I am using Autodesk SSA version of SWMM. I am getting unreasonable results that are too high when the inlet is completely submerged by a flow that is say 5 times the inlet capacity. The program appears to calculate the flow in the upstream link based on the depth at the inlet based on an iterative calculation. The peak flow is obviously too high. This flow then continues downstream and makes all the downstream flows too high. However, when I check the Total Inflow on the Time Series Plot, the Total Inflow to the inlet looks about right. Can anyone help me on this? I have also joined the AUTODESK blog and asked the same question. Our company is modeling an entire drainage system for a small town in Colorado.