Inlets allow flow from Inflows (Catchment Area, Green Roof, Roof and or Input Hydrograph), or from an incoming Connections, to be captured and routed into a Junctions, Manhole or  Stormwater Control  or bypassed to another location.

Inlets are created as part of a  Junctions Manhole 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 & connections.


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

Inlet Type

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 There are two types:

Point Inflow - The flows passing through are seen as entering at the top end of the Stormwater Controls - SWC

Lateral Inflow- The flows passing through are seen as entering along the length of the Stormwater Controls - SWC

Inlet Destination (Bioretention and Swale SWCs only)

It is possible to specify which component of a complex stormwater control that an inlet connects too. This is only available for Bioretention or Swale (with Trench on) Stormwater Controls. 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 checkboxes to select which items connect to each inlet of the Stormwater Control 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 4 types of Inlet capacity that can be specified:

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

Percentage Flow - Specify a percentage of the flow that will bypass the system .

Rated by Flow - Specify Approach Flow vs Captured Flow as a table.

Workflow - What's next...?

Inflows connect to either Junctions or Stormwater controls via Inlets. Specify an Outlet on these objects then choose to connect to another Junction or Stormwater Control.