This is a water snake I photographed at Hidden Valley lake a few weeks ago.

This photo was taken near the dam on the eastern side of the lake.  The snake was almost three feet in length, which based upon the research is fairly good sized for this kind of snake.  Water snakes, or Northern Water Snakes as they are sometimes known, are not poisonous but can be aggressive and have a painful bite.  They feed on frogs, fish, and other water-based prey.  These snakes are found throughout Virginia according to the VDGIF map of occurance for this species.