dredging does nothing regarding salt water intrusion
Not directly, but the more marsh you put between the gulf and an inland ecosystem the harder it is for the saltwater to get in. You can't stop the tides, but the idea of putting a bunch of shite between yourself and it is not a bad idea. A combination of marsh creations, freshwater diversions, shoreline stabilizations, and other methods on every project would be ideal, but nobody wants to spend the money required. There are great restoration projects out there that can't get past all of the permitting and funding hurdles. Everyone wants to do something on someone else's dime, in unattainable time frames.