Here a GUI Windows tool for make a dump of local and remote subversion repositories:
https://falsinsoft-software.blogspot.com/p/svn-backup-tool.html
The tool description says:
This simply tool allow to make a dump backup of a local and remote subversion repository. The software work in the same way of the "svnadmin" but is not a GUI frontend over it. Instead use directly the subversion libraries for allow to create dump in standalone mode without any other additional tool.
Hope this help...