the fire protection efforts for the Whitewood I Project in a comprehensive manner. Implementation of the measures detailed in this FPP will reduce the risk of wildfire at this site and will improve the ability of firefighters to fight fires on and adjacent to the property, irrespective of the cause or location of ignition.
It must be noted that during extreme fire conditions, there are no guarantees that a given structure will not burn.
Precautions and minimizing actions identified in this report are designed to reduce the likelihood that fire will impinge upon Whitewood I Project assets or threaten its visitors. Additionally, there are no guarantees that fire will not occur in the area or that fire will not damage property or cause harm to persons or their property. Implementation of the required construction features provided by the applicable codes and the fuel modification measures provided in this FPP will reduce the site ’s vulnerability to wildfire. It will also help accomplish the goal of this FPP to assist firefighters in their efforts to defend structures.
It is recommended that Whitewood I Project maintain a conservative approach to fire safety. This approach must include maintaining the landscape and structural components according to the appropriate standards and embracing a preparedness stance on evacuation. This project is not to be considered a shelter-in-place development. However, the fire agencies and/or law enforcement officials may, during an emergency, as they would for any new development providing the layers of fire protection as the Whitewood I Project, determine that it is safer to temporarily refuge residents on the site. When an evacuation is ordered, it will occur according to pre-established evacuation decision points or as soon as notice to evacuate is received, which may vary depending on many environmental and other factors. Fire is a dynamic and somewhat unpredictable occurrence, and it is important for anyone living at the WUI to educate themselves on practices that will improve safety.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
66 FEBRUARY 2024
INTENTIONALLY LEFT BLANK
14499 67 FEBRUARY 2024
10 List of Preparers
Michael Huff
Discipline Director
Dudek
Noah Stamm
Fire Protection Specialist/Urban Forester III
Dudek
Lesley Terry
CADD Specialist
Dudek
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
68 FEBRUARY 2024
INENTIONALLY LEFT BLANK
14499 69 FEBRUARY 2024
11 References
Anderson, Hal E. 1982. Aids to Determining Fuel Models for Estimating Fire Behavior. USDA Forest Service Gen.
Tech. Report INT-122. Intermountain Forest and Range Experiment Station, Ogden, Utah.
Andrews, P.L. 1980. Testing the fire behavior model. In Proceedings 6th conference on fire and forest meteorology. April 22 –24, 1980. Seattle, WA: Society of American Foresters. Pp. 70 –77.
Andrews, Patricia L., Collin D. Bevins, and Robert C. Seli. 2008. BehavePlus fire modeling system, version 3.0:
User’s Guide. Gen. Tech. Rep. RMRS-GTR-106 Ogden, UT: Department of Agriculture, Forest Service, Rocky Mountain Research Station. 132p.
Brown, J.K. 1982. Fuel and fire behavior prediction in big sagebrush. USDA Forest Service Res. Pap. INT-290. 10p.
Bushey, C.L. 1985. Comparison of observed and predicted fire behavior in the sagebrush/ bunchgrass vegetation- type. In J.N. Long (ed.), Fire management: The challenge of protection and use: Proceedings of a symposium. Society of American Foresters. Logan, UT. April 17–19, 1985. Pp. 187–201.
City of Murrieta Fire & Rescue. 2023. Operations_About the Department. Accessed in August 2022 and again in July 2023. https://www.murrietaca.gov/349/Operations
City of Murrieta Fire & Rescue. 2023. Community Risk Reduction. Accessed in August 2022 and again in July 2023. https://www.murrietaca.gov/689/Community-Risk-Reduction FireFamily Plus 2008. http://www.firelab.org/project/firefamilyplus.
FRAP (Fire and Resource Assessment Program). 2008. California Department of Forestry and Fire Protection.
Website Accessed October 2019, at: http://frap.cdf.ca.gov/.
Gordon, Hazel and T. C. White. 1994. Ecological Guide to Southern California Chaparral Plant Series for Tranverse and Penninsular Ranges: Angeles, Cleveland, and Riverside National Forests. USDA Forest Service Pacifica Southwest Region. R5-ECOL-TP-005. 162 p.
ISSUU. City of Murrieta. 2022 Murrieta Fire & Rescue Annual Report. April 18, 2023. Access July 2023. https://issuu.com/cityofmurrieta/docs/2022_mfr_annual_report_final_reduced Keeley, J.E. and S.C. Keeley. 1984. Postfire recovery of California coastal sage scrub. The American Midland Naturalist 111:105-117.
Keeley, J.E. and C.J. Fotheringham. 2003. “Impact of Past, Present, and Future Fire Regimes on North American Mediterranean Shrublands.” In Fire and Climatic Change in Temperate Ecosystems of the Western Americas, edited by T.T. Veblem, W.L. Baker, G. Montenegro, and T.W. Swetnam, 218–262. New York, New York: Springer-Verlag.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
70 FEBRUARY 2024
Keeley, J.E. 2004. “Invasive Plants and Fire Management in California Mediterranean -
Climate Ecosystems.”
Edited by M. Arianoutsou.
In 10th MEDECOS
-
International Conference on Ecology, Conservation
Management
. Rhodes, Greece.
Linn
, R.
2003
. “
Using Computer Simulations to Study Complex Fire Behavior .”
Los Alamos National Laboratory,
MS D401. Los Alamos, NM.
Michael Brandman Associates. 2007. Draft Biological Resources Assessment Report, Arboretum Project, Perris
,
Riverside
County, California. December 2007.
Quarles, S.L. and F.C. Beall. 2002. Testing protocols and fire tests in support of the performance -
based codes. In
‘
Proceedings of the California 2001Wildfire Conference: 10
Years after the 1991 East Bay Hills Fire
’
, 10
–
12 October 2001, Oakland, California. University of California, Forest Products Laboratory, Technical Report 35.01.462, pp. 64
–
73. Richmond, California.
Rothermel, Richard C. 1983. How to predict the spread and intensity of forest and range fires. GTR INT -
143. Ogden,
Utah: USDA Forest Service Intermountain Research Station.161 Rothermel, R.C., and G.C. Rinehart. 1983. “Field procedures for verification and
adjustment of fire behavior predictions.” Res. Pap. INT -
142. Ogden, UT:
U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 25 p.
Rothermel, R.C., and G.C.
Rinehart. 1983.
“
Field procedures for verification and adjustment of fire behavior predictions.
”
Res. Pap. INT
-
142. Ogden, UT: U.S
.
Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 25 p.
Scott, Joe H. and Robert E. Burgan. 2005. Standard fire behavior fuel models: a comprehensive set for use with Rothermel
’
s surface fire spread model. Gen. Tech. Rep. RMRS
-
GTR
-
153. Fort Collins, CO: U.S. Department
of Agriculture, Forest Service, Rocky Mountain Research Station. 72 p.
Sneeuwjagt, R.J., and W.H. Frandsen. 1977. “Behavior of experimental grass fires vs. predictions based on Rothermel ’
s
fire model.”
Canadian Journal of Forest Resources
. 7:357
–
367.
Syphard A.D., and J.E. Keeley. 2016. “Historical Reconstructions of California Wildfires Vary by Data Source.” International Journal of Wildland Fire
25(12):1221
–
1227.
https://doi.org/10.1071/WF16050
.
Weise, D.R. and J. Regelbrugge. 1997. Recent chaparral fuel modeling efforts. Prescribed Fire and Effects Research Unit, Riverside Fire Laboratory, Pacific Southwest Research Station. 5p.
