creative interchange

I've been using the word "confluence" a lot lately - so often, in fact, that I decided to look it up to be sure that I wasn't misusing it in some way. According to Webster, the first definition of confluence is "a flowing together of two or more streams," with a second meaning of "a gathering, flowing, or meeting together at one juncture or point."  To me, it's a perfect word to describe a trend that's redefining the watershaping industries - that is, a growing confluence between the pool/spa and pond/stream industries. Coming from the pool/spa side of the discussion, I can recall a time not very long ago when ponds and streams were only rarely if ever considered by anyone in my business.  What could pools and spas possibly have in common with