Hey Zoe"
Where in Ohio is thi?
I was just wondering I am in Ohio and the water level fluctuates a great deal around here and you will need for water to be able to get in the pond. Rain flow will help but I am not sure if that will be good enough. Probably will be, but I would like my pond to be below the water line of the surrounding properties. If you do excavate I would consider that to be changed?