WHITEWOOD I
RESIDENTIAL DEVELOPMENT PROJECT
-
FIRE PROTECTION PLAN
14499
71 FEBRUARY 2024
INTENTIONALLY LEFT BLANK
Appendix A
Representative Project
Photograph Log
APPENDIX
A
/
PHOTOGRAPH LOG
–
WHITEWOOD I PROJECT
14499
A
-
1 OCTOBER
202
2 Photograph
taken from the southeast corner of the project site
at the intersection of Arendt
Lane and Clinton Keith Road
looking west along the southern boundary of the project site.
Photograph taken from the southeast corner of the project site at the intersection of Arendt Lane and Clinton Keith Road looking northwest into the project site.
APPENDIX
A
/
PHOTOGRAPH LOG
–
WHITEWOOD I PROJECT
14499
A
-
2 OCTOBER
202
2 Photograph looking
north
along
Arendt Lane,
with the project site to the west and
underdeveloped parcels to the east
, standing
at the southeast corner of the project site.
Photograph looking east along
Clinton Keith Road
and into the
underdeveloped lands east of the
project site, taken from the southeast corner of the project site at the intersection of Arendt Lane and Clinton Keith Road.
APPENDIX
A
/
PHOTOGRAPH LOG
–
WHITEWOOD I PROJECT
14499
A
-
3 OCTOBER
202
2 Photograph looking north
west
across the
southern
portion of the Project site towards
an
existing
single
-
family
home
, standing in the
southeast
portion of the Project site along
the
southern
property boundary
.
Photograph looking east across the southern boundary of the Project site towards an existing single
-
family home, standing in the
sou
theastern portion of the Project site along the southern property boundary.
APPENDIX
A
/
PHOTOGRAPH LOG
–
WHITEWOOD I PROJECT
14499
A
-
4 OCTOBER
202
2 Photograph looking
south
west
across
the
intersection of Whitewood Road and Clinton Keith
Road
looking
towards Vista Murietta High School.
Photograph looking northwest across
Whitewood Road
towards the Skyview Ridge residential
area
, st
anding
at the southwest corner of the Project site.
APPENDIX
A
/
PHOTOGRAPH LOG
–
WHITEWOOD I PROJECT
14499
A
-
5 OCTOBER
202
2 Photograph looking
east
across the
southern
portion at the existing
naturally vegetated
Project
Site
, standing
at the southwest corner
.
Photograph looking
sout
h
across Clinton Keith Road
towards
naturally vegetated lands soon to
be
developed, standing
along the west boundary of the project site near the
southwest corner
.
APPENDIX
A
/
PHOTOGRAPH LOG
–
WHITEWOOD I PROJECT
14499
A
-
6 OCTOBER
202
2 Photograph looking
southeast
across the
southwest portion of the
pr
oject site
showing natural
vegetation within the Project site and underdeveloped lands to the south,
standing
on the western boundary
of
the
Project site
near the southwest corner.
Photograph looking
east
across the project site towards the eastern property boundary
showing disturbed vegetation, standing along the western boundary of the Project Site between the southeast and northeast corners.
APPENDIX
A
/
PHOTOGRAPH LOG
–
WHITEWOOD I PROJECT
14499
A
-
7 OCTOBER
202
2 Photograph looking
north along the western boundary of the Project site showing existing vegetation and disturbed areas, standing on the western boundary between the northwest and southeast corners
.
Photograph looking south along the
western boundary of the Project site showing existing
vegetation and roadside of Whitewood Road, standing on the western boundary between the northwest and southeast corners.
APPENDIX
A
/
PHOTOGRAPH LOG
–
WHITEWOOD I PROJECT
14499
A
-
8 OCTOBER
202
2 Photograph looking east along the northern boundary of the Project site showing disturbed
vegetation and adjacent property with a structure, standing at the northwest corner of the Project site along Whitewood Road.
Photograph looking north from the northwest corner of the Project site along Whi tewood
picturing the adjacent property to the north of the Project site including existing structures and fences.
APPENDIX
A
/
PHOTOGRAPH LOG
–
WHITEWOOD I PROJECT
14499
A
-
9 OCTOBER
202
2 Photograph looking east from the northeast corner of the Project site showing the soon to be developed adjacent property to
the east of the Project and recent vegetation disturbance from grading.
Appendix
B
Project Vicinity
Fire History
Map
5 -
M
i
l
e
B
u
f
f
e
r
P
r
o
j
e
c
t
B
o
u
n
d
a
r
y
Q
u
a
n
t
i
t
y
o
f
T
i
m
e
s
B
u
r
n
e
d
1 2
3 4
S
O
U
R
C
E
:
B
A
S
E
M
A
P
-
E
S
R
I
M
A
P
P
I
N
G
S
E
R
V
I
C
E
;
F
I
R
E
D
A
T
A
-
C
A
L
F
I
R
E
2 0
2 2
0 2
1 M
i
l
e
s
D
a
t
e
:
7 /
2 4
/
2 0
2 3
-
L
a
s
t
s
a
v
e
d
b
y
:
l
t
e
r
r
y
-
P
a
t
h
:
Z
:
\
P
r
o
j
e
c
t
s
\
j
1 4
4 9
9 0
0 \
M
A
P
D
O
C
\
D
O
C
U
M
E
N
T
\
F
i
r
e
P
r
o
t
e
c
t
i
o
n
\
A
p
p
e
n
d
i
x
B
F
i
r
e
H
i
s
t
o
r
y
2 0
2 2
.
m
x
d
F
i
r
e
H
i
s
t
o
r
y
M
a
p
F
i
r
e
P
r
o
t
e
c
t
i
o
n
P
l
a
n
f
o
r
t
h
e
W
h
i
t
e
w
o
o
d
I
P
r
o
j
e
c
t
A
P
P
E
N
D
I
X
B
Appendix
C
BehavePlus
Fire Behavior Analysis
Summary
FIRE BEHAVIOR MODELING SUMMARY
WHITEWOOD I
RESIDENTIAL DEVELOPMENT
PROJECT
,
WILDOMAR
, CALIFORNIA
1 4
4 99
1 OCTOB
ER
2022
1 BehavePlus Fire Behavior Modeling History
Fire behavior modeling has been used by researchers for approximately 50+ years to predict how a fire will move through a given landscape (Linn 2003). The models have had varied complexities and applications throughout the years. One model has become the m
ost widely used as the industry standard for predicting fire behavior on a given landscape. That model, known as “BEHAVE”, was developed by the U. S. Government (USDA Forest Service, Rocky Mountain Research Station) and has been in use since 1984. Since th at time, it has undergone continued research,
improvements, and refinement. The current version, BehavePlus 6.0, includes the latest updates incorporating years of research and testing. Numerous studies have been completed testing the validity of the fire behavior
models’ ability to predict fire behavior given site specific inputs. One of the most successful ways the model has been improved has been through post
-
wildfire modeling (Brown 1972, Lawson 1972, Sneeuwjagt and Frandsen 1977, Andrews 1980, Brown 19
82, Rothermel and Rinehart 1983, Bushey 1985, McAlpine and Xanthopoulos 1989, Grabner, et. al. 1994, Marsden
-
Smedley and Catchpole 1995, Grabner 1996, Alexander 1998, Grabner et al. 2001, Arca et al. 2005). In this type of study, Behave is used to model fi re behavior based on pre
-
fire conditions
in an area that recently burned. Real
-
world fire behavior, documented during the wildfire, can then be compared to the prediction results of Behave and refinements to the fuel models incorporated, retested, and so o n.
