In addition to general system maintenance, content will need to be weeded, which includes monitoring for things such as orphaned pages, duplication of content, or an unbalanced structure.
One of the great advantages of a wiki is that you can easily add a link to a page that doesn’t yet exist, but that you believe needs to be added at some point. However, over a period of time you need to monitor these empty links to determine if they are really necessary. You may find that the subject has already been covered on another page, and you need to merge the pages.
Given the open nature of a wiki, it is also possible that two or more people may create separate pages on identical, or closely related, subjects. (This is more likely to happen in the early days of the wiki implementation before the user community becomes fully familiar with the navigation and search model of the wiki.) As part of the maintenance process you need to monitor, and where necessary, merge duplicated pages.
In the early days of wiki implementation you may also find that the initial structure that you outlined (if you outlined any) becomes unbalanced. This can also happen in a totally open wiki where the structure grows organically. An unbalanced structure is one where certain articles and pages develop multiple, nested sub-pages while others remain as single pages with no attached hierarchy. When sketched out, such a structure will appear to have some areas where it is totally flat and others areas with a fairly complex hierarchical structure. In some cases you may need to move pages around to create a more balanced structure and improve navigation.