BMP Calculator

Water Storm Systems

Water Storm Systems

Design InputsUnits in parentheses

Customer Data

Stormwater BMP – Inputs

V_runoff (ft³)

–

Q_in (ft³/h)

–

t_total (h)

–

Results

Click “Calculate”…
Disclaimer – Stormwater BMP Estimation Tool (Crumpler Pipe) This simulator provides preliminary estimates to support early-stage design of stormwater BMPs (detention/infiltration). It does not replace the judgment of a licensed Professional Engineer nor local/state regulations. Rainfall intensities, depths, runoff coefficients (C), and drainage criteria must be verified with the applicable authorities and/or current design manuals. Use at your own risk. Quick Read The geometric layout of the stormwater system (pipes) must follow the recommended separation criteria in the Stormwater BMP manual. Reference Guidance Use the volume-based method with a design event duration of 10 to 15 minutes, return periods of 25–100 years, and ensure full drainage within ≤ 72 hours. References: – ASCE MOP 77, Section 3.3.2 – U.S. EPA (2009) – FHWA HEC-22 (2013), Section 6 – ASTM F2648-20 – NOAA Atlas 14: https://hdsc.nws.noaa.gov/pfds/
CPP Stormwater BMP System
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QR Stormwater BMP Catalog QR Interactive Flipbook
Tip: drag the image while zoomed to pan around (double-click to reset).
Reference image: CPP – Stormwater BMP.
Flat surface – reserved (BMP)
Design Notes (BMP)
• This tool uses a volume-based detention approach with infiltration and orifices.
• Drain-down check is compared to a 72 h criterion (example; confirm with your local code).
• Confirm rainfall depths/intensities, soils, and construction details with your local/state BMP manuals.
• Runoff coefficients (C) and spacing tables are used as guidance only.
Tip: Gray fields are computed automatically from other inputs.

Sizing Report – CPP Stormwater BMP

P.O. Box 2068, Highway 24 West, Roseboro, NC 28382
cppsales@cpp-pipe.com • 910-525-4046 • 1-800-334-5071

1. Customer Data

2. BMP Inputs

3. Results



    
4. Additional Summaries

    


    


    
5. Tutorial Videos

    
    
      
  • Tutorial 1 – Introduction to CPP BMP: https://www.youtube.com/watch?v=4sk1X3rzya4
    • 
      
  • CPP – Who we are?: https://www.youtube.com/watch?v=NY4XcVn4Zdg
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6. Resources (QR – Catalog & Flipbook)

    

      
        QR BMP Catalog
      
      
        QR Flipbook
      
    


    


    
7. Equations Used

    
i = P / t_c

    
V_runoff = (C_imp·A_imp + C_perv·A_perv)·P

    
Q_in = V_runoff / t_c

    
V_pipe = π·(D/2)^2·L

    
Q_inf = k·(D·L)

    
Q_h = n·C_d·A_o·√(2gH)·3600


    
8. Disclaimer – Stormwater BMP Estimation Tool (Crumpler Pipe)

    

      This automated tool provides preliminary estimates only for stormwater detention/infiltration systems using CPP products.
      Results are approximate and not a final design. All system designs must be reviewed and approved by a licensed Professional
      Engineer or certified installer per local regulations. Final approval requires site-specific analysis and compliance with
      federal, state, and local codes. Use at your own risk; this tool does not replace professional judgment or permit requirements.
    

    

      Quick Read

      The geometric layout of the stormwater system (pipes) must follow the recommended separation criteria in the Stormwater BMP manual.
    

    

      Reference Guidance

      Use the volume-based method with a design event duration of 10 to 15 minutes, return periods of 25–100 years, and ensure full drainage within ≤ 72 hours.
      


      References:

      – ASCE MOP 77, Section 3.3.2

      – U.S. EPA (2009)

      – FHWA HEC-22 (2013), Section 6

      – ASTM F2648-20

      – NOAA Atlas 14: https://hdsc.nws.noaa.gov/pfds/