My first move would be to stock pure strains cutties from other sources on those waters wecutties no longer exsist or are in low numbers. Remove as many undesireables first if necessary.
What has to be remembered is not every lake or stream in watershed that historically had a certain type of native fish necessarily had those native fish. What i mean by that is take Athabasca Rainbows for example,They were not found in every lake and stream in the upper Athabasca watershed. I don't have a problem adding them but when I hear people say that rainbows or cutties have been wiped out of certain waters I ask the question..Where those fish ever there in the first place ?