Making a raised pond but looking for feed back

[Ynott116]

i have a crappy paint blue print for you all and my idea.
so id like to make a 12' by 6' pond 6' deep at the lowest end.
I would like to do one 3'' bottom drain to a plywood water proof sump 8' by 30'' 2' tall
then run it back to the pond clearly, idk why but i have been considering a retro bottom drain over the bottom drain/
I feel better cutting a bulk head on wood would fit me better, if i did a bottom drain yes i would cement it in but it would be on dirt.
i am digging the hole then putting boards above ground up on ground lvl anchored down. Please let me know ur thoughts!

 

[GBBUDD]

HARD TO TELL WHAT your thinking some labeling would help bead , rdf, sieves , bog