Headloss Curves

A headloss condition must be specified at each end of a conduit. The headloss condition represents the extra energy loss due to turbulence at a manhole or junction.

Headloss conditions are specified in the US headloss type and DS headloss type fields for the conduit by selecting a headloss curve. There are a number of built-in headloss curves available; alternatively a user-defined curve may be specified:

The default headloss condition for an individual conduit is the global value specified in the User Defined Defaults; this has a default value of normal manhole headloss.


In order to use the FHWA headloss condition for networks created in versions of InfoWorks ICM prior to version 3.5, it is necessary to validate the network. Validating the network will update the built-in headloss curves to include the FHWA curve type.


Headloss Curve Data Fields