Chapter 6 — WATER SUPPLY AND DISTRIBUTION
601.2 Water Supply and Flushing.
California Plumbing Code (Title 24, Part 5) · 2025 edition · updated 2026-09-12 · California
Italicized text is a California amendment to the model code, as printed in the official publication.
Each plumbing fixture shall be provided with an adequate supply of potable running water piped thereto in an approved manner, so arranged as to flush and keep it in a clean and sanitary condition without danger of backflow or cross-connection. Water closets and urinals shall be flushed using an approved flush tank or flushometer valve.
Exceptions:
(1) Listed fixtures that do not require water for their operation and are not connected to the water supply.
(2) Where not deemed necessary for safety and sanitation by the Authority Having Jurisdiction. (3) [HCD 1 & HCD 2] For limited-density owner-built rural dwellings, potable water shall be available to the dwelling site, although such water need not be pressur- ized. Where water is not piped from a well, spring, cistern or other source, there shall be a minimum reserve of 50 gallons (189 L) of potable water available. Where water delivery is pressurized, piping shall be installed in accor- dance with the provisions of this chapter. (4) [HCD 1, HCD 2 & DWR] For all residential occupan- cies, alternate water sources may be allowed as speci- fied in Chapter 15 of this code in addition to potable
water.
(5) [BSC-CG & DWR] For non-residential occupancies, alternate water sources may be allowed as specified in Chapter 15 of this code.
(6) [DWR] Where a public agency requires a building to use recycled water to flush water closets and urinals in accordance with California Water Code 13554. 601.2.1 Submeters. [HCD 1] Submeters (or meters) shall be installed to measure potable and reclaimed (recycled) water (hot and cold) that is supplied for the exclusive use of an individual dwelling unit within a newly constructed, multiunit rental residential structure; or for the use of an individual dwelling unit within a newly constructed mixed-use rental residential/commer- cial structure. Submeters (or meters) shall be installed in accordance with this code and the manufacturer’s installation instructions.
See Water Code Section 517 for definitions of “multiunit residential structure” and “mixed-use resi-
dential and commercial structure.” See also Civil Code commencing with Section 1954.201.
Exemptions:
(1) Long-term health care facilities as defined in Health and Safety Code Section 1418.
(2) Low-income housing as defined in Health and Safety Code Section 17922.14 (c)(2)(B).
(3) Residential care facilities for the elderly as defined in Health and Safety Code Section 1569.2 (p)(1).
(4) Housing at a place of education as defined in Title 24 of the California Code of Regulations, Califor- nia Building Code, Part 2, Section 202.
(5) Time-share property as defined in Business and Pro- fessions Code Section 11212, Subdivision (aa).
601.2.1.1 Approved Submeters. [HCD 1] Sub- meters (or meters) shall be approved in accordance with the Business and Professions Code, Division 5.
601.2.1.2 Submeter Testing. [HCD 1] Submeter (or meter) testing shall be in accordance with the California Code of Regulations, Title 4, Division 9, Chapter 3, Article 1; Civil Code, Division 3, Part 4, Title 5; and Business and Professions Code, Divi- sion 5.
601.2.2 Hot and Cold Water Required. In occupancies where plumbing fixtures are installed for private use, hot water shall be required for bathing, washing, laundry, cooking purposes, dishwashing or maintenance. In occupancies where plumbing fixtures are installed for public use, hot water shall be required for bathing and washing purposes. This requirement shall not supersede the requirements for individual temperature control limitations for public lavatories and public and private bidets, bathtubs, whirlpool bathtubs, and shower control valves.
Get a plain-English answer with a citation back to this text.
Ask AI about this code▸Contents — California Plumbing Code (Title 24, Part 5)
- Chapter 1 — GENERAL CODE PROVISIONS
- Chapter 2 — DEFINITIONS
- Chapter 3 — GENERAL REGULATIONS
- Chapter 4 — PLUMBING FIXTURES AND FIXTURE FITTINGS
- Chapter 5 — WATER HEATERS
▸Chapter 6 — WATER SUPPLY AND DISTRIBUTION
Overview- 601.1 Applicability.
