Hydraflow Storm Sewers uses the Approximate Method to compute Junction Losses. HEC 22 states this method is not to be used for Final Design.
The images below explain this.
From HEC 22:
This is the equation to use for final design:
Please give your feedback to the C3D management here to tell them to address these deficiencies:
http://usa.autodesk.com/adsk/servlet/index?siteID=123112&id=1109794
Fred Ernst, PE
C3D 2024
Ernst Engineering
www.ernstengineering.com