Mason,
That really looks nice! You put a lot of time into that pond and it shows!
Your pics reminds me of the New England I used to know. (Not sure if I told you but I lived 10 miles south of the New Hampshire line when I was a kid).
Three questions:
Are you sure your pond is 1/4th acre? Looks a little smaller in the picture although as we all know pictures can be deceiving. Smaller would be better for cooling.
The other question is are you related to the Kennedy's? You look a little like them.

Oh and how warm does the river get max temp in the summer?