Pond Boss Forums POND CONSTRUCTION Selecting a site starting the dream

It has been fascinating reading for a year or so and now it is my turn to jump in the pond fray. Like so many before me the questions seem to be the same and everyone is so helpful, if no one minds I will throw out a couple of mine.

We are purchasing a small 13.11 acre plot in Green County Wisconsin. My dream is to build a pond for swimming and fishing. I have a topo map with 10 foot drops (tried to include it but was unable maybe next time if I can figure how. The Watershed is strong but much of it seems to drain just outside my property. I did ask the potential neighbors if I could buy a section of their property and while they were open to the idea they would not commit. I am getting soil samples from Green County Land and Soil. Looking at the proposed site:

1. I was hoping to build a 2-3 acre but am concerned about
water supply/watershed. Using a topo map or anything else,
how do calculate pond size?
2. Since I am new to all of this, is it easier to build a
smaller pond say 1 acre and then expand later?
3. Can anyone recommend a dirt person in Green County,
Wisconsin? I did get a list from the County but no one they
recommended.

Thanks for the inputs. I can not take possession of tha land until the corn is harvested in November so I have all winter to read and plan.