Trade Exam · Module 2
Water Conservation and CALGreen
California sets some of the lowest fixture flow limits in the country, and they are written into the 2025 California Plumbing Code with references to CALGreen, the state's green building code. This lesson covers the flow and flush limits you must price and install, the Civil Code rule that makes you replace older noncompliant fixtures when you pull a permit on a pre-1994 building, and the permit and identification rules for gray water, recycled water and rainwater systems.
Key Takeaways
- CSLB lists "water conservation" as a Planning and Estimating subject (about 22% of the C-36 trade exam).
- Flush limits: water closets 1.28 gpf (CPC 411.2); wall-mounted urinals 0.125 gpf and other urinals 0.5 gpf (412.1).
- Flow limits: showerheads 1.8 gpm at 80 psi (408.3); residential lavatory faucets 1.2 gpm at 60 psi (407.2.2); public lavatory faucets 0.5 gpm at 60 psi (407.2.1); sink faucets 2.2 gpm at 60 psi (420.2); kitchen faucets 1.8 gpm at 60 psi (420.2.1).
- Commercial pre-rinse spray valves: 1.00, 1.20 or 1.28 gpm by product class, with an integral automatic shutoff (CPC 420.3, Table 420.3).
- Civil Code 1101.4: on a pre-1994 single-family home, a permit applicant doing alterations must replace all noncompliant fixtures (toilets over 1.6 gpf, urinals over 1.0 gpf, showerheads over 2.5 gpm, interior faucets over 2.2 gpm) before final approval.
- Gray water, recycled water and on-site treated water are CPC Chapter 15; rainwater catchment is CPC Chapter 16. Alternate water source piping is identified with purple (601.3.3).
- A permit is required for alternate water source systems (1501.3), except a clothes washer system that meets 1503.1.1 [HCD 1].
Why This Matters
CSLB's C-36 study guide lists "water conservation" as a subject in Planning and Estimating, which is about 22 percent of the trade exam. For your business, conservation rules decide which fixtures you can buy, and a Civil Code rule can add fixtures to a job the customer never asked about.
CPC and CALGreen
CALGreen is the California Green Building Standards Code, Part 11 of Title 24. The 2025 California Plumbing Code (Part 5) carries California's fixture limits and, in many sections, points to CALGreen (for example, CPC 408.3 says residential showerheads shall comply with Division 4.3 of CALGreen). The numbers in this lesson are taken from the 2025 CPC text.
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