You can enable the use of districting in your instance by doing the following: 
  1. Go to Setup -> App Setup -> Develop -> Custom Settings. 
  2. Click Manage next to Luminate CRM Settings. 
  3. Click Edit. 
  4. In the Enable Districting field, enter "USE_DISTRICTING." 
  5. Click Save. 
 
Districts will then populate as part of the Contact Standardization task, which is enabled under the Utilities tab. You can also click Run Now next to Contact Standardization in the Utilities tab as well.