What's new in SewerGEMS V8i SELECTseries 2? [TN]

Product(s): SewerGEMS
Version(s): V8i SELECTseries 2 (
Area:  N/A





The SELECTseries 2 release of SewerGEMS includes many new features and improvements. Let's explore each of these in detail.

Note: please see this technote for the new features in SewerGEMS Sanitary V8i SELECTseries 2.

-Support for Newer Platforms and Operating Systems
-SWMM Long Term Continuous Simulation
-SWMM Interface Files (including Hot Start)
-SWMM Calculation Engine Update
-SWMM RTK Method
-Catchment to Catchment SWMM Hydrology Support
-Easier sharing of data between Implicit Dynamic Wave, SWMM and SewerCAD solvers
-Improvements to the Dynamic Wave Solver (Implicit calculation engine)
-Improvements to the Hydrology Calculation Engine
-Improved Pond Outlet Structure User Interface
-Network Tracing Queries
-More Flexible Date/Time Formatting
-Engineering-Style profiles
-Improved Profile Creation
-Element Property Inferencing tool
-Scenario Comparison Tool
-Hydrology Alternative Editor Improvements
-Inroads Import/Export
-Formula-based User Data Extensions
-Symbology Definitions
-Seed File Support
-Create XML Reports from Flextables
-New Selection Tool for User Notifications


Support for Newer Platforms and Operating Systems

SewerGEMS now supports the following:

  • Windows 7 32 and 64 bit
  • AutoCAD 2010 and 2011
  • Microstation 08.11.07.XX
  • ArcGIS 9.3.1
  • ProjectWise 08.11.07.XX



SWMM Long Term Continuous Simulation

A long term continuous simulation is a simulation that spans multiple storm events and must typically account for things that a single return event would not, such as snow melt and monthly temperature. In previous versions, the SWMM calculation engine had the ability to compute a long term continuous simulation, but the SewerGEMS user interface was mainly designed for single event based simulations.  In V8i SELECTseries 2, several features have been added to accommodate long term continuous simulations:

  •   New storm data type: Historical Rainfall File
    • Allows you to select a standard SWMM rainfall file containing intensity, incremental depth or cumulative depth data, which could span many storm events.

    • Supports the following standard SWMM rainfall file formats:
      • DSI-3240 and related formats which record hourly rainfall at U.S. National Weather Service (NWS) and Federal Aviation Agency stations, available online from the National Climatic Data Center (NCDC) at www.ncdc.noaa.gov/oa/ncdc.html.
      • DSI-3260 and related formats which record fifteen minute rainfall at NWS stations, also available online from NCDC.
      • HLY03 and HLY21 formats for hourly rainfall at Canadian stations, available online from Environment Canada at www.climate.weatheroffice.ec.gc.ca.
      • FIF21 format for fifteen minute rainfall at Canadian stations, also available online from Environment Canada.
      • A standard user-prepared format where each line of the file contains the station ID, year, month, day, hour, minute, and non-zero precipitation reading, all separated by one or more spaces.


  • Climatology Data
    • Under Components > SWMM Extensions > Climatology, you can enter climatology conditions, including temperature; the evaporation that can occur for standing water on subcatchment surfaces, for subsurface water in groundwater aquifers, and from water held in storage units; wind speed data; snow melt; and areal depletion.



  • Additional New SWMM Calculation Options
    • Simulation end date/time
    • Start/end street sweeping dates
    • Report filtering - allows you to choose a selection set of catchments, nodes and links to save results for. Useful for a long term continuous simulation, since the amount of result data can be very large.
    • Pattern mode- This option allows you to choose whether SewerGEMS will treat pattern loads as SWMM patterns or as a generated hydrograph
      • SWMM can only define inflow patterns in one hour increments, so the hydrograph option will be more accurate
      • The hydrograph option could result in a very large amount of output when running a long term continuous simulation
      • If using the SWMM Pattern option and the pattern isn't defined on the hour for every hour, interpolation/extrapolation will be performed


  • Statistical Analysis Tool
    • Since a long term continuous simulation can generate a lot of output data, the user will typically want to look at statistical results
    • Statistical analysis tool is located under Analysis > Statistics. It is a manager, so you can save multiple statistical analysis.
    • The Event Time Period field allows you to choose the length of the time period that defines an event. These can be Daily, Monthly, Annually or Event dependent. In the Event-Dependent case, the event period depends on the number of consecutive reporting periods where the simulation results are above the threshold values defined below in the Event Thresholds section of the dialog. That is, how much rain constitutes an event and what period of time between non-zero rain constitutes a separate event.
    • The "has minimum event value" and "has minimum event volume" fields allow you to refine the criteria that delineates events.
    • The "Separation time" is the minimum number of hours that must occur between the end of one event and the start of the next event. Events with fewer hours are combined together.



