The Terrain Models manager allows you to add and manage terrain models.

Multiple terrain models can be added to the model and the boundary lines of the terrain models can be shown at the same time, but only one terrain model can be active. (It is possible to merge multiple terrain models into one using tools external to Bentley StormCAD .) The active terrain model can be used to dynamically update node ground elevations when existing nodes are moved within the active terrain model or when a new node is laid out in the active terrain model. If no terrain model is active, node ground elevation will not be updated.

• The Active Terrain model is marked with this icon:
• Inactive terrain models are marked with this icon:

When a terrain model is active, the coordinates in the status bar in the bottom right corner of the Bentley StormCAD window will display the Z coordinates as derived from the active terrain model for any point within the terrain model, as below:

The boundary of void area in the terrain model are displayed to indicate areas that do not have surface data.

The toolbar consists of the following buttons:

	New	Opens the DTM settings dialog, allowing you to choose the terrain model file to add and to set the unit used by the source file.
	Delete	Removes the currently highlighted terrain model.
	Rename	Rename the currently highlighted terrain model.
	Edit	Opens the DTM settings dialog box, allowing you to change the terrain model settings.
	Activate Terrain Model	Sets the currently highlighted terrain model as the Active terrain model. Node ground elevations will be updated when existing nodes are moved or when a new node is laid out. The Active terrain model is marked with this icon:
	Deactivate Terrain Model	Deactivates the currently active terrain model. Elevations are will not be updated. Inactive terrrain models are marked with this icon:
	Downstream Trace	Clicking this button opens a submenu containing the following commands: Downstream Trace: Selecting this option opens a Downstream Trace dialog. Clicking in the drawing pane within the active terrain model when this dialog is active will set the start point for the downstream trace. Clear Trace Results: Removes trace results from the drawing pane view.
	Zoom To	Centers the drawing pane view on the active terrain model.
	Catchment Delineation	Sets the option to run catchment delineation when adding or moving an inlet in active terrain model. (See Catchment Delineation)
	Catchment Delineation Settings	Opens catchment delineation settings dialog. (See Catchment Delineation Settings)
	Batch Build Gutter Cross Sections from Terrain Model	Opens the Generate Gutter Cross-Sections dialog (see Generate Gutter Cross-Sections below).
	Help	Displays online help for the Terrain Models Manager.

The presence of the icon next to a terrain model tells you that the data is not available. This issue can occur for two reasons:

• The selected file is no longer in the specified location
• The data cannot be read. This can occur if the data source is not in correct format, or if the data source can only be read by a 32 bit version of the software, and you are currently running the 64 bit version.

When catchment delineation is set to active and an inlet is moved in active terrain model, the catchment for the moved inlet, the catchments for the downstream inlet and the affected catchments will be updated.

If multiple inlets are moved, catchment delineation will not be run and the user needs to manually run catchment delineation to update the affected catchments.

Note that the terrain model data is not stored in the model. The path to the data is stored in the model, and the terrain model data is read when the product is started.

To apply the ground elevation for selected nodes, right-click an active terrain model and select “Apply Ground Elevation to Selected Nodes”. Any selected nodes within the boundaries of the terrain model will have its ground elevation updated if the option, “Update Ground Elevation from Terrain Model?” is set to true.

Generate Gutter Cross-Sections

This dialog allows you to generate gutter cross-sections for multiple gutters in your model.

For more information on how the software generates cross sections, and what the various parameters mean, see the Gutter Section Viewer Dialog topic.