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Design Data

Hydraulic Capacity of Culverts

ACPA-Website-Icon-DD11-Hydraulic-Capacity-Of-Culverts-1Design Data 11:  Hydraulic Capacity of Culverts

The most widely accepted formula for evaluating the hydraulic capacity of non-pressure sewers is the Manning Formula.

  • Q = discharge in cubic feet per second
  • n = Manning’s roughness coefficient
  • A = cross-sectional area of flow in square feet
  • R = hydraulic radius in feet (equals the area of the flow divided by the wetted perimeter)
  • S = slope of pipe line in feet of vertical drop per foot of horizontal distance