--- title: "(USA) Introduction Chapter 2 - Size Mitigation" canonical: "https://help.innovyze.com/space/infodrainage2021v1/16548246/(USA)%20Introduction%20Chapter%202%20-%20Size%20Mitigation" format: markdown --- | **File/s needed: ** | | --- | | Click to download the **.** | ## Add Arch Chamber Since CAD does not represent Stormwater Controls (i.e. Ponds, Swales, Raingardens) as richly in Plan as InfoDrainage does, the Pipe Network that was imported is overly simplified and uses ‘dummy’ objects as placeholders for designers who are forced to split their work between several tools. To achieve proper Runoff Mitigation an Underground Detention **Arch Chamber** needs to be added, which can be easily done by converting the ‘dummy’ junction into a full Stormwater Control (SWC). 1. Continue working on your model or open **ID_US_Introduction_Project_Ch2.iddx**. 2. Right-click **Standard MH (11)** and select **Change Template**. We could change more than one object at once but on this occasion, we are only changing one manhole.> Macro (inline-media-image) 3. Select **Arch Chamber** from the **Select Template** list. Under **Select Name**, select **Rename **and enter to Arch Chamber. Select **OK** to close the dialog.> Macro (inline-media-image) > Macro (inline-media-image) 4. Double-click or right-click and select **Edit** to review the Arch Chamber Stormwater Control (SWC) properties.This facility uses the Parabolic Arch Chamber configuration type and the individual chamber section lengths, wall thickness, diameter and height are all as noted in manufacturer specifications. Any change to input that would affect the facility extents will be represented in Plan, just like any changes to the Plan layout will update dimension details within the SWC properties. Use the **Click to Show Images** icon in the lower left of the dialog to view a schematic of what the underground detention chambers looks like. 5. The embedded parameters allow for the fill material above and around the chambers to be applied toward facility storage. Notice that the schematic view of the detention facility can be switched from Plan (top down) view to a Section (or an on-end profile) view.> Macro (inline-media-image) > Macro (inline-media-image) 6. Under the **Outlets** tab, from the **Outlet Type** drop down list, select **Orifice** and enter a **Diameter **of** 0.5 ft** and set the** Invert Level **to** 167.3 ft**. This will set an orifice 1.5 ft above the base of the Chambers. Select **OK** to close the SWC dialog.> Macro (inline-media-image) ## Reconnect System Since InfoDrainage allows for ‘AS-BUILD’ layout and details of stormwater systems, it is valuable to place the Inlets and Outlet of this facility at the real world proposed locations to ensure connection inverts, lengths, and slopes are accurate. 1. Right-click the **Arch Chamber SWC** and select **Specify Inlet/Outlet Location**, select** one** of the Inlets/outlet. You can then drag and drop the Inlet/Outlet to the appropriate location. Repeat process for all objects until they are located as shown. > Macro (inline-media-image) > Macro (inline-media-image) 2. When the Pipe Network was imported, any Junctions that fall on unconnected Inflow Areas are automatically connected to the adjacent Junction. If there are multiple Junctions imported on top of the same Inflow Area, only one will be connected, so it is important to review if all of the automatic connecting occurred as expected. In the case of Comm (3) and the Arch Chamber SWC, it appears that the Inflow Area connected automatically to the structure downstream of the Arch Chamber SWC. This can be easily updated by **right click** on **Comm (3)** and select** Reconnect Inflow.** Then **place the inlet** **next to the parking island** as shown.> Macro (inline-media-image) > Macro (inline-media-image) 3. Now that the Arch Chamber SWC has been configured, add a flow path as shown in order to view a Profile of the drainage system. Right-click the **Flow Paths** layer, select **Add** and click once on the Junction at the top-middle of the site then once at the downstream most Junction at the lower right corner of the site. Hit the** Esc key** to end the action, then right-click the **Flow Path **layer and select **Show Profile**.> Macro (inline-media-image) > Macro (inline-media-image) > Macro (inline-media-image) > Macro (inline-media-image) ## Automatically Correct Data Just like in the Plan view, the **Flow Path** shown in the Profile view can be zoomed into by using the mouse wheel and panned by using the mouse or by the view controls in the top left of the dialog. Notice in the Profile that while the Pipe Connections which were imported from GIS were brought into the software at the correct invert elevations the Junctions between pipes are not set to the correct elevations. 