Outfalls are terminal nodes of the drainage system used to define final downstream boundaries under Dynamic Wave flow routing. For other types of flow routing they behave as a junction. Only a single link can be connected to an outfall node, and the option exists to have the outfall discharge onto a subcatchment's surface.

The boundary conditions at an outfall can be described by any one of the following stage relationships:


The input parameters for an Outfall are listed in the table below:

Field Description
Name User-assigned outfall name
X-Coordinate Horizontal location of the outfall on the Study Area Map. If left blank then the outfall will not appear on the map.
Y-Coordinate Vertical location of the outfall on the Study Area Map. If left blank then the outfall will not appear on the map.
Inflows Click the ellipsis button (or press Enter) to assign external direct, dry weather or RDII inflows to the outfall.
Treatment Click the ellipsis button (or press Enter) to edit a set of treatment functions for pollutants entering the node.
Invert El. Invert elevation of the outfall (feet or meters).
Tide Gate YES - tide gate present to prevent backflow NO - no tide gate present
Route To Optional name of a subcatchment that receives the outfall's discharge.
Type Type of outfall boundary condition:
FREE:: outfall stage determined by minimum of critical flow depth and normal flow depth in the connecting conduit
NORMAL: outfall stage based on normal flow depth in the connecting conduit
FIXED: outfall stage set to a fixed value
TIDAL: outfall stage given by a table of tide elevation versus time of day
TIMESERIES: outfall stage supplied from a time series of elevations
Fixed Stage Water elevation for a FIXED type of outfall (feet or meters).
Tidal Curve Name Name of the Tidal Curve relating water elevation to hour of the day for a TIDAL outfall (double-click to edit the curve).
Time Series Name Name of time series containing time history of outfall stage for a TIMESERIES outfall (double-click to edit the series).