Placing Drainage Outlets
The drainage outlet is the terminal point of the site drainage network — where collected water discharges to a final destination such as a street gutter, a soakaway pit, or the garden boundary.
Drainage OutletThe Outlet object places the terminal discharge point for a drainage network. Every drain pipe and catch basin ultimately connects to an outlet, giving contractors a clear endpoint to build to. You choose between three outlet types — Soakaway, Boundary Outfall, and Storm Sewer — and a fixture style (Pipe End, Headwall, or Pop-up Emitter) that controls how the outlet appears in 3D and on printed plans. Place one outlet per independent discharge point.
Activate the Place Outlet tool
In Drainage mode, click the Place Outlet button in the toolbar. The cursor changes to a placement crosshair. Move the cursor to the location on the canvas where the drainage network terminates.
Click to place the outlet
Click on the canvas at the discharge location — typically at the site boundary near a street gutter, at a designated soakaway location in the garden, or at a garden edge where water can daylight. The outlet appears as a symbol on the 2D plan.
Set the outlet type in the Inspector
Select the placed outlet to open the Inspector. Set the outletType field to one of the three options: toStreet, toSoakaway, or toGardenEdge. The plan symbol and annotation label update to reflect the selected type. For toStreet, you can add a reference to the public drain connection point in the notes field.
Connect the outgoing pipe from the catch basin
Switch to the Draw Pipe tool and draw the final pipe from the catch basin (or from the last drain in the network) to the outlet point. The pipe endpoint snaps to the outlet's connection point. Set the pipe diameter in the Inspector to match the capacity required to carry the total collected flow.
Connect the drain pipe to the outlet
Place a Drain Pipe from the Conveyance & Discharge section and draw a pipe from the last catch basin in the run to the outlet. Repeat for each independent drainage branch that discharges at this point.
Name the outlet
In the General section, give the outlet a descriptive Name so it reads clearly on the plan and in any export — for example, 'Rear soakaway' or 'Front boundary outfall'.
For a soakaway, record the pit dimensions in the outlet's Name field or a nearby note. Soakaway sizing is site-specific and depends on local soil percolation and the contributing catchment area — document the design assumptions so the contractor can verify compliance.
The outlet type is a design annotation; it does not drive automated hydraulic calculations. Pipe sizing and burial are set independently on each Drain Pipe in the Inspector.
Deleting an outlet that is connected to a pipe leaves that pipe with an open end. Reconnect the pipe to a new outlet or remove the dangling segment before exporting the plan.
Frequently Asked Questions
What is the difference between the three outlet types?
Soakaway discharges into a subsurface percolation pit — water infiltrates the surrounding soil. Boundary Outfall daylights at the site boundary, discharging to an adjacent channel, ditch, or gutter. Storm Sewer ties the network into a public storm drain. The chosen type appears in plan annotations and documentation.
Can I place more than one outlet on the same plan?
Yes. Place one outlet for each independent discharge point — for example, a soakaway at the rear and a boundary outfall at the front. Connect the relevant catch basins and pipes to each one separately.
Which fixture style should I use for each outlet type?
For Soakaway, Pop-up Emitter is common as it sits flush until pressure builds. For Boundary Outfall, Pipe End or Headwall are typical — Headwall suits an outfall in a retaining wall or embankment. For Storm Sewer, Pipe End is standard.
Does the outlet type affect hydraulic calculations or pipe sizing?
No. The outlet type is a design annotation. Pipe sizing and burial are set independently on each Drain Pipe. The outlet type is used in plan annotations, reports, and cost documentation.