Disappearing Marshland

Most satellite images of the Louisiana shoreline give a false sense of substance. Take this one for instance:



It shows landmass that doesn't really exist.

The radar image below gives the reality:




There is more water than land in the approaches leading up to New Orleans. Hurricane Katrina destroyed a lot of those marsh lands but they've been in decline for decades. Lake Borgne is becoming part of the Gulf of Mexico. New Orleans and south east Louisiana is sitting very precariously on slender strips of land. How soon will that little strip of land that reaches from New Orleans to Venice be there?