<p>I'm administering a svn repo for a project where the source wasn't imported with a single top level directory. As a result, there are about 15 separate 'projects' instead of one. How can I merge these into one folder while maintaining the change history?</p>

<p>*hint: svn move doesn't work in this case.</p>

<p>[edit]
whoops, dupe of <a href="https://stackoverflow.com/questions/267256/combining-multiple-svn-repositories-into-one">Combining multiple SVN repositories into one</a></p>

If you don't care about retaining all the history of one of the repositories, you can just create a new directory under one project's repository, then import the other.
If you care about retaining the history of both, then you can use 'svnadmin dump' to dump one repository, and 'svnadmin load' to load it into the other repository. The revision numbers will be off, but you'll still have the history.
Copied from here:
http://subversion.tigris.org/faq.html#multi-merge