Risk of Hurricane Storm Surge Damage Threatens 6.5M U.S. Homes

Article

CoreLogic, a global property information, analytics and data-enabled services provider, released its 2014 storm surge analysis featuring estimates on both the number and reconstruction value of single-family homes exposed to hurricane-driven storm surge risk within the United States.

According to the findings, more than 6.5 million homes along the U.S. Atlantic and Gulf coasts are at risk of storm surge inundation, representing nearly $1.5 trillion in total potential reconstruction costs. More than $986 billion of that risk is concentrated within 15 major metro areas.

This exposure could constitute significant risk for homeowners and financial services companies, as many at-risk homes lack protection from insurance coverage.

The analysis examined homes along the coastlines of 19 states and the District of Columbia in the Gulf and Atlantic regions, extending as far west as Texas and as far north as Maine. Florida ranks number one for the highest number of homes at risk of storm surge damage, with nearly 2.5 million homes at various risk levels and $490 billion in total potential exposure to damage.

At the local level, the New York metropolitan area, which encompasses northern New Jersey and Long Island as well, contains not only the highest number of homes at risk for potential storm surge damage (687,412), but also the highest total reconstruction value of homes exposed, at more than $251 billion.

To enhance accuracy, the storm surge analysis has been expanded from prior years’ reports to encompass additional categories of single-family residential structures including mobile homes, duplexes, manufactured homes and cabins, among other non-traditional home types. The addition of these categories, along with new construction, contributed to a higher number of total homes identified within potential surge areas. The values represent estimates of reconstruction costs, taking into account labor and materials, and are based on 100-percent or total destruction of the residential structure. Depending upon the amount of surge water from a given storm, there may be less than 100 percent damage to the residence, which would result in a lower realized reconstruction cost.

While scientific predictions are pointing to lower-than-normal storm activity for 2014, the risk of significant damage to homes is a constant threat.

“Though the 2013 hurricane season will be remembered for the fact that no storms made landfall along the U.S. coast, this reprieve from hurricane-related damage should not lead to complacency in preparing for future storms and the potential life-threatening conditions they can bring,” said Dr. Thomas Jeffery, senior hazard scientist for CoreLogic Spatial Solutions. “This year’s season is projected to be slightly below normal in hurricane activity, but the early arrival of Hurricane Arthur on July 3 is an important reminder that even a low-category hurricane or strong tropical storm can create powerful riptides, modest flooding and cause significant destruction of property.”

The 2014 analysis shows that total exposure varies significantly from state to state given differences in population, trends in residential development, geographic risk factors, length of coastline and other distinguishing factors. Florida and Texas, for example, are within the top five states for number of properties at risk primarily because of their extensive coastlines. Louisiana and New Jersey, on the other hand, have a smaller coastal area overall, yet are included in the top five list as a result of relatively low elevation that allows storm surge inundation to extend farther inland and affect more homes.

The concepts in this analysis also complement Federal Emergency Management Agency (FEMA) flood zone information to provide a snapshot of potential damage exposure at the property level, as many properties located outside designated FEMA flood zones are still at risk for storm surge damage. The standard FEMA flood zones are designed to identify areas at risk for both freshwater flooding as well as storm surge based on the likelihood of either a 100-year or a 500-year flood event. They do not differentiate risk based on storm severity, and as a result, do not effectively define the total extent of the risk possible along coastal areas.

To illustrate varying degrees of flood risk exposure, homes that are not located within FEMA 100-year floodplains were compared against the number of homes located in surge inundation zones, as well as those located in both surge and FEMA Special Flood Hazard Areas (SFHA).

Homeowners who live outside the FEMA flood zones typically do not carry flood insurance, given that there is no mandate to do so, and therefore may not be aware of the potential risk storm surge poses to their properties. Among select major metro areas, Virginia Beach-Norfolk-Newport News, VA-NC has the highest percentage of homes (86 percent) at risk of storm surge, but not designated in a FEMA flood zone. Philadelphia-Camden-Wilmington, PA-NJ-DE-MD and Jacksonville, Fla. also top the list at 85 percent and 76 percent, respectively. Even in New York-Newark-Jersey City, NY-NJ-PA, 68 percent of homeowners at risk of flood or surge inundation would not be required to carry flood insurance because they are not located within a designated FEMA 100-year floodplain.

Additional findings in the CoreLogic storm surge analysis include:

The five states with the highest total number of properties at risk include: Florida (2,488,277), Louisiana (738,165), New York (466,919), New Jersey (445,928) and Texas (434,421).

The five states (including the District of Columbia) with the lowest total number of properties at risk include: the District of Columbia (3,895), New Hampshire (10,853), Maine (23,439), Rhode Island (26,558) and Delaware (48,534).

