CWUIC · California Wildland-Urban Interface Code
What water supply is required for new buildings and subdivisions?
If you build or subdivide in a California WUI area, you must provide an approved water supply that can deliver the fire flow the California Fire Code requires; the CWUIC (§§ 402.1.2, 404.2, 404.5) mandates the supply, timing during parcel map approval, and reliability measures such as standby power.
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
New subdivisions and new buildings in WUI areas must be provided with an approved water supply capable of delivering the required fire flow for both structural protection and wildland fire exposure. This requirement for subdivisions is stated in § 402.1.2 and the general requirement to provide the required fire flow to the premises is stated in § 404.2 . The magnitude of the required fire flow is determined using the California Fire Code (Appendix B or BB), as referenced in § 404.5 .
The most important rule: new subdivisions and new/relocated structures in the WUI must have an approved water source that can deliver whatever fire-flow the California Fire Code requires for that building or exposure (CWUIC §§ 402.1.2 and 404.2) .
Requirements in detail
Who this applies to
- New subdivisions (as determined by the local jurisdiction) — must meet water-supply requirements during planning/parcel map approval (see § 402.1.2 and § 402.1.2.1) .
- New or relocated individual structures in the WUI — must have a conforming water supply (see § 402.2.2, which cross-references the same water-supply requirements) .
What “required water supply” means (high level)
- An approved water supply must be capable of supplying the required fire flow for structural fire protection and for wildland fire exposure to the premises (CWUIC § 404.2) .
- The method for determining needed fire flow is by the California Fire Code (calculate per Appendix B or BB), as required by CWUIC § 404.5 .
Decision table — key dimensions and where the code points you
| Decision factor | What you must provide / value to check | Code Reference |
|---|---|---|
| Applicability — subdivisions | Provide water supply to the subdivision at planning/parcel map stage | § 402.1.2 and § 402.1.2.1 |
| Required water supply (concept) | Water source must supply the required fire flow for buildings and wildland exposure | § 404.2 |
| How to determine fire flow | Use California Fire Code fire‑flow methodology (Appendix B or BB as applicable) | § 404.5 |
| Acceptance of non‑municipal supplies | Where municipal water is unavailable, NFPA 1142 or comparable systems may be accepted; mobile tenders or containment may qualify if volume is immediately available | Appendix mapping / guidance (see CCR 1275.02 referenced in Appendix H) § 1275.02 (see Appendix H) |
| Pump reliability / standby power | Standby power required for stationary pumps so the required supply can be provided; minimum 2 hours unless exception applies | § 404.10.3 |
(Notes: CWUIC defers to the California Fire Code for numeric fire‑flow values and detailed hydrant spacing/design. See the code references above for where the CWUIC points you to the CFC and NFPA guidance.)
Exceptions & special cases
- The CWUIC does not list specific numeric fire‑flow values; instead it requires that the required fire flow be determined in accordance with the California Fire Code (Appendix B/BB) — CWUIC § 404.5 . In short: CWUIC sets the obligation and points to the CFC for numbers.
- Where a municipal‑type water supply is unavailable, the state accepts alternative systems that meet or exceed the CFC or, where appropriate, NFPA 1142 (National standard for suburban/rural water supplies), and emergency supplies (mobile water tenders or reservoirs) are permitted if the specified quantity is immediately available; see CCR 1275.02 as mapped in Appendix H of the CWUIC (see § 1275.02 in Appendix H) .
- Standby power exceptions: a standby power supply for stationary water facilities is not required if (1) the primary power service is underground and approved by the code official, or (2) the facility serves no more than one single‑family dwelling — see § 404.10.3 .
- Local jurisdictions may set additional or more specific requirements (the code repeatedly cross‑references local approval and the California Fire Code), so plan‑check/early coordination with the local fire code official is required (see § 402.1.2 and the cross‑references) .
Common mistakes
- Assuming a single universal gpm value applies everywhere. The CWUIC requires use of the California Fire Code method to determine the required fire flow — the CWUIC itself does not list fixed gpm numbers (§ 404.5) .
- Waiting until construction to provide water. For subdivisions the water supply requirement applies during the tentative/parcel map process — don’t leave it to final permit stage (§ 402.1.2.1) .
- Overlooking reliability: failing to provide required standby power for pumps or failing to ensure access to draft sites and hydrants can render a system non‑conforming (see § 404.10.3 and related sections) .
- Not coordinating with the local fire agency on acceptance of alternative sources (mobile tenders, tanks, NFPA 1142 designs) — Appendix H guidance indicates alternatives are acceptable when approved, but approval is local (see CCR mapping in Appendix H) .
