The System Health page has a storage paths tab which shows information relating to the storage checks that relevant import modules perform. The modules perform these checks every 5 minutes. In addition to showing the information in the user interface high and low watermarks are checked (and visually shown in the user interface are they are exceeding limits).
Here is an example of the output area health:
Used space is shown for UNC paths as well as Amazon and Azure paths. Watermarks are also checked for those storage types.