Owners of coastal properties are getting hit by a rising tide of bad news. Higher sea levels slashed home values in 17 states from Maine to Mississippi by $15.8 billion over a dozen years, according to updated research from the nonprofit First Street Foundation.

Florida showed the greatest loss in relative home values at $5.4 billion, followed by New Jersey at $4.5 billion and New York at $1.3 billion.

The research from First Street, which is based in Brooklyn, New York, so far focuses on the impact of rising water levels from 2005 to 2017 for 25.6 million coastal properties, rather than the cost of damages tied to specific events such as Superstorm Sandy, which ravaged New Jersey and New York in 2012, or New England storms known as nor'easters. Researchers use assessed property values and layered in potential lost appreciation versus similar homes, among other factors.

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Biggest loser



Ocean City, New Jersey, lost the most among urban areas on the list, with more than $530 million in value wiped out by rising water levels, according to the First Street analysis. Perhaps surprisingly, Ocean City lost more than No. 2 Miami Beach, Florida ($337 million), which is often cited as a prime example of accelerating erosion tied to higher ocean levels. Eight of the 20 cities with the most property value lost over the study period are in New Jersey, while seven are in Florida.

The researchers plan to release data in coming months for the rest of the coastal U.S. and then move on to major rivers. This week, they added data for Maryland, Delaware and Pennsylvania to previously released regions, including New England, Southeastern U.S. and Gulf Coast states Alabama and Mississippi.

In the mid-Atlantic, increased tidal flooding from 2005 to 2017 extracted $862.1 million in relative property value, the researchers found. Maryland saw a loss of $555.7 million, Delaware almost $300 million and Pennsylvania roughly $10 million.

Homeowners can find the information on a website called FloodIQ, which gives access to public data crunched in a way previously undertaken only by private companies such as insurers and Wall Street firms, which use the data to evaluate investments and risk. Coastal homes may face greater dangers from flooding and storms than inland properties, damping their market value and crimping a region's tax base.

Heading inland

The First Street Foundation's studies provide the latest evidence that rising seas are shifting people's preferences away from living along coastlines. Last year, a torrent of studies, from the Union of Concerned Scientists to the Journal of Financial Economics, showed rising seas are eroding property values amid climate change.

Another study out this month in the journal Nature Communications looked at 540 urban areas in the U.S. It projected that by 2080, climate conditions will "shift considerably and become either more akin to contemporary climates" in cities sometimes hundreds of miles to the south or "will have no modern equivalent."

The data on FloodIQ takes into account only past events. Researchers said they took pains to create a "like-for-like" comparison for what's called "sunny-day flooding," or rising water strictly due to higher tides, by eliminating other factors that typically affect a real estate market.

"Hits home" for property owners

The site has seen "really a visceral response" from homeowners looking up properties to see the direct impact of rising sea levels, Matthew Eby, First Street Foundation's executive director, said in an interview with CBS MoneyWatch.

It "really hits home for a lot of folks -- the idea that 'OK, well, what should I do now?' Or 'do I need to take some resilience measures?' Or 'is it time to move?' A whole host of options come up, and you can see them thinking it through," Eby said.

Cities with the largest value declines so far:

1. Ocean City, New Jersey, $530 million

2. Miami Beach, Florida, $337 million

3. Hollywood, Florida, $305 million

4. Charleston, South Carolina, $266 million

5. Saint Petersburg, Florida, $244 million

6. North Beach Haven, New Jersey, $217 million

7. Sea Isle City, New Jersey, $209 million

8. Fort Lauderdale, Florida, $194 million

9. New York City, New York, $185 million

10. Atlantic City, New Jersey, $175 million

11. Avalon, New Jersey, $166 million

12. Key Largo, Florida, $160 million

13. Brigantine, New Jersey, $159 million

14. Mount Pleasant, South Carolina, $149 million

15. Jacksonville, Florida, $146 million

16. North Wildwood, New Jersey, $138 million

17. Key West, Florida, $133 million

18. Freeport, New York, $131 million

19. Milford City, Connecticut, $127 million

20. Mystic Island, New Jersey, $126 million