- Failing to mark/maintain access to water sources and hydrants — CWUIC requires identification and unobstructed access (see § 404.7 and § 404.8) .
Worked example — concrete scenario (illustrative)
Scenario: A developer proposes a new five‑lot subdivision in a WUI area. The local fire code official determines, following the California Fire Code Appendix B method, that the development requires a fire flow of 1,500 gpm for structural protection during an incident (this numeric result comes from the CFC calculation — CWUIC requires delivery of the fire flow but does not itself prescribe the number) — see § 404.2 and § 404.5 .
Steps to comply (example numbers are illustrative; use the CFC to calculate your actual flow):
- Confirm required fire flow via CFC Appendix B/BB (local fire code official). CWUIC requires this flow be made available to the premises (§ 404.2, § 404.5) .
- Decide supply method: municipal hydrant system vs. on‑site storage/pumps or mobile water tender. If municipal water is unavailable, design per NFPA 1142 or other approved method (see Appendix H mapping / CCR 1275.02) .
- If using on‑site storage: size stored water to supply 1,500 gpm for the required duration. For example, if the required duration is 2 hours, required volume = 1,500 gpm × 120 minutes = 180,000 gallons. The CWUIC requires pump reliability/standby power so the stationary pumps can provide the required supply (minimum 2 hours backup per § 404.10.3) .
- Provide approved hydrant(s) or fire valves and ensure their location and access meet the jurisdiction’s version of the CFC/CWUIC requirements (hydrant design/spacing is handled through the CFC/CWUIC cross‑references) .
- Document and show compliance at the tentative/parcel‑map stage so the subdivision plat/conditions require the water system to be installed or guaranteed before final map approval (§ 402.1.2.1) .
Important: the numeric 1,500 gpm in this example is hypothetical; the actual required fire flow must be determined by the California Fire Code method and approved by the local fire code official (CWUIC § 404.5) .
Related provisions
- § 402.1.2.1 — Parcel map approval; water supply requirements apply during tentative/parcel map processing .
- § 404.3 — Draft sites for natural water sources and requirements for pumper access points .
- § 404.4 — Hydrant design, number, and spacing (references to CFC Appendix C or CC) .
- § 404.7 — Obstructions; water sources and hydrants must remain unobstructed .
- § 404.8 — Identification; marking of water sources, hydrants and fire valves .
- § 404.9 — Testing and maintenance of water sources, draft sites and hydrants .
- § 404.10 (and § 404.10.3) — Water supply reliability and standby power requirements (minimum 2 hours for stationary power systems unless excepted) .
- Appendix H / CCR 1275.02 — Acceptance of NFPA 1142, mobile water tender, combined storage, freeze/crash protection guidance (as mapped in CWUIC Appendix H) .
Code references
Grounded in the retrieved California Wildland-Urban Interface Code — click a citation to read the verbatim passage:
CWUIC § 4-1 High relevance — show source text
2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE 4-1
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4 WILDLAND-URBAN INTERFACE AREA REQUIREMENTS
User notes:
About this chapter: Chapter 4 provides requirements that apply to all occupancies in the wildland-urban interface and pertain to all of the following:
Fire service access to the property that is to be protected, including fire apparatus access roads and off-road driveways.
Premises identification.
Key boxes to provide ready access to properties secured by gated roadways or other impediments to rapid fire service access.
Fire protection water supplies, including adequate water sources, pumper apparatus drafting sites, fire hydrant systems and system reliability.
Fire department access to equipment such as fire suppression equipment and fire hydrants.
SECTION 401—GENERAL
401.1 Scope. Wildland-urban interface areas shall be provided with emergency vehicle access and water supply in accordance with this chapter.
401.2 Objective. The objective of this chapter is to establish the minimum requirements for emergency vehicle access and water supply for buildings and structures located in the wildland-urban interface areas.
401.3 General safety precautions. General safety precautions shall be in accordance with this chapter. See also Appendix A.
SECTION 402—APPLICABILITY
402.1 Subdivisions. Subdivisions shall comply with Sections 402.1.1 and 402.1.2.
402.1.1 Access. New subdivisions, as determined by this jurisdiction, shall be provided with fire apparatus access roads in accordance with the California Fire Code; the California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 2, Article 2; and access requirements in accordance with Section 403.
402.1.2 Water supply. New subdivisions as determined by this jurisdiction shall be provided with water supply in accordance with Section 507 of the California Fire Code; California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 2, Article 4; and Section 404.
