Tank level change not corresponding to net outflow

Product(s): WaterCAD, WaterGEMS
Version(s): 08.XX.XX.XX, 10.XX.XX.XX
Area: Output and Reporting


When graphing a tank, the change in level, HGL or percent full does not appear to correspond with the "Flow (Out net)". For example the "Percent Full" is increasing while its "Flow (net out)" is also increasing.


This could be due to the graph not displaying intermediate timesteps. In your calculation options, if you have "Reporting Time Step" set to "constant" or "variable", the graph may be missing out on what happens between timesteps, leading to counterintuitive graph results. For example, the tank may actually be filling and draining rapidly, but because of the reporting time step, the graph might be skipping over those cycles.

An example before and after is below.

Before - Reporting Time Step set to 1.00 hours:

After: Reporting Time Step set to "All":

See Also

Controls not being followed