Configure the format of the local working copy
A working copy is a directory that contains a collection of files which you can use as your private work area, as well as some extra files, created and maintained by Subversion. For example, each directory in your working copy contains an administrative directory named .svn.
You can have local working copies created with Subversion 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, or 1.9. PhpStorm handles all these formats, giving you a choice to upgrade to the new format or preserve the legacy one.
Switching to another Subversion format is always associated with a specific working copy (directory) under the Subversion control. In other words, one cannot upgrade to a newer Subversion format at the IDE level, but only to a directory under Subversion control.
To change the format of the local working copy, do the following:
Open the Subversion tool window Alt+9.
In the Subversion tool window Alt+9, switch to the Subversion Working Copies Information tab.
This tab is only available, when the current project sources are entirely or partially under Subversion control.
Scroll to the information on the required directory and click the Change link.
In the Convert Working Copy Format dialog, that opens, select the desired format option.