Understanding OpenFlows Drainage Functionality in OpenRoads Designer

Product(s): Civil Products (as listed below) 
Version(s): CONNECT Edition, V8i
Area: Modeling


The purpose of this TechNote is to help you understand the OpenFlows Hydraulics and Hydrology (H&H) functionality in Drainage and Utilities ( previously Subsurface Utilities), within Bentley's Civil products. It explains which programs it is available in, and the availability of Hydraulics & Hydrology tools within them. 


The OpenFlows - Hydraulics and Hydrology functionality that is available in the OpenFlows SewerGEMS, CivilStorm, StormCAD and SewerCAD products was introduced in the SELECTseries 4 (SS4) version ( of Bentley Civil products. Prior to that Subsurface Utility Engineering (SUE) tools were introduced in SELECTSeries 3 Civil products (version Since then the CONNECT Edition products have been introduced. These supersede the MX, InRoads, PowerCivil and GEOPAK products.

Here is the list of Civil products for which OpenFlows - Hydraulics and Hydrology functionality is available:

  • OpenRoads Designer
  • OpenRail Designer
  • OpenSite Designer
  • GEOPAK Suite
  • Power GEOPAK
  • InRoads Suite
  • Power InRoads
  • Power RailTrack
  • PowerCivil
  • MXRoad
  • MXRoad Suite

Note: this does not apply to these products if they are used in the AutoCAD environment.

OpenFlows - Hydraulics and Hydrology functionality within Drainage & Utilities will help users design and analyze all underground utilities, in a single product. Hydraulic model data is stored in a SQLITE file imbedded into the DGN file.

OpenFlows license management within civil products.

Note: for a video demonstration, see: Activating Advanced Drainage Capabilities in OpenRoads Designer: Part 1 | Part 2

  • StormCAD license (the ability to use the StormCAD solver for analysis and design of up to 100 inlets is included)
  • If you own a license for another storm/sewer product, the functionality for that product will be available. In other words, if you own a SewerGEMS, CivilStorm, StormCAD or SewerCAD license, you will be able to use its functionality in the Civil product, along with more than 100 inlets.
  • Select your inlet/link limit using the Feature Level Selector, so that the proper license is used.
  • The availability of the various licenses that can be activated in Drainage & Utilities (e.g. CivilStorm, SewerCAD) can now be configured by the Site Administrator, using CONNECT Licensing.
    • Previously, Drainage & Utilities didn’t know whether a license for one of these products was available or not, so a generic message telling you that usage would be logged, and additional charges might occur, was displayed. Now, availability is controlled by CONNECT Licensing, which means that you can see exactly what product licenses and feature levels (number of inlets or links) are available. 
  • If you are in the OpenAccess program, you will also have access to all storm/sewer products.

How to change active OpenFlows license

See also: What if I need more than 100 inlets in StormCAD?

The following features are included in Civil products:

  • Conflict Management / Clash Detection
  • Subsurface / Drainage Utilities attributes
  • 3D Modeling of all Underground Utilities
  • Integrated with OpenRoads
  • Storm/Sanitary Hydraulics and Hydrology Analysis and Design

OpenFlows - Hydraulics and Hydrology Functionality - how it works in Civil products

With the availability of the Drainage & Utilities tools within your Civil products, you can perform the following things:

  • Design / Analysis of new or existing storm-sewer models within the Civil product
  • What if analysis, scenario and alternatives management as is possible in Hydraulics & Hydrology products
  • Directly import existing storm-sewer models into Civil products
  • The DGN file can be directly opened back in Bentley's storm and sewer products (SewerGEMS, CivilStorm, StormCAD and SewerCAD).
  • Clash detection of the utilities like water, gas, waste water, thermal, electrical, storm water, petroleum etc. 
  • Reference the Bentley OpenFlows Storm and Sewer models in the form of DGN files, to perform the clash detection or to compare the position of e.g. storm water lines with the water lines.
  • Storm and Sanitary design tools integrated with Civil tools.
    • While laying out the network you can extract the elevation from the existing terrain model, so you don't need to enter the elevations manually.
    • Elevations can be ruled to road/site design surfaces
    • Position can be ruled to geometry
  • 3D modeling of the hydraulic elements within the Civil products.

