You are in a tuff area proceed with caution spend time and perk the site up at Ricketts Glen as fast as they build em quite a few drain out We built a 6 acre lake in Laporte and went down 22 foot to silence a spring As you go up to Laporte big blue clay[pressure crushed sedimentry blue stone] the best for a pond.
Do not rush it wait a year hire some one to dig 10 yd test holes and see what the soil is and the you can die an upper hole and see if you get bleed off to a lower hole etc. Jhon Edwards is in Ricketts he might be able to guide you he is an older gentleman of 78 and a pain in the ass but well versed on a pond explore. Tell him Scott says hello
best of luck


Scott Trava
Catskill Pond
http://catskillpond.com
scott@catskillpond.com
Returning Catskill Waters To A Simpler Time
EST. 1923