1. Close or minimize the Profile view and under the **Preliminary**** Sizing **ribbon select **Synchronize Manhole Invert Levels (Synchronize MH ILs)**. This will Automatically set the manhole inverts to the lowest connected pipe connection. > Macro (inline-media-image) > Macro (inline-media-image) 2. View the **Flow Path Profile** view again to see the corrected pipe network. > Macro (inline-media-image) ## Size Pipe Network Now that the Arch Chamber SWC has been added and configured, **Automatically Size **the **Pipe Network** within the **Connections.** 1. Double click the **Connections Layer** on the Tree View, or by select** Connections** on the **Preliminary Sizing ribbon**.> Macro (inline-media-image) > Macro (inline-media-image) 2. Pipe Networks can be sized based on Flow Paths - select a **Flow Path** from the drop down list and notice that the Connections list is sorted with Connections and Branch Lines based on the Flow Path selection. Sizing will occur for all Connections contained in the Flow Path and all Branch Lines. Select** Network Design Wizard** to perform preliminary sizing of the Pipe Network.> Macro (inline-media-image) 3. Once the** Network Design Wizard** is opened, a new or existing Flow Path can be selected for sizing, including the entire Flow Path and all of its tributary branches. Since only one Flow Path has been created, simply select **Next** to proceed to Flow Criteria.> Macro (inline-media-image) 4. As the **Network Design Wizard** uses the Rational method for peak runoff flows based on the Preliminary Sizing input within the attached Inflow Areas, select the** Greenville IDF Table** as the Rainfall Source and select the** 10 year return period** as the event sizing for the pipe network.  These Rainfall Sources can be reviewed under the Rainfall ribbon if desired. Click **Next**.> Macro (inline-media-image) 5. The Design Options can be reviewed in the next step of the wizard. First click the ellipsis next to **Pipe Size Library**. A default Pipe Sizing Library has already been created and loaded. A list of typical pipe diameters and associated min/max design slopes will be shown. These may vary per manufacturer but these values will be used for the sake of the tutorial project.> Macro (inline-media-image) > Macro (inline-media-image) 6. Select** OK** to return to the **Network Design Wizard**. 7. In this example project, a design engineer has already laid out the desired invert elevations and slopes of the stormwater pipe network. In order to only size pipe diameters, select** Slopes and Invert Levels **under the** Lock Slope Options **drop-down menu. Select** Next** on the **Network Design Wizard** to proceed.> Macro (inline-media-image) 8. The **Summary of Changes** table lists the changes made to the network, with cells highlighted in orange to indicate the value has changed. By hovering over a highlighted value the previous value can be seen. As the invert elevations and slopes of the pipe network were locked only Diameter changes were made to accommodate incoming flow to the system, based on the Preliminary Sizing Inflow Area parameters and the constraints chosen in the 'Flow Criteria' step of the wizard. Select **Finish** to apply updates and review the **Network Design Report**.> Macro (inline-media-image) 9. Upon selecting **Finish** for the Network Design Wizard, by default the **Network Design Report** will be shown. There are several result formats to choose from, including the standard **HEC-22** Preliminary Sizing Report format. Review the design results as desired and close the dialog when completed. Additional toolbar options exist to change **Network Design Criteria**, **Recalculate Rational Results** and **Audit changes against Network Design Criteria**.> Macro (inline-media-image) 10. To check manholes are aligned, we can also run the **Synchronize MH ILs** as a separate step after the wizard by selecting it from the **Network Design** section of the **Preliminary Sizing** ribbon. ## Validate System Data 1. For a system wide check for any potential discrepancies, under the **Analysis** ribbon select either **Validate** or **Go** – this will run an audit of the storm system and list any potential issues in the model.> Macro (inline-media-image) 2. When the **Comm (3)** Inflow Area was connected to a new destination the original Inlet specification is no longer applicable. **Check the Connectivity box** and then select** Apply **to automatic update this item.> Macro (inline-media-image) 3. At this point all inconsistencies between the Junctions and the Connections have been noticed and automatically corrected. The Validate dialog shows no discrepancies are outstanding. Select **OK** to close the dialog.> Macro (inline-media-image) 4. Now the stormwater system is ready for full hydraulic analysis – browse to the **Analysis** ribbon and select **Go** to solve the model.