Customers sometimes contact us to report situations where break nodes seem to be displaying flood depths that are not coherent with the specified ground level.
Break nodes have no internal area and should only be used to model changes in gradient or direction within pressurised stretches of InfoWorks CS networks.
When a manhole is created then the flood volume and flood depth are both measured from the flood level. As default the flood level will be at the same elevation as the ground level associated with that manhole.
Manholes can be changed to break nodes and it is in situations like this that the misleading flood depths can be created. When a manhole is changed to a break node then the flood depth field disappears, the data from the flood level is still stored as a property of the node in case it is ever reverted back to a stored flood type node. This preservation of data can cause the flood depth displayed in results to show values differing from those expected.
Should this be encountered then the best procedure to remove the inconsistencies would be to make a selection list of all the break nodes, then set them to flood type stored, then ensure that the flood level flag is set to #D in order to ensure that the flood depths take the values from the ground levels and then revert these nodes back to break nodes.