Not sure if that last option is entirely feasible. For one thing, there's no dam to raise the height of, per se. This pond is (or at least, once was) a bowl-shaped excavated-type pond with no damming involved. All told, it would probably be best to just drain and dredge.
I think he either owns, or at least has fairly easy access to, a dozer, backhoe, tractavator, bobcat, etc. (All of the above? I can't remember!). Probably wouldn't be a tough sell to convince him that he needs such "toys", but would be a pretty tough sell to get him to work on the pond with 'em. And I'm not sure that I feel competent enough to operate these machines...I do well to even drive a lawnmower.
