I've created the repository and add the users to access it.
Full access to manage VisualSVN Server via VisualSVN Server Management console requires the user to be a member of local VisualSVN Server Admins group. Users who are members of this group have full access to manage repositories, authorization access rules and server settings. For instructions on configuring the remote administration feature see the article "Configuring Remote Administration".
VisualSVN Server 2.7+ allows you to assign non-administrators as repository supervisors (i.e. managers). Supervisors don't have full access to administer VisualSVN Server but can manage authorization access rules for particular repositories. Access rules management is done via VisualSVN Repository Configurator tool remotely.