It costs a lot of money to rehabilitate a lake.
There are a lot of lakes that we don't want warmwater fish in. Now, I am a total warmwater fish advocate, BUT, we do have lakes that are meant to be trout only. This is, in part, due to the fact that we will use the lake itself to raise the trout. In Region 5 we call these fingerling waters. Mineral Lake, Swift Reservoir, Northwestern Reservoir are just a couple of lakes that we close early in the fall in order to plant fingerlings and allow the lake to become a fingerling nursery.
When people decide that there should be bass, pike or other warmwater fish in these lakes it messes with the management plans that we have carefully and specificaly set up for these waters.
So we have to go in an rehab a lake. Lowland lakes are as big a problem as high lakes. We have people that plant sturgeon everywhere with little care that sturgeon can and do carry fish diseases that can affect other fish. Just because a fish doesn't look sick, does not mean it is not a carrier that can affect a lake population.
I think if people want certain species in a lake, they should contact their local bio and TALK to them about it. Find out what the management issues are. There may be VERY good reasons as to why certain species should not be stocked. Or, in some cases, it may turn out that there is room for the species wanted and we can make something work out. Like Kress like. We put channel catfish in there four years ago and it has worked out great.
Bottom line is DON'T STOCK FISH IN LAKES. You wouldn't want to get caught or turned it doing it anyway. It wouldn't be pretty.