Fire behavior modeling conducted on this site includes a relatively high -
level of detail and analysis which results in
reasonably accurate representations of how wildfire may move through available fuels on and adjacent the property.
Fire behavior calculat
ions are based on site
-
specific fuel characteristics supported by fire science research that analyzes heat transfer related to specific fire behavior. To objectively predict flame lengths, spread rates, and fireline intensities, this analysis incorporated
predominant fuel characteristics, slope percentages, and representative fuel models observed on site. The BehavePlus fire behavior modeling system was used to analyze anticipated fire behavior within and adjacent to key areas just outside of the proposed l ots.
Predicting wildland fire
behavior is not an exact science. As such, the movement of a fire will likely never be fully predictable, especially considering the variations in weather and the limits of weather forecasting. Nevertheless, practiced and expe
rienced judgment, coupled with a validated fire behavior modeling system, results in useful and accurate fire prevention planning information. To be used effectively, the basic assumptions and limitations of BehavePlus must be understood.
▪
First, it must be realized that the fire model describes fire behavior only in the flaming front. The primary driving force in the predictive calculations is dead fuels less than one -
quarter inch in diameter. These are
the fine fuels that carry fire. Fuels
greater than one inch have little effect while fuels greater than three inches have no effect on fire behavior.
▪
Second, the model bases calculations and descriptions on a wildfire spreading through surface fuels that are within six feet of the ground and contiguous to the ground. Surface fuels are often classified as grass, brush, litter, or slash.
▪
Third, the software assumes that weather and topography are uniform. However, because wildfires almost always burn under non
-
uniform conditions, length of projection period and choice of fuel model must be carefully considered to obtain useful predictions.
FIRE BEHAVIOR MODELING SUMMARY
WHITEWOOD I
RESIDENTIAL DEVELOPMENT
PROJECT,
WILDOMAR
, CALIFORNIA
1 4
4 99
2 OCTOB
ER
2022
▪
Fourth, the BehavePlus fire behavior computer modeling system was not intended for determining sufficient fuel modification zone
/defensible space
widths. However, it does provide the average length of
the flames, which is a key element for determining “defensible space” distances for minimizing structure ignition.
Although BehavePlus has some limitations, it can still provide valuable fire behavior predictions which can be used as a tool in the decision
-
making process. In order to make reliable estimates of fire behavior, one must understand the relationship of fuel
s to the fire environment and be able to recognize the variations in these fuels. Natural fuels are made up of the various components of vegetation, both live and dead, that occur on a site. The type and quantity will depend upon the soil, climate, geograp
hic features, and the fire history of the site. The major fuel groups of grass, shrub, trees, and slash are defined by their constituent types and quantities of litter and duff layers, dead woody material, grasses and forbs, shrubs, regeneration, and trees . Fire behavior can be predicted largely by
analyzing the characteristics of these fuels. Fire behavior is affected by seven principal fuel characteristics: fuel loading, size and shape, compactness, horizontal continuity, vertical arrangement, moisture co ntent, and chemical
properties.
The seven fuel characteristics help define the 13 standard fire behavior fuel models 1 and the five custom fuel
models developed for Southern California
2 . According to the model classifications, fuel models used in BehavePlus have been classified into four groups, based upon fuel loading (tons/acre), fuel height, and surface to volume ratio.
Observation of the fuels in the field (on site) determines which fuel models should be applied in BehavePlus. The
following describes the distribution of fuel models among general vegetation types for the standard 13 fuel models and the custom Southern California fuel models:
▪
Grasses
Fuel Models 1 through 3
▪
Brush
Fuel Models 4 through 7, SCAL 14 through 18
▪
Timber
Fuel Models 8 through 10
▪
Logging Slash
Fuel Models 11 through 13
In addition, the aforementioned fuel
characteristics were utilized in the recent development of 40 new fire behavior fuel models
3 developed for use in BehavePlus modeling efforts. These new models attempt to improve the accuracy of the standard 13 fuel models outside of severe fire season conditions, and to allow for the simulation of fuel treatment prescriptions. The following desc
ribes the distribution of fuel models among general vegetation types for the new 40 fuel models:
▪
Non
-
burnable
Models NB1, NB2, NB3, NB8, NB9
▪
Grass
Models GR1 through GR9
▪
Grass
-
shrub
Models GS1 through GS4
1 Anderson, Hal E. 1982. Aids to Determining Fuel Models for Estimating Fire Behavior. USDA Forest Service Gen. Tech. Report IN T
-
122. Intermountain Forest and Range Experiment Station, Ogden, UT.
2 Weise, D.R. and J. Regelbrugge. 1997. Recent chaparral fuel modeling efforts. Prescribed Fire and Effects Research Unit, Rive rside
Fire Laboratory, Pacific Southwest Research Station. 5p.
3 Scott, Joe H. and Robert E. Burgan. 2005. Standard fire behavior fuel models: a comprehensive set for use with Rothermel's surface fire spread model. Gen. Tech. Rep. RMRS
-
GTR
-
153. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mo
untain Research Station. 72 p.
FIRE BEHAVIOR MODELING SUMMARY
WHITEWOOD I
RESIDENTIAL DEVELOPMENT
PROJECT,
WILDOMAR
, CALIFORNIA
1 4
4 99
3 OCTOB
ER
2022
▪
Shrub
Models SH1 through SH9
▪
Timber
-
understory
Models TU1 through TU5
▪
Timber litter
Models TL1 through TL9
▪
Slash blowdown
Models SB1 through SB4
BehavePlus software was used in the development of th
e
Whitewood I
Residential Development P
ro
ject
(Proposed
Project)
Fire Protection Plan
(
FPP
)
Report
in order to
evaluate potential fire behavior for the Project site. Existing site conditions were evaluated, and local weather data was incorporated into the BehavePlus modeling runs.
2 Fuel Models
Dudek utilized the BehavePlus software package to analyze fire behavior potential for the Proposed
Project site in
Wildomar
, California
.
Refer
to Figure
7 ,
Fire Behavior Modeling Map
for
fire modeling scenario locations.
As is
customary for this type of analysis,
four
fire
scenarios were evaluated, including
one
summer, onshore weather
condition (
south
west
o
f
the Project Site) and
three
extreme fall, offshore weather condition (
north/north
east
, and
east
of the Project Site).
The Project site is
currently va
cant and is
surrounded by
a
variety of land uses including
existing
rural
single
-
family residential
developments directly to the
north, west,
east
,
and further south; Vista
Murrieta High School to the southwest; a commercial development further to the west; and
a
naturally
-
vegetated
land further to the east and south
.
With that said, f
uels and terrain
within
and adjacent to
the Project development
area
could
possibly
p
roduce flying embers that may affect the
P
roject, but defenses have been built into the
new
re
sidential
structure
s
to
prevent ember penetration and to extinguish fires that may result from ember penetration.
It is the fuels
directly
adjacent to and within fuel modification zones that would have the potential to affect the P
roject’s structures from a radiant and convective heat perspective as well as from direct flame impingement.
