Mike Otto is great, very nice guy, I've had him out to my place for consulting. He is practically a legend in pond consulting and building.
If Mike is busy..another guy I am using to build a retention pond below my dam is Lee Thornton in Edgewood, Texas. Lee actually built my 4 acre lake before I owned the property. Great guy, very reasonable, and honest as they come.
Lee Thornton:
(214) 394-7970
(903) 896-4862
ps: If later on you narrow down your list and want to see a lake Lee built you can come look at mine...I'm only 18-20 mins from Emory. My lake stayed pretty full through the drought. You should probably talk to Mike Otto, HighFlyer's guy, and Lee Thornton.