Using SWMM Networks in ICM

The following provides a brief outline describing how data may be set up in InfoWorks ICM in order to run simulations using SWMM networks.

The first step is to add a SWMM network to the database in the Explorer window, and then open the new SWMM network on the GeoPlan.

Data can now be added to the network. A typical process is listed below:

• Set the various options for the model parameters. These can be updated at any time but you may find it useful to make sure that the following fields are set before adding network objects:
  • Network flow units
  • Force main equation - this setting determines if the Roughness D-W or the Roughness H-W field is displayed for conduits with a Shape set to Force_main.
• Add the objects that comprise the network. SWMM network objects are categorised as nodes, links, subcatchments, points and polygons, and can be added to the network using the appropriate grid window, by digitising on the GeoPlan or by importing from existing network data. If you are importing network data from SWMM5 text files, then the model parameters options you may have already set may be overwritten by the imported values.
• Specify the time varying event data that is to be used in a simulation for this network. This can be Scalar TSD objects and/or Spatial TSD objects or events. See below for further information.
• If one or more rainfall events are to provide the time varying data, then link the rainfall events to the applicable network objects.
• If a regulator structure is to be controlled according to one or more rules, ensure that these are defined using the Control Rule Editor.
• Define any other database items, such as SWMM Climatology and SWMM Time Patterns, if applicable.
• Specify the snow parameters if a simulation is to model snow melt.
• If you want to include a 2D simulation as well as a 1D one in a run, ensure that the network contains 2D nodes, at least one 2D zone and a ground model, and that a 2D mesh has been generated. See Creating 2D Meshes and 2D Simulations for further information.
• Ensure that all the applicable model parameters options have been set.
• Validate the network. A list of warning and error messages may be displayed. If the network contains any errors, correct these and then re-validate. Although a simulation can be run on a network that contains warnings, it cannot be run on a network that contains any errors.
• Add a SWMM Run (if not already added at the same time as the other database items), and specify the parameters for the simulations to be included in the run.

  If the run is to include any 2D simulations, ensure that any tolerance and advanced 2D simulation parameters have been set.

  SWMM simulations in InfoWorks ICM use dynamic wave routing. This routing method is described in the SWMM Reference Manual Volume II, Hydraulics, which can be downloaded from the EPA website.

• Run the simulations.
• View the results of the simulations.

Events in InfoWorks ICM are database items which are not tied to a particular type of network so the same event can be applied to either a SWMM or an InfoWorks network, provided it is applicable to that type of network. The following types of events can be used in a SWMM network:

• Rainfall - rainfall intensities for a particular storm and associated data:
  • Temperature profiles. These are used for modelling snow melt
  • Evaporation profiles to be applied to rainfall profiles
• Level - level hydrographs applied to outfalls type of nodes
• Inflow - inflow hydrographs
• Regulator - time-varying profiles used to control regulator structures
• SWMM pollutograph - defines a water quality input to the system. A SWMM pollutograph is used with an Inflow or Level event.

Note that the parameters required to be defined for an event used in a SWMM network may be different to that for an InfoWorks network, and that this is indicated in the relevant help topic.