Appendix F —
This appendix presents detailed discussion on Kitsap County approved methods for the hydrologic/hydraulic analysis and design of pipe conveyance, culverts, and open channel systems. For public road projects, the WSDOT Highway Runoff Manual hydrologic/hydraulic methods may be used if preferred over these methods.
Sections
Figures
Figure F.1. Rainfall Intensity-Duration Curves.
Figure F.2. Nomograph for Sizing Circular Drains Flowing Full.
Figure F.3. Circular Channel Ratios.
Figure F.4. Backwater Calculation Sheet.
Figure F.5. Backwater Calculation Sheet Notes.
Figure F.6. Backwater Pipe Calculation Example.
Figure F.7. Bend Head Losses in Structure.
Figure F.8. Junction Head Loss in Structure.
Figure F.9. Inlet/Outlet Control Conditions.
Figure F.10. Headwater Depth for Smooth Interior Pipe Culverts with Inlet Control.
Figure F.11. Headwater Depth for Corrugated Pipe Culvert with Inlet Control.
Figure F.12. Head for Culverts (Pipe w/n = 0.012) Flowing Full with Outlet Control.
Figure F.13. Head for Culverts (Pipe w/n = 0.024) Flowing Full with Outlet Control.
Figure F.14. Critical Depth of Flow for Circular Culverts.
Figure F.15. Open Channel Flow Profile Computation.
Figure F.16. Open Channel Flow Profile Computation (Example).
Figure F.17. Mean Channel Velocity vs. Medium Stone Weight and Equivalent Stone Diameter.
Tables
Table E.1. Construction Site Sediment Transport Potential Worksheet
Table F.1. Runoff Coefficients – “c” Values for the Rational Method.
Table F.2. Manning’s “n” Values for Pipes.
Table F.3. Constants for Inlet Control Equations.
Table F.4. Entrance Loss Coefficients.
Table F.5. Values of Roughness Coefficient “n” for Open Channels.
Equations
Equation F.2. Manning’s equation
Equation F.3. Volumetric flow rate equation
Equation F.4. Headwater depth in unsubmerged inlet conditions (Form 1)
Equation F.5. Headwater depth in unsubmerged inlet conditions (Form 2)
Equation F.6. Headwater depth in submerged inlet conditions
Equation F.8. Outlet control headwater depth (Backwater Analysis Method)
Equation F.9. Total head for a single reach (Direct Step Analysis Method)
Equation F.10. Specific energy for a single reach (Direct Step Analysis Method)
Equation F.11. Distance between cross‑sections (Direct Step Analysis Method)