Why the spread results are different from stormCAD and Flowmaster .The results are nearly in 6 ft difference though the inputs are same.
The 9.42 discharge is from IN 6-1 and flow from gutter 3 (8.46+0.96).
In StormCAD, gutter "GU-3" is "V-Shaped".
In FlowMaster, the gutter calculations in your image are for a conventional shape.
If you want to compare the StormCAD results to FlowMaster, it would be more appropriate to use the triangular channel worksheet.
Note that the values entered in the FlowMaster image above are approximate and therefore the results will not match StormCAD exactly. For example, in StormCAD the gutter cross slope is 0.021ft/ft and the road cross slope is 0.020ft/ft. In StormCAD the gutter's Manning n value is 0.013 and the road's n value is 0.015 etc.
Bentley Technical Support
I have one more question.
Please help me to solve it.
How spread calculation is done in upstream of inlet before flow capture or after?
How did you assign 9.45 cfs. I add it and only became (IN6-1+GU-3=8.46+0.22=8.68)
May be I am missing something.
This is what I see using the model you uploaded.
0.96 cfs from gutter "GU-3":
8.49 cfs from catchment "IN 6-1":
0.96 cfs + 8.49 cfs = 9.45 cfs approaching catch basin "IN6-1" (on the surface):