Runoff flow rate from two drainage areas to one pond

[Serene111]

Hello,

I was directing the runoff from two drainage areas to one detention pond, but the inlet flow at the pond doesn't equal to the sum of the runoff from the two areas. Could you please help me to understand what is wrong?

Thanks,
Serene

 

[psmart]

Remember that you're dealing with a hydrograph, and not a constant flow. When you add two hydrographs, the volume will always by the sum of the two (conservation of mass) but the peak flows will add only if they occur at exactly the same time. For details see

http://www.hydrocad.net/peakflow.htm

Peter Smart
HydroCAD Software

http://www.hydrocad.net

 

[Serene111]

Got it, thanks, Peter.