TUFLOW SWMM Tutorial M02

Introduction

This tutorial, Module 2 of the TUFLOW SWMM tutorial dataset will demonstrate how to model underground stormwater pipe networks using SWMM, linked to the TUFLOW HPC 2D solution scheme.
TUFLOW SWMM Tutorial Module 2 builds from the model created in TUFLOW SWMM Tutorial Module 1. The completed TUFLOW SWMM Module 1 model is provided in the TUFLOW_SWMM_Module_02\TUFLOW folder of the download dataset as the starting point for this tutorial. If you are not already familiar with TUFLOW SWMM linking, we recommend first completing Module 1 before this tutorial.

QGIS Project Initialization

QGIS Version 3.34 or newer, and QGIS TUFLOW Plugin 3.9.0.49 or newer are required to access the SWMM Processing Tools described in the following sections. For installation, see Installation of TUFLOW Plugin.
Define the Coordinate Reference System (CRS), also called ‘Projection’, for the QGIS workspace:

1. Open QGIS.
2. Go to Project > Properties…
3. In the CRS tab, type ‘WGS 84 / UTM Zone 60S’.
4. Select the matching projection in the 'Predefined Coordinate Reference Systems' section.
5. Click ‘Apply’ and ‘OK’.
6. Ensure that the projection is set correctly by viewing the bottom right hand corner of the workspace. It should read ‘EPSG:32760’.

Load in the project GIS layers:

1. Click on the ‘Load TUFLOW Layers from TCF’ symbol from the TUFLOW Plugin toolbar.
   
   
   
2. In File Explorer, navigate to the TUFLOW_SWMM_Module_02\TUFLOW\runs folder and select TS01_5m_001.tcf.
3. Click ‘Open’ and ‘OK’.

Style the TUFLOW layers. Suggested styling steps were provided in TUFLOW SWMM Tutorial Module 1. They have not been duplicated here. Refer to the QGIS Project Initialization section in the preceeding Module if you require help.

SWMM Inputs

Create SWMM GeoPackage Spatial Database

In QGIS, create a SWMM GeoPackage database for the new pipe network features we'll be adding to the model:

1. Go to Processing > Toolbox from the top drop menu options to open the Processing Toolbox panel.
2. Go to TUFLOW > SWMM in the processing tool list and select 'GeoPackage - Create'. This opens the dialog shown below.

   • To set the ‘CRS for GeoPackage’: Click the drop down menu and select ‘Project CRS: EPSG:32760 - WGS 84 / UTM zone 60S’.
   • To set the ‘Initial SWMM Sections’: Click the …, and tick on:
     • Project--Title, Project--Report.
     • Nodes--Junctions, Nodes--Outfalls.
     • Links--Conduits, Links--Streets, Links--Inlets.

   In Module 1 we also included Project--Options in the GeoPackage file. Project--Options is not required this time. The reason being, this Tutorial model will use two SWMM INP files. The file created during Module 1 (for the road culverts), and the INP to be created from this GeoPackage (for the underground pipe network inputs). When TUFLOW processes SWMM inputs, it combines the multiple INP files into one before simulation. As such, the details from the Module 1 Project--Options input will be used in this tutorial. If Project--Options are inculded in multiple Geopackage/INP files, the entry that is referenced lowest in the TUFLOW SWMM Control (TSCF) will be used.

   • To define the ‘GPKG filename to create’: Click the …, select ‘Save to File’. Navigate to the TUFLOW\model\swmm folder and save the GeoPackage Database as sw02_001.gpkg.

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GIS Data Entry

A GeoPackage called Urban_Development.gpkg is provided in the TUFLOW_SWMM_Module_02\Tutorial_Data folder. It contains three SWMM input layers:

• Pipes: defines the underground pipe network location, type and geometry.
• Junctions: defines the pipe network inlets.
• Outfalls: defines the pipe network outlet.

