When viewing output from wet well and comparing it to the flow in a pressure pipe downstream, it appears that the results to not match up well. For instance, there are spikes in flow from the wet well that do not occur downstream.
First, make sure Output Increment and the Calculation Time Step are the same general order of magnitude and a relative precise value. For instance, having a calculation time step of 0.025 hours and an Output Increment of 0.05 hours is suitable for many models. If the Output Increment was set at a large value, this might account for the different if attenuation occurs.
Second, check the Continuity Error reported in the Calculation Summary. If this is high, some adjustments to the model or to the calculation options may be needed. Check the Help topic "Troubleshooting DynamicWave Model Calculations" or the this link for some options you can try.
Troubleshooting unstable SewerGEMS and CivilStorm results using the implicit solver