TUFLOW SWMM Tutorial M01

Introduction

In this module, three culverts are added to represent flow through three separate road embankments. EPA SWMM is used as the solution scheme for the 1D culvert flow calculations, dynamically linked with the TUFLOW HPC 2D solution scheme.

TUFLOW SWMM Tutorial Module 1 builds from the model created in TUFLOW Tutorial Module 2 (in the TUFLOW Only tutorial dataset). The completed Module 2 model is provided in the TUFLOW_SWMM_Module_01\TUFLOW folder of the download dataset as the starting point for this tutorial. If you are not already familiar with TUFLOW, we recommend first completing Module 1 and 2 of the "TUFLOW Only" Tutorials to establish an understanding of 2D modeling, before progressing to learning how to link 1D EPA SWMM to 2D TUFLOW.

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.
Firstly, 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_01\TUFLOW\runs folder and select M02_5m_001.tcf.
3. In the Load Layers Pop-up, select:
   • Ordering Options: Alphabetical
   • Grouping Options: Group by Control file
   • Raster Load Options: Load Normally
4. Click ‘Open’ and ‘OK’.

Style the TUFLOW layers however you desire. Common steps to do this are:

1. Click on the ‘Apply TUFLOW Styles to Open Layers’ symbol from the TUFLOW Plugin toolbar.
   
   
   
2. Change the symbology of the DEM:
   • Right click on the DEM file in the Layers panel and select 'Properties'.
   • From the Symbology tab, under 'Band Rendering' select the following options:

   • Render type: Singleband pseudocolor
   • Color ramp: Spectral
   • Color ramp: Invert Color Ramp
   • Mode: Equal Interval

   • From the Transparency tab, set the Global Opacity to 75%.
   • Click 'Apply' and 'OK'.
   
   
   
   
3. Create a hillshade of the DEM:
   • Right click on the DEM file in the Layers panel and select 'Duplicate Layer'.
   • Right click on the DEM_copy and select 'Rename Layer'. Rename the layer to DEM_Hillshade.
   • Right click on the DEM_Hillshade file and select 'Properties'.
   • From the Symbology tab, under 'Band Rendering' select the following options:

   • Render type: Hillshade
   • Z Factor: 3

   • Click 'Apply' and 'OK'.
   
   
   
   

Save the QGIS Workspace:

1. Go to Project > Save As.
2. Navigate to the TUFLOW_SWMM_Module_01 folder and type SWMM_M01 as the filename with the extension .qgz.

SWMM Inputs and 1D/2D Linking

Create SWMM GeoPackage Spatial Database

Create a new folder in the TUFLOW_SWMM_Module_01\TUFLOW\model folder called swmm. This is the location where all SWMM inputs will be saved.

In QGIS, create the SWMM GeoPackage Database:

1. Go to Processing > Toolbox from the top dropdown 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 …, and tick on:
     • Project--Title, Project--Options, Project --Report.
     • Nodes--Junctions, Nodes--Outfalls.
     • Links--Conduits, Links--Streets.
   • To define the ‘GPKG filename to create’: Click …, select ‘Save to File’. Navigate to the TUFLOW\model\swmm folder and save the GeoPackage database as sw01_001.gpkg.

3. Click ‘Run’.
4. Once the tool has finished, click ‘Close’.
5. In File Explorer, navigate to the TUFLOW\model\swmm folder and drag and drop sw01_001.gpkg into QGIS.
6. When prompted by QGIS, under 'Options', tick on 'Add layers to group', then select 'Add Layers' to open all vectors within sw01_001.gpkg. By default, all items in the available list should have been selected.
7. In the QGIS Layers panel, move sw01_001.gpkg to the top of the list. This will ensure the data within this database file is displayed above all other layers in the project.

GIS Data Entry

A GeoPackage database called SWMM_Culverts.gpkg is provided in the TUFLOW_SWMM_Module_01\Tutorial_Data folder. It contains three layers:

• Conduits: defines the culvert location, type and geometry.
• Junctions: defines the upstream culvert inverts.
• Outfalls: defines the downstream culvert inverts.

