We have just last week repaired two pipes. Yours seems a little tougher fix. You have supplied good information and we have looked at three ponds also in paulding county. I know that was one of the harder hits areas during the flood. Leaning toward filling it with concrete via pressure grouting from the backside then installing a sihpon system.

However best to look at the site. I can tackle small repairs. The ones we did were on broken vertical pipes only 8" diamemter on one, pretty easy. On the other it was a 10" vertical and we sleeved it with 15 inch sdr-35 pvc pipe and about as much as two folks can manhandle. We used a 8 foot section. WHen talking 12" pipe you might get away with sleeve of 15" it boils down to how long a section we need to tackle. Keep in mind this is what we call a temporary fix meaning. Might last year or so. I know one is stil in place I did back in 1999. Like I said best to look at total replacement from description but let us know. I work with another guy I can send out if interested. thanks and good luck.

Greg Grimes
www.lakework.com