Email Templates can be translated for a while now. The way it's supposed to work is to install/enable a Language Pack, add a new Email Template Set with the Language set to the Language Pack, the Email Template Set will be created with the default translations from Crowdin, and then you go in and customize to your liking.
There is currently an issue with the language packs however where translations don't work for Email Template Sets (Language Pack build issue). We are eventually going to rebuild the Language Packs so that the translations work right away for new Email Template Sets.
The workaround for now is to add a new template set in English and then manually translate them.
Once you have the Email Template Set translated you can configure the desired Departments to start using it.