- 601.2 Water Supply and Flushing.
- 601.3 Identification of a Potable and Nonpotable Water System.
- 601.4 Schools of Cosmetology and Cosmetological
- 601.5 Meat and Poultry Processing Plants.
- 601.6 Collection Centers and Facilities. [AGR]
- 601.7 Renderers. [AGR]
- 601.8 Horse Meat and Pet Food Establishments. [AGR]
- 602.1 Prohibited Installation.
- 602.2 Cross-Contamination.
- 602.3 Backflow Prevention.
- 602.4 Approval by Authority.
- 603.1 General.
- 603.2 Approval of Devices or Assemblies.
- 603.3 Backflow Prevention Devices, Assemblies, and Methods.
- 603.4 General Requirements.
- 603.5 Specific Requirements.
- 604.1 Pipe, Tube, and Fittings.
- 604.2 Lead Content.
- 604.3 Copper or Copper Alloy Tube.
- 604.4 Hard-Drawn Copper or Copper Alloy Tubing.
- 604.5 Flexible Connectors.
- 604.6 Cast-Iron Fittings.
- 604.7 Malleable Iron Fittings.
- 604.8 Previously Used Piping and Tubing.
- 604.9 Epoxy Coating.
- 604.10 Plastic Materials.
- 604.11 Solder.
- 604.12 Flexible Corrugated Connectors.
- 604.13 Water Heater Connectors.
- 605.1 Copper or Copper Alloy Pipe, Tubing,
- 605.2 CPVC Plastic Pipe and Joints.
- 605.3 CPVC/AL/CPVC Plastic Pipe and Joints.
- 605.4 Ductile Iron Pipe and Joints.
- 605.5 Galvanized Steel Pipe and Joints.
- 605.6 PE
- 605.7 PE-AL-PE Plastic
- 605.8 PE-RT.
- 605.9 PEX
- 605.10 PEX-AL-PEX Plastic Tubing and Joints.
- 605.11 Polypropylene (PP) Piping and Joints.
- 605.12 PVC
- 605.13 Stainless Steel Pipe
- 605.14 Slip Joints.
- 605.15 Dielectric Unions.
- 605.16 Joints Between Various Materials.
- 606.1 General.
- 606.2 Fullway Valve.
- 606.3 Multidwelling Units.
- 606.4 Multiple Openings.
- 606.5 Control Valve.
- 606.6 Accessible.
- 606.7 Multiple Fixtures.
- 606.8 [OSHPD 1, 1R, 2, 3, 4 & 5]
- 606.9 Check Valve Required.
- 606.10 Leak Detection Devices.
- 607.1 General.
- 607.2 Private Well Water Tanks.
- 607.3 Potable Water Tanks.
- 607.4 Venting.
- 607.5 Overflow.
- 607.6 Valves.
- 608.1 Inadequate Water Pressure.
- 608.2 Excessive Water Pressure.
- 608.3 Expansion Tanks, and Combination Tempera-ture and Pressu…
- 608.4 Pressure Relief Valves.
- 608.5 Discharge Piping.
- 608.6 Water-Heating Devices.
- 608.7 Vacuum Relief Valves.
- 609.1 Installation.
- 609.2 Trenches.
- 609.3 Under Concrete Slab.
- 609.4 Testing.
- 609.5 Unions.
- 609.6 Location.
- 609.7 Abutting Lot.
- 609.8 Pumps.
- 609.9 Low-Pressure Cutoff Required on Booster Pumps for Water …
- 609.10 Disinfection of Potable Water System.
- 609.11 Water Hammer.
- 609.12 Pipe Insulation.
- 610.1 Size.
- 610.2 Pressure Loss.
- 610.3 Quantity of Water.
- 610.4 Sizing Water Supply and Distribution Systems.
- 610.5 Sizing per Appendices A, C,
- 610.6 Friction and Pressure Loss.
- 610.7 Conditions for Using Table 610.4.
