You can export a model to MicroDrainage .sws format.

To export the current model to a MicroDrainage .sws file:

1. Select File > Export > MicroDrainage.
2. If there is more than one network, select the outfall for the network to export.
3. In the Select MicroDrainage File dialog, type the name of the sws file , then click Save.
4. If you prefer, you can use the existing conduit labels as the Pipe Numbers on export to MicroDrainage, if you do not wish the values to change on export. Simply select "Use Link Labels as Pipe Numbers" in the branch labeling section of the MicroDrainage Export options dialog.

Notes on exporting data:

Outfalls

All outfalls can be selected. Headwalls which serve as outfalls can also be selected.

• All outfalls are exported with label "Outfall"
• Outfalls are exported with circular structures with a 0 mm diameter
• The ground elevation is exported as a cover level
• The invert of the outfall is ignored

Laterals

• All laterally connected catchments will be consolidated and applied to start node of the reference conduit
• All laterally connected fixed\constant loads will be consolidated and applied to the start of lateral's reference pipe

Catchments

• All catchments associated with the start node of the pipe as well as all laterally connected catchments associated with the pipe are consolidated into a single catchment
• Each area is multiplied by its runoff coefficient, and the resultant values are summed
• The longest Tc of each of the catchment is applied to the Time of Concentration attribute of the Micro Drainage Pipe

Manholes

• All manholes, transitions, catch basins, and non-outfall headwalls will be exported as MicroDrainage manholes
• The MicroDrainage manhole will have the same label as the Bentley element
• The shape data will exported as follows: For Manholes, and Catch Basins - the diameter is exported if the structure is circular, otherwise the length and width are exported if the structure is rectangular. For Transitions and Headwalls - they are exported as circular structures with a diameter of zero.
• The ground elevation is exported as the cover level
• The Sump Depth is determined based on the distance of lowest adjacent pipe invert to the invert of the structure
• Only constant loads on the Wet Weather Inflow collections on the node are summed and exported as the base flow on the downstream pipe

Conduits

• The label of the exported conduit is based on the UK dendritic numbering mechanism of branch pipe
• The diameter of the pipe is exported
• The Manning's n is exported to the Manning's n property
• The active length of the pipe (User Defined or Scaled) is exported to the length property of the conduit
• The Upstream and Downstream invert levels are exported based on the active invert levels of the conduit
• Upon export all conduits will be oriented from upstream to downstream towards the outfall
• If the conduit has a shape other than circular, Bentley SewerCAD will approximate the shape as a series of eleven X-Y coordinates for open channels, or two eleven point series that represent both the base and the cover, for closed sections. For regular section shapes, such as a box, or a trapezoidal open channel, eleven points are enough to model the conduit shape accurately. For other regular closed shapes, such as egg and arch, both series of eleven points are used for the channel and the cover, so the shape will still be reasonably well represented. With irregular sections though, the data can result in more than eleven points in each series, which MicroDrainage cannot accommodate in the Conduit Library file (.SEC)”; each line in a Depth-Width curve will use two points in the base or cover series, so the eleven points that are allowed in each can be quickly used up. In this case, the data is truncated so that only the first eleven points are written to the file, and a User Notification is created to warn you that this has happened. The truncated data may appear as a partial conduit when viewed in MicroDrainage. In all cases, the area and wetted perimeter values that are also written to the file are calculated to full accuracy, so the hydraulic results should not be affected. These curves will be exported to a MicroDrainage Conduit Library file (.SEC) which will have the same name and location as the exported MicroDrainage .SWS file.

Channels

Bentley SewerCAD imports section definitions from a MicroDrainage Conduit Library file (.SEC). If the section is open, the channel X-Y coordinates will be imported as an Irregular Channel. However, if the section is closed the channel and cover X-Y coordinates will be converted to a Depth-Width curve and imported as Irregular closed channel. Bentley SewerCAD also recognizes the MicroDrainage shape codes 1-65. If one of those codes is specified the appropriate shape and dimensions will be import as specified in the MicroDrainage documentation.

Unsupported Elements

• Links - these types of link are excluded from the export: Channels, Gutters, and Pressure Pipes
• Nodes and Polygons - these types of nodes and polygons cannot be present in the network: Cross Sections, Pond Outlet Structures, Pumps, Wet Wells, Ponds, and Pressure Junctions