402.1.2.1 Parcel map approval. Water supply requirements shall apply in the tentative and parcel map process when new parcels are approved by the local jurisdiction.
402.2 Individual structures. Individual structures shall comply with Sections 402.2.1 and 402.2.2.
402.2.1 Access. Individual structures hereafter constructed or relocated into or within wildland-urban interface areas shall be provided with fire apparatus access in accordance with the California Fire Code; the California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 2, Subsection 1273; and Section 403 .
402.2.2 Water supply. Individual structures hereafter constructed or relocated into or within wildland-urban interface areas shall be provided with a conforming water supply in accordance with the California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 2, Article 4; California Fire Code Section 507; and Section 404.
CWUIC § 104.2.2.7 High relevance — show source text
Outbuilding 202
Peer Review 104.2.2.7, 202 Permits
Application 105.4 Approval 105.5 Expiration 105.8 Issuance 105.6 Preliminary inspection 105.4.1 Refusal to issue 105.6.1
Required 105.2 Retention 105.9
Revocation 105.10 Validity 105.7 Work exempt from permit 105.3 Placarding as Unsafe 109.3.5.3 Powers and Duties of the Code
Official 104.1
Practical Difficulties 104.2.3 Protection of Pumps and Water Storage Facilities Appendix A, A107
Rafter Tail 202 Referenced Standards 102.4, Chapter 7 Registered Design Professional 104.2.1.2, 104.2.2.6.2, 106.1, 202 Residential Unit 202 Retroactivity 101.4 Ridgelline 202 Road 202 Roof Covering 202 Roof Covering System 202 Roof Coverings, Replacement or Repair of 507
Roof Deck 202
Scope 101 Self-Defense Mechanism Appendix G Service Utilities 111
Slope 202 Spark Arrestors 605 Stop Work Order 113 Storage of Firewood and Combustible Materials 607 Strategic Ridgeline 202 Structure 202
Subdivision 202
Technical Assistance 104.2.1 Temporary Uses, Equipment and Systems 107 Tree Crown 202
Trees 603.4.2
2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE INDEX-1
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INDEX
Undeveloped Ridgeline 202 Unenclosed Accessory Structure 202
Vegetation Control Appendix A, A102 Vegetation management compliance 106.4 Vegetation Management Plan Appendix B Vents 504.10
Vertical Curve 202
Water Supply Adequate water supply 404.5 Applicability 402 Draft sites 404.3 Hydrants 404.4 Identification 404.8
Obstructions 404.7 Reliability 404.10 Required water supply 404.2 Subdivisions 402.1 Testing and maintenance 404.9 Water sources 404.2
Wildfire 202
Wildland 202
Wildland-Urban Interface Area 202
Wildland-Urban Interface Area Designations 302 Declaration 302.1
Mapping 302.2 Review 302.3
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HISTORY NOTE APPENDIX
2025 California Wildland-Urban Interface Code California Code of Regulations, Title 24, Part 7
HISTORY:
CWUIC § 603.4.2 High relevance — show source text
Trees 603.4.2
2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE INDEX-1
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INDEX
Undeveloped Ridgeline 202 Unenclosed Accessory Structure 202
Vegetation Control Appendix A, A102 Vegetation management compliance 106.4 Vegetation Management Plan Appendix B Vents 504.10
Vertical Curve 202
Water Supply Adequate water supply 404.5 Applicability 402 Draft sites 404.3 Hydrants 404.4 Identification 404.8
Obstructions 404.7 Reliability 404.10 Required water supply 404.2 Subdivisions 402.1 Testing and maintenance 404.9 Water sources 404.2
Wildfire 202
Wildland 202
Wildland-Urban Interface Area 202
Wildland-Urban Interface Area Designations 302 Declaration 302.1
Mapping 302.2 Review 302.3
INDEX-2 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE
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HISTORY NOTE APPENDIX
2025 California Wildland-Urban Interface Code California Code of Regulations, Title 24, Part 7
HISTORY:
- (SFM 08/24)—Adoption by reference of the 2024 International Wildland-Urban Interface Code with necessary amendments relocated from the California Building Code, California Residential Code and California Fire Code to become the 2025 Califor- nia Wildland-Urban Interface Code . Approved by the California Building Standards Commission on February 26, 2025, filed with Secretary of State on March 7, 2025, and effective on January 1, 2026.
