You are currently reviewing an older revision of this page.
In SewerGEMS or Civilstorm, why do I see zero overflow for a manhole during a time step in which the HGL at that manhole is above the rim?Problem Number 32696
First, make sure you do not have a bolted cover. If you do not, then this is likely caused by tailwater. In such a case, you can overcome this issue by increasing the LPI coefficient in the advanced calculation options. For example, try a value of 12.0. This allows the calculation solver to have more dynamic effects and account for the overflow from backwater. Note that this will only work for circular conduits.
Troubleshooting unstable SewerGEMS and CivilStorm results using the Implicit solver