TUFLOW SWMM Tutorial M03

Introduction

This tutorial, Module 3 of the TUFLOW SWMM tutorial dataset, demonstrates how to add SWMM urban hydrology to a 1D / 2D SWMM stormwater pipe network / 2D TUFLOW HPC catchment model. TUFLOW SWMM Tutorial Module 3 builds from the model created in TUFLOW SWMM Tutorial Module 2. The completed TUFLOW SWMM Module 2 model is provided in the TUFLOW_SWMM_Module_03\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 and 2 before this tutorial.

Project Initialization

QGIS

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’.

TUFLOW Plugin

Next we need to configure the QGIS TUFLOW Plugin settings to link with the project folder where we will build our model:

1. Go to Plugins > TUFLOW > Editing > Configure / Create TUFLOW Project.
2. Change the folder which contains TUFLOW to the TUFLOW_SWMM_Module_03 folder.
3. Set the GIS Format to GPKG.
4. Click 'OK' and save the workspace by selecting Project > Save As.
   
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TUFLOW Model

Load and Style TUFLOW Model Files

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_03\TUFLOW\runs folder and select TS02_5m_001.tcf.
3. In the Load Layers window, select:
   • Ordering Options: Alphabetical
   • Grouping Options: Group by control file
   • Raster Load Options: Load Normally
4. Click ‘Open’ and ‘OK’.

Style the TUFLOW layers. Suggested styling steps were provided in TUFLOW SWMM Tutorial M01. They have not been duplicated here.

Increment TUFLOW GeoPackage File

Save a copy of TS02_001.gpkg with a new name (TS03_001.gpkg). This project initialization step is recommended so prior model versions from a project are not broken as a result of changes being made to GIS inputs.

1. In the QGIS Layers Panel, select (left click) 2d_bc_M01_001_L.
2. Click on the Increment Selected Layer symbol from the TUFLOW Plugin toolbar. This opens the dialog shown below.
   
   
   

   • Source Layer: Automatically set to the selected layer, 2d_bc_M01_001_L.
   • Output Database: Click 'Browse...'. This will automatically open to the TUFLOW\model\gis folder. Set the new output database name to TS02_001.gpkg and click 'Save'.
   • Output Layer Name: This was automatically incremented to, 2d_bc_M01_002_L. Change the value to 2d_bc_M01_001_L.
   • Delete the pre-filled 'Incremented Layer' entry in the table. We do not wish to modify the version number associated with the 2d_bc file. This current exercise will not change the version number of any of the GIS layer inputs, it is simply establishing a copy of the existing GeoPackage where future edits will be saved to.
   • Select 'Remove Source Layer from Workspace'.
   • Select 'Increment Layer and Preserve Database'.

3. Click 'OK'.
   

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Increment SWMM GeoPackage File

SWMM pipe network junction attributes need to be updated when converting a TUFLOW 2D direct rainfall / SWMM 1D model (Module 2) into a format that uses SWMM hydrology instead of direct rainfall. Similar to the versioning of the TUFLOW Geopackage File, we will increment the SWMM pipe network database name so we do not alter the inputs necessary for TS03_5m_001.tcf to function without issue.

1. Left click sw02_001 in the QGIS Layers panel.
2. Waiting for Rusty's SWMM Increment Selected Layer tool.
3. Set the new Database name to sw03_001.gpkg
4. Select OK.

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Save QGIS Project Workspace

Save the QGIS Workspace:

1. Go to Project > Save As.
2. Navigate to the TUFLOW_SWMM_Module_03 folder and type SWMM_M03 as the filename with the extension .qgz.

SWMM Inputs

Update SWMM GeoPackage Spatial Database

In previous tutorials we have created new SWMM GeoPackage databases for our new entries. This tutorial will demonstrate a different update approach. Instead of creating a new SWMM GeoPackage database, we will update an existing database (sw03_001) by adding new SWMM Sections for the hydrology elements we will be incorporating into the model in this tutorial.

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 - Add Sections'.
3. Select the following:

   GPKG filename modify: TUFLOW_SWMM_Module_03\TUFLOW\model\swmm\sw03_001.gpkg

   CRS for GeoPackage: Project CRS: EPSG:32760 - WGS 84 / UTM zone 60S.

