Northern Water Snake (Juvenile)

good call, I didn't feel 100% about it so I really should have just made a comment. I was thrown by the apparent size - without much scale I thought it was larger for some reason and discounted juvenile coloration.

This is definitely not a Copperhead. Copperheads have hour glass shaped blotches, and the blotches on this shape are very square, which is very indicative of Nerodia.