Access .sql script files on other partition or hdd
Turns out this was much easier to fix than I though. Being completely new to both SQL and postgres I foolishly assumed that psql had something to do with the problem. As it turns out the directory /media/user in which Storage is mounted did not have Read &amp; Write permissions set for other users, so even though I would have been allowed to access the file inside Storage I could not get these. 

Changing the permission in /media/user solved the problem. In the future I'll make sure that all directories in a path are accessible to me.

Thanks again for the help and advice.