heybud- I don't think you need to worry too much. It is always hot and dry in this part of Texas in the summer. Your pond has been there for awhile and it must have a deep reserve or you would not have 9# flathead catfish still alive. I would be careful to not overstock until it is full and you have more experience with the variation in pond levels. Check into water wells to help you keep it full. The story about the adjacent land with a plugged flowing spring makes me think you have plenty of underground water. Have you measured the deepest part to see how much reserve you have? A 200' well in this area will only cost you $2500-3000.

Please no more rain for a month! :|