Bringing a Hydraulic Model from OpenRoads Designer to OpenFlows FLOOD

Product(s): OpenFlows FLOOD
Version(s): and


OpenFlows FLOOD can couple 2D surface runoff models to 1D hydraulic models built with CivilStorm and SewerGEMS by importing the stsw file. However the stsw file is not available in this format when using stormwater/sewer modeling tools integrated with OpenRoads Designer. In this case all model data is stored within a DGN file.

In this wiki article, you will learn how to generate the stsw file when you only have the DGN file. The stsw file is a file format handled by the standalone versions of the OpenFlows Storm and Sewer modeling tools, such as SewerGEMS and CivilStorm. It stores the drawing information of the network, and it works connected with other file extensions, such as the sqlite (database), dwh, etc.

As of the version of OpenFlows FLOOD, its 1D/2D model connector is not able to read the DGN file directly and requires the .stsw, dwh and sqlite files generated by SewerGEMS and/or CivilStorm.


To generate a stsw we can run CivilStorm or SewerGEMS from its standalone platform and load the DGN file.

Once loading the hydraulic model, the user can save the model choosing the stsw file format.

As an example, let’s take the case presented in the video below where a stormwater network was modeled using CivilStorm/SewerGEMS integrated with OpenRoads Designer.

Model’s current scenario runs a 6 hours simulation using the Explicit Solver - SWMM (a requirement to couple to OpenFlows FLOOD).

The first step is to open the DGN file that has the hydraulic model and open it using the standalone platform of CivilStorm or SewerGEMS. Be aware of the version compatibility between CivilStorm/SewerGEMS and OpenRoads.

Start CivilStorm/SewerGEMS and select “Open Hydraulic Model” from the Welcome Dialog, or select File > Open and change the file format file to “MicroStation DGN”.

You will be prompted to select the the Design Model where the Hydraulic Model is stored into the DGN file. Once loaded the model, select File > Save As to generate the set of files (stsw, dwh, sqlite). The video below shows an example of application.

Having the stsw, dwh and sqlite created, you can couple the hydraulic model to a simulation run. See our learning resources to learn how run the hole process of modeling with OpenFlows FLOOD.

 See Also

OpenFlows FLOOD Learning Resources