This should have been a case study in Climatopolis (I've read through page 200 or so, so maybe it is coming later). The article points out that Norfolk, built on filled in marsh, has sunk more since 1930 than New Orleans. Yikes, but they seem to be trying to address the problem with adaptation (in a costly way):
Larchmont residents have relentlessly lobbied the city to address the [sea level rise] problem, and last summer it broke ground on a project to raise the street around the “u” by 18 inches and to readjust the angle of the storm drains so that when the river rises, the water does not back up into the street. The city will also turn a park at the edge of the river back into wetlands — it is now too saline for lawn grass to grow anyway. The cost for the work on this one short stretch is $1.25 million.
The expensive reclamation project is popular in Larchmont, but it is already drawing critics who argue that cities just cannot handle flooding in such a one-off fashion. To William Stiles, executive director of Wetlands Watch, a local conservation group, the project is well meaning but absurd. Mr. Stiles points out that the Federal Emergency Management Agency has already spent $144,000 in recent years to raise each of six houses on the block.
At this pace of spending, he argues, there is no way taxpayers will recoup their investment.
“If sea level is a constant, your coastal infrastructure is your most valuable real estate, and it makes sense to invest in it,” Mr. Stiles said, “but with sea level rising, it becomes a money pit.”
via www.nytimes.com