A lot of folks get stumped on it because its somewhat unintuitive. That's because the total watershed is recalculated at each junction, and the time of concentration is recalculated as well. So they use Q=CIA, but the "I" gets smaller the further down the network you go because it's a longer Tc.
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -
