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    Plumbing Fixture Flow Rates

    Plumbing Fixture Flow Rates

    New postby sefnfot on Thu Jun 28, 2018 4:30 am

    What is the shower flow rate for Santa Monica, CA starting July 2018?
    I found this story that puts it at 1.8 gpm while I can only find the pdf listed below on the city website.
    This story
    the city website pdf
    Posts: 4
    Joined: Fri Jul 15, 2016 2:04 pm

    Re: Plumbing Fixture Flow Rates

    New postby Jerry Peck - Codeman on Sat Jun 30, 2018 11:54 am

    I was able to reach my man in California, he will be able to answer your question better than I can.

    My apologies for the delay in getting back to your question.
    Jerry Peck - CodeMan

    Construction and Litigation Consultant
    Construction Litigation Consultants, LLC.
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    Jerry Peck - Codeman
    Site Admin
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    Joined: Fri Dec 12, 2008 12:06 pm

    Re: Plumbing Fixture Flow Rates

    New postby GunnarAlquist on Sat Jun 30, 2018 3:41 pm

    Hiya sefnfot,

    The enforcement of codes in California gets a bit complicated. As of January 1, 2017, California has been enforcing the 2016 California Building Standards Code which incorporates the 2016 California Plumbing Code (a modified version of the 2015 Uniform Plumbing Code) and the 2016 Green Building Standards Code. The 2016 Codes should be enforced until the 2019 Codes are adopted by the state beginning January 1, 2020.

    Clear as mud?

    Shower flow rates are covered in the Green Code rather than the Plumbing Code (the relevent section is below). Until 2020, the shower flow rate will stay at 2.0 gpm.

    In addition, the way I read the code, it looks like 2.0 gpm is the maximum allowable flow rate for the entire shower, no matter how many showerheads or valves are present. However, I often see multiple shower valves in stall showers, so some jurisdictions may not be enforcing this part of the Green Code. It would be best to ask someone at the city to make sure.

    The article that you reference is from 2015, so I can't imagine the author has the ability to see that far into the future, unless they have some inside information. To the best of my knowledge, the 2019 Code has not been published.

    Another possibility may be that Santa Monica has a local regulation that is tighter than California's. I visited the City of Santa Monica's website, but could find no local ordinances regarding shower water flow rates. The only thing that I can think of is to check with their building/permit office and ask if they have a local ordinance that requires a lower flow rate.


    Below is from the 2016 Green Building Standards Code:
    4.303.1.3 Showerheads.
    4.303.1.3.1 Single showerhead.
    Showerheads shall have a maximum flow rate of not more than 2.0 gallons per minute at 80 psi. Showerheads shall be certified to the performance criteria of the U.S. EPA WaterSense Specification for Showerheads.

    4.303.1.3.2 Multiple showerheads serving one shower. When a shower is served by more than one showerhead, the combined flow rate of all showerheads and/or other shower outlets controlled by a single valve shall not exceed 2.0 gallons per minute at 80 psi, or the shower shall be designed to allow only one shower outlet to be in operation at a time.
    Note: A hand-held shower shall be considered a showerhead.
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    Joined: Sat Jun 30, 2018 3:16 pm

    Re: Plumbing Fixture Flow Rates

    New postby GunnarAlquist on Sun Jul 01, 2018 12:24 am

    Or, I may be incorrect about the limit for the entire shower.

    Jerry and I have been discussing the wording of this particular code and the code is worded in such a way that it may allow more than one valve in a shower. This would then allow 2.0 gpm per valve. Since the intent of this particular code is water efficiency, it seems to me that the limit would apply to the entire shower. However, the wording does not support my conclusion and would explain why multiple shower valves are installed in large showers.
    Posts: 2
    Joined: Sat Jun 30, 2018 3:16 pm

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