SWMM Interface Files (including Hot Start)

The SWMM calculation engine can use several different kinds of interface files that contains either external imposed inputs (e.g., rainfall or infiltration/inflow hydrograph) or the results of previously run analysis (e.g., runoff or routing results). As of SELECTseries 2, SewerGEMS can now utilize these interface files

  • Rainfall file - This file is created internally by SWMM and collates a series of separate rain gage files into a single rainfall data file. The file can be reused in the next run to save on calculation time, since the engine will not need to create rainfall file again in the next run.
  • Runoff file - used to save the catchment runoff results generated from a simulation run. If the catchment runoff is not changed in a future run, the runoff interface file can be re-used to save on runoff calculation time.
  • RDII file - a text file that contains a time series of rainfall-dependent infiltration/inflow flows for a specified set of drainage system nodes. The file can be generated from a previous SWMM run when Unit Hydrographs and nodal RDII inflow data have be defined for the project, or it can be created outside of SWMM.
  • For these rainfall, runoff and RDII files, you can choose to either save or use. When choosing to save, the file will be generated based on the results when you computer the model. When choosing to use, the simulation will use the selected file.
  • Hot Start file - contains the hydraulic and water quality results for the drainage system at the end of a run. The file can be saved and re-used in the subsequent run to define the initial conditions.
  • Routing interface files (inflow/outflow) - stores a time series of flows and pollutant concentrations that are discharged from the outfall nodes of a drainage system model. This file can serve as the source of inflow to another drainage system model that is connected at the outfalls of the first system. This allows very large systems to be broken into smaller sub-systems that can be analyzed separately and linked together through the routing interface file.
  • These interface files are generated or accessed from the Calculation Options, when the SWMM calculation engine is selected.



SWMM Calculation Engine Update

The Explicit (SWMM) calculation engine has been updated to version 5.0.018. Meaning, when you choose "Explicit" as the "Engine Type" in the calculation options, version 5.0.018 of the calculation engine will be used when you compute a simulation.




The RTK method available in previous versions of SewerGEMS is different from EPA-SWMM's implementation. In SELECTseries 2, SewerGEMS now supports the SWMM RTK method for estimating RDII.

  • Configure the RTK unit hydrograph from Components > SWMM RTK Unit Hydrographs
  • Assign the RTK set to manholes and enter the sewershed area

  • Differences between SWMM RTK and Implicit RTK implementations:
    • SWMM adds RTK hydrographs to nodes (manholes) whereas Implicit uses catchments
    • SWMM requires additional Initial Abstraction parameters (Dmax, Drec and Do)
    • SWMM RTK can vary by month





Catchment to Catchment SWMM Hydrology Support

  • The EPA-SWMM catchment runoff method supports routing of runoff from one catchment to another.
  • The Runoff Method must be set to "EPA-SWMM Runoff".
  • Simply select the next downstream catchment from the "Outflow Element" property.



Easier sharing of data between Implicit Dynamic Wave, SWMM and SewerCAD solvers

Several changes have been made to improve the compatibility between SewerGEMS Sanitary (SewerCAD) and both the implicit and explicit calculation engines in SewerGEMS. This effects cases where you are moving model files between these three calculation engines.

  • Pump Station Handling
    • In previous versions of SewerGEMS, a single pump node could represent multiple pumps in parallel and would need to have a suction element specified. This was quite different from the way that SewerCAD operates. So, in an effort to increase compatibility between both programs, each pump in SewerGEMS must now be a separate node. The on/off controls as well as the selection of pump definition are seen directly in the pump's properties:
    • When opening a SewerGEMS model that was saved in a previous version with multiple pumps in a single pump node, they will be converted to separate pump nodes. The pump definitions and controls will be maintained, and virtual pressure pipes will be added next to these new pumps, to maintain hydraulic equivalency.