The
BehavePlus software requires site
-
specific variables for surface fire spread analysis, including fuel type, fuel moisture, wind speed, and slope data. The output variables used in this analys is include flame length (feet), rate of
spread (feet/minute), fireline intensity (BTU/feet/second), and spotting distance (miles). The following provides a description of the input variables used in processing the BehavePlus models for the Proposed Project
site. In
addition, data sources are
cited,
and any assumptions made during the modeling process are described .
2 .1
Vegetation (Fuels)
To support the fire behavior modeling efforts conducted for th e
Whitewood I
Residential Development
Project
, the
different vegetation types observed
within the
P
roject areas
and
adjacent to the
P
roject
site were classified into the
aforementioned numeric fuel models. As is customary for this type of analysis, the terrain and fuels within
and
adjacent to
the project area
were used for d
etermining flame lengths and fire spread. It is these fuels that would have the potential to affect the
P
roject’s structure from a radiant and convective heat perspective as well as from direct flame
impingement.
Fuel beds, including
the
m
oderate
-
to
-
high
-
load
shrub
and gras
s
-
shrub
fuels (Fuel
Model
s
Gs2,
Sh2
,
and Sh5
)
f
ound
throughout the interior portion of the Project site, as well as in the adjacent areas
to the north
, south, and east
.
These fuel types can produce flying embers that may affect the project, but defenses have been built into the structure
s
to prevent ember penetration. Table 1 provides a description of the three
existing
fuel models observed in the vicinity of the site that were subsequently used in the analysis for this P
roject. A total
of
four
fire modeling scenarios were completed for the Project area. The se
modeling scenario locations
were
selected based on the
p
robability
of
a
fire approaching from these directions during a Santa Ana wind -
driven fire
FIRE BEHAVIOR MODELING SUMMARY
WHITEWOOD I
RESIDENTIAL DEVELOPMENT
PROJECT,
WILDOMAR
, CALIFORNIA
1 4
4 99
4 OCTOB
ER
2022
event (fire scenario
s
1, 2, and 3
) and an on
-
shore weather pattern (fire scenario
4 ). Dudek also conducted modeling
of the site for post
-
Fuel Modification Zones’ (FMZ) recommendations for this project (Refer to Table 2 for post
-
FMZ
fuel model descriptions). Fuel modification includes
the
establishment of
fully
-
irrigated zones on the periphery of
the
new
residential structure
. For modeling the post
-
FMZ treatment condition, fuel model assignments were re -
classified for the
FMZ
s
0 and 1
(Fuel Model
Gr1
)
.
Gs2
Moderate
-
load, Dry
climate grass
-
shrubs
Represents the grass
-
shrub vegetation located
throughout and adjacen
t to the Project without
maintenance.
<2.0 ft.
Sh2
Moderate
-
load, Dry
Climate Shrubs
Represents the
shrubs/chaparral vegetation
located
throughout and
adjacent to the Project
without maintenance.
<2.0 ft.
S
h
5 High
-
l
oad
,
Dry
Climate
S
hrub
s
Represents the shrubs/chaparral vegetation
located throughout and adjacent to the Project
without
maintenance
.
>4
.0 ft.
Gr1
Short, sparse, dry
climate grasses
Fuel Modification Zone
s
0 and
1 : irrigated landscape
throughout the
Project site
<
1.0 ft.
2.2 Topography
Slope is a measure of angle in degrees from horizontal and can be presented in units of degrees or percent. Slope is important in fire behavior analysis as it affects the exposure of fuel beds. Additionally, fire burning uphill spreads faster than those bu
rning on flat terrain or downhill as uphill vegetation is pre -
heated and dried in advance of the
flaming front, resulting in faster ignition rates.
The Project site exhibits relatively flat terrain with n atural s
lope values
ranging from
approximately
3 % to
7 %
measured
around the perimeter of the Project
area
from U.S. Geological
Survey (USGS) topographic maps
.
2 .
3 Weather
Analysis
Historical weather data for the
Wildomar
region was utilized in determining appropriate fire behavior modeling inputs for the Project area. 50
th
and 97
th
percentile moisture values were derived from Remote Automated Weather Station (RAWS) and utilized in the fire behavior modeling efforts conducted in support of this report. Weather data sets from the
Santa Rosa Plateau
RAWS (ID number 045
623
)
4 were utilized in the fire modeling runs.
4 Santa Rosa Plateau
RAWS Station Latitude and Longitude
33.517608,
-
117.228842
FIRE BEHAVIOR MODELING SUMMARY
WHITEWOOD I
RESIDENTIAL DEVELOPMENT
PROJECT,
WILDOMAR
, CALIFORNIA
1 4
4 99
5 OCTOB
ER
2022
RAWS fuel moisture and wind speed data were processed utilizing the Fire Family Plus software package to determine atypical (97
th
percentile) and typical (50
th
percentile) weather conditions. Data from the RAWS was
evaluated from August 1 through November 30 for each year between 2015
and 20
2 1
(extent of available data
record) for 97
th
percentile weather conditions and from June 1 through September 30 for each year between 201
5 and 20
2 1
for 50
th
percentile weather conditions.
Following analysis in Fire Family Plus, fuel moisture information was incorporated into the Initial Fuel Moisture file used as an input in BehavePlus. Wind speed data resulting from the Fire Family Plus analysis was also determined. Initial wind direction
and wind speed values for the
two
BehavePlus runs were manually entered
during the data input phase. The input wind speed and direction is roughly an average surface wind at 20 feet above the vegetation over the analysis area. Table 3 summarizes the wind a nd weather input variables used in
the Fire BehavePlus modeling efforts
.
Fuel Models
Gr1 (Post),
Gs2, Sh2, and Sh5
(Pre)
Gr1 (Post),
Gs2,
Sh2,
and
Sh5
(Pre)
1 h fuel moisture
7 %
1 %
10 h fuel moisture
8 %
2 %
100 h fuel moisture
1 3
%
5 %
Live herbaceous moisture
5 2
%
30%
Live woody moisture
1 0
4 %
60%
20 ft. wind speed
1 6
mph (sustained winds)
1 8
mph (sustained winds);
wind gusts
of
50 mph
Wind Directions from north
(degrees)
2 1
0 4
0, 80, and 120
Wind adjustment factor
0.4 0.4
Slope (uphill)
3 %
4 %
to 7%
3 Fire Behavior Modeling Efforts
As mentioned, the BehavePlus
fire behavior modeling software package was utilized in evaluating anticipated fire behavior adjacent to the Proposed Project site.
Four
focused analyses were completed
for both the existing project
site conditions and the post project conditions
, each assuming worst
-
case fire weather conditions for a fire
approaching the project site from the
north/northeast, east, and south/southwest
.
The results of the modeling
effort included anticipated values for surface fires flame length (feet), rate of spread (mph), fireline intensity (Btu/ft/s)
, and spotting distance (miles)
.
The aforementioned fire behavior variables are an important component in understanding fire risk and fire agency response capabilities. Flame length, the length of the flame of a spreading surface fire within the flaming front, is measured from midway in the active flaming combustion zone to the average
tip of the flames (An
drews, Bevins, and Seli 2008). Fireline intensity is a measure of heat output from the flaming front, and also affects the potential for a surface fire to transition to a crown fire. Fire spread rate represents the speed at which the fire progresses throug
h surface fuels and is another important variable in initial attack and fire suppression efforts (Rothermel and Rinehart 1983). Spotting distance is the distance a firebrand or ember can travel down wind and ignite receptive fuel beds
.
