Since steel rusts at about the same rate if O2 and water is present, that might buy you some time. Whether it's 6 mos-a year or 5 years I have no idea. Who's to say the pipe inside the dam isn't rusted thru too?

Get a plumber who has one of those cameras on a snake to inspect it first.

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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).