Spike in EGL or HGL in profile view when lateral pipes connect at a higher elevation

Product(s): SewerGEMS, CivilStorm, StormCAD, SewerCAD
Version(s): and earlier
Area: Output and Reporting


When viewing a profile of a series of pipes, an unexpected spike (increase) in the energy grade line (EGL) or hydraulic grade line (HGL) is seen at the node locations where there is another conduit connecting at a higher elevation. Example:


The problem is that, when there is a second incoming pipe at a higher elevation, the EGL or HGL "in" from that pipe can be higher than the EGL in from the other incoming pipe included in the profile. Since there's only one EGL "in" result field for the node, it displays the one from the tributary/lateral pipe and the profile ends up looking strange like the example above.

This can be considered a reporting quirk; the results should be OK. You may be able to get the profile appearance to improve by adjusting the "virtual flow depth" calculation option, but this may only contain the "spike" within the node instead of across the pipe.

An improvement to this situation is being investigated for a future release. Reference Enhancement # 890313