Prewitt Reservoir primary use is for irrigation purposes. Water levels are constantly fluctuating, many times the waterline is several hundred yards from the boat ramps. As far as topography of the lake, it is mostly a big basin with nothing specatacular for depth variations. Obviously the dam area has the deeper water and rock structure. The water is also very stained.
All I thought it was good for was carp, cats, and wipers.
I spent many summer days at Prewitt tearing up the sandhills in the dune buggy and catching carp and the occasional bullhead. When I went past there last summer, there wasn’t a boat on it and it looked almost dried up.