Even without seeing " up close" and personal photos....
The most common that comes to mind would be the Northern Water Snake
I found this great link, I hope it helps (seems to be more put together in MASS then in CT
(Hey I do not want any jeers or leers.lol, What the heck fire away Our state sucks on laws etc...

http://www.masnakes.org/snakes/north...ter/index.html

I hope this helps