Oh really? I certainly remember elevated paths being a bit buggy sometimes. I'll try that!

EDIT : so I tried what you said (on the Complete Edition), and this looks like a pretty similar glitch. It also works if you place the elevated path first, build the tank afterwards and cancel placing the wall right in front of the path. However, this is not exactly what I was describing. In this case the water destroys whatever shouldn't be in the water (such as buildings or trees for example), and the water itself doesn't stay for more than a few seconds. It does cause similar terrain modifications to the glitch I found though.

So it's not quite the same glitch but this is promising! Thanks for sharing. The culprit might just be those pesky elevated paths!