I would recommend an inspection of any pond by a qualified pond builder. Just like a house inspection a pond inspection is very critical. A friend of mine almost bought a piece of land with pond on it in the Catskills near the Delaware river. Even though I looked it over for him we missed some very serious issues about how the spillway and embankment were built that could cause the whole embankment to give way.
We had the guy who built my pond do an inspection and needless to say we both got quite an eductaion and my friend saved himself from a potentially expensive and disasterous situation.
Where in Upstate New York are you? If you are near the Catskills I would give Catskill Pond a call. Check out his web site here:
http://www.frontiernet.net/~catpond/ The money you spend on a professional pond inspection is well worth it.
