I can give a little background. The first permit to manage an outlet was given for Lake Powell. The alleged reason was to open the outlet when the lake level rose above a certain height, to lower the water in the lake because of septic tanks and docks being underwater. Since then Walton County has pursued permits to do the same thing with Eastern, Western, Alligator and Oyster lakes. I'm not sure what the status of those permit applications is - someone will probably come along and tell us. Except in the case of Oyster Lake, it is more the level of the water in the lakes than the location of the outlets. At Oyster Lake, there is an owner on the east side of the outlet who is involved in a lawsuit with the county. He wants the outlet "managed" so he can build on a lot there. His lawsuit has also halted the restoration plans for Oyster Lake. The county got a grant to build a bridge on 30A there where it crosses the outlet. There is an old culvert there that blocks inward flow of gulf water into Oyster Lake, it is at the wrong elevation for natural functioning of the outlet.
I'm told that in the good old days some of the lakes, especially Powell and Western, stayed open for longer periods and more frequently and that the salinity was higher - lots of salt water fish were caught in those lakes. But the sand has built up at most of the outlets in the last few years. It used to be more common for locals to open the outlets frequently with shovels and such. In the overall long term picture I think these swings in salinity and vegetation have happened lots, but folks have a hard time taking a longterm view. Also in the past before all the development, well, if the lake level stayed high for a while it didn't bother anyone much, and when it finally opened up it didn't threaten anyone who built close to the outlet. The county has also been trying to get rid of all the septic tanks around the lakes - not sure what the status is of those, but personally I don't swim in the outlets when they open up.