InfoDrainage 2020.2 Help Documentation infodrainage2020v2

Inlets allow flow from Inflows or from an incoming Connections to be captured and routed into Junctions, ManholesStormwater Controls (SWC) or bypassed to another location.,

Inlets are created as part of a JunctionsManhole or Stormwater Control to stipulate how much of the approaching flow will enter the structure.

Each system can have one or more inlets with each inlet able to support multiple incoming inflows and connections.


Junction or Stormwater Control: look for the Inlets Tab within the Properties form

Inlet Types

It is possible to specify how the incoming flow will enter the system as this will affect the time it takes the water to pass through the Stormwater Controls - SWC. The Inlet types are:


The Inlet type will be ignored in a SWC if the Consider Longitudinal Delay option is turned off. This is found on the Pond, Tank, Cellular Storage and Chamber options. It is also not selected for a Soakaway as that never considers longitudinal delay.

Inlet Destination 

It is possible to specify which component of a complex SWC that an inlet connects too. This is only available for Bioretention or Swale (with Trench on) SWC. There are two options:

  • Ponding Area - The flows are seen as entering into the top of the SWC. i.e. the Ponding Area or Swale.
  • Subsurface Area - The flows are seen as entering into the bottom of the SWC. i.e. the Filter Area or Trench.

Incoming Items

This is the list of incoming Inflows and Connections that are entering the given inlet. Use the check boxes to select which items connect to each inlet of the SWC or Junction.

Bypass Destination

This is the destination connection that any flow bypassing the inlet will be routed. This needs to be drawn as a Bypass Connection on the Plan.

Capacity Type

There are several types of Inlet capacity that can be specified:

Some of the options may not be available for your region. For more information, refer to the Regionalisation topic.
  • No Restriction - The incoming flow enters the system unrestricted.
  • Low/High Flow - Specify a low and high filters that are applied to the flow to determine how much flow enters the system.
  • Rated by Flow - Specify Approach Flow vs Captured Flow as a table.
  • HEC-22 - Specify an inlet compliant with HEC-22.