WSPRO Contraction Loss Method

The Water Surface Profile (WSPRO) method is a contraction model that uses step backwater calculations and empirical loss coefficients.
This method is not limited to the WSPRO program.
  1. Base the model on providing approach and exit cross sections (cross sections 1 and 4) at distances from the downstream and upstream faces approximately equal to the bridge opening length.
  2. Compute the flow in Zones 1 and 3 using step backwater computations with a weighted flow length based on 20 equal conveyance tubes. Refer to
    Bridge Waterways Analysis Model
     (Shearman et al., 1986) for details on this method. (See
    Reference
    for details on obtaining this document.)