I am looking at purchasing around 10-20 acres in NE Texas with plans to put in a 1 acre pond. All else being equal, which type of topography is better suited....relatively flat terrain with sufficient watershed for an excavated pond or a sloping topography with a seasonal creek that can be dammed?

I'm curious as to which terrain would be more expensive for pond construction? I will essentially select the piece of land that will be best suited for a pond. I plan to use the NRCS web soil survey to try and select a location with enough clay so I don't end up having to truk in clay or use a liner.

Also, how much watershed is suggested for a 1 acre pond 12-14ft deep? Any suggestions for selecting property best suited are appreciated.

Thanks