I fully admit I haven't put a ton of research into vetting these charities. I've put the research into understanding why they're important, and let groups like Goodnet and such do the vetting. I just hope I'm not promoting a charity that's a front for other things.
But as far as I know, Water.org is good, as are Project: Water and Water Is Life. (That last one I had heard of before but forgot about until I was getting screenshots for this video... I recorded me saying the tagline in my video before being reminded of it.)
Project 4 Awesome: http://projectforawesome.com/
Water.org: They liked their URL so much they named the organization after it!
Charity: Water: https://www.charitywater.org/
A charity not mentioned on the list of 7 I had in the video. Christian charity whose statement of faith shows a focus on evangelism. Again, I haven't spent any time figuring out if it's a good charity, so if you want to donate, do your research!