To populate the GeoPackage created in the previous section:

1. In Windows Explorer, navigate to the TUFLOW_SWMM_Module_02\Tutorial_Data folder. Drag and drop the Urban_Development.gpkg into QGIS. By default, all items in the GeoPackage will be selected. Click 'Add Layers'.
2. In the QGIS Layers Panel, right click on the Pipes layer and select 'Zoom to Layer'.
3. Use the 'Select Features' tool to highlight all items included in Pipes.
4. Select 'Edit' from the top QGIS tab and 'Copy Features' from the drop down manu.
5. Select the Links--Conduits layer in the Layers Panel by left clicking on it once.
6. Make the Links--Conduits layer editable by clicking the 'Toggle Editing' symbol .
7. Select 'Edit' from the top QGIS tab and click 'Paste Features' from the drop down menu.
8. Toggle the editing off to save the edits.
   
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9. Copy the objects from Junctions into Nodes--Junctions. Junctions are considered inlets, and should be defined at the upstream end of culverts.
10. Copy the objects from Outfalls into Nodes--Outfalls. Outfalls are treated as outlets, and are required at the downstream end of culverts.
11. Close Urban_Development.gpkg
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12. Inspect the attribute information within the respective layers to familiarize yourself with the data.
    
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GIS Data Updates

The provided GIS data requires numerous updates, prior to our model simulation. We have built these updates into this tutorial to demonstrate some of the available TUFLOW SWMM model built processing tools.

The following updates are being made to Objects and Layers within sw02_001.gpkg

Update SWMM Inlet Usage Layer Details

An Inlet Usage Layer defines the physical location of inlets to the pipe network. It also defines some of the site specific geometry, such as Inlet, Elevation, Slope, Placement type (on-grade or on-sag). To reduce data entry requirements for this tutorial, a complete Inlet Usage Layer has been provided, swmm_iu_TS02_001.

1. Save a copy of swmm_iu_TS02_001 from TUFLOW_SWMM_Module_02\Tutorial_Data to TUFLOW_SWMM_Module_02\TUFLOW\Model\swmm
   

When you progress from this tutorial to project modelling, you will need to create an Inlet Usage Layer yourself. The template file for this is available from model/gis/empty/swmm_iu_empty.gpkg. The file is created during the initial Write Empty step of the model build process (refer to TUFLOW Tutorial Model 1)

The "Inlet" Attribute within the Inlet Usage Layer is an ID reference to inlet geometry and associated information listed within TS02_001.gpkg Links--Inlets. A single inlet type was referenced in the provided Inlet Usage Layer inputs, "Combo1". In recognition of this we need to create the entry for "Combo1" in the Inlet Layer.

1. In the QGIS Layers Panel, select (left click) Inlet and toggle on editing.
2. Right click Inlet and Select Open Attribute Table.
3. Click Add Feature before entering the following attributes:
   • Name: Combo1
   • Type: COMBINATION
   • Grate_Length: 1.5
   • Grate_Width: 0.5
   • Grate_Type: P_BAR-50
   • Curb_Length: 1.5
   • Curb_Height: 0.2
   • Curb_Throat: VERTICAL
4. Toggle off editing and save the update.

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Update Streets Details

Street cross-section information is needed for SWMM on-grade inlet flow calculations. We referenced a single street cross-section type in the SWMM Inlet Usages file (via the StreetXSEC attribute). We will now define the cross-section details for "Xsec1".

1. In the QGIS Layers Panel, select (left click) Streets and toggle on editing.
2. Right click Streets and Select Open Attribute Table.
3. Click Add Feature before enteringthe following attributes:
   • Name: Xsec1
   • Tcrown: 10
   • Hcurb: 0.2
   • Sx: 4
   • nRoad: 0.014
   • a: 0
   • W: 0
   • Sides: 1
   • Tback: 5
   • Sback: 4
   • nBack: 0.016
4. Toggle off editing and save the update.

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Update Conduit Details

Step 1 involves updating the From Node and To Node attribute information in Links--Conduits. This information is necessary to "build" the 1D SWMM network. It defines the Link/Node connections. The information we will be adding to Links--Conduits is extracted from Nodes--Junctions and Nodes--Outfalls automatically using the Conduits - Assign Node Fields tool from the Processing Toolbox.

