Canon question

The Marvel rule sometimes seems to be "Xavier's mansion has whatever it needs to have for the story", but let's at least try to be consistent.

Although it we didn't see it in the movie (that I recall), a number of fics describe the X-mansion as being near water (I know Special had a boathouse, for instance). What body of water would this be? The Hudson, or some smaller tributary of it? Certainly not the ocean?

I vaguely remember seeing some maps of the mansion grounds at one point that did feature water, but the site that housed them is down. Help?