Working with Outfall nodes

In the case of Dynamic Wave routing, outfall nodes are downstream boundaries for the network. For the other versions of the solver, Outfall nodes will behave in the same way to Junction nodes.

Only a single inflow pipe (link) can be connected to an Outfall node. No outflow pipes (links) can be connected to an Outfall node.

The Outfall node Properties Window is shown below.

Click in the Name field, type a new name and press the Enter key on your keyboard to adjust the label provided to your outfall. This is populated by default based on values set on the Model Defaults window, recall how to edit these defaults from the Urban Networks section. Note that if you change the name of a node, this label will be automatically updated in any connecting links so there is no further work to be done.

The X-coordinate and Y-coordinate are automatically filled based on the node location in the map view.

A Description and/or Tag can be optional provided. You may find tags helpful to group components together - this can be a way to categorise specific nodes. To edit these, click in relevant the field, type a new value, and press the Enter key.

External Inflows can be defined and allowed to enter Junction nodes. Please refer to the Urban Inflow page for further details.

Addition of pollutants to specify Treatment is not currently available within the software, although pre-defined pollutants will be unaffected.

The Invert Elevation of the Outfall node is populated by default based on the value set on the Model Defaults window, recall how to edit these defaults from the Urban Networks section. This parameter can be edited by clicking in the field provided, typing a new value, and pressing the Enter key.

The Tide Gate option is set to NO by default. Click in this field and select YES from the drop-down provided on the right if required. This will incorporate a flapped gate on the outfall, meaning water cannot re-enter the system from this point.

The Route To field is blank by default. This option allows for the outfall to discharge onto a subcatchment (i.e. a specified urban Subcatchment node). To use this option, click in the field, type the subcatchment name and press the Enter key on your keyboard. Note this field will remain blank if your outfall is discharging onto a 2D subcatchment (i.e. a domain being modelled in 2D), in which case link-elements will be required to integrate 1D urban and 2D components. The field will also remain blank if your outfall is discharging into an open channel (i.e. a river being modelled in 1D), in which case link-references will be required to integrate 1D urban and river components.

You must provide the Type of the outfall. This specifies the stage in the outfall. By default, this is set to FREE, meaning the stage will be determined by the minimum of the critical and normal flow depths in the connecting conduit. You also can set the type to NORMAL to use the normal flow depth in the connecting conduit. Neither of these options require any further details to be specified.

Alternative options for the outfall Type are all chosen by clicking in the field and selecting the required boundary condition from the drop-down provided on the right.

FIXED sets the outfall stage to a fixed value, in which case the value must be provided in the Fixed Outfall : Fixed Stage field.

TIDAL sets the outfall stage to a table of tide elevation (against time of day) data, in which case this data must be provided in the Tidal Outfall : Curve Name field. Double-click in this field to open the specific Tidal Curve Editor window to enter the series. Please note methods for adding/editing curves are the same as those for timeseries data, as described in How to build a 1D urban model - stage 3: adding inflow.

TIMESERIES sets the outfall stage to a timeseries of stage data, in which case this data must be provided in the Time Series Outfall : Series Name field. Double-click in this field to open the standard Time Series Editor window to enter the series. Please note methods for adding/editing timeseries data are as described in How to build a 1D urban model - stage 3: adding inflow.