2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE HIST-1
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HIST-2 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE
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CWUIC § 1274.02 High relevance — show source text
[CCR, Title 14 §1274.02]
403.2.4 Addresses for Buildings. (a) All Buildings shall be issued an address by the Local Jurisdiction which conforms to that jurisdiction's overall address system. Utility and miscellaneous Group U Buildings are not required to have a separate address; however, each Residential Unit within a Building shall be separately identified. (b) The size of letters, numbers and symbols for addresses shall conform to the standards in the California Fire Code, California Code of Regulations Title 24, Part 9. (c) Addresses for residential Buildings shall be reflectorized.
[CCR, Title 14 §1274.03]
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WILDLAND-URBAN INTERFACE AREA REQUIREMENTS
403.2.5 Address installation, location and visibility. (a) All buildings shall have a permanently posted address which shall be plainly legible and visible from the Road fronting the property. (b) Where access is by means of a private Road and the address identification cannot be viewed from the public way, an unob- structed sign or other means shall be used so that the address is visible from the public way. (c) Address signs along one-way Roads shall be visible from both directions. (d) Where multiple addresses are required at a single driveway, they shall be mounted on a single sign or post. (e) Where a Road provides access solely to a single commercial or industrial business, the address sign shall be placed at the near- est Road intersection providing access to that site, or otherwise posted to provide for unobstructed visibility from that intersection.
(f) In all cases, the address shall be posted at the beginning of construction and shall be maintained thereafter.
[CCR, Title 14 §1274.04]
SECTION 404—WATER SUPPLY
404.1 General. An approved water source shall have an adequate water supply for the use of the fire protection service to protect buildings and structures from exterior fire sources or to suppress structure fires within the wildland-urban interface area of the jurisdiction in accordance with this section.
404.2 Required water supply. An approved water supply capable of supplying the required fire flow for structural fire protection and wildland fire exposure shall be provided to the premises on which facilities, buildings or portions of buildings are hereafter constructed or moved into or within the jurisdiction in accordance with Section 507 of the California Fire Code.
404.3 Draft sites. Approved draft sites shall be provided at natural water sources intended for use as fire protection for compliance with this code. The design, construction, location, access and access maintenance of draft sites shall be approved by the code official.
404.3.1 Access. The draft site shall have emergency vehicle access from an access road in accordance with Section 403.
404.3.2 Pumper access points. The pumper access point shall be either an emergency vehicle access area alongside a conforming access road or an approved driveway not longer than 150 feet (45 720 mm). Pumper access points and access driveways shall be designed and constructed in accordance with all codes and ordinances enforced by this jurisdiction. Pumper access points shall not require the pumper apparatus to obstruct a road or driveway.
CWUIC § 402.1.1 Medium relevance — show source text
402.1.1 Access. New subdivisions, as determined by this jurisdiction, shall be provided with fire apparatus access roads in accordance with the California Fire Code; the California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 2, Article 2; and access requirements in accordance with Section 403.
402.1.2 Water supply. New subdivisions as determined by this jurisdiction shall be provided with water supply in accordance with Section 507 of the California Fire Code; California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 2, Article 4; and Section 404.
402.1.2.1 Parcel map approval. Water supply requirements shall apply in the tentative and parcel map process when new parcels are approved by the local jurisdiction.
402.2 Individual structures. Individual structures shall comply with Sections 402.2.1 and 402.2.2.
402.2.1 Access. Individual structures hereafter constructed or relocated into or within wildland-urban interface areas shall be provided with fire apparatus access in accordance with the California Fire Code; the California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 2, Subsection 1273; and Section 403 .
402.2.2 Water supply. Individual structures hereafter constructed or relocated into or within wildland-urban interface areas shall be provided with a conforming water supply in accordance with the California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 2, Article 4; California Fire Code Section 507; and Section 404.
402.3 Existing conditions. Existing buildings shall be provided with address markers in accordance with Sections 403.2.4 and 403.2.5 . Existing roads and fire protection equipment shall be provided with markings in accordance with Sections 403.4 and 404.8, respectively.
SECTION 403—ACCESS
USER NOTE: The standards in Section 403 applicable to roads shall not apply to roads used solely for agriculture; mining; or the management of timberland or harvesting of forest products. [CCR, Title 14 §1270.03(d)]
403.1 General. Roads and driveways, whether public or private, unless exempted under 14 CCR § 1270.03(d), shall provide for safe access for emergency wildfire equipment and civilian evacuation concurrently, and shall provide unobstructed traffic circulation during a wildfire emergency consistent 403.1.1 to 403.1.9. [CCR, Title 14 §1273.00]
403.1.1 Section 403 definitions. When used in Section 403, the term listed below shall be defined as follows:
DEFENSIBLE SPACE. The area within the perimeter of a parcel, development, neighborhood or community where basic wildland fire protection practices and measures are implemented to defend against encroaching wildfire or to escape structure fires. The perimeter as used in this regulation [CCR Title 14] is the area encompassing the parcel or parcels proposed for construction and/or development, excluding the physical structure itself. The area is characterized by the establishment and maintenance of emer- gency vehicle access, emergency water reserves, road names and identification, and fuel modification measures. [CCR Title 14 §1270.01(f)]
CWUIC § 1274.04 Medium relevance — show source text
or otherwise posted to provide for unobstructed visibility from that_ intersection.
