California (CA) Plumbing Code & Permit Rules
California Plumbing Code (based on UPC) (2022) · Updated 2026-05-31
Data: State plumbing boards, ICC, IAPMO, EPA Last verified: 2026-05-31
California has some of the strictest plumbing regulations in the country. A licensed plumber is required for most work, annual backflow testing is mandatory, and seismic strapping is required for water heaters. Homeowners should budget for professional plumbing services and compliance costs.
Plumbing Code
California follows the California Plumbing Code (based on UPC) (2022 edition).
CPC = UPC with heavy California-specific amendments; most restrictive state
Key Regulations
| Regulation | Status | Details |
|---|---|---|
| Plumbing Code | UPC (2022) | California Plumbing Code (based on UPC) |
| Homeowner DIY | Not allowed | Licensed contractor (C-36) required for all plumbing work |
| Water Heater Permit | Required | Mandatory seismic straps (upper + lower); C-36 license required; inspections mandatory |
| Backflow Testing | Annual, required | Strict enforcement; all assemblies protecting public water supply |
| Seismic Strapping | Required | Water heater restraint |
DIY Plumbing in California
California requires a licensed plumber for most plumbing work. Licensed contractor (C-36) required for all plumbing work
While this increases costs, it ensures:
- Work meets current code requirements
- Proper permitting and inspection
- Warranty and liability protection
- Safe connections to water and sewer systems
Backflow Prevention
California requires annual backflow testing to protect the public water supply from contamination. Testing must be performed by a SWRCB-certified tester (new cert required from July 1, 2025).
Non-compliance penalty: Water service may be shut off if testing is not completed on schedule.
Water Conservation Requirements
California has state-specific water conservation mandates. Most restrictive: max 1.8 GPF toilets, 1.8 GPM showerheads, 1.2 GPM faucets (CalGreen)
Lead Service Line Replacement
California has an active lead service line replacement program. $4.8B allocated for lead service line replacement (Prop 1)
Data Sources
- California state plumbing board and licensing agency
- International Code Council (ICC)
- IAPMO
- EPA Safe Drinking Water Act
Updated as regulations change.
Need a licensed plumber in California?
Plumbing regulations vary by city. Connect with a licensed professional who knows your local code requirements.
Find a Licensed Plumber →Frequently Asked Questions
What plumbing code does California follow?
California follows the California Plumbing Code (based on UPC) (2022 edition).
Can I do my own plumbing work in California?
No, California requires a licensed plumber for most plumbing work.
Do I need a permit to replace a water heater in California?
Yes, California requires a permit for water heater replacement. A licensed plumber is required for the installation.
Is backflow testing required in California?
Yes, California requires annual backflow testing.
Does California require seismic strapping for water heaters?
Yes, California requires seismic strapping for water heaters. This typically involves two metal straps securing the water heater to the wall to prevent toppling during an earthquake.