InfoSewer Flow Attenuation Sensitivity 

The three Run manager parameters, Maximum Number of Segments, Minimum Travel Distance and the Minimum Travel Distance in InfoSewer and H2OMAP Sewer affect the shape and flow attenuation of the flow in a link.  The effect of using the flow attenuation is to reduce the peak flow and spread out the flow compared to the No Flag option (Figure 1). 

Figure 1.  Effect of the Flow Attenuation Option in infoSewer and H2OMAP Sewer

via Blogger http://www.swmm5.net/2013/08/infosewer-flow-attenuation-sensitivity.html