I asked this question a long time ago... as my diving was going to be part of the pond clean up.
Essentially, Rod and I decided NOT to do it due to several hazards- fishing line (entanglement issues), appliances and carpet rolls on the bottom (among other things.... we know this from rescue divers that pulled a little boy out that drowned when he fell thru the ice. They said conditions were really bad!), no good entry/exit.... muddy. The pond was not very big around.... but we know it's 35 feet deep. We know it IS mapped for depth, drop offs, drainage, etc... but couldn't get our hands on the map (lovely city dragging their feet). Also... we DID have the water tested... as we didn't want to jump into cess pool. The water quality of our neighborhood pond came back fine (safe) but, without knowing all the other "stuff" in there, we decided NOT to dive it. Now... let me say, we were only going to bring up the easy stuff... no heavy salvage from the bottom... didn't want to endanger ourselves. But we scrapped the whole idea, cause it just wasn't safe enough, so... no diving the neighborhood pond for us.