I'm betting that if you pushed muddy water/debris with the 3/4" pipe, the 6" pipe is cracked and tree roots started growing inside in search of water during the dry spell. I'd look at that area again......

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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).