When using TortoiseSVN (which, BTW, uses Drupal as it's website CMS, YAY!) as your interface to subversion, deleting files from the repository may not be obvious. To delete the files on your local checkout, first you indicate you want the files deleted, then you commit the deletion to the repository.
If you use the command line, the steps are:
% svn rm dir1
% svn ci -m "Removed the directory" dir1
Committed revision 92.
With TortoiseSVN, you'll execute these same commands with the GUI, using your mouse instead.
First, select the file, files, directory or directories you want to delete.
Then, go to the menu: File > TortoiseSVN > Delete
You've now indicated to the subversion repository that you want to delete the selected files. To actually delete them, you need to commit your change.
Go to the menu File > SVN Commit
Don't forget to provide a good comment for your change! If you can, succinctly explain why you made your change, as well as the change you made.