    • A virtual pipe basically means that the flow that enters the upstream end instantly goes to the downstream end, with no hydraulic effects. It’s essentially a way to connect elements without impacting the hydraulics. This will eliminate the complexities involved with the manifold that would otherwise be created, just downstream of the pump station.
    • If you need to account for the pipes adjacent to the pumps, choose "false" for "is virtual?" and enter those properties. The node immediately upstream of each pump must either be a wetwell or a pond though. (you can only have one pipe between the wetwell and the pump).
    • Pumps can still be organized into "Stations" using the new Pump Stations manager. See further below.
    • For best compatibility between SewerGEMS and SewerCAD/SewerGEMS Sanitary, it is recommended that you use the "multiple point" pump curve type.

  • Pump Station Tool
    • In order to retain the benefits associated with grouping pumps together (e.g. a single place to view controls etc.) a new pump station tool has been added. It is available under Components > Pump Stations.
    • Click the new button to organize pumps into a pump station. Select the pump node elements that belong to each pump station, then you'll be able to edit their properties in a tabular view. You can also create a report of the each pump station.


  • Controls
    • When using the Explicit (SWMM 5) calculation engine, you can now choose which SWMM Control set will be used. SWMM control sets are defined under Components > SWMM Extensions > Control Sets. The new calculation option is called "Apply SWMM Control Set?" and is located in the calculation options, when the engine type is set to Explicit. If this field does not show up for you, please apply the latest patch.

  • You can choose to have the Explicit (SWMM 5) calculation engine ignore controls that you've entered in the properties of pumps. This way, you can define more complex conditions in your SWMM control sets.

  • An Operational alternative has been added. Similar to SewerCAD and SewerGEMS Sanitary, this can be used to change pump controls between scenarios. In previous versions, SewerGEMS pump controls were stored in the Physical alternative.

  • You can now specify a SWMM label for your conduit control structures. This can be used as a unique identifier when referring to the control structure in a SWMM control set (Explicit calculation engine only.)

    • Conduit Control Structures
      • SewerGEMS Sanitary (and SewerCAD) now have the ability to place control structures at either end of a conduit.

    • This increases fidelity when moving between SewerGEMS and SewerGEMS Sanitary, since all three products now have a control structure feature.
    • Just like in SewerGEMS, this can be used to model weirs, orifices, depth-flow curves and functional-based flow control devices.
    • SewerCAD and SewerGEMS Sanitary still require a diversion rating curve for diversions. These conduit control structures are inline.
    • Headloss Alternatives
      • In previous versions, SewerGEMS did not have a Headloss alternative. This caused some complexities when moving models between SewerGEMS and SewerCAD (or SewerGEMS Sanitary) because SewerCAD (and SewerGEMS Sanitary) has a separate Headloss alternative.
      • In V8i SELECTseries 2, SewerGEMS now has a headloss alternative. So, headloss alternative information from a SewerCAD or SewerGEMS Sanitary model will be directly converted without any data loss or confusion.
    • Conduit Shapes
      • In previous versions, SewerCAD/SewerGEMS Sanitary had a different set of available conduit cross sectional shapes compared to SewerGEMS.
      • In V8i SELECTseries 2, trapezoidal, triangular and rectangular shapes have been added to SewerGEMS, to match the available shapes in SewerCAD/SewerGEMS Sanitary.
    • SWMM Flow Dividers
      • In previous versions, it was not possible to import Flow Divider information from an EPASWMM 5 .inp file. They were imported as manholes and the diversion information was not imported, since the manhole element did not support it. This also means that flow dividers could not be used when computing a model with the SWMM calculation engine.
      • In V8i SELECTseries 2, Flow Dividers are now supported. They are maintained when importing and exporting SWMM 5 files, and can also be used with the SWMM calculation engine.
      • In SWMM, flow dividers are configured in a node, which points to a target link to divert flow to. In SewerGEMS, the flow divider is configured in the conduit where diverted flow will be routed. 
      • To set up a flow divider when using the SWMM calculation engine, choose "true" for "Is Diversion Link?" in the properties of the conduit that will receive diverted flow. You can then select from the four SWMM divider types:



    Improvements to the Dynamic Wave Solver (Implicit calculation engine)

