The water conditions/quality has improved vastly in the area actually.
The reason the fish left/died was due to the high phosphorus content, which I believe is still being worked on, but the early results are that it is within acceptable limits so walleye, whitefish and pike are currently spawning and doing well there, last year I read that a large number of first year stocked walleye were being caught, I believe they were 3 years old at that point