- 610.8 Size of Meter and Building Supply Pipe Using Table 610.4.
- 610.9 Size of Branches.
- 610.10 Sizing for Flushometer Valves.
- 610.11 Sizing Systems for Flushometer Tanks.
- 610.12 Sizing for Velocity.
- 610.13 Exceptions.
- 611.1 Application.
- 611.2 Air Gap Discharge.
- 611.3 Connection Tubing.
- 611.4 Sizing of Residential Softeners.
- 612.1 Installation.
- 613.1 The domestic water-heating equipment and distribu-
- 613.2 At least two pieces of hot-water-heating equipment shall
- 613.3 Instantaneous heaters are permitted for supplying hot
- 613.4 Water storage tanks shall be fabricated of corrosion-
- 613.5 Temperature control valves shall be provided to auto-
- 613.6 Hot-water distribution system serving patient care areas
- 613.7 At fixtures where water exceeding 125°F (52°C) is acces-
- 613.8 Sectionalizing valves shall be provided as required by S…
- 613.9 Hot water distribution shall include test ports and valved
- 614.1 Dialysis water feedlines shall be CPVC (chlorinated
- 614.2 All piping for multistation or central dialysis units sh…
- 614.3 All valves shall be located in accessible locations.
- 614.4 Piping and valves shall be identified according to their…
- 614.5 A means of preventing backwashing or flushing of the
- 614.6 A continuous audible alarm shall sound at the nurses’
- 614.7 Water treatment equipment and water used for dialysis
- 614.8 A diagram of all piping as installed shall be posted at …
- 615.1 Uses Not Permitted.
- 615.2 [OSHPD 1, 1R, 2, 3, 4 & 5]
- 615.3 [OSHPD 1, 1R, 2, 3, 4 & 5]
- 616.1 For new acute care hospital buildings submitted after
- 616.2 The emergency supply of water shall be provided at ade-
- 616.3 Storage tank connections and circulation shall be
- Chapter 7 — SANITARY DRAINAGE
- Chapter 8 — INDIRECT WASTES
- Chapter 9 — VENTS
- Chapter 10 — TRAPS AND INTERCEPTORS
- Chapter 11 — STORM DRAINAGE
- Chapter 12 — FUEL GAS PIPING
- Chapter 13 — HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICA…
- Chapter 14 — FIRESTOP PROTECTION
- Chapter 15 — ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS
- Chapter 16 — NONPOTABLE RAINWATER CATCHMENT SYSTEMS
- Chapter 17 — REFERENCED STANDARDS
- Appendix A — RECOMMENDED RULES FOR SIZING THE WATER SUPPLY SYS…
- Appendix B — EXPLANATORY NOTES ON COMBINATION WASTE AND VENT S…
- Appendix C — ALTERNATE PLUMBING SYSTEMS
- Appendix D — SIZING STORM WATER DRAINAGE SYSTEMS
- Appendix E — MANUFACTURED/MOBILE HOME PARKS AND RECREATIONAL V…
- Appendix F — FIREFIGHTER BREATHING AIR REPLENISHMENT SYSTEMS
- Appendix G — SIZING OF VENTING SYSTEMS
- Appendix H — PRIVATE SEWAGE DISPOSAL SYSTEMS
- Appendix I — INSTALLATION STANDARDS
- Appendix J — COMBINATION OF INDOOR AND OUTDOOR COMBUSTION AND …
- Appendix K — POTABLE RAINWATER CATCHMENT SYSTEMS
- Appendix L — SUSTAINABLE PRACTICES
- Appendix M — PEAK WATER DEMAND CALCULATOR
- Appendix N — IMPACT OF WATER TEMPERATURE ON THE POTENTIAL FOR …
- Appendix O — NON-SEWERED SANITATION SYSTEMS
- Appendix P — PROFESSIONAL QUALIFICATIONS
- Appendix Q — INDOOR HORTICULTURAL FACILITIES
- Appendix R — TINY HOUSES
- Appendix S — ONSITE STORMWATER TREATMENT SYSTEMS