Maybe I'm wrong, but I always measure a pond depth from the water surface to the deepest spot.

My way of thinking is that if you want a pond that is, say, 20' deep, but the water leaks out at anything greater than 6' water depth, there's no way that I could consider it a 20' deep pond......

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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).