Hi Josh being from North Alabama I have probably the same type of soil as you so am wondering if you hit the limestone shelf when you were digging? My pond loses an inch or so a day in the summer and is just a little bigger than yours 190 by 90 and is 8 ft deep. Currently with the lack of rain I am about 3' low. I currently feed water from a shallow well that is only providing about 2500 gallons a day due to the surface water table being low. When I have the funds I am going to take it down to 80' to have a better supply of water. You might want to look into getting a well dug to supply water for your pond since like me you are strictly filling it with run off and when we don't get but 2 inches of rain in a month and a half there isn't much we can do. Hope that helps.

Bob