The following equations are used in FishXing to calculate the wetted perimeter, top width, and cross-sectional area of the flow through a circular culvert that is not-embedded.

Definition Sketch for Geometry of an Embedded Culvert:

Equations Used in the Calculation of Culvert Geometry:

            Where:

          R              = Radius of culvert

          yH2O      = Depth of water in the culvert

         AH2O        = Cross sectional area of flow

          P_bottom = Perimeter of water on the bottom (Zero if not embedded)

          P_sides      = Perimeter of pipe from sunken depth to water level

          T         = Top width of water surface