(f) In all cases, the address shall be posted at the beginning of construction and shall be maintained thereafter.
[CCR, Title 14 §1274.04]
SECTION 404—WATER SUPPLY
404.1 General. An approved water source shall have an adequate water supply for the use of the fire protection service to protect buildings and structures from exterior fire sources or to suppress structure fires within the wildland-urban interface area of the jurisdiction in accordance with this section.
404.2 Required water supply. An approved water supply capable of supplying the required fire flow for structural fire protection and wildland fire exposure shall be provided to the premises on which facilities, buildings or portions of buildings are hereafter constructed or moved into or within the jurisdiction in accordance with Section 507 of the California Fire Code.
404.3 Draft sites. Approved draft sites shall be provided at natural water sources intended for use as fire protection for compliance with this code. The design, construction, location, access and access maintenance of draft sites shall be approved by the code official.
404.3.1 Access. The draft site shall have emergency vehicle access from an access road in accordance with Section 403.
404.3.2 Pumper access points. The pumper access point shall be either an emergency vehicle access area alongside a conforming access road or an approved driveway not longer than 150 feet (45 720 mm). Pumper access points and access driveways shall be designed and constructed in accordance with all codes and ordinances enforced by this jurisdiction. Pumper access points shall not require the pumper apparatus to obstruct a road or driveway.
404.4 Hydrants. Hydrants shall be designed and constructed in accordance with nationally recognized standards. The location and access shall be approved by the code official. The number and spacing of fire hydrants shall be in accordance with Appendix C or CC of the California Fire Code, as applicable.
404.5 Adequate water supply. Fire-flow requirements shall be determined in accordance with Appendix B or BB of the California Fire Code, as applicable.
404.6 Reserved.
404.7 Obstructions. Access to water sources required by this code shall be unobstructed at all times. The fire department shall not be deterred or hindered from gaining immediate access to water source equipment, fire protection equipment or hydrants.
404.8 Identification. Water sources, draft sites, hydrants and fire protection equipment and hydrants shall be clearly identified in a manner approved by the code official to identify location and to prevent obstruction by parking and other obstructions. Each fire hydrant and access to a water supply shall be identified in accordance with one of the following: 1. Where located along a driveway, a reflectorized blue marker with a minimum dimension of 3 inches (73 mm) shall be located on the driveway address sign and mounted on a fire-retardant post. 2. Where located along an access road: 2.2. A reflectorized blue marker with a minimum dimension of 3 inches (73 mm) shall be mounted on a fire-retardant post. The signpost shall be within 3 feet (914 mm) of said fire hydrant with the sign not less than 3 feet (914 mm) nor greater than 5 feet (1524 mm) above ground, in a horizontal position and visible from the driveway. _2.3.
