The other issue is drinking water. There is barely enough as it is, and the local sources are vulnerable to salt water intrusion. That might do for Miami even before the streets are underwater. No amount of added fill will help that problem.

http://www.1900storm.com/rebuilding/

It would work well enough if we can get a handle on climate change. Failing that, Miami flooding will be the least of anyone’s worries.

The other geographical feature that stops the Everglades from retreating northward is the cross-state canal system at Lake Okeechobee. As part of the flood control system, the Army Corps of Engineers built canals connecting the lake (which was originally a natural feature, but has been surrounded by levees) to rivers on either side: the Caloosahatchie to the west, and I don’t recall the name of the one to the east. You can sail a boat from Fort Myers to Stuart (I think that’s the city on the east end, but I’m reconstructing the map from memory) without encountering salt water, or at least you could when I lived in Florida.

The Everglades is actually a river, about 100 km wide and something like 150 km long. If the water flow is permanently (not just seasonally, as sometimes happens in the dry season) lost, you lose the ecosystem entirely.

However, what really tugs at my heart is what will happen to the once great Everglades. Even without the rising sea level it was only a remnant of its former glory. Now the saltwater and mangrove habitat of Florida Bay is encroaching further inland into the River of Grass. The freshwater ecosystem will retract further north, but since it is bordered on its north by hundreds of thousands of acres of sugar cane fields it will be squeezed out of existence.

Apparently I spoke too soon about Jeb Bush’s ban on speaking the words “Climate Change” in his state. Maybe he’s being ignored, or aggressively being challenged.
At the Fifth Annual Southeast Florida Regional Climate Leadership Summit, Broward County Mayor, Christine Jacobs can be seen discussing climate change in front of a screen plastered with logo of Florida next to the words “Southeast Florida Regional Compact CLIMATE CHANGE” (19:40).