   SWMM Sections to add: Hydrology--Raingages, Hydrology--Subcatchments

4. Click 'Run'.

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The above steps have added the new Sections to the SWMM GeoPackage database. The new additonal sections however are not currently displayed in the QGIS layers panel. We need to close the database and reopen it to view the change.

1. Right click sw03_001 in the QGIS layer panel and select Remove Group....
2. In File Explorer, navigate to the TUFLOW\model\swmm folder and drag and drop sw03_001.gpkg into QGIS.
3. When prompted by QGIS, under 'Options', tick on 'Add layers to group', then select 'Add Layers' to open all vectors within sw03_001.gpkg. By default, all items in the available list should have been selected.
4. In the QGIS Layers panel, move sw03_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 when we are making edits.

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SWMM GIS Data Entry

A GeoPackage called Urban_Hydrology.gpkg is provided in the TUFLOW_SWMM_Module_03\Tutorial_Data folder. It contains one SWMM input layer:

• SWMM_Subcatchments: defining the 1D SWMM urban hydrology subcatchment delineation and associated parameters.

It also contains a TUFLOW input layer

• TUFLOW_Subcatchments: defining the remaining 2D TUFLOW catchment hydrology subcatchment delineation.
  

SWMM

To populate the SWMM GeoPackage created in the previous section:

1. In Windows Explorer, navigate to the TUFLOW_SWMM_Module_03\Tutorial_Data folder. Drag and drop the Urban_Hydrology.gpkg into QGIS.
2. When prompted by QGIS select SWMM_Subcatchments. Click 'Add Layers'.
3. In the QGIS Layers panel, right click on the SWMM_Subcatchments layer and select 'Zoom to Layer'.
4. Use the 'Select Features' tool to highlight all items included in SWMM_Subcatchments.
5. Select 'Edit' from the top QGIS tab and 'Copy Features' from the drop down menu.
6. Select the sw03_001 > Hydrology--Subcatchments layer in the Layers panel by left clicking on it once.
7. Make the sw03_001 > Hydrology--Subcatchments 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. Remove Urban_Hydrology.gpkg from QGIS.
    
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SWMM GIS Data Updates

The following updates shall be made to sw03_001.gpkg.

Update SWMM Hydrology--Raingage

The information within Hydrology--Raingage (Note: 'Gage' is the American spelling of 'Gauge' in Oxford English) defines the pluviographs in the catchment. We will link to two different rain gages in this example.

1. In the QGIS Layers panel, select (left click) Hydrology--Raingage and toggle on editing.
2. Right click Hydrology--Raingage and select 'Open Attribute Table'.
3. Click 'Add Feature'. Enter the following attributes (leave all other fields as NULL):

   Name	Form	Intevl	SnowCatchDeficiency	Format	Tseries
   RF_G1	Volume	0.15	1	TIMESERIES	RF_FC04
   RF_G2	Volume	0.15	1	TIMESERIES	RF_FC07

   Remaining attributes remain blank.
   SWMM entries are case sensitive. If the input above uses upper case, please double check your data entry does too.

4. Turn off editing and save the information.

For a summary of the attributes associated with Hydrology--Raingage, refer to TUFLOW 2023-03-AD Release Notes (Table A.11) and the SWMM5 Reference Manual - Volume 1 (Hydrology).

Update SWMM Hydrology Subcatchments

The information within Hydrology--Subcatchments defines the subcatchment parameters (including catchment area, width, slope, percent impervious, outlet specification and infiltration details).

1. All required data entries have been pre-filled in the supplied dataset except the Area information. SWMM requires the hydrology subcatchment area information in hectares. In the QGIS Layers panel, select (left click) Hydrology--Subcatchments and toggle on editing.
2. Right click Hydrology--Subcatchments and select 'Open Attribute Table'.
3. Choose Area as the target field.
4. Type the calculation expression: $area / 10000.
5. Click, Update All.
6. Turn off editing and save the information.
7. Before moving on to the next step, inspect the attribute information within Hydrology--Subcatchments to familiarize yourself with the data. A summary of the attributes associated with the Layer, refer to TUFLOW 2023-03-AD Release Notes (Table A.38) and the SWMM5 Reference Manual - Volume 1 (Hydrology). A few demonstration features have been included in the dataset.
   • Two rainfall gages are linked to the subcatchments. Downstream subcatchments linked to rain gage RF_G1. Upstream subcatchments are linked to rain gage RF_G2.
   • Subcatchment SPit11A and SPit11A are being routed to subcatchment SPit11C before entering the SWMM pipe network. All other hydrology subcatchments route directly to a SWMM Node--Junctions.
   
