If ever there's a new owner (neighbor), then you would have to clearly communicate the property lines. However, it's best to know your state's laws. Many states ceed access to an entire body of water if a land owner has land that abuts to only a portion of the body of water.

Regarding what 'spring fed' means, I think that technically means that the pond is fed water via a spring, or multiple springs. I does not indicate size of a pond, I think.

Excerpt from Robert Crais' "The Monkey's Raincoat:"
"She took another microscopic bite of her sandwich, then pushed it away. Maybe she absorbed nutrients from her surroundings."