1. In the QGIS Layers Panel, select (left click) Links--Conduits and toggle on editing.
2. In the Processing Toolbox, select the 'Edit Features In-Place' tool . This allows the editing of an existing layer, instead of the creation of a new layer.
3. Go to TUFLOW > SWMM in the processing tool list and select 'Conduits - Assign Node Fields'. This opens the dialog shown below.
4. Tick on the SWMM Node Layers: Nodes--Junctions and Nodes--Outfalls.
5. Select 'Modify All Features'.
6. Once the tool has finished, click 'Close'.
7. View the attributes associated within Links--Conduits to verify the data processing has been completed correctly. The From Node and To Node attribute information is now configured correctly.
   
8. Toggle off editing and save the update.

Tip: If you wish to only update select objects during a future modelling project, instead of the entire Link--Conduits dataset, select the target objects first using the Feature by Area tool. The Conduits - Assign Node Fields tool will provide an option to Modify Selected Features, instead of Modify All Features.
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Update Losses

Step 2, update the loss attributes in the Links--Conduits Layer. These values will be entered automatically using the Conduits - Assign losses tool from the Processing Toolbox.

1. In the QGIS Layers Panel, select (left click) Links--Conduits and toggle on editing.
2. In the Processing Toolbox, select the 'Edit Features In-Place' tool . This allows the editing of an existing layer, instead of the creation of a new layer.
3. Go to TUFLOW > SWMM in the processing tool list and select 'Conduits - Assign losses'. This opens the dialog shown below.
   • Select the inlet usage layer: swmm_iu_TS02_001.
   • Entrance loss furthest upstream = 0.5
   • Entrance loss for channels not furthest upstream = 0.2
   • Exit loss furthest downstream = 1.0
   • Exit loss for channels not furthest downstream = 0.4
4. Select 'Modify All Features'.
5. After the tool processing has finished, click 'Close'.
6. Toggle off editing and save the update.

1D/2D Linking

The 1D SWMM / 2D TUFLOW linkage locations to connect the pipe network inlets to the surface have already automatically been defined in the SWMM Inlet Usage Layer, swmm_iu_TS02_001, using the "Conn1D_2D" attribute.

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To compete the pipe network 1D/2D linkage is needed at the outlet of the pipe network.

1. In the QGIS Layers Panel, select (left click) Links--Conduits and toggle on editing.
2. Select the most downstream object in Links--Conduits.
3. In the Processing Toolbox, go to TUFLOW > SWMM and select 'BC - Create channel endpoint 1D/2D connections'. This opens the dialog shown below.

   • Input Conduits Layer: Links--Conduits
   • Tick: Select features only
   • Offset Distance: 2
   • Length of BC lines: 10
   • Tick: Set 2D cell elevation to 1D culevrt invert at 1D/2D connection cells if needed.
   • Output Layer:

   Click the ... and select 'Save to GeoPackage'.

   Navigate to the TUFLOW\model\swmm folder and select sw02_001.gpkg. Click Save.

   A dialog will open. In the Layer Name box, write 2d_bc_SWMM_Pipe_Network_Connections_001_L.

   Click 'OK'.

4. Click 'Run'.
5. Once the tool is finished, click 'Close'.
6. 2d_bc_SWMM_Pipe_Network_Connections_001_L should appear in the Layers Panel.

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Update SWMM Junction Details

1. In the QGIS Layers Panel, select (left click) Nodes--Junctions and toggle on editing.
2. In the Processing Toolbox, select the 'Edit Features In-Place' tool. This allows the editing of an existing layer, instead of the creation of a new layer.
3. Go to TUFLOW > SWMM in the processing tool list and select Junctions - Set attributes processing tool. This opens the dialog shown below.

