How to change the shape of the outflow hydrograph?

[Yingchen]

Hi ,

I am a beginner in using SWMM 5. I simulated some single events , but there are same problems with my results .

The peak discharge simulated is bigger than the measurement, and the tails of the hydrograph is much samller. The change of the hydrograph is so sharply .

I want to know which parameters or option I can set to change the shape of the hydrograph ,i.e, which way I can take to attenuate the peak discharge and make the hydrograph more gently .

There is the hydrograph for my simulation .

I am urgently to have the right result .I wish someone could help me .Thanks

[swmmguy]

is your sewershed a combined one or separate one?
if your hydrograph includes any baseflow or just pure runoff?
generally speaking,
for combined sewershed, you need decrease your sewershed width, or increase your infilrate rate for your case. These two parameters are sensitive.
you may also consider increase depression storage or manning's n value.

If your sewershed is a separate one, just adjust RTK value.