The following are the cases in which a geometric network should be deleted and recreated:
· When adding a new populated feature class to the network.
· When adding or removing a weight from the network (See the note below for more information).
· When the snapping tolerance is too small on a previous build.
· When changing a feature class from simple to complex edge or vice versa.
· When adding a specific junction feature class as a source or sink, or removing its ancillary role.
· When renaming the geometric network.
Support for adding a weight to a geometric network was added at ArcGIS 9.2.