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File/s needed: 
Click to download the METRIC model files.

  1. Continue with your previous file or open XP_Tutorial3.xpdx

    Items can be added to the plan and connected individually, or drawn as a connected "Treatment Train" using the Add Train tool in the Build menu. The former approach, adding items individually, will be used here. The treatment train begins with the Inflow of the Developed Areas that drains to a series of Manholes, from here the site runoff is conveyed to a Dry Pond.
  2. Make sure you are still working in the Developed Phase

  3. First, the Inflows must be defined for the developed site. For this example, we will be placing two inflows into the area to better represent the drainage characteristics of the developed site. Ensure Snap is turned on, this can be done in the Plan ribbon, then outline the two inflow areas as shown below, selecting Catchment Area from the Add Inflow drop down menu.

  4. Now that we have placed our catchment areas, we will alter their templates so that they contain the characteristics of our developed land. Right-click the first inflow area and select Change Template. Within the window that opens, select both Catchment Areas in the first column, select Urb-Res-Dev from the list of available templates.

  5. Rename the larger area to Inflow 1 and the smaller area to Inflow 2.

  6. Double-click each inflow area to see how the software has automatically calculated the size of the area based off of the points we selected. Here we can also see that there is the ability to alter the seasonal Volumetric Runoff Coefficient (Cv) values for the specific inflow area. As can be seen for both inflows, the Winter Cv value has not yet been specified. To rectify this, we will type 0.84 as our winter Cv value, in line with the Wallingford Procedure, for both inflow areas. Once completed, click Apply and then OK.

  7. Under the Build ribbon, select the Add Network option and then select Shallow MH from the Next Item drop down. Move the pointer to the location on the site where the first manhole will be installed and use the left mouse button to place the manhole. You will notice that the software automatically assigns the inflow area to the junction when it is placed in Plan View. Next select Standard Pipe from the Add Connection drop down and continue placing the manholes as shown below. Press the Esc key to end the run of pipes.

    Note - If the Inflow icon is in the way, select the Inflow icon then hold Shift on the keyboard and drag the icon on screen to move it without moving the Area.

  8. Under the Build ribbon, select the Add Stormwater Control option and then the Dry Pond SWC. Move the pointer to the location on the site where the Dry Pond is installed and use the left mouse button to draw the outline of the Dry Pond SWC (similar to the outline shown in the figure below). When you have finished drawing the polygon, use the right mouse button to end the drawing action. 

    Note: SWC outlines can be redrawn at any point by right clicking on the SWC and selecting Replace Outline


  9. One final connection needs to be made from the most northern manhole into the Dry Pond. Right-click the Manhole and select Add Connection, selecting Standard Pipe from the options. Connect into the lower left hand corner of the Dry Pond and an inlet will appear.

  10. To understand what elevations were adopted and how well the treatment system connects, we can view a long section Profile. Add Network mode automatically created a Flow Path, we just need to add the Dry Pond. Expand the Flow Paths item at the bottom of the Tree View and right-click on Train. Select Edit, then select the Dry Pond icon to add this. Hit the Esc key in order to stop tracing. You can rename the flow path if you wish by right-clicking and selecting ‘Rename’ on the flow path in the ‘Flow Paths’ tree.

    Note: You can turn off labels on Plan using the Display Settings accessible from the right-click menu.

  11. Right-click the new Flow Path and select Show Profile (alternatively, select the Flow Path under View, Profiles) to display a profile of the flow path.


  12. Edit the Dry Pond SWC by double-clicking it from the Profile view or on Plan. Note that by using the template, we have a 1.5 m deep pond with a top area automatically set based on how the outline was drawn. The base area needs to be set. Before altering this, we will change the top area to 1000 m2 to maintain similar results. Use the Sizing Calculator and select side slope, input 1:2 slope. We will maintain the Top Area. Select OK and note how the depth-area-volume table and associated schematic have been updated.

    Note: The values will vary depending on the exact drawing of the dry pond.

  13. Select the Outlets tab, select the + button and from the available Outlet Types select the Multiple option. As is common for a Pond SWC, we will have an orifice outlet to control low flows and a higher level weir control for more severe rainfall events.

    We will be using the pond to control the initial runoff by allowing base infiltration (which can be seen in the Advanced tab of the Dry Pond window). This will help us achieve Runoff Reduction and prevent the Water Quality event discharge from leaving the site. Therefore, add 0.3 m to the Invert Level automatically picked up as the Base Level of the Pond. This will place our outlet control 0.3 m above the base, preventing any discharge until that depth is reached.

  14. Select the Edit button above the depth-outflow table. Select the icon, select Orifice and Weir from the list. We could manually enter values for the orifice and weir or we could use the wizard calculator to help.

  15. Use the  button  to reveal the depth-flow input table. 

  16.  Enter the following design depth-flow values into the wizard calculator. 
    • Orifice: 0.5 m Design Depth; 20 l/s Design Flow
    • Weir: 0.7 m Design Depth; 60 l/s Design Flow

  17. Click the calculator button Solve for displayed controls. Click each row of the Control List table to see the results. A 0.12 m diameter for the Orifice and a 0.24 m width for the weir has been calculated automatically by the program. 

  18. Click OK and see the Depth – Outflow table populated.

  19. Click OK to close the Dry Pond.

    Note: If Inlets and Outlets now fall outside of the SWC, the Inlet and Outlet icons will disappear automatically and the links will connect directly to the SWC icon. The Inlets/Outlets are not deleted, only removed from the graphical view, they can be redrawn by right clicking on the SWC icon and choosing the Specify Inlet/Outlet Location command.