Visual InterDev
You can delete a site diagram from a Web application in the Project Explorer. When you delete a site diagram, you delete the .wdm file from the project; you do not delete any of the pages represented in the site diagram.
To delete a site diagram
In the Project Explorer, right-click the name of the diagram that you want to delete.
From the shortcut menu, choose Delete.
-or-
Press the DELETE key.