Creating Subcatchments

This topic illustrates how to create dummy subcatchment boundaries and how to create subcatchments.

A subcatchment represents the physical area from which a manhole or other inflow node collects water in a network.


This stage assumes that you have started InfoWorks ICM and that Master database, containing the ICM Basic Tutorial, is opened in the Explorer window, showing the 'Langley Catchment Study' model group.

Creating Dummy Subcatchment Boundaries

If you import subcatchment information from other sources or an external database, or create a subcatchment on the Subcatchment Grid View of the Subcatchments Grid (see below), then it is likely that the boundary is undefined.

To create dummy subcatchment boundaries:

  1. Open the 'Langley for Subcatchments' network. ClosedEither right-click the network in the Explorer window and select Open from the pop-up menu, or drag the network icon into the InfoWorks ICM main window.
  2. Select the Subcatchment | Create Dummy Boundaries...option from the Model menu.

    A confirmation window is displayed.

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  3. Click Yes to create the dummy boundaries.

    InfoWorks ICM creates circular boundaries for all subcatchments that do not have boundary information. The area of the circle represents the Total Area of the subcatchment as entered on the grid or property sheet.

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The subcatchment boundary can now be edited in the same was as with any other subcatchment.

Creating Subcatchments

Subcatchments can be created on the GeoPlan View or the Grid View.

Changing the Display of Subcatchments on the GeoPlan

It is possible to customise the display of subcatchments in the GeoPlan:

  1. Right-click the GeoPlan and select Properties and Themes... from the pop-up menu, and the GeoPlan Properties and Themes window is displayed:

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    The parameters in the Subcatchment row in the Layers and Themes tab allow you to edit the display. For example, you can use the Display box to turn the display on and off.

  2. Choose a different colour for the display of the subcatchments by selecting a colour from the corresponding Default Colour drop-down list.
  3. Click OK to accept the change and close the GeoPlan Properties and Themes window.

    If we take the dummy subcatchment boundaries' example at the beginning of this topic ('Langley for Subcatchments' network) and choose a shade of blue as the Default Colour and click OK, the network will look like this:


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Creating Subcatchment Boundaries

New Subcatchment/Storage Area Dialog

Subcatchments Grid