   
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SWMM Project--Options

SWMM Project--Options define the SWMM simulation controls, such as hydrology computation timestep. Project--Options are not required in the new geopackage database we are creating for this Tutorial. This is because this model will be constructed from multiple SWMM input (INP) files:

• The SWMM INP file sw01_001(road culverts).
• The SWMM INP file sw03_001 (underground pipe network inputs and SWMM hydrology).

When TUFLOW processes SWMM inputs, it combines the multiple INP files into one single INP prior to simulation. For this model, the simulation control parameters defined in Module 1 (sw01_001) Project--Options will apply. Options relevant to this tutorial that have already been defined in the Module 1 input include:

• flow_units: set to metric.
• infiltration method: set to Green Ampt.
• wetstep hydrology timestep: set to 1 minute.
• dry step hydrology timestep: set to 1 minute.

Note: If we wanted to change the Project--Options as a result of this modules additional data, Project--Options should have been included as a item in the earlier SWMM Geopackage Update step, or SWMM Geopackage Create step if using the model development workflow demonstrated in the previous tutorials. If the SWMM INP file reference is specified lower in the TCSF control file, the information contained in the file supersedes any duplicate information defined by INP files higher in the TCSF control file .

Update SWMM Nodes--Junctions

When coupling SWMM hydrology with a 1D pipe network, updated Nodes--Junction attribute details are needed if converting from 2D direct rainfall (rain-on-grid) model design. Now the SWMM hydrology inputs are complete, we will make the necessary changes to Nodes--Junctions in sw03_001.gpkg.

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 Subcatchments: Hydrology--Subcatchments
   • Input Inlet Usage Layers: swmm_iu_TS02_001
   • Input BC Connection Layers: 2d_bc_SWMM_Pipe_Network_Connections_001_L
   • Maximum Depth Option: Set to 0.0
   • Nodes recieving subcatchment flows (if connected to 2D): Set Apond = 0.0; Ksur = 0.0 (overwrites options below)
   • Nodes connected to 2D with Inlets (Maximum depth) = Use global option
   • Nodes connected to 2D with Inlets (Ysur): 0
   • Nodes connected to 2D with Inlets (Area of ponding): 25
   • Nodes connected to 2D without Inlets (Ysur): 0
   • Nodes connected to 2D without Inlets (Area of ponding): 50
   • Nodes without 2D Connection (Surcharge Depth): 50
   • Nodes without 2D Connection (Area of ponding): 1

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. For a summary of the attributes associated with the Inlets--Inlets layer, refer to TUFLOW 2023-03-AD Release Notes (Table A.30) and the SWMM Reference Manual - Volume 2 (Hydraulics).

Export SWMM INP File

We will now export SWMM INP files with the pipe network and SWMM urban hydrology inputs.

1. In the Processing Toolbox, go to TUFLOW > SWMM and select 'GeoPackage - Write to SWMM inp'. This opens the dialog shown below.
2. Select the GeoPackage Input File: Navigate to the TUFLOW\model\swmm folder and select sw03_001.gpkg.
   Click 'Run'.
3. By default, this tool will save the SWMM inp files in the same folder location and with the same name as the GeoPackage input files. In this case, it saved the INP files to the TUFLOW\model\swmm folder.
4. Once the tool is finished, click 'Close'.
   
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TUFLOW GIS Updates

We will be reverting the TUFLOW model back to a configuration that uses inflows from an external hydrology model (as per Module 1), instead of 2D direct rainfall (Module 2), in the areas not covered by SWMM urban hydrology. We will need to use a new TUFLOW source area inflow layer, instead of reusing the input from Module 1 so we do not double counting the flow generated over the area now represented by SWMM.

