I would say absolutely, yes, to this question. Given that Google don’t look like they are going anywhere, and their entire business relies on being very secure, it would seem to me that Google Drive may very well be one of the very safest places to store any documents. Google is also going to do things in line with the new GDPR regulations, so again, no issues there.
For me, I think it is best to use Google Drive in conjunction with G Suite and I highly recommend any school to sign up for G Suite for Education. This gives you lots of power for collaboration. You can restrict certain documents to people within your domain address, which can be useful for internal documents, that you might not want to be public just yet, such as draft policies. You also get unlimited storage, which is probably more important!
Even without this, it is a useful enough tool for storage but storage isn’t unlimited in personal accounts so you might as well upgrade while the going is good. Best of all, it is free to do so.
Last Update: Apr 7, 2018