What is an i-model and why does it show as a prerequisite? How do I publish an i-model?

Applies To 

WaterGEMS, SewerGEMS, WaterCAD, CivilStorm, StormCAD, SewerCAD, HAMMER

Version(s): CONNECT Edition through 10.03.*, V8i Select Sereis 3+
Area:  Output and Reporting


This article describes the process by which a user can export their model to an i-model file. i-model publishing is included with version V8i SELECTseries 3 through version 10.03.* of the OpenFlows products. 

When downloading the products from the Software Downloads site, the "i-model publishing engine" shows as a dependency. It is required in order to use the i-model publishing capability.  If you are using CONNECT Edition Update 4 (10.04.XX.XX) or greater, the i-model export functionality is no longer supported.

f you would like to send your model data and output to someone who does not have the OpenFlows software, please see the instructions in this Wiki article - How to share a read-only version of a hydraulic model for anyone to view.

What is an i-model?

An i-model is an immutable container for rich multi-discipline information published form known sources in a known state at a known time.
  • It is portable.
  • It is read-only.
  • It can be viewed by users that do not have the hydraulics and hydrology product from which the i-model was created.
  • The topology, as well as the attributes and results (for a particular time-step) can be viewed in MicroStation, ProjectWise, Bentley Navigator and Bentley View.  Since Bentley View is free, i-models provide a way for anyone to easily view data and results for a WaterCAD/GEMS or HAMMER model file.  Here is a link to Bentley View.
  • The file name for an i-model is filename.i.dgn
  • If you want to view the model on Bentley Map Mobile, you can generate a Map Mobile i-model as well. The file name for this will be filename.imodel.
  • i-model exports could potentially used for BIM workflows


The i-model publishing engine must be downloaded and installed separately and can be found in the Software Downloads site under the product's download area. See: Downloading OpenFlows / Hydraulics and Hydrology Software

Note: on the download site, the i-model publishing engine is only designated as "32-bit", but will work with both versions (for i-model export).

Why does i-model show as a prerequisite for OpenFlows products?

Although it is not required to be installed, the i-model publishing engine is shown as a prerequisite on the download page for OpenFlows products so as to be visible to those who may want to use it. It is only necessary if you intend to publish i-models. If you have no need to publish i-models you do not need to download and install this optional component. It will not have any effect on the product functionality aside from i-model export.

How to Publish an i-model

First, you will want to select the desired scenario and time-step. Once you have, go to File > Export > Publish i-model. This will generate a file that can be viewed on Bentley View or Bentley Map. If you want to create a file you can use with Bentley Map Mobile (which can be used on mobile devices), you would go to File > Export > Publish Bentley Map Mobile i-model.

With either option, a dialog similar to the one below will open, with the defaults set so that all elements and properties are included in the i-model.


 The top left pane is a summary of the element types to be included in the i-model.  If a box by the element type is checked, that element type is included.  The Table/Properties column reflects the selections on the right side of the dialog in terms of which elements and properties are to be included. The bottom left portion of the dialog box is used to identify which elements are to be included in the i-model.

If the "Publish a subset of elements based on the Flex Table filters" box is checked, only those elements that are in the filtered flex table will be included in the i-model. If the "Exclude topologically inactive elements" box is checked, only active elements (Is Active? = True) are included in the i-model.

The user will usually not need to include all element properties in the i-model.  The right side of the dialog is to identify which properties of the elements are going to be included in the i-model.  The default is "All Properties".  If the user wants to only include a subset of properties, the user should create a flex table with only those properties and select that flex table from the drop down list.

Note that currently (as of 10.02.01.XX) the "Table/Properties" flextable selection is only used to get the attributes to export, and will not retain any custom labeling applied in the flextable itself.

Annotating / labeling Elements in the exported i-model

See: Annotating elements in an i-model

See Also

 How to share a read-only version of a hydraulic model for anyone to view

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