    • Enhanced Robustness
    • Improvements for special facilities
    • Better performance than SWMM for event-based hydrology
    • Improved performance for larger models



    Improvements to the Hydrology Calculation Engine

    • The PondPack V8i numerical engine is now used for catchment hydrology calculations.
      • Improved performance when retrieving catchment results
    • Improved Storm Data user interface
      • Consistent with current versions of Bentley StormCAD and Bentley PondPack
      • Types of storm events organized into folders on the left
      • Graphical view of the storm distribution




    Improved Pond Outlet Structure User Interface

    • The PondPack V8i numerical engine is now used for pond outlet structure calculations, providing enhanced performance.
    • The user interface for configuring pond outlet structures now also matches PondPack V8i
    • Pond outlet rating curves can be computed and viewed from within this new user interface.
    • The rating table can be viewed in tabular form
    • The User Defined Rating Table and Vortex Valve outlet structure components can now be used
      • Vortex Valves must first be configured under Components > Vortex Valves
      • Vortex Valves can be stored in the engineering library
      • Several HydroInternational vortex valves are available in the default vortex valve library





    Network Tracing Queries

    Advanced network tracing queries can now be performed, from the Network Navigator tool (View > Network Navigator). These can be very useful for cleaning up defects in a model or locating other modeling problems.


    • Initially Isolated Elements - locates elements that are initially disconnected from the rest of the system. For example a segment of piping with no outfall.
    • Find Connected - locates elements that are physically connected to a selected element.
    • Find Disconnected - locates elements that are not physically connected to a selected element.
    • Find Shortest Path - retrieves a list of elements in the shortest path between two selected elements.
    • Trace Upstream - locates elements that are upstream of the selected element
    • Trace Downstream - locates elements that are downstream of the selected element
    • Find loops in network - locates loops in the network. For example a flow split that re-joins downstream.


    More Flexible Date/Time Formatting

    In previous versions, time was displayed as either date/time (such as 07/09/2010 7:45 PM) time from start in decimal (such as 7.75) or time from start in clock time (such as 07:45:00). In V8i SELECTseries 2, you can now customize which time format SewerGEMS uses.

    • This applies to numerous different things, such as graphs, tabular data, inflow hydrographs, the Time Browser, etc)
    • When looking at a time field, right click and choose "units and formatting". You can now select from an array of time formats
      • For graphs, right click on the time axis and choose "time properties" to bring this up

    • .The "EPS Results Browser" is now called the "Time Browser". Instead of just showing clock time, it now shows decimal clock time along with a second column that can be customized, like mentioned above.




    Engineering-Style profiles

    In previous versions, only one type of profile was available. This "regular" profile was useful for model review, but lacked some of the things that were more useful for presentation purposes. SELECTseries 2 now includes two profile viewing options: the old style "regular" profile, and a new engineering style profile. Note that any defined profile path can be displayed in either format.



    Features of the engineering style profiles include:

    • Customizable annotations - annotate any property (including result fields and user data extensions), adjust the annotation's location, offset, rotation and also add leader lines and arrows


    • Easily adjust the scale, colors and size of the profile.


    • Ability to save default annotation settings – After setting up an annotation in an engineering profile, you can store them as defaults and apply to other annotations. You can also store the entire annotation definition to a global default, which can be applied to other profiles in the same model or in other models on the same computer. More information on this can be found in this Technote.
    • Ground profiling - allows you to enter a Station vs. Elevation table to define the ground elevation along the length of a pipe. The automatic method (the only option in the "regular" profiles) simply draws a straight line between the ground elevation of the adjacent nodes.





    Improved Profile Creation

    • Automatic path selection – when creating a profile, just select the upstream and downstream nodes and the profile will automatically include the elements between them. Intermediate points can be specified.



    Element Property Inferencing tool

    The new Element Property Inferencing tool (located under the Tools menu) allows you to populate missing elevation information. This feature was previously available in SewerCAD and SewerGEMS Sanitary.




    Scenario Comparison Tool

    • The scenario comparison tool (under the “Tools” menu) enables you to compare input values between any two scenarios to identify differences quickly.

    In the above example, the infiltration and inflow alternative was different between the two scenarios. One contains inflow information and the other does not.



