Do NOT do anything drastic - wait. This issue has been discussed up/down here (simple search would have show you many threads) and it seems to be mostly related to TimeMachine (even if you are NOT using it!) and local snapshots. OSX now seems to keep last ~24-48 hours of snapshots in local TimeMachine as backups always. Deleting a file does not release the space now... It just moves the file to trash, while keeping it in TimeMachine snapshot, and eventually, may be, even delete the file ;-) As long as you do not need the space, no reason not to keep the file around, just in case...
There are procedures how to delete snapshots using tmutils, but realistically, easiest may be just let it be - it will eventually be released on its own. I believe the general consensus is also, that if you need the space, system will (automatically) delete these backups on its own.
In other words, in Apple opinion, you are "overthinking it" and should just use the computer. It should get out of your way. That said, some reported over time, that they had problems with the space. The ways how to clean TM can easily find here by search or google it.
But you do not have a problem, so do not try to fix it (like deleting that folder from the other thread).