find . -name ".svn" -exec rm -rf {} \;

from http://www.dzone.com/snippets/remove-all-svn-folders

and

http://stackoverflow.com/questions/1294590/how-to-remove-all-svn-directories-from-my-application-directories

svn schema

The image is from : http://www.codeproject.com/Articles/20603/Accessing-the-Subversion-repository-from-NET-using