I'd contact the county NCRS Office and see if they can take a soil sample and give their advice for a pond in that location.

I prefered to err on the deeper side rather than on the shallower side when I dug my pond. I went down 22', and by the time the banks were stabilized, erosion filled in almost 4' of the lowest part of the pond. I went that deep because I knew that I didn't have good soil and the pond level would fluctuate with the available ground water. So far in the past 2 years the pond has fluctuated almost 4'.

By uninvited guests I meant fish species. Bullheads for one, and the creek could also possibly bring Carp along for the ride as well.

If you run into good clean clay, stockpile it to line the pond, compacting it with a sheepsfoot roller in 6" lifts and make it a total of 24" thick. That will really seal the bottom and sides.

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).