HEC-RAS Network Export

The following objects can be exported from InfoWorks ICM to HEC-RAS file format:

InfoWorks ICM Object	HEC-RAS Object
River Reach	River Reach Cross Sections Lateral Structures
Storage Area and associated Storage Node	Storage Area
Bridge	Cross Sections Bridge
2D Zones	Storage Area (2D)
Roughness Zones	Land Cover (L C ) Regions
2D Boundaries	BC Lines
General Lines	Break Lines
Base Linear Structures	Connections

The Export Process

To export network data to HEC-RAS files:

1. Open the network to be exported
2. Select Export | to HEC-RAS files from the Network menu. This displays a standard Windows Save As dialog
3. Select a path to which files will be exported, enter a file name and click Save

A .prj and .g01 file will be exported to the selected path.

For details of the objects exported and conversions made by the exporter, see the Conversion Notes below.

Conversion Notes

River Reaches

InfoWorks ICM River Reaches are exported as HEC-RAS River Reach objects, cross sections and lateral structures.

River reach link

The river reach link geometry is exported to a HEC-RAS river reach object.

Where a river reach is connected to another single reach, the connecting reaches will be merged into a single HEC-RAS river reach object.

Where more than two river reaches are connected, a junction is exported, connecting the reaches.

River reach cross sections

River reach cross section geometry is exported to a HEC-RAS cross section object.

Field mappings and conversions of InfoWorks ICM river section fields to HEC-RAS cross section fields:

HEC-RAS field	InfoWorks ICM Export
River Station	Export assigns a number
Station	Offset
Elevation	Bed level
n Val	Roughness Manning's n (only values at changes in n are exported)
Main Channel Bank Station: Left Bank	Set to first offset value = 0
Main Channel Bank Station: Right Bank	Set to last offset value
Downstream Reach Lengths	Set to length of river reach link between current section and downstream section

River reach bank data

River reach bank data is exported as a series of HEC-RAS lateral structure objects between river reach cross sections. X,Y co-ordinates are exported.

Storage area and node

InfoWorks ICM storage areas and their corresponding nodes are exported as HEC-RAS storage area objects.

The Level - Area values in the InfoWorks Storage array are converted into HEC-RAS Elevation Volume curve values.

Bridges

InfoWorks ICM bridge objects are exported as HEC-RAS cross sections and bridge structures.

InfoWorks US/DS link section data and US/DS bridge section data are exported as cross sections in the same way as river reach cross sections.

InfoWorks Bridge deck data is exported as HEC-RAS bridge deck data; the same values being exported to both upstream and downstream sides of the bridge:

HEC-RAS field	InfoWorks ICM Export
Station	Offset
High chord	Level
Width	Set to distance between US bridge section and DS bridge section

Note: the export of bridge openings is not currently supported by the exporter. Bridge openings must be added manually.

2D Zones

InfoWorks ICM 2D Zones objects are exported as HEC-RAS 2D Storage Area objects. Perimeter geometry is exported and the roughness will be set to the default Manning's in HEC RAS. As no meshing is exported, re-meshing will need to occur in HEC-RAS.

Roughness Zones

InfoWorks ICMRoughness Zones are exported as HEC-RAS Land Cover (LC) Region objects. Geometry is exported but roughness is not exported as the mechanism for determining it is significantly different between HEC-RAS and InfoWorks ICM.

2D Boundaries

InfoWorks ICM2D Boundaries are exported as HEC-RAS BC Line objects. Geometry is exported, but the Boundary line type, Bed load boundary type and Suspended load boundary type are not exported.

Base Linear Structures

InfoWorks ICM Base Linear Structures are exported as HEC-RAS Connections objects. Geometry is exported, with the Structure type exported as Weir and the Weir type exported as Broad Crested.

General Lines

InfoWorks ICM General Lines are exported as HEC-RAS Break Line objects. Geometry is exported.