How to create a 1D-SWMM link

Why link these two pieces of software?

Flood Modeller 1D Solver has been specially developed to represent flows in the open channels whereas SWMM is one of the most wide-spread software to model storm drainage in urban environments. For this reason and thanks to the uprising concept of integrated development it has become necessary to link these pieces of software in order to represent accurately the interactions between surface channels and pipe networks taking advantage of the specific tools included in each software.

Which software is linked?

In this situation, a Flood Modeller 1D model and a SWMM model (US Environmental Protection Agency’s Storm Water Management Model) are linked.

Types of links

The linking process does not provide any capability to build or edit SWMM models. It assumes that the SWMM model being linked has already been created in appropriate software, e.g. the EPA SWMM user interface. An existing SWMM model can be linked to a 1D model only via selected SWMM node types. These are:

If you have a geo-referenced 1D Model then it is possible to define these links within the Flood Modeller interface and therefore visualise the locations of your SWMM node points. The tool imposes no restrictions as to which 1D node you can create a SWMM connection at. However, care should be taken when selecting a suitable connection point as not all 1D node types represent a realistic linking option, e.g. on-line storage reservoirs are not compatible, use off-line instead.

How can this be done?

The process to create 1D-SWMM link file is described in detail in the section How to link a SWMM model to a 1D model using the map view

Once the 1D-SWMM link file has been generated you can set the linked simulation through the 1D simulation file going to the ‘Links’ tab and associating the SWMM control file (.inp) and the SWMM Link file (.isl) to the active simulation.

What you have to be careful with when creating a SWMM Link

When creating a SWMM Link, instabilities may appear in your simulation. To avoid instabilities it is likely that a smaller time step will be required in the linked model than in the two standalone models, this will represent more computational effort required with longer simulation times.