CWUIC § 302.1 Medium relevance — show source text
2|Purpose|Y|||||||51176|4201| |302|Wildland-Urban
Interface Area
Designations|Y||||||||| |302.1|Mapping|Y|||4904.2||||51178|4202
4203(a)
4204| |302.2|Review of wildland-
urban interface areas|Y|||||||51181|4204| |Chapter 4|Wildland-urban interface area requirements|Wildland-urban interface area requirements|Wildland-urban interface area requirements|Wildland-urban interface area requirements|Wildland-urban interface area requirements|Wildland-urban interface area requirements|Wildland-urban interface area requirements|Wildland-urban interface area requirements|Wildland-urban interface area requirements|Wildland-urban interface area requirements| |401|General|Y||||||||| |401.1|Scope|Y||||||||| |401.2|Objective|Y||||1273.00||||| |401.3|General safety
precautions|Y||||||||| |402|Applicability|Y|||||||||APPENDIX H-26 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE
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APPENDIX H—REFERENCED CALIFORNIA DOCUMENTS
2025 CWUIC—continued Col2 Adopted
Yes/NoIWUIC
SectionCBC
SectionCFC
SectionTitle 14,
Division 1.5
SectionTitle 19,
Division 1
SectionGov Code
SectionPRC
SectionHSC
SectionSection Title Title Title Title Title Title Title Title Title Title Chapter 4 Wildland-urban interface area requirements Wildland-urban interface area requirements Wildland-urban interface area requirements Wildland-urban interface area requirements Wildland-urban interface area requirements Wildland-urban interface area requirements Wildland-urban interface area requirements Wildland-urban interface area requirements Wildland-urban interface area requirements Wildland-urban interface area requirements 402.1 Subdivisions Y 402.1.1 Access Y 503 402.1.2 Water supply Y 507 402.1.2.1 Parcel map approval Y 1275.01 402.2 Individual structures Y 503
507402.2.1 Access Y 503 402.2.2 Water supply Y 507 402.3 Existing conditions N 505.1 403 Access Y 1273 403.1 General Y 1273.00 403.1.1 Section 403 definitions Y 1270.01(f) 403.1.2 Width Y 1273.01(a)
1273.CWUIC § 402.1.1 Medium relevance — show source text
1|Subdivisions|Y||||||||| |402.1.1|Access|Y|||503|||||| |402.1.2|Water supply|Y|||507|||||| |402.1.2.1|Parcel map approval|Y||||||1275.01||| |402.2|Individual structures|Y|||503
507|||||| |402.2.1|Access|Y|||503|||||| |402.2.2|Water supply|Y|||507|||||| |402.3|Existing conditions|N|||505.1|||||| |403|Access|Y||||1273||||| |403.1|General|Y||||1273.00||||| |403.1.1|Section 403 definitions|Y||||1270.01(f)||||| |403.1.2|Width|Y||||1273.01(a)
1273.01(b)
1273.01(c)||||| |403.1.3|Road Surfaces|Y||||1273.02(a)
1273.02(b)
1273.02(c)||||| |403.1.4|Grades|Y||||1273.03(a)
1273.03(b)||||| |403.1.5|Radius|Y||||1273.04(a)
1273.04(b)||||| |403.1.6|Turnarounds|Y||||1273.05(a)
1273.05(b)
1273.05(c)
1273.05(d)
1273.05(e)
1273.05(f)
1273.05(g)||||| |Figure A|Turnaround with two
10' traffic lanes|Y||||Figure A||||| |Figure B|Turnaround with one
10' traffic lane|Y||||Figure B||||| |403.1.7|Turnouts|Y||||1273.06||||| |403.1.8|Road and driveway
structures|Y||||1273.07(a)
1273.07(b)
1273.07(c)
1273.07(d)||||| |403.1.9|Dead-end roads|Y||||1273.08(a)
1273.08(b)||||| |403.10|Gate Entrances|Y||||1273.09(a)
1273.09(b)
1273.09(c)
1273.09(d)||||| |403.2|Signing and Building
Numbering|Y||||Article 3||||| |403.2.1|Intent|Y||||1274.00||||| |403.2.2|Road signs|Y||||1274.01||||| |403.2.3|Road Sign
Installation, Location
and Visibility|Y||||1274.02(a)
1274.02(b)
1274.02(c)
1274.02(d)||||| |403.2.4|Addresses for
Buildings|Y||||1274.03(a)
1274.03(b)
1274.03(c)||||| ||||||||||||2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE APPENDIX H-27
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CBC § G107 Medium relevance — show source text
- The costs of providing governmental services during and after flood conditions including maintenance and repair of public utilities and facilities such as sewer, gas, electrical and water systems, streets and bridges.
G106.7 Conditions for issuance. Variances shall only be issued by the board where all of the following criteria are met:
A technical showing of good and sufficient cause that the unique characteristics of the size, configuration or topography of the site renders the elevation standards inappropriate.
A determination that failure to grant the variance would result in exceptional hardship by rendering the lot undevelopable.
A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, nor create nuisances, cause fraud on or victimization of the public or conflict with existing local laws or ordinances.
A determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.
Notification to the applicant in writing over the signature of the floodplain administrator that the issuance of a variance to construct a structure below the base flood level will result in increased premium rates for flood insurance up to amounts as high as $25 for $100 of insurance coverage, and that such construction below the base flood level increases risks to life and property.
SECTION G107—SUBDIVISIONS
G107.1 General. Any subdivision proposal, including proposals for manufactured home parks and subdivisions, or other proposed new development in a flood hazard area shall be reviewed to verify all of the following:
- Such proposals are consistent with the need to minimize flood damage.
- Public utilities and facilities, such as sewer, gas, electric and water systems, are located and constructed to minimize or eliminate flood damage.
