From HSWire.com, Protecting Cities From Floods Cheaper Than Postflood Damage Repairs.  Some excerpts from the article:

Researchers say that global warming is here to stay, and thus it is time to start making plans for dealing with the inevitable flooding which will occur as ocean levels rise as a result of warmer water and melting snow and ice. Approximately a billion people currently live in areas which are most at risk — low-lying coastal areas. It is not likely that towns and cities will be moved farther inland, so other measures need to be taken. The researchers say that flood prevention strategies are well established, for example, building levees, barrier islands, etc., so it is not difficult to draw up estimates for such schemes for individual areas.

Planning carries a lower cost than reacting. * * * Researches have concluded that it would be more cost effective for the economies of most coastal areas to employ flood prevention strategies rather than pay to clean up after flooding that occurs as a result of global warming. In a paper published in the Proceedings of the National Academy of Sciences, the researchers discuss likely flooding scenarios in the future as global warming cause ocean levels to rise, and the costs of building structures to prevent flood damage.

A PNAS release quotes the researchers to say that global warming is here to stay, and thus it is time to start making plans for dealing with the inevitable flooding which will occur as ocean levels rise as a result of warmer water and melting snow and ice. They note that approximately a billion people currently live in areas that are likely to be at risk — low-lying coastal areas. Since it is not likely that towns and cities will be moved farther inland, other measures need to be taken. The researchers say that flood prevention strategies are well established, for example, building levees, barrier islands, etc., so it is not difficult to draw up estimates for such schemes for individual areas. What is difficult is convincing cities and towns to spend billions of dollars on preventing floods which will not occur for many years.

The full text of the article cited in the Proceedings of the National Academy of Sciences can be found here.  Adapting to sea level rise cheaper than potential flooding costs.