1. Click on the ‘Import Empty File’ symbol from the TUFLOW plugin toolbar.
2. Select '2d_sa' from the Empty Type list.
3. In the Run ID box write 'TS03_001'.
4. Tick the 'Regions' Geometry Type.
5. Tick 'Convert to Geopackage'.
6. In the Spatial Database Options, select 'All to one'. Navigate to the TUFLOW_SWMM_Module_03\TUFLOW\model\gis folder and select TS03_001.gpkg. Click Save and hit 'OK'.
7. 2d_sa_TS03_001_L should now appear in the QGIS Layers panel.
8. In Windows Explorer, navigate to the TUFLOW_SWMM_Module_03\Tutorial_Data folder. Drag and drop the Urban_Hydrology.gpkg into QGIS, and when prompted by QGIS select TUFLOW_Subcatchments. Click 'Add Layers'.
9. Select the TUFLOW_Subcatchments layer in the Layers panel by left clicking on it once.
10. Use the 'Select Features' tool to highlight the four regions included in TUFLOW_Subcatchments.
11. Select 'Edit' from the top QGIS tab and 'Copy Features' from the drop down menu.
12. Select the 2d_sa_TS03_001_R layer in the Layers panel by left clicking on it once.
13. Select 'Edit' from the top QGIS tab and click 'Paste Features' from the drop down menu.
14. Toggle the editing off for 2d_sa_TS03_001_R to save the edits.
15. Remove Urban_Hydrology.gpkg from QGIS.
    

The polygon entry we have updated refers to a new subcatchment name for the region adjacent to the SWMM subcatchments. The new name is FC06.62, instead of FC06. When we update the TUFLOW Control files we will configure the file references so we are sourcing data from a new flow file obtained from an external hydrology model that has been updated with the reduced catchment area, in recognition of SWMM being used for the flow estimate in the proposed urban development area.

Note: Common hydrology software used in combination with TUFLOW by modelers include: HEC-HMS, RORB, Drains, WBNM, URBS and more.

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TUFLOW Boundary Updates

As a result of the changes beng made to the TUFLOW inflows, new TUFLOW boundary condition csv files are also needed. Updated files have been provided in the TUFLOW_SWMM_Module_03\Tutorial_Data' folder. Save bc_dbase_TS03_001.csv and TS03_01p2hr.csv to the TUFLOW_SWMM_Module_03\TUFLOW\bc_dbase folder. These files provide the values and model linkages to the new hydrology inflows, which include the FC06.62 entry.

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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 TS02_5m_001.tcf in a Text Editor (Notepad++ is recommended). Save the file as TS03_5m_001.tcf in the TUFLOW_SWMM_Module_03\TUFLOW\runs folder.
2. Using the 'Open File' function in Notepad++:

   • Open TS02_001.tbc, and save the file as TS03_001.tbc in the TUFLOW\model folder.
   • Open TS02_001.tscf, and save the file as TS03_001.tscf in the TUFLOW\model folder.

   
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TUFLOW Control File (TCF)

1. Open TS03_001.tcf.
2. Make the following reference updates:
   Spatial Database == ..\model\gis\TS03_001.gpkg ! Specify the location of the GeoPackage Spatial Database
   BC Control File == ..\model\TS03_001.tbc ! Reference the TUFLOW Boundary Condition Control File
   BC Database == ..\bc_dbase\bc_dbase_TS03_001.csv ! Reference the Boundary Condition Database
   SWMM Control File == ..\model\TS03_001.tscf ! Reference the SWMM (1D) Control File
   
   
3. Comment out the Map Cuttoff Depth command using a !. It is only necessary for 2D direct rainfall (rain on grid) modelling (SWMM Tutorial 2).
   !Map Cutoff Depth == 0.05
   
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TUFLOW Boundary Control File (TBC)

1. Open TS03_001.tbc.
2. Comment out the Global Rainfall BC command using a !. It is only necessary for 2D direct rainfall (rain on grid) modelling (SWMM Tutorial 2)
   !Global Rainfall BC == RF_FC04
   
3. Add the following commands:
   • Read GIS SA == 2d_sa_TS03_001_R  ! Reads in 2D source area - Excluding SWMM areas
   • Read BC Timeseries == RF_FC04 | RF_FC07 ! TUFLOW BC Database / SWMM Rain Gage Linkage
     