    Hydrology Alternative Editor Improvements

    The hydrology alternative dialog box can now be easily filtered, to show only the input fields related to the type of catchment information you're interested in. In the past, this window showed all input fields at once, which was cumbersome since there are many different runoff methods, each with different input fields. For example if all your catchments use the SCS CN loss method, simply click "SCS CN" on the left side, and you'll see only the fields relevant to your model.



    Inroads Import/Export

    You can now export your SewerGEMS model to Inroads Storm and Sanitary as well as import an Inroads drainage database to create a SewerGEMS model.

    • File > Export > Inroads and File > Import > Inroads
    • Only the drainage database is required to import the pipe network. Other supporting files are optional.
    • If you've imported an Inroads file and then later export it, you can choose to synchronize to the existing .sdb file.
    • Note that there is not a perfect one-to-one relationship between the InRoads and SewerGEMS data models, so where SewerGEMS has to make assumptions on what data to use, a User Notification is generated. Please see the help documentation for the element map between SewerGEMS and Inroads.
    • A possible common workflow:
      • Lay out a new site/road in InRoads
      • Determine catchment areas using the terrain modeling tools and add some preliminary drainage pipes and inlets in InRoads Storm & Sanitary
      • Import that Storm & Sanitary file in SewerGEMS for further analysis (for example, create a number of Scenarios using the powerful Scenario Manager)
      • Create a final design in SewerGEMS, then save and export that back to InRoads (either by updating the original .sdb file or creating a new one)
      • Use InRoads for plan and profile preparation



    Formula-based User Data Extensions

    In the past, a user data extension always contained user-entered information. Now, you can create a user data extension whose value is calculated based on other existing fields. For example, you can create a field whose value is equal to the square root of the difference between one input field and another user data extension.


    • User data extensions are accessed from Tools > User Data Extensions
    • Choose “Real (Formula)” for the “data type”
    • Be sure to choose the correct dimension, unit and numeric formatter. For example the result shown in the above example user data extension is a length dimension, with elevation as the formatter. This means that this field will use the correct units (feet, a unit of length) and the same format settings (decimal precision, etc) as other elevation fields.
    • In the formula editor, double click attributes at the top to populate the correct field name at the bottom. Right click to change the unit as necessary.
    • Many math functions (such as square root, absolute value, etc) are available in the formula editor window and you can also use IF/than/else statements.


    Symbology Definitions

    You will now have a dropdown at the top of the Element Symbology manager, which allows you to configure which symbology should be applied. For example, you may have one symbology definition for helping you with data input and a few for the different types of presentations you may want to make.

    • Click the ellipsis button next to the dropdown at the top of the Element Symbology manager to create new symbology definitions
    • All color coding and annotations that you create will always show up. Symbology definitions simply keep track of the status of the check boxes, for annotations, color codings are the element type itself
    • Create a new symbology definition, choose it from the dropdown, then check or uncheck the desired items.




    Seed File Support

    • Seed files allow you to save project settings and data as a template (the seed file has a .sgs extension). You can then reuse these settings/data while creating new projects using the data from the previously saved seed file.



    • For example, you can start a new project, import all the conduits that you typically use into the catalog, set up your color coding and annotations, and import typical local storm information or unit load types. Then, choose to “Save to seed”. Now, when you start a new project, instead of choosing to create a new project, choose File > Seed > New From Seed and pick the seed you saved. This way, you don’t have to set up standards each time.
    • A seed file contains a full SewerGEMS model file, not just catalogs and element symbology. It is essentially like compressing the model files into a zip file.



    Create XML Reports from Flextables

    • XML reports can be generated from a flextable and allow you to apply your own XML style sheet to customize the look of the report.



    • Style sheets are selected in the XML report viewer from the Options menu > Apply Style Sheet > Custom. It uses a standard .XSL file, which requires knowledge of XML to create.
    • In addition to be a transportable format (you can save to .html) xml data can be presented in many and varying ways.  By producing a style sheet, you can open differing “views” on the same XML data.



    New Selection Tool for User Notifications


    • Use the new “select all elements with message ID...” button to select all elements that have the same message type as the selected notification. 
    • In addition to viewing the location of these elements in the drawing pane (highlighted in red), you can also create a selection set or filter a flextable.

    See Also

    What's new in SewerCAD V8i SELECTseries 2?

    Product TechNotes and FAQs

    OpenFlows Product Tech Notes And FAQs


    External Links

    Bentley LEARN Server