- Adequate drainage is provided to reduce exposure to flood hazards.
G107.2 Subdivision requirements. The following requirements shall apply in the case of any proposed subdivision, including proposals for manufactured home parks and subdivisions, any portion of which lies within a flood hazard area:
- The flood hazard area, including floodways, coastal high-hazard areas and coastal A zones, as appropriate, shall be delineated on tentative and final subdivision plats.
- Design flood elevations shall be shown on tentative and final subdivision plats.
- Residential building lots shall be provided with adequate buildable area outside the floodway.
- The design criteria for utilities and facilities set forth in this appendix and appropriate International Codes shall be met.
2025 CALIFORNIA BUILDING CODE APPENDIX G-5
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
APPENDIX G—FLOOD-RESISTANT CONSTRUCTION
SECTION G108—SITE IMPROVEMENT
G108.1 Development in floodways. Development or land-disturbing activity shall not be authorized in the floodway unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice, and prepared by a registered design professional, that the proposed encroachment will not result in any increase in the base flood level.
G108.2 Coastal high-hazard areas and coastal A zones. In coastal high-hazard areas and coastal A zones:
New buildings and buildings that are substantially improved shall only be authorized landward of the reach of mean high tide.
The use of fill for structural support of buildings is prohibited.
CWUIC § 404.10.2 Medium relevance — show source text
404.10.2 Clearance of fuel. Defensible space shall be provided around water tank structures, water supply pumps and pump houses in accordance with Section 603.
2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE 4-7
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WILDLAND-URBAN INTERFACE AREA REQUIREMENTS
404.10.3 Standby power. Standby power shall be provided to pumps, controllers and related electrical equipment so that stationary water supply facilities within the wildland-urban interface area that are dependent on electrical power can provide the required water supply. The standby power system shall be in accordance with Section 2702 of the California Building Code and Section 1203 of the California Fire Code . The standby power source shall be capable of providing power for not less than 2 hours.
Exceptions:
- Where approved by the code official, a standby power supply is not required where the primary power service to the stationary water supply facility is underground.
- A standby power supply is not required where the stationary water supply facility serves not more than one singlefamily dwelling.
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4-8 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
CALIFORNIA WILDLAND-URBAN INTERFACE CODE – MATRIX ADOPTION TABLE
CHAPTER 5 – SPECIAL BUILDING CONSTRUCTION REGULATIONS
(Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)
Adopting Agency BSC BSC-
CGSFM Col5 HCD Col7 Col8 DSA Col10 OSHPD Col12 Col13 Col14 Col15 Col16 BSCC DPH AGR DWR CEC CA SL SLC Adopting Agency BSC BSC-
CGT-24 T-19* 1 2 1/AC AC SS 1 1R 2 3 4 5 5 5 5 5 5 5 5 5 Adopt Entire Chapter Adopt Entire Chapter as
amended (amended sections
listed below)X Adopt only those sections that
are listed below[California Code of Regulations,
Title 19, Division 1]Chapter / Section 501.1 X 501.2 X 501.4 – 501.4.1 X 502_Reserved_ X 503.1 X 503. CWUIC § 1.859 Medium relevance — show source text
78|–|1.859|0.463| |35.31|–|2.247|0.559| |38.84|–|2.667|0.663| |42.37|–|3.121|0.775| |45.90|–|3.607|0.895| |49.43|–|4.125|1.022| |52.97|–|–|1.157| |56.50|–|–|1.299| |60.03|–|–|1.449| |63.56|–|–|1.607| |67.09|–|–|1.772| |70.62|–|–|1.944| |81.21|–|–|2.503| |91.81|–|–|3.127| |102.40|–|–|3.813|
For SI units: 1 standard cubic foot per minute = 28.32 SLPM, 1 inch = 25 mm, 1 foot = 304.8 mm, 1 pound-force per square inch = 6.8947 kPa
Notes: 1 Based on pressure of 14.7 psig (101 kPa) at 68°F (20°C). 2 Based on pressure of 55 psig (379 kPa) at 68°F (20 °C).