  • The CONNECT Edition Civil products also enable more Report options than the SELECTseries 4 versions:

Updating a Drainage and Utilities model after changes are made in a storm or storm sewer standalone product

A Storm or Storm Sewer file can be updated in standalone and opened in Subsurface Utilities using the steps below:

1) Open the .DGN file using any of the hydraulics and hydrology Select Series 5 or CONNECT version standalone products.

2) Update and save the file

3) Open the file in one of the Civil products.

4) Go to the Drainage & Utilities workflow > Tools > Synchronize Drawing...  the file should update.

Tools in OpenFlows storm-sewer products available within Drainage and Utilities.

  • Catchment Delineation is available when placing and moving catch basins.
  • The Place Pond tool includes a “From Terrain Model” option, which automatically creates an Elevation/Area collection by analyzing the selected terrain model. This collection is automatically updated if the terrain model changes.
  • The ability to Create Dimensionless Rainfall Curves from a CSV file has been added, primarily to read temporal pattern data from the Australian Rainfall and Runoff data hub.
  • LoadBuilder tool to import sanitary loading information using shapefile.
  • Support for OpenFlows gutter sections functionality. This creates intermediate sections along a gutter element by sectioning a terrain model. Spread widths are calculated at each section.
  • The default value for a User Data Extension (UDX) can be overridden in a feature definition, so you can assign one User Data Extension to multiple feature definitions and use a different default value for each one.
  • Flow arrows are displayed for drainage conduits in Element Symbology. 
  • Support for OpenFlows Tap and Property Connection types in the Structure Type property of a node feature definition.
  • Ability to use the local design constraint for a conduit, instead of the default design constraint.to set the depth of cover. This lets you override default values such as the depth of cover, minimum velocity, etc., which can be helpful if the conduit is modelling an open section such as a ditch.
  • Critical storm analysis tool and Critical storm analysis wizard are also available to assist in streamlining the process of creating scenarios, alternatives, calculation options and storm events for a specific set of return periods and durations with starting from 10.08.xx,xx versions. 
  • Ability to perform batch pipe split functionality which automatically inserts nodes in conduits if they are within an offset tolerance specified. 
  • Added support for UK Flood Estimation Handbook 2013 Rainfall Data starting with version. 

 Tools not available from OpenFlows products 

  • Theissen Polygon
  • Pump modeling
  • Customer elements
  • Change tracking feature
  • Quick graph
  • Element property inferencing

Version Compatibility

Each version of OpenRoads/OpenSite uses a certain version of the underlying OpenFlows technology for drainage. When the need arises to open models between these products and the OpenFlows products (such as SewerGEMS or StormCAD), one needs to consider the corresponding version to ensure compatibility. 

See: Platform Compatibility Chart – Civil Products – OpenFlows Products

Training and Learning

OpenRoads Designer - Learning

Learning Resource Guide for new users of Bentley SewerGEMS

Training for drainage functionality in OpenRoads Designer

Activating advanced drainage capabilities in civil product

There is On-demand Answer Hour session video about activating advanced drainage capabilities in civil product. Which includes understanding StormCAD 100 inlets license within civil products, how to utilize 100 inlets license, how to change license to other available license options like StormCAD unlimited, SewerGEMS, CivilStorm, what is meaning and usage of each particular license and which one you should utilize to match your project requirements all this is covered in this answer hour session.

Note on Terminology

  • Starting with OpenRoads Designer version, the term "SUBSURFACE UTILITIES AND DESIGN ANALYSIS" has been officially changed to "DRAINAGE AND UTILITIES" though the functionalities are same. 


See Also

Platform Compatibility Chart – Civil Products – OpenFlows Products

Subsurface Utilities (SUE and StormCAD) Video Clips, TechNotes & FAQs

Performing clash detection of storm/sewer/water models using Bentley Products

Video: Clash Detection

OpenRoads Special Interest Group (SIG) FAQs

OpenRoads Designer CONNECT Edition - Wiki Articles and Videos 

Answer Hour: Activating Advanced Drainage Capabilities in OpenRoads Designer