With the gate on the pond side, if there's any pinhole in the pipe, it won't be constantly leaking into the dam. Plus, with the pipe on the bottom, it's under more pressure than if it were on the top of the water column.

Personally, if I were doing it for my pond, I'd look into a siphon system, running near the top of the dam.

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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).