2025 CALIFORNIA PLUMBING CODE 291
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HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICAL VACUUM SYSTEMS
TABLE 1323.1.4(5) PRESSURE LOSS FOR VACUUM (continued)
FLOW
RATE
(SCFM)1VACUUM LOSS (inch of mercury)
PER 100 FEET FOR COPPER TUBE2Col3 Col4 Col5 Col6 FLOW
RATE
(SCFM)13⁄4 INCH
TUBE1 INCH
TUBE11⁄4 INCH
TUBE11⁄2 INCH
TUBE2 INCH
TUBE49.43 – – – 3.645 0.956 52.97 – – – 4.122 1.081 56.50 – – – 4.626 1.212 63.56 – – – – 1.495 70.62 – – – – 1.803 77.68 – – – – 2.138 84.74 – – – – 2.497 91.81 – – – – 2.882 98.87 – – – – 3.291 105.93 – – – – 3.724 112.99 – – – – 4.181 CWUIC § 404.9 Medium relevance — show source text
May_ 1988.
404.9 Testing and maintenance. Water sources, draft sites, hydrants and other fire protection equipment required by this code shall be subject to periodic tests as required by the code official. Such equipment installed under the provisions of this code shall be maintained in an operative condition at all times and shall be repaired or replaced where defective. Additions, repairs, alterations and servicing of such fire protection equipment and resources shall be in accordance with approved standards.
404.10 Reliability. Water supply reliability shall comply with Sections 404.10.1 through 404.10.3.
404.10.1 Objective. The objective of this section is to increase the reliability of water supplies by reducing the exposure of vegetative fuels to electrically powered systems.
404.10.2 Clearance of fuel. Defensible space shall be provided around water tank structures, water supply pumps and pump houses in accordance with Section 603.
2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE 4-7
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WILDLAND-URBAN INTERFACE AREA REQUIREMENTS
404.10.3 Standby power. Standby power shall be provided to pumps, controllers and related electrical equipment so that stationary water supply facilities within the wildland-urban interface area that are dependent on electrical power can provide the required water supply. The standby power system shall be in accordance with Section 2702 of the California Building Code and Section 1203 of the California Fire Code . The standby power source shall be capable of providing power for not less than 2 hours.
Exceptions:
- Where approved by the code official, a standby power supply is not required where the primary power service to the stationary water supply facility is underground.
- A standby power supply is not required where the stationary water supply facility serves not more than one singlefamily dwelling.
�
4-8 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
CALIFORNIA WILDLAND-URBAN INTERFACE CODE – MATRIX ADOPTION TABLE
CHAPTER 5 – SPECIAL BUILDING CONSTRUCTION REGULATIONS
(Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)
Frequently asked questions
What numeric fire‑flow number does the CWUIC require for a new house?
The CWUIC requires that the premises be provided with the required fire flow, but it does not list numeric gpm values itself — the CWUIC directs you to the California Fire Code (Appendix B or BB) to calculate the actual required fire flow (§ 404.2, § 404.5) .
Does the CWUIC allow mobile water tenders instead of fixed hydrants?
Yes — where a municipal‑type water supply is unavailable, emergency water may be provided by a fire‑agency mobile water tender or an approved containment as long as the specified quantity is immediately available; acceptance is subject to local approval and NFPA guidance per the Appendix mapping (CCR 1275.02) .
When must the water supply be provided for a subdivision?
Water supply requirements apply during the tentative and parcel map process — the developer must address water supply as part of subdivision approval (see § 402.1.2 and § 402.1.2.1) .
Is standby generator power always required for water pumps?
CWUIC requires standby power for stationary water facility pumps so they can provide the required water supply, with a minimum 2 hours capacity; exceptions apply where primary power is underground (with approval) or the facility serves only one single‑family dwelling (§ 404.10.3) .
Who approves alternative water supply designs (e.g., NFPA 1142 systems)?
The local code official / fire agency must approve alternative designs. CWUIC’s Appendix H indicates NFPA 1142 designs can be accepted where municipal water is not available, but approval is local (see Appendix H / CCR 1275.02) .
More in California Wildland-Urban Interface Code
- Administration and Definitions
- Board of Appeals, Administration & Enforcement (permits, code official duties, appeals process)
- Wildland‑Urban Interface Area Designation & Mapping
- Fire Service Access & Water Supply (fire apparatus roads, driveways, hydrants, draft sites, standby power)
- Wildland‑Urban Interface Area Requirements (access, water, premises identification, key boxes)
- Referenced Standards & Test Methods
- Special Building Construction Regulations (ignition‑resistant construction, roof/vent/assembly requirements)
- Appendices and Model Ordinances (vegetation plans, severity‑zone adoption, home‑hardening guidance)
- Fire Protection Requirements (fire protection plans, systems, safety element provisions)
- Referenced California Documents & Matrix (CCR/Title 14 & 19 cross‑references, statutory references)
- Vegetation Management & Defensible Space (vegetation plans, maintenance, fire‑smart characteristics)
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