Four
fire modeling s
cenario locations were selected to better
FIRE BEHAVIOR MODELING SUMMARY
WHITEWOOD I
RESIDENTIAL DEVELOPMENT
PROJECT,
WILDOMAR
, CALIFORNIA
1 4
4 99
6 OCTOB
ER
2022
understand the different fire behavior that may be experienced on or adjacent the site based on slope and fuel conditions; these
fire scenarios are explained in more detail below:
▪
A
fall
,
extreme
o
ff
-
shore fire (
97 th
percentile weather condition)
burning
through
moderate
-
load
grass shrub/shrub and chaparral dominat
ed vegetation
directly north of the property
. The terrain
is
flat
(approximately
5 % slope) with potential ignition sources from a
car
and/
or structure fire originating
within the existing
rural
residential
homes to the north
Project site
. This type of fire would typically spread
through the
grass shrub/shrub and chaparral
dominated vegetation
relatively
slow towards the
northern
portion
s
of the residential
development
site
, pre
-
development
.
▪
A fall
,
extreme
o
ff
-
shore fire (
97 th
percentile weather condition)
burning
through moderate
-
load
grass shrub/shrub and chaparral dominat
ed vegetation
n
orth
east
of the property
. The terrain
is
flat
(approximately
7 % slope) with potential ignition sources from a
car and/or structure fire originating within
the existing rural residential homes to the north
east or within the naturally
-
vegetated areas farther to the
east/northeast of the
Project site
. This type of fire would typically spread
relatively
slow towards the
eastern
portions of the residential development site, pre
-
development
.
▪
A fall
,
extreme
o
ff
-
shore fire (
97 th
percentile weather condition)
burning
through high
-
l
oad
grass shrub and chaparral dominat
ed vegetation
east of the property
. The terrain
is
flat
(approximately
4 %
slope) with potential ignition sources from a
car and/or structure fire originating within the existing rural residential homes to the east, from a car fire along Clinton Keith Road, or within the naturally -
vegetated
areas farther to the east/south of the Project site
. This type of fire would typica
lly spread
relatively slow
towards the eastern and southern portions of the residential development site, pre -
development.
▪
A
summer
, o
n
-
shore fire (
50 th
percentile weather condition)
burning
through high
-
l
oad
grass
shrub and chaparral dominat
ed vegetation
south of the property and across Clinton Keith Road
. The terrain
is
flat
(approximately
3 % slope) with potential ignition sources from
car fire along Clinton Keith Road or
within the naturally
-
vegetated areas farther to the south of the Project site . This type of fire would typically
spread
relatively slow towards the eastern and southern portions of the residential development site, pre -
development
.
4 Fire Behavior Modeling Results
The results presented in Table
s
4 and
5 depict values based on inputs to the BehavePlus software and are not intended to capture changing fire behavior as it moves across a landscape. Changes in slope, weather, or pockets of different fuel types are not accounted for in this analysis. For planni ng purposes, the averaged worst
-
case fire
behavior is the most useful information for conservative fuel modification design. Model results should be used as a basis for planning only, as actual fire behavior for a gi ven location will be affected by many factors, including unique weather patterns, small
-
scale topographic variations, or changing vegetation patterns.
As presented
in Table 4
,
wildfire behavior
adjacent to the
Project site is expected to be primarily of moderate
to
high
intensity
through the non
-
maintained
surface
grass
-
shrub
/shrub
-
chaparral
dominated
fuels
directly
adjacent
FIRE BEHAVIOR MODELING SUMMARY
WHITEWOOD I
RESIDENTIAL DEVELOPMENT
PROJECT,
WILDOMAR
, CALIFORNIA
1 4
4 99
7 OCTOB
ER
2022
to
the
Project
site
. W
orst
-
case fire behavior under
p
eak weather conditions (represented by Fall Weather, Scenario
3 ) is anticipated to be a wind
-
driven fire from the
east
/north
ea
st
during the fall.
Under such conditions, expected
surface flame length
are
expected to
r
each
approximately
21 feet with wind speeds of 50+ mph. Under this
scenario, fireline intensities reach
4,041
BTU/feet/second with moderate spread rates of
4.2 mph and could have
a spotting distance up to
2. 4
miles away
.
W
ildfire behavior
through the non
-
maintained
shrub
-
chaparral
dominated
fuels
farther to the south
being fanned
by 1
6 mph sustained
winds
,
from the
west
/northwest
and pushed by
on
-
shore
ocean breezes typically exhibit less
severe fire behavior due to lower wind speeds and higher humidity. Under typical onshore weather conditions,
a
surface
vegetation
fire could have flame lengths
approaching
1 5
feet in height and spread rates
of approximately
0.8 mph. Spotting distances, where airborne embers can ignite new fires downwind of the initial fire, can originate
approximately 0.5
miles
away
.
As depicted
in
Table
5 ,
post development fire behavior expected in
the irrigated and replanted with plants that are
acceptable with the
Riverside County Fire Department/Cal Fire
(FMZ Zone
s
0 and
1 –
Gr1)
under peak weather
conditions
experience a significant reduction in flame length and intensity.
Fuel modification would result in
a reduction to
approximately
4.0 feet by the time the
interior irrigated landscapes
of the FMZ (Zone
s
0 and
1 ) are reached. During on
-
shore weather conditions, a fire approaching
from the
west/
sou
thwest
towards the development footprint would
have
low
fire intensity and spotting distances due to the higher live and dead fuel moisture contents. These reduction of flame length s
and intensities are assumed to occur within the
100
feet of fuel modification
that is achieved for most of the.
Therefore,
the FMZs proposed for the
P
roject are approximately
2.5 -
times the flame length of the worst
-
case fire scenario
under peak weather conditions
in the hillsides
east
/north
east
of the Project
site and approximately 8
-
times the
flame lengths within the development footprint
and would provide adequate defensible space to augment a wildfire approaching the perimeter of the Project site.
Moderate
-
load
grass
-
shrub (Gs2)
10.5 (
20.5 )
3 9
33 (4,04
1 )
1.0 (
4.2 )
3 1.0
(
2.4 )
3 Moderate
-
load shrubs (Sh2)
8.5 (
15.9 )
5 8
8 (2,3
34 )
0.2 (
1.0 )
0. 2
(1.
0 )
Moderate
-
load grass
-
shrub (Gs2)
10.4 (20.5)
3 932 (4,040)
1.0 (4.2)
3 1.0 (
2.4 )
3 Moderate
-
load shrubs (Sh2)
8.4 (15.9)
587 (2,333)
0.2 (1.0)
0.2 (1.0)
High
-
load shrubs
(
Sh5)
25.8 (44.7)
3 6,643 (21,997)
2.1 (6.8)
3 2.1 (6.8)
3 High
-
load shrubs
(
Sh5)
14.4 1,865
0.8 0.5
Note:
1. W
ind
-
driven
surface
fire.
2. MPH=miles per hour.
3. Flame length, spread rate, and s
potting distance from a wind driven surface fire; it should be noted that the wind mph in parenthesis represent
peak gusts of 50 mph
.
FIRE BEHAVIOR MODELING SUMMARY
WHITEWOOD I
RESIDENTIAL DEVELOPMENT
PROJECT,
WILDOMAR
, CALIFORNIA
1 4
4 99
8 OCTOB
ER
2022
Fuel Model NB1
N/A
N/A
N/A
N/A
Fuel modification zone
s
0 and
1 (
Gr1
)
4.0 (
4.0 )
3 115 (115)
0.7 (0.7)
3 0.
