Symbol |
Definition |

**A** |
area, m^{2} (ft^{2)} |

**b**_{c} |
channel span across bars, m (ft) |

**C**_{d} |
discharge coefficient |

**C**_{e} |
dimensionless culvert exit head loss coefficient |

**C**_{0} |
dimensionless culvert head loss coefficient (C_{e}+K_{e}) |

**d** |
particle size of interest, m (ft) |

**D**_{i} |
particle size representing i% finer (Example, D_{16} is the particle size representing 16% finer) |

**f** |
dimensionless Darcy Weisbach friction factor |

**g** |
acceleration due to gravity, m/s^{2} (ft/s^{2}) |

**h** |
bank height, m (ft) |

**HW** |
headwater elevation above the culvert entrance invert, m (ft) |

**K**_{e} |
dimensionless culvert entrance head loss coefficient |

**L** |
length, m (ft) |

**h**_{t} |
critical bank height, m (ft) |

**n** |
Fuller-Thompson coefficient for adjusting bed mixture gradation |

**n** |
Manning's roughness coefficient |

**Q** |
flow, m^{3}/s (ft^{3}/s) |

**q** |
unit discharge, m^{3}/s/m (ft^{3}/s/ft) |

**q**_{c} |
critical unit discharge, m^{3}/s/m (ft^{3}/s/ft) |

**Q**_{100} |
one hundred year flow, m^{3}/s (ft^{3}/s) |

**R** |
hydraulic radius, m (ft) |

**S** |
slope, m/m (ft/ft) |

**S**_{f} |
friction slope, m/m (ft/ft) |

**V** |
velocity, m/s (ft/s) |

**y** |
depth of water, m (ft) |

**Z** |
baffle height, m (ft) |

**τ** |
shear stress, Pa (lb/ft^{2}) |

**τ**_{c} |
critical shear stress, Pa (lb/ft^{2}) |

**γ** |
specific weight of water, Pa (lb/ft^{2}) |

**τ**^{*} |
dimensionless Shield's parameter |

**Φ** |
angle of repose (degrees) |