To populate the GeoPackage database created in the previous section:

1. In Windows Explorer, navigate to the TUFLOW_SWMM_Module_01\Tutorial_Data folder. Drag and drop the SWMM_Culverts.gpkg into QGIS.
2. When prompted by QGIS, under 'Options', tick on 'Add layers to group'. By default, all items in the GeoPackage database will be selected. Click 'Add Layers'.
3. In the QGIS Layers panel, right click on the SWMM_Culverts >> Conduits layer and select 'Zoom to Layer'.
4. Use the 'Select Features' tool to highlight all items included in Conduits.
5. Select 'Edit' from the top QGIS tab and 'Copy Features' from the drop down menu.
6. Select the sw01_001.gpkg >> Links--Conduits layer in the Layers panel by left clicking on it once.
7. Make the Links--Conduits layer editable by clicking the 'Toggle Editing' symbol .
8. Select 'Edit' from the top QGIS tab and click 'Paste Features' from the drop down menu.
9. Toggle the editing off to save the edits.
   
   

   
   

10. Similarly, copy the objects from Junctions into Nodes--Junctions. Junctions are considered inlets, and should be defined at the upstream end of culverts.
11. Also copy the objects from Outfalls into Nodes--Outfalls. Outfalls are treated as outlets, and are required at the downstream end of culverts.
12. Toggle off editing and save the edits.
13. Remove SWMM_Culverts.gpkg.
    
    

    
    

14. Inspect the attribute information within the respective layers to familiarize yourself with the data.
    
    

GIS Data Updates

The provided GIS data requires numerous updates before proceeding to a model simulation. We have intentionally built these updates into this tutorial to demonstrate some of the available TUFLOW SWMM model build processing tools. The following updates are being made to Objects and Layers within sw01_001.gpkg.

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'.
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. Turn off editing to save the edits.
8. 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.
   Tip1: If you wish to only update a selection of objects, instead of selecting 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.'
   Tip2: Unique Node ID's are required for the SWMM network to function error free. If you are following this workflow for a project model build, please ensure the Nodes--Junctions and Nodes--Outfalls object ID information is unique. If duplicate ID values are assigned to multiple objects, consider using the 'Integrity - Make object names unique' TUFLOW SWMM processing tool to ensure all ID values are unique before using 'Conduits - Assign node fields'.
   
   

   
   

Update Losses

Step 2, update the loss attributes in the Links--Conduits layer. These values will be entered manually in this example using default values. Variation to the default values can be used in project models to reflect site specific information if desired.

1. In the QGIS Layers panel, select (left click) Links--Conduits and toggle on editing.
2. Right click Links--Conduits and select 'Open Attribute Table'.
3. Update the following fields:

   • losses_Kentry: 0.5
   • losses_Kexit: 1.0
   • losses_Kavg: 0.0

   The video below demonstrates how to do this one entry at a time, or via the bulk attribute update options in QGIS.
4. Turn off editing to save the edits.
   
   

An urban pipe network is added to the model in TUFLOW SWMM Module 2. In that situation, different loss attributes are required for the road culverts and underground stormwater pipe network links. To simplify the loss attribute update step in that situation, we will be using the 'Conduits - Assign node fields' processing tool. However, it is not necessary for this Module 1 tutorial, because all the 1D SWMM inputs are embankment culverts all using the same loss parameters.

Create 1D/2D Connections

The following instructions introduce a new tool that automates the creation of 1D/2D connections. Due to the limitations of SWMM boundary conditions, HX lines are required for the upstream end of the culvert (rather than SX), and SX connections are used at the downstream end of the culvert.

1. In the QGIS Layers panel, select (left click) Links--Conduits.
2. 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
   • Offset Distance: 2
   • Length of BC lines: 10
   • Tick on 'Set 2D cell elevation to 1D culvert 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 sw01_001.gpkg. Click Save.

   A dialog will open. In the Layer name field, write 2d_bc_SWMM_Culvert_Connections_001_L.

   Click 'OK'.

3. Click 'Run'.
4. Once the tool is finished, click 'Close'.
5. The 2d_bc_SWMM_Culvert_Connections_001_L appears in the Layers panel. Select 'Apply TUFLOW Styles to Current Layer'.
   
   

Note: The positions of the HX and SX connections may not be completely accurate, so it is recommended to check the output. In this module, 2d_bc_SWMM_Culvert_Connections_001_L is checked in TUFLOW SWMM Tutorial 01 Check Files.