   • Input Inlet Usage Layers: SWMM_Inlet_Usage
   • Input BC Connection Layer: 2d_bc_SWMM_Pipe_Network_Connections_001_L
   • Nodes connected to 2D with Inlets (Ysur): 0
   • Nodes connected to 2D with Inlets (Area of ponding): 5
   • Nodes connected to 2D without Inlets (Ysur): 0
   • Nodes connected to 2D without Inlets (Apond): 50
   • Nodes without 2D Connection (Surcharge Depth): 50
   • Nodes without 2D Connection (Area of ponding): 0

4. Select 'Modify All Features'.
5. Once the tool has finished, click 'Close'.
6. View the attributes associated within Nodes--Junctions to verify the data processing has been completed correctly.
7. Toggle off editing and save the update.
   
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SWMM Options

The model we are building will use two SWMM INP files.

• TS01_001.inp was already created in TUFLOW SWMM Tutorial Module 1. It contained details defining the three embankment culverts under the roads crossing the dominant flow paths. It also contained the associated 1D SWMM / 2D TUFLOW connection Layer objects. TS01_001.inp has been included in the base model we are using for Module 2. No changes will be made to it. TS01_001.inp includes the Option commands necessary to execute a SWMM simulation.
• We will create a new INP file for the SWMM pipe network inputs (covered in the next Section). Because SWMM Options are already inculded in TS01_001.inp, they are not needed in this second (new) INP file. As such, no new SWMM Option commands are necessary for this tutorial.

Note: if more than one INP file includes SWMM Option commands, the details included in the INP file referenced lower in SWMM Control File (TSCF) will take precedence.

Export SWMM INP File

We will now create a new INP file for the SWMM pipe network inputs. To do this, we need to convert TS02_001.gpkg into a SWMM INP file.

1. In the QGIS Layer Panel, select TS02_001.gpkg and right click Links--Conduits. Select TUFLOW > 'SWMM - Export inp file'. This opens the dialog shown below.
2. Select TS02_001.gpkg as the GeoPackage Input File.
3. Set the SWMM output filename to TS02_001.inp in the TUFLOW_SWMM_Module_02/TUFLOW/model/swmm folder.
4. Select "Run", then "Close" after the processing is complete.

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TUFLOW Boundary Updates

We will be using TUFLOW's 2D direct rainfall (also known as rain on grid) functionality for the catchment inflow boundary condition approach to demonstrate flows into the pipe network inlets. There are a wide range of direct rainfall options built into TUFLOW, including:

• Globally uniform rainfall. This method applies temporally varied rainfall uniformly (spatially) over the entire model.
• Spatially varying rainfall. This method applies temporally varied rainfall with spatial variation defined using polygon delineation, grid raster files or inbuilt TUFLOW TIN triangulation routines.
  

The focus of this tutorial is not demonstration of the available direct rainfall options. As such, we will be using the simplest approach, globally uniform rainfall. It does not require any GIS updates to implement he boundary condition change. Updates will be limited to boundary condition database and Control File syntax. Both are addressed in the next section. If you are interested in learning about the available direct rainfall options, please refer to TUFLOW Tutorial Module 6.

It is common to use depth varying manning's roughness when using direct rainfall. A Materials File using depth varying inputs has been provided. Save materials_TS02_002.csv from TUFLOW_SWMM_Module_02\Tutorial_Data to TUFLOW_SWMM_Module_02\TUFLOW\model.

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TUFLOW Geometry Update

We will update TUFLOW's 2D elevation and landuse to represent changes associated with the urban development.

1. Within the QGIS Browser Panel, navigate to the TUFLOW_SWMM_Module_02\Tutorial_Data\Urban_Development.gpkg folder. Drag and drop the following layers into TS02_001.gpkg for us to use in our model:
   • 2d_ztin_TS02_Development_001_R
   • 2d_ztin_TS02_Development_001_L
   • 2d_ztin_TS02_Development_001_P
   • 2d_mat_TS02_Development_001_R
   • 2d_mat_TS02_Buildings_001_R

The focus of this tutorial is not demonstration of 2D geometry updates. If you are interested in learning about the above 2d_ztin and 2d_mat changes, please refer to TUFLOW Tutorial Module 2.

