Time of concentration value

Question

I need rain water network design for a particular region.. I was asked to adhere to the following design parameters 
 rainfall intensity= 20 mm/h , runoff coefficient=0.5, total area= 6.6 hec 
 Do you need to calculate a time of concentration ( Tc) and input it in flextable ? . Does the amount of important effects in the final accounts

MPachlhofer · Answer

Ased, 
 
Yes, the time of concentration value will certainly effect the necessary information that you need to extract from the model because it determines the flow rates that you'll be getting off of your catchments. 
 
Regards, 
Mark

Jesse Dringoli · Answer

With the rational method, catchment intensity ("I" in Q=CIA) is based on the Tc. 
 You will need to enter the Tc in the catchment properties or flextables. The current versions of our stormwater products do not automatically calculate the Tc based on for example a terrain model/contour map. We do however have a few different methods available where you can enter some known parameters to calculate the Tc. The screenshot below is StormCAD V8i SELECTseries 4. You can read more about this in the Help.