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TUFLOW SWMM Control File (TSCF)

1. Open TS03_001.tscf.
2. Replace Read SWMM == swmm\sw02_002.inp with the following command:
   Read SWMM == swmm\sw03_001.inp ! 1D SWMM Pipe Network and SWMM Hydrology Input File
   
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Running the Simulation

1. Save a copy of _run_TS02_HPC.bat as _run_TS03_HPC.bat in the TUFLOW_SWMM_Module_03\TUFLOW\runs folder.
2. Update the batch file to reference the TS03_5m_001.tcf :
   set exe="..\..\..\exe\2023-03-AD\TUFLOW_iSP_w64.exe"
   set run=start "TUFLOW" /wait %exe% -b
   %run% TS03_5m_001.tcf
3. Double click the batch file in Windows Explorer to run the simulation.
   
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Check Files

Review the SWMM INP and simulation report files from the TUFLOW_SWMM_Module_03\TUFLOW\results folder to confirm the new hydrology inputs are being processed correctly:

• View TS03_5m_001_swmm.inp in a text editor to confirm the conbining of the two input INP files has occured correctly. Also use the QGIS Processing tool, GeoPackage - Create from SWMM inp , to view the information in QGIS.
• View TS03_5m_001_swmm_curves.inp in a text editor to confirm the rainfall time series that has been used by the SWMM hydrology engine matches the input dataset.
• View TS03_5m_001_swmm.rpt in a text editor to confirm the model computation is healthy in term of mass conservation.

Results Output

SWMM.rpt Output

The SWMM simulation report can be opened using a text editor to review the 1D SWMM hydrology results.

1. In File Explorer, navigate to TUFLOW\results and open TS01_5m_001_swmm.rpt in Notepad++.
2. Type Ctrl+F to display the "Find" options in Notepad++.
3. Search for "Subcatchment Time Series Results" to navigate to the subcatchment hydrology results.

QGIS Result Viewing

1. Open TUFLOW Viewer from the TUFLOW Plugin toolbar.
   
   
   
   
2. Open 1D and 2D results: Select File > 'Load Results'. Navigate to the TUFLOW\runs folder and select TS01_5m_001.tcf.
3. The video example below opens the 1D and 2D results, using the first of the above options. When asked 'Do you want to open result GIS layer?', select 'Yes'. Five new files will load to the Layers panel:

   • TS03_5m_001_swmm_ts_P: 1D SWMM Node and outlet water level results
   • TS03_5m_001_swmm_ts_L: 1D SWMM conduit flow results
   • TS03_5m_001_PLOT_P: 1D ESTRY and 2D plot output water level and velocity results (Note: There are no ESTRY results from this simulation)
   • TS03_5m_001_PLOT_L: 1D ESTRY and 2D plot output flow results (Note: There are no ESTRY results from this simulation)
   • TS03_5m_001: 2D TUFLOW results

   
   
   
   
4. In the QGIS Layers panel, select (left click) TS03_5m_001 to establish it as the active dataset. Click on a scalar dataset 'Depth' under the Result Type in the TUFLOW Viewer 'Map Outputs' list. Move the time slider to observe how the 2D results vary at different times during the simulation.
   Note: The styling of the Map Outputs can be changed by right clicking on each result dataset and editing the 'Properties'.
   
   
   
   
5. In the QGIS Layers Panel, left click TS03_5m_001_swmm_ts_P and select 'Zoom to Layer(s)'.
6. Right click TS03_5m_001_swmm_ts_P again, and select 'Show Labels'.
7. Use the 'Select Features' tool to highlight Pit 19. View the following results using the Time Series plot.
   • Lateral Inflow: SWMM hydrology subcatchment inflow
   • Flood Losses: Water passing through the pipe inlet (a positive value represents surcharge to the surface)
8. Tick on 'Show Current Time'.
   
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Back to TUFLOW SWMM Tutorial 1

Conclusion

• EPA SWMM urban hydrology was added to the model (replacing 2D drect rainfall / rain-on-grid)
• The 1D SWMM pipe urban pipe network junction attributes were updated to accomodate for the change in model configuration from 2D direct rainfall to 1D SWMM hydrology.

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