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Simulation Control Files

To avoid the potential risk of overwriting existing control files accidentally, we will start by saving new control files where we will be making subsequent syntax updates during the following steps.

1. Open TS01_5m_001.tcf from the TUFLOW_SWMM_Module_02\TUFLOW\runs folder in a Text Editor (Notepad++ is recommended).
2. Save a copy of TS01_5m_001.tcf as TS02_5m_001.tcf.
3. Open the following files using the Open File function in Notepad++:
   • Open TS01_001.tbc, and save the file as TS02_001.tbc.
   • Open M02_001.tgc, and save the file as TS02_001.tgc.
   • Open TS01_001.tscf, and save the file as TS02_001.tscf.
4. After creating the new control files, update the following references in TS02_5m_001.tcf:
   Spatial Database == ..\model\gis\TS02_001.gpkg ! Specify the location of the GeoPackage Spatial Database
   Geometry Control File == ..\model\TS02_001.tgc ! Reference the TUFLOW Geometry Control File
   BC Control File == ..\model\TS02_001.tbc ! Reference the TUFLOW Boundary Conditions Control File
   SWMM Control File == ..\model\TS02_001.tscf ! Reference the SWMM (1D) Control File
   
5. Save TS02_5m_001.tcf.

TUFLOW Boundary Control File (TBC)

1. Open TS02_001.tbc. If using Notepad++, right click the file reference in TS02_5m_001.tcf and select Open File.
2. Comment out the 'Read GIS SA' command by placing '!' before the command:
   ! Read GIS SA == 2d_sa_M01_001_R
   
3. Add the following new command lines:
   Global Rainfall BC == RF_FC04 ! Reads in global rainfall
   Read GIS BC == swmm\sw02_001.gpkg >> 2d_bc_SWMM_Pipe_Network_Connections_001_L ! Links the 1D Pipe Network Outlets to the 2D domain
4. Save the TBC.

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TUFLOW Geometry Control File (TGC)

1. Open TS02_001.tgc.
2. Add the following additional command lines to TS02_001.tgc:
   Create TIN Zpts == 2d_ztin_Development_001_R | 2d_ztin_Development_001_L | 2d_ztin_Development_001_P ! Links the 1D Pipe Network Outlets to the 2D domain
   Read GIS Mat == 2d_mat_Development_001_R
3. Save the TGC.

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TUFLOW SWMM Control File (TSCF)

1. Open TS02_001.tscf.
2. Add the following command lines after Read SWMM == swmm\TS01_001.inp
   Read SWMM == swmm\TS02_001.inp ! 1D SWMM Pipe Network Input File
   Read GIS SWMM Inlet Usage == swmm\swmm_iu_TS02_001 >> swmm_iu_TS02_001 ! 1D SWMM Pipe Network Inlet Usage Layer
   
3. Save the TSCF.
   

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Running the Simulation

1. Save a copy of _run_M02_HPC.bat as _run_TS02_HPC.bat in the TUFLOW_SWMM_Module_02\TUFLOW\runs folder.
2. Update the batch file to reference the TS02_5m_001.tcf :
   set exe="..\..\..\exe\2023-03-AD\TUFLOW_iSP_w64.exe"
   set run=start "TUFLOW" /wait %exe% -b
   %run% TS02_5m_001.tcf
3. Double click the batch file in Windows file explorer to run the simulation.

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If your model simulation did not run. Here is a link to some comon Tutorial Trouble Shooting advice.

Check Files and Results Output

Complete the steps outlines in the following link to review check files and simulation results from the TUFLOW SWMM model simulation:

TUFLOW SWMM Tutorial 02 Check Files
TUFLOW SWMM Tutorial 02 Results

Conclusion

• EPA SWMM Culverts were added to convey water through the structures under the three roads in the tutorial model.
• Check files were used to review the application of the boundary links.
• Results through the 1D network structures were assessed.

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