What are the limitations of importing/exporting EPANET files?

Applies To 
Product(s): WaterCAD, WaterGEMS
Version(s): 10.00.xx.xx, 08.11.xx.xx
Area:  Layout and Data Input
Original Author: Terry Foster, Bentley Technical Support Group

When we do an import/export with EPANET files the only data that will be retained or unaltered is the data that is supported in both EPANET INP format and WaterGEMS or WaterCAD.

Note:

WaterCAD / WaterGEMS exports the EPANET files into .INP file formats. However if you are looking a way to export them as .NET file formats of EPANET then you need to open the .INP files exported from WaterCAD / WaterGEMS into EPANET and export them from EPANET into .NET formats.

Items in WaterGEMS and WaterCAD that are not supported in EPANET:

  • VSPs
  • VSPBs
  • Fire Flow
  • Flushing
  • Pressure Dependent Demands
  • Variable reporting time steps
  • Demand/Roughness Adjustments
  • Continuous patterns
  • Elements like Hydropneumatic tanks, air valves, etc.
  • Top-filling options for a tank
  • All HAMMER properties
  • User data
  • Energy costs
  • All presentation settings
  • Isolating valves/criticality
  • All ModelBuilder, LoadBuilder, Darwin, TRex and Skelebrator settings
  • Spot-elevations
  • Isolation Valves
  • Pump curves (EPANET exporter generates a CURVE.  However such curves are always imported back - during round-trips - as multi-point pump definition.  So if the original pump-definition was a 1-point or 3-point curve the round-trip may not come back to the exact original pump definition type.)
  • Unit Demands
  • Selection Sets
  • Queries
  • Graphs
  • Data from extensions (Calibrator/Designer/Capital-cost)
  • Customer meters
  • Tap/Laterals

One other thing that happens when importing EPANET files is that two extra pipes are added for every directed node.  They are labeled as something similar to "was added during EPANET import".  So when the WaterGEMS or WaterCAD model thus created is exported back to EPANET those extra pipes are removed and the original directed node is rebuilt without the extra pipes.

Pumps and Valves

Pumps and valves are seen as link elements in EPANET, whereas WaterCAD and WaterGEMS see them as nodes. Therefore on export to EPANET, a new link element must be created to use as the pump/valve. To do that, two overlapping junctions are created to connect to it. The link in EPANET will have the same name as the pump/valve did in WaterCAD or WaterGEMS. In EPANET, an icon will display for the pump and valve, but when trying to double-click on it, the junction could be selected by mistake.

For Example, take a look the following valve in WaterGEMS/WaterCAD:

Here's what it looks like after exporting to and opening in EPANET:

When hovering the mouse over, it may look as if it's a junction:

However if you click and drag, you'll see its actually two junctions overlapping (at the original location of the valve in WaterGEMS/WaterCAD) with the PRV link element between them:

Note:

  • The extra pipes created on either side of the valve/pump will have a very large diameter (99 inches or 2,514.6 mm) and short (near-zero) length so that no additional headloss is introduced. So, the hydraulic results should not be impacted and should match EPANET
  • For a pump, the elevation of the pump and adjacent newly created junction nodes should also not impact the hydraulics. The hydraulic grade will remain the same and the only impact of the elevation would be on the calculated pressure. For a valve such as a PRV, you may need to check the elevations if the PRV is using a pressure setting, since the pressure is calculated based on the elevation and the HGL.

See Also

Should the EPANET solver and the WaterGEMS solver give the same results for a model?

How are units handled when exporting a WaterGEMS/WaterCAD model to an EPANET model (.inp)?

What are the difference between WaterGEMS/CAD and EPANET?

  • Created by
  • When: Thu, Nov 7 2013 1:03 PM
  • Last revision by Bentley Colleague
  • When: Tue, Oct 29 2019 12:20 PM
  • Revisions: 16
  • Comments: 0
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