Before you get too far: WTF = Water Tank Find. Unlike the other tanks near here, this one has been this color for a while.
I first did one of these caches thanks to DudleyGrunt and I'm trying to keep mine very similar to his, so give me a break on the plagiarism.
Please take note of where you find this one and be sure to replace it in the same place. Thanks!
You will need the Log Password that is printed on the BITcache to log your find online.
Also, while you are there, please take an "artistic" photo to include with your log. If you have any problems with the photo, it is not a requirement, but I would definitely appreciate seeing them. You do not necessarily need to be in the photo.
For more information on how water towers work (when the military isn't using them to host the alien horde), see this article at HowStuffWorks.com.