2 (
0.5 )
3 Fuel Model NB1
N/A
N/A
N/A
N/A
Fuel modification zone
s
0 and
1 (
Gr1
)
4.0 (
4.0 )
115 (115)
0.7 (0.7)
0. 2
(
0.5 )
Fuel Model NB1
N/A
N/A
N/A
N/A
Fuel modification zone
s
0 and
1 (
Gr1
)
4.0 (
4.0 )
115 (115)
0.7 (0.7)
0. 2
(
0.5 )
Fuel Model NB1
N/A
N/A
N/A
N/A
Fuel modification zone
s
0 and
1 (
Gr1
)
1.9 22
0.2 0.1
Note:
1. W
ind
-
driven
surface
fire.
2. MPH=miles per hour.
3. Flame length, spread rate, and s
potting distance from a wind
driven surface fire; it should be noted that the wind mph in parenthesis represent peak gusts of 50 mph
The following describes the fire behavior variables (Heisch and Andrews 2010) as presented in Tables
4 and
5 :
▪
Flame Length (feet):
The flame length of a spreading surface fire within the flaming front is measured from midway in the active flaming combustion zone to the average tip of the flames.
▪
Fireline Intensity (Btu/ft/s):
Fireline intensity is the heat energy release per unit time from a one -
foot wide
section of the fuel bed extending from the front to the rear of the flaming zone. Fireline intensity is a function of rate of spread and heat per unit area, and is directly r elated to flame length. Fireline intensity and the
flame length are related to the heat felt by a person standing next to the flames.
▪
Surface Rate of Spread (mph):
Surface rate of spread is the "speed" the fire travels through the surface fuels. Surface fuels include the litter, grass, brush and other dead and live vegetation within about 6 feet of the ground.
The information in Table
6 presents an interpretation of the outputs for
five
fire behavior variables as related to fire
suppression efforts. The results of fire behavior modeling efforts are presented in Table s
4 and
5 . Identification of
modeling run locations is presented graphically in
Figure
7 of the
FPP
Report
.
FIRE BEHAVIOR MODELING SUMMARY
WHITEWOOD I
RESIDENTIAL DEVELOPMENT
PROJECT,
WILDOMAR
, CALIFORNIA
1 4
4 99
9 OCTOB
ER
2022
Under 4 feet
Under 100
BTU/ft/s
Fires can generally be attacked at the head or flanks by persons using hand tools. Hand line should hold the fire.
4 to 8 feet
100
-
500 BTU/ft/s
Fires are too intense for direct attack on the head by persons using hand tools. Hand line cannot be relied on to hold the fire. Equipment such as dozers, pumpers, and retardant
aircraft can be effective.
8 to 11 feet
500
-
1000 BTU/ft/s
Fires may present serious control problems
--
torching out,
crowning, and spotting. Control efforts at the fire head will probably be ineffective.
Over 11 feet
Over 1000 BTU/ft/s
Crowning, spotting, and major fire runs are probable. Control efforts at head of fire are
ineffective.
Appendix
D
Ignition
-
Resistant Construction Requirements
APPENDIX
D
/
IGNITION
-
RESISTA
NT
CONSTRUCTION REQUIREMENTS
14499
D
-
1 O
CTOBER
202
2 As
of the
date
of this
fire protection plan
, the following are the
requirements for ignition resistant construction
for
The
Proposed Project
,
including requirements under
Chapter 7A
of
the California
Building Code (CBC).
In
addition
,
exterior building cons
truction
including roofs,
eaves, exterior
walls, doors,
windows,
decks, and other
attachments
must
meet the
most current
CBC Chapter
7A ignition resistance requirements at the
time of building
permit application.
1. All structures will be built with a Class
A
r
oof
a
ssembly, including a Class A roof covering. Roofs shall have a roofing assembly installed in accordance with its listing and the manufacturer’s installation instructions.
2. Where the roof profile allows a space between the roof covering and roof deck ing, the spaces shall be
constructed to prevent the intrusion of flames and embers, be fire stopped with approved materials or have one layer of
minimum
72 -
pound
mineral
-
surfaced non
-
perforated cap sheet compl
ying with ASTM D
3909
installed over the combus
tible decking. However
,
openings on barrel tiles or similar roof coverings,
must be fire stopped (bird stopped) with approved materials to prevent the accumulation of debris, bird nests, etc
.
between the tiles and decking material.
3. W
hen provided, exposed v
alley flashings shall be not less than 0.019
-
inch (No. 26 galvanized sheet gage)
corrosion
-
resistant metal installed over a minimum 36
-
inch
-
wide underlayment consisting of one layer of
minimum
72 -
pound
mineral
-
surfaced non
-
perforated cap sheet complying wi
th
ASTM D 3909
running the
full length of the valley.
4. All rain gutters, down spouts and gutter hardware shall be constructed from metal or other non -
combustible material to prevent wildfire ignition along eave assemblies.
5. All chimney, flue or stovepipe ope
nings
attached to a fireplace, stove, or other solid or liquid fuel burning equipment or device shall
be equipped with
an approved spark arrester. An approved spark arrester is defined as a device
intended to prevent sparks from escaping into the atmospher e and
constructed of
nonflammable materials, having a 12
-
gauge minimum thicknesses
with openings no greater than ½ inch,
or
other
alternative
material
the Fontana Fire Protection District
determines to provide equal or better
protection.
It shall be instal
led to be visible for the purposes of inspection and maintenance.
6. The
exterior
surface
materials
shall
be
non
-
combustible
, including hard
or ignition resistant
, such as
stucco
. In
all
construction,
exterior
walls
shall
extend
from
the
top
of
the
foundation
to
the
roof
and
terminate
at
2 -
inch
nominal
solid
blocking
between
rafters
at all roof
overhangs,
or
in
the
case
of
enclosed
eaves,
terminate
at the
enclosure.
7. All
eaves,
fascias
,
and
soffits
will
be
enclosed
(boxed)
with
non
-
combustible
materials.
This
s
hall
apply
to
the
entire
perimeter
of
each
structure.
Eaves
of
heavy
timber
construction
are
not
required
to
be
enclosed
as
long
as
attic
venting
is
not
installed
in
the
eaves.
For
the
purposes
of
this
section,
heavy
timber
construction
shall
consist
of a
minimum
of
4 ”
x
6 ”
rafter
tails
.
8. Paper
-
faced
insulation
shall
be
prohibited
in
attics
or ventilated
spaces.
9. Automatic interior fire sprinklers
for
commercial buildings
shall be installed according to the National Fire
P
rotection Association (NFPA) 13
requir
ements.
10. Roof
vents,
dormer
vents,
gable
vents,
foundation
ventilation
openings,
ventilation
openings
in
vertical
walls,
or
other
similar
ventilation
openings
shall
be
louvered
and
covered
with
1/16
-
inch,
noncombustible,
corrosion
-
resistant
metal
mesh or
o
ther
approved
material that
offers
equivalent
protection.
