I think it's fine. Overall the book is pretty vague on this. I think in general it either has to be a significant structure or tied in some way to a significant event or emotion, which may be hard to conceptualize in regards to creating a fountain or pool... so my suggestion would be to instead have its creation affiliated with something like a punk rock christening, like the band performs some ritual music after it is built or something similar, maybe each player burns a point of Essence?