Time of Concentration Question

[iloveoreos]

Hello,

For a fairly large site (~25 acres) the point furthest away from the existing detention basin, storm water would sheet flow into the inlet and that would be my sheet flow. Afterwards, would the travel time through the pipe to the basin (~1600') be counted towards overland flow?

Also, does TR-55 method use pipe flow?

 

[psmart]

The flow in the pipe would presumably be channel flow rather than overland flow. TR-55 will accommodate this as channel flow.


Peter Smart
HydroCAD Software

http://www.hydrocad.net

 

[Martin Finch Jr EIT]

Peter Smart is correct, he is my hero. Anyways , if the sheet flow is less than 100-ft than it is considered sheet flow, any length over 100 feet would be considered shallow conc. flow. The remaining length of your flow path is most definitely channel flow.
GL