11. Attic or foundation ventilation louvers or ventilation openings in vertical walls shall not exceed 144 square inches per openi
ng and shall be covered with 1/16
” inch mesh corrosion
-
resistant metal
screen or other
APPENDIX
D
/
IGNITION
-
RESISTA
NT
CONSTRUCTION REQUIREMENTS
14499
D
-
2 O
CTOBER
202
2 approved material that offers equivalent protection. Ventilation louvers and openings may be incorporated as part of access assemblies
.
12. N
o
attic
ventilation
openings
or
ventilation
louvers
shall
be
permitted
in
soffits,
in
eave
overhangs,
b
etween
rafters
at
eaves,
or
in
other
overhanging areas.
13. All
fences
and
gate
assemblies
(fences,
gate
s,
and
fence
posts)
attached or within five feet of a structure
shall
be
of
non
-
combust
i
ble material
or pressure
-
treated exterior fire
-
retardant wood
.
14. All
p
rojections
(exterior
balconies,
decks,
patio
covers,
unenclosed
roofs
and
floors,
and
similar
architectural
appendages
and
projections)
or
structures
less
than
five
feet
from
a
building
shall
be of
non
-
combustible
material,
one
-
hour
fire
resistive
construc
tion
on
the
underside,
heavy
timber
construction,
pressure
-
treated
exterior
fire
-
retardant
wood
or
ignition
resistant
construction.
When
such
appendages
and
projections
are
attached
to
exterior
fire
-
resistive
walls,
they
shall
be
constructed
to
maintain
same
fire
-
resistant standards
as
the exterior
walls
of
the
structure.
15. Accessory
structures
attached
to
buildings
with
habitable
spaces
and
projections
shall
be
in
accordance
with
Chapter 7A of the CBC.
16. Detached
accessory
structures
located less
than
50 fee
t from
a building
containing habitable
space
shall
be
constructed
in
accordance
with
Chapter
7A
of
the
CBC
.
▪
Accessory structures less than 120 square feet in floor area located at least 30 feet from a building containing a habitable space.
17. Exte
r
ior
doors shall
be
approved
non
-
combustible
construction,
solid
core
wood
and
shall
conform
to
the
performance
requirements
of
standard
SFM
12 -
7A
-
1 or
shall
be
of
approved
noncombustible
construction,
or
solid
core
wood
having
stiles
and
rails
not
less
th
a
n
1⅜
inches
thick
with
interior
field
panel
thickness
no
less
than
1¼
inches
thick,
or
shall have
a
fire
-
resistance rating of
not
less
than
20 minutes
when
tested
according
to
National Fire Protection Association (NFPA) 252
.
18. All
glass
or
other
transparent
,
translucent
or
opaque
glazing
materials
,
that
is
used
in
exterior
windows, including
skylights, or exterior glazed door assemblies
shall
be
constructed
of
multi
pane glazing with one tempered pane
meeting the requirements of Section 2406 (2
016
CBC) Safety
Glazing
.
19. Vinyl window assemblies are deemed acceptable if the windows have the following characteristics:
▪
Frame
and
sash
are
comprised
of
vinyl material with welded
corners
▪
Metal
reinforcements
in
the
interlock
area
▪
Glazed with
insulating
glass,
annealed,
o
r
tempered
(one layer
of
which
must
be
tempered
glass).
▪
Frame
and
sash profiles
are
certified
in
AAMA
Lineal
Certification
Program
.
▪
Certified and
labeled to ANSI/AAMA/NWWDA 101/LS2
-
97 for
Structural Requirements
.
Appendix
E
MFR
Prohibited Plant List
Botanical Name
Common Name
Comment
B
Trees
Abies species
Fir
F
Acacia species (numerous)
Acacia
F, I
Agonis juniperina
Juniper Myrtle
F
Araucaria species (A. heterophylla,
A. araucana, A. bidwillii)
Araucaria (Norfolk Island Pine,
Monkey Puzzle Tree, Bunya Bunya)
F
Callistemon species (C. citrinus, C.
rosea, C. viminalis)
Bottlebrush (Lemon, Rose,
Weeping)
F
Calocedrus decurrens
Incense Cedar
F
Casuarina cunninghamiana
River She
-
Oak
F
Cedrus species (C. atlantica, C.
deodara)
Cedar (Atlas, Deo
dar)
F
Chamaecyparis species (numerous)
False Cypress
F
Cinnamomum camphora
Camphor
F
Cryptomeria japonica
Japanese Cryptomeria
F
Cupressocyparis leylandii
Leyland Cypress
F
Cupressus species (C. fobesii, C.
glabra, C. sempervirens,)
Cypress (Tecate,
Arizona, Italian,
others)
F
Eucalyptus species (numerous)
Eucalyptus
F, I
Juniperus species (numerous)
Juniper
F
Larix species (L. decidua, L.
occidentalis, L. kaempferi)
Larch (European, Japanese,
Western)
F
Leptospermum species (L.
laevigatum, L. pe
tersonii)
Tea Tree (Australian, Tea)
F
Lithocarpus densiflorus
Tan Oak
F
Melaleuca species (M. linariifolia, M.
nesophila, M. quinquenervia)
Melaleuca (Flaxleaf, Pink, Cajeput
Tree)
F, I
Metrosideros excelsus
New Zealand
Christmas
tree
FR
Picea (numerous)
Spruce
F
Palm species (numerous)
Palm
F, I,
FR
Pinus species (P. brutia, P.
canariensis, P. b. eldarica, P.
halepensis, P. pinea, P. radiata,
numerous others)
Pine (Calabrian, Canary Island,
Mondell, Aleppo, Italian Stone,
Mon
terey)
F
Platycladus orientalis
Oriental
A
rborvitae
F
Podocarpus species (P. gracilior, P.
macrophyllus, P. latifolius)
Fern Pine (Fern, Yew, Podocarpus)
F
Douglas
F
ir
F
W
ildland Urban Interface Undesirable Plant
s
&
Tree
s
Applies to the High & Very High Fire Hazard Severity Zones F
= Flammable I = Invasive FR = Freezes
Pseudotsuga menziesii
Botanical Name
Common Name
Comment
B
Schinus species (S. molle, S.
terebenthifolius)
Pepper (California and Brazilian)
F, I
Tamarix species (T. africana, T.
aphylla, T. chinensis, T. parviflora)
Tamarix (Tamarisk, Athel Tree, Salt
Cedar, Tamarisk)
F, I
Taxodium species (T. ascendens, T.
distichum, T. mucronatum)
Cypress (Pond, Bald, Monarch,
Montezuma)
F
Taxus species (T. baccata, T.
brevifolia, T. cuspidata)
Yew (English, Western, Japanese)
F
Thuja species (T. occidentalis, T.
plicata)
Arborvitae/Red Cedar
F
Tsuga species (T. heterophylla, T.
mertensiana)
Hemlock (Western, Mountain)
F
Groundcov
ers, Shrubs & Vines
Acacia species
Acacia
F, I
Adenostoma fasciculatum
Chamise
F
Adenostoma sparsifolium
Red Shanks
F
Aeonium decorum
Aeonium
FR
Aeonium simsii
No common name
FR
Agave attenuata
No common name
FR
Agave victoriae
-
reginae
No common nam
e
FR
Agropyron repens
Quackgrass
F, I
Alogyne huegeii
Blue
H
ibiscus
FR
Anthemis cotula
Mayweed
F, I
Arbutus menziesii
Madrone
F
Arctostaphylos species
Manzanita. Also note that Eastwood
Manzanita grows to 8 feet.
