System Type

InfoWorks ICM supports separate sub-systems within an InfoWorks network. This allows separate drainage systems to be modelled for surface drainage and foul drainage for example. The available sub-systems are:

System Type	Description
Storm	Rainfall collection system
Foul	Wastewater collection system (UK terminology)
Sanitary	Wastewater collection system (US terminology)
Combined	Rainfall and wastewater collection system
Overland	Overland floodwater collection system
Other	Other system type

Each sub-system is modelled independently, and you can have a set of overlapping subcatchments for each one.

In effect, there are no hydraulic differences in the way these sub-systems are modelled. However, you would normally expect differences in the way the networks are constructed. For example, a storm system will have subcatchment surfaces that contribute runoff. There is unlikely to be runoff contribution into a foul system.