Problems opening GEOPAK Drainage file exported from StormCAD

Product(s): Bentley StormCAD
Version(s):, 10.XX.XX.XX
Area: Output and Reporting


When exporting my StormCAD model to GEOPAK, the exported model will not open in GEOPAK drainage or appears to be incomplete.


First, several improvements to the GEOPAK export feature have been added in the SELECTseries 5 release of StormCAD (and SELECTseries 4 of OpenRoads). If you have not done so already, it is strongly recommended that you install SELECTseries 5 or (when available) higher. If you're using SELECTseries 4, these improvements are also included in the latest cumulative patch set. You can read about downloading patches here:

Also, GEOPAK Drainage tends to be more sensitive to any missing data input or other data entry issues compared to StormCAD. First, Validate the StormCAD model and ensure that the data entry is correct and that results are reasonable. Here is a list of other data entry problems to be careful of:

1) The Maximum Gutter Depth, and Manning's n (inlet) and Catalog inlet curb opening length fields for catchbasin nodes need to be set greater than zero
2) All Catchbasin nodes need to reference catalog inlets and need to have at least one attached catchment. Catchbasin nodes that act as junctions should be morphed into transitions or manholes.
3) No gutters should be leaving from an inlet in sag
4) All inlets on grade need to have a bypass gutter
5) The Tc of a catchment needs to be less than the maximum duration in the IDF curve
6) Elements that are topologically inactive will still be exported to GEOPAK. These can either be addressed in GEOPAK or deleted from the StormCAD model before export.

See Also

Best practices for working with GEOPAK drainage files exported from StormCAD