An overview of the Geometric Network toolset
The Geometric Network toolset contains tools to create, manage, and run trace tasks on geometric networks.
A geometric network is a set of connected edges and junctions, along with connectivity rules, that are used to represent and model the behavior of a common network infrastructure in the real world. Water distribution, electrical lines, gas pipelines, telephone services, and water flow in a stream are all examples of resource flows that can be modeled and analyzed using a geometric network. With a geometric network you can perform various network analyses such as finding loops or circuits within a network or trace upstream or downstream to find the source of flow within a network.
Tool 
Description 

Adds an edgeedge connectivity rule to a geometric network. 

Adds an edgejunction connectivity rule to a geometric network. 

Creates a geometric network in a geodatabase using the specified feature classes, role for each feature class, and the specified weights with weight associations. 

Removes a connectivity rule from the geometric network. 

Removes an empty feature class from a geometric network. 

Sets the flow direction for a geometric network based on either the digitized direction or the source/sink settings in the geometric network.  
Solves the specified network analysis problem based on the flags, barriers, and specified weight properties. 