Outfall Nodes

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.

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

·       The critical or normal flow depth in the connecting conduit

·       A fixed stage elevation

·       A tidal stage described in a table of tide height versus hour of the day

·       A user-defined time series of stage versus time.

The principal input parameters for outfalls include:

·       Invert elevation

·       Boundary condition type and stage description

·       Presence of a flap gate to prevent backflow through the outfall.