Update 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 BC Connection Layers: 2d_bc_SWMM_Culvert_Connections_001_L
   • Nodes connected to 2D without Inlets (Ysur): 0
   • Nodes connected to 2D without Inlets (Apond): 50

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

   
   

SWMM Options

1. In the QGIS Layers panel, select (left click) Project--Options and toggle on editing.
2. Right click Project--Options and select 'Open Attribute Table'.
3. Update the following options:
   • START_DATE: 2020-01-01 (Date Format: YYYY-MM-DD)
   • REPORT_STEP: 00:05:00
4. Turn off editing to save the edits.

Export SWMM INP File

SWMM is not able to read the sw01_001.gpkg database directly, therefore, we need to convert the GeoPackage file to a SWMM INP file format.

1. In the Processing Toolbox, go to TUFLOW > SWMM and select 'GeoPackage - Write to SWMM inp'.

   • GeoPackage Input File: Navigate to the TUFLOW\model\swmm folder and select sw01_001.gpkg.
     

2. By default, this tool will save the SWMM inp file in the same folder location and with the same name as the GeoPackage input file. In this case, it will save sw01_001.inp to the TUFLOW\model\swmm folder.
3. Click 'Run'.
4. Once the tool is finished, click 'Close'.
   
   

Simulation Control Files

The following steps will require use of a text editor. The tutorial demonstration uses Notepad++. For its configuration information refer to Notepad++ Tips.

To differentiate the TUFLOW SWMM tutorials from the TUFLOW/ESTRY tutorials, TS will be used as the new file prefix in this series of tutorials. 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.

Set up the simulation control files:

1. Open M02_5m_001.tcf in a Text Editor (Notepad++ is recommended). Save the file as TS01_5m_001.tcf in the TUFLOW_SWMM_Module_01\TUFLOW\runs folder.
2. Open M01_001.tbc using the "Open File" function in Notepad++. Save the file as TS01_001.tbc in the TUFLOW_SWMM_Module_01\TUFLOW\model folder.
3. Create a new blank text file called TS01_001.tscf and save it in the TUFLOW_SWMM_Module_01\TUFLOW\model folder.
   
   
   
   

TUFLOW Control File (TCF)

1. Open the TS01_5m_001.tcf
2. Make the following reference update:
   BC Control File == ..\model\TS01_001.tbc ! Reference the TUFLOW Boundary Conditions Control File
3. Add the following line in the 'Model Inputs' section:
   SWMM Control File == ..\model\TS01_001.tscf ! Reference the SWMM (1D) Control File
4. Add the following line in the 'Output Settings' section:
   NetCDF Output Start Date == 2020-01-01 00:00 ! Sets the output units for the NetCDF time variable
5. Save the TCF.
   
   
   
   

TUFLOW Boundary Control File (TBC)

1. From TS01_001.tcf, right click TS01_001.tbc and select 'Open File'. This opens TS01_001.tbc into a new tab in Notepad ++.
2. Add the following command line after 'Read GIS SA == 2d_sa_M01_001_R':
   Read GIS BC == swmm\sw01_001.gpkg >> 2d_bc_SWMM_Culvert_Connections_001_L ! Links 1D SWMM culverts to the 2D TUFLOW domain
3. Save the TBC.
   
   
   
   

TUFLOW SWMM Control File (TSCF)

A new control file, the TUFLOW SWMM Control File (TSCF), is introduced. SWMM is a 1D hydraulic solver. All 1D SWMM files and commands are referenced in the TUFLOW SWMM Control File.

1. From TS01_001.tcf, right click TS01_001.tscf and select 'Open File'. This opens TS01_001.tscf into a new tab in Notepad ++.
2. Add the following command:
   Read SWMM == swmm\sw01_001.inp ! 1D SWMM culvert input file
   
3. Save the TSCF.
   
   
   
   

Running the Simulation

1. Save a copy of _run_M02_HPC.bat as _run_TS01_HPC.bat in the TUFLOW_SWMM_Module_01\TUFLOW\runs folder.
2. Update the batch file to reference the TS01_5m_001.tcf :
   set exe="..\..\..\exe\2023-03-AD\TUFLOW_iSP_w64.exe"
   set run=start "TUFLOW" /wait %exe% -b
   %run% TS01_5m_001.tcf
3. Double click the batch file in File Explorer to run the simulation.
   If the model simulation doesn't run, here is a link to some common Trouble Shooting advice.
   
   
   
   

Check Files and Results Output

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

TUFLOW SWMM Tutorial 01 Check Files
TUFLOW SWMM Tutorial 01 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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