F
Arundo donax
Giant Reed
F, I
Ar
temisia species (A. abrotanium, A.
absinthium, A. californica, A.
caucasica, A. dracunculus, A.
tridentata, A. pynocephala)
Sagebrush (Southernwood,
Wormwood, California, Silver, True
tarragon, Big, Sandhill)
F
Atriplex species (numerous)
Saltbush
F, I
A
vena fatua
Wild Oat
F
Baccharis pilularis
Coyote Bush
F
Bambusa species
Bamboo
F, I
Bougainvillea species
Bougainvillea
F, I, FR
Brassica species (B. campestris, B.
nigra, B. rapa)
Mustard (Field, Black, Yellow)
F, I
Bromus rubens
Foxtail, Red
B
rome
F
, I
Botanical Name
Common Name
Comment
B
Bromus carinatus
California
B
rome
Grows to 5’, Dies if cut
Castanopsis chrysophylla
Giant Chinquapin
F
Cardaria draba
Hoary Cress
I
Carpobrotus species
Ice Plant, Hottentot Fig
I
Carissa macrocarpa
Green
C
arpet
N
atal
P
lum
FR
Ceonothus griseus “ Louis Edmunds
Louis Edmunds Ceanothus
Grows higher than 18”
Ceonothus griseus var. horizontalis
Carmel Creeper Ceonothus
Grows higher than 18”
Ceonothus griseus var. horizontalis
“yankee point”
Yankee Point Ceonothus
Grows higher than 18”
Ceonothus m
egacarpus
Big
P
od
C
eonothus
Grows higher than 18”
Cirsium vulgare
Wild Artichoke
F,I
Conyza bonariensis
Horseweed
F
Coprosma pumila
Prostrate Coprosma
F
Cortaderia selloana
Pampas Grass
F, I
Cynara Cardunculus
Atichoke
T
histle
F
Cytisus scoparius
Sc
otch Broom
F, I
Delosperma “alba”
White
T
railing Ice Plant
F
Dodonaea viscosa
Hopseed Bush
F
Drosanthemum Floribundum
Rosea Ice plant
F
Eriodictyon californicum
Yerba Santa
F
Eriogonum species (E. fasciculatum)
Buckwheat (California)
F
Fremontodendro
n species
Flannel Bush
F
Hakea suaveolens
Sweet Hakea
FR
Hedera species (H. canariensis, H.
helix)
Ivy (Algerian, English)
I
Helix Canariensis
English Ivy
F
Heterotheca grandiflora
Telegraph Plant
F
Hordeum leporinum
Wild
B
arley
F, I
Juniperus specie
s
Juniper
F
Lactuca serriola
Prickly Lettuce
I
Lamprathus aurantiacus
Bush Ice Plant
F
Lamprathus spectabilis
Trailing Ice Plant
F
Larix species (numerous)
Larch
F
Larrea tridentata
Creosote
B
ush
F
Leymus condensatus
Giant Wild Rye
Grows to 9’ tall
Lolium multiflorum
Ryegrass
F, I
Botanical Name
Common Name
Comment
B
Lonicera japonica
Japanese Honeysuckle
F
Mahonia species
Mahonia
F
Mimulus aurantiacus
Sticky Monkeyflower
F
Miscanthus species
Eulalie Grass
F
Muhlenbergia species
Deer Grass
F
Nassella ( stipa)leprida
Foothill
N
eedl
egrass
Grows higher than 18”
Nassella (stipa) pulchra
Purple
N
eedlegrass
Grows higher than 18”
Nerium Oleander
Oleander
Toxic
Nicotiana species (N. bigelovii, N.
glauca)
Tobacco (Indian, Tree)
F, I
Pennisetum setaceum
Fountain Grass
F, I
Perovskia a
troplicifolia
Russian Sage
F
Phoradendron species
Mistletoe
F
Pickeringia montana
Chaparral Pea
F
Rhus (R. diversiloba, R. laurina, R.
lentii)
Sumac (Poison oak, Laurel, Pink
Flowering)
F
Ricinus communis
Castor Bean
F, I
Rhus Lentii
Pink Flowering Su
mac
F
Rosmarinus species
Rosemary ( except dwarf/prostrate
variety)
F
Salvia species (numerous)
Sage
F, I
Salsola australis
Russian Thistle
F, I
Senecio serpens
No common name
FR
Solanum Xantii
Purple Nightshade (toxic)
I, Toxic
Solanum Douglasii
Do
uglas Nightshade
Toxic
Silybum marianum
Milk Thistle
F, I
Strelizia nicolae
Giant
B
ird of
P
aradise
FR
Strelizia reginae
Bird of
P
aradise
FR
Thuja species
Arborvitae
F
Urtica urens
Burning Nettle
F
Vinca major
Periwnkle
I
See next page for important Notes and Informaion
Notes:
A.
F
=
Fl
ammable,
I =
I
nvasive,
FR
= Fr
eezes.
B.
The
Fi
re Dis
tric
t
has
a
l
is
t
o
f
app
roved trees
that
c
an be us
ed
for
l
andscaping and street
trees.
Information:
1. Plants
on this
l
ist
t
hat
a
re considered invasiv
e are a partial
l
ist
o
f
c
ommonly
f
ound
plants.
There are many
ot
her
pl
ants
c
onsidered invasiv
e that
s
hould not
be planted in a fuel
modification zone and they
c
an be found on The California Invas
ive Plant
C
ouncil’s
Website
www.cal
-i
p
c.org/ip/inventory/index.php
.
2. For
t
he purpose of
us
i
ng
this
l
ist
as
a
guide in selecting
pl
ant
m
aterial,
i
t
i
s
s
tipulated that
all
pl
ant
m
aterial
w
ill
bur
n under
v
arious
c
onditions.
3. The absence
o
f
a particular
pl
ant,
s
hrub,
groundcover,
or
t
r
ee
from
t
his
l
ist
does
not
neces
sa
rily
m
ean
it
is
fire resistiv
e and
does
not
i
mply
that
a
particular
pl
ant,
s
hrub,
groundcov
er,
or
t
ree will
be approved by
t
he
Fi
re
Co
de
Of
ficial
f
or
l
andscaping
i
n the
Wildland Urban
I
nterface
Fi
re Area.
4. All
vegetation used in Vegetation Management
Zones
and elsewhere
in
the Wildland
Urban Interface
Fire Area shall
be subject
to approval
of
the
Fi
re
Co
de
Of
ficial.
5. Landscape architects
m
ay
s
ubmit
pr
opos
als
f
or
us
e of
c
ertain vegetation on a project
specific
basis.
They
shall
als
o
submit
justifications
as
t
o
t
he
fir
e
resistivity
of
the
proposed vegetation.
6. Native
and/or
drought
t
olerant
plants
a
re
enc
ouraged.
7. Notwithstanding
t
he ty
pe of
pl
ant
i
ncluded or
not
i
ncluded on this
l
ist,
s
pacing
and
configuration of
pl
antings
,
which
a
re
c
ritica
l
to
s
topping
f
ir
e
spread,
shall
be
in
accordance
w
ith
Murrieta Fire & Rescue standards.
8. This
list
was
compil
ed
wit
h
t
he
assistanc
e
of
wildl
and
ur
ban
interfac
e
landscape
con
su
ltants.
It
has
been
reviewed and
appr
ov
ed
by
Murrieta Fire & Rescue and may be
revised or updated as neces
sary.