The five states with the highest value of reconstruction costs for homes at risk include: Florida ($490,403,653,377), New York ($182,474,294,695), Louisiana ($161,062,467,382) New Jersey ($134,194,963,314) and Virginia ($92,001,482,217).

The five states with the lowest value of reconstruction costs for homes at risk include: District of Columbia ($394,437,173), New Hampshire ($2,649,086,294), Maine ($6,629,856,369), Rhode Island ($7,389,384,876) and Alabama ($10,333,310,460).

The reconstruction value of the homes exposed to storm surge damage in the Gulf is much less than the reconstruction value of homes in the Atlantic region. The total reconstruction cost value of homes along the Atlantic coast is nearly $951 billion, which is approximately double the value of at-risk properties in the Gulf region at just over $545 billion.

Storm Surge Risk Level (Storm Category)	Total Homes Potentially Affected	Total Estimated Reconstruction Cost (U.S. dollars)
Extreme (Affected by a Category 1-5 storm)	1,698,510	$410,311,136,086
Very High (Category 2-5)	1,422,302	$328,864,859,770
High (Category 3-5)	1,562,755	$358,386,053,345
Moderate (Category 4-5)	1,159,506	$267,920,396,772
Low (Category 5)	669,105	$131,010,761,964
Total	6,512,178	$1,496,493,207,937

Rank	State	Extreme	Very High	High	Moderate	Low	Total
1	Florida	$165,897,104,806	$87,833,392,383	$100,149,415,929	$66,285,325,433	$70,238,414,826	$490,403,653,377
2	New York	$52,507,586,381	$44,946,290,850	$49,330,325,343	$35,690,092,121	N/A	$182,474,294,695
3	Louisiana	$32,093,743,120	$20,863,168,290	$60,324,715,609	$30,195,498,766	$17,585,341,597	$161,062,467,382
4	New Jersey	$35,481,183,707	$52,757,497,109	$22,040,754,156	$23,915,528,342	N/A	$134,194,963,314
5	Virginia	$21,841,973,286	$24,727,761,843	$21,125,036,730	$17,984,142,912	$6,322,567,446	$92,001,482,217
6	Texas	$7,087,911,852	$10,934,862,299	$19,093,100,616	$21,596,543,413	$17,844,003,459	$76,556,421,639
7	South Carolina	$27,753,414,114	$12,587,049,770	$13,178,862,500	$9,042,760,201	$5,714,959,963	$68,277,046,548
8	Massachusetts	$9,724,029,035	$17,005,251,525	$21,270,736,012	$14,998,153,704	N/A	$62,998,170,276
9	North Carolina	$15,240,651,298	$11,140,071,525	$10,815,898,891	$8,527,781,798	$7,845,320,710	$53,569,724,222
10	Maryland	$11,856,448,820	$9,687,832,004	$6,433,018,198	$6,846,887,233	N/A	$34,824,186,255
11	Connecticut	$8,972,737,674	$8,000,267,149	$7,249,691,647	$8,755,618,092	N/A	$32,978,314,562
12	Georgia	$10,073,078,318	$9,827,457,212	$4,910,948,595	$3,312,344,274	$1,359,659,962	$29,483,488,361
13	Mississippi	$2,909,086,132	$3,848,632,388	$5,094,422,106	$4,498,942,887	$1,793,435,179	$18,144,518,692
14	Pennsylvania	$321,556,789	$5,809,547,530	$6,184,854,639	$4,806,610,676	N/A	$17,122,569,634
15	Delaware	$3,714,154,308	$3,297,365,039	$4,157,600,924	$3,836,711,320	N/A	$15,005,831,591
16	Alabama	$1,294,626,444	$2,345,175,836	$1,824,810,598	$2,561,638,760	$2,307,058,822	$10,333,310,460
17	Rhode Island	$1,704,012,530	$1,755,100,803	$1,932,489,875	$1,997,781,668	N/A	$7,389,384,876
18	Maine	$1,404,632,358	$820,799,901	$2,195,324,309	$2,209,099,801	N/A	$6,629,856,369
19	New Hampshire	$433,205,114	$677,219,225	$972,432,591	$566,229,364	N/A	$2,649,086,294
20	District of Columbia	N/A	117,089	$101,614,077	$292,706,007	N/A	$394,437,173
Total	$410,311,136,086	$328,864,859,770	$358,386,053,345	$267,920,396,772	$131,010,761,964	$1,496,493,207,937

Region	Atlantic Coast Homes (Potential)	Atlantic Coast Structure Damage Exposure (Estimated)	Gulf Coast Homes (Potential)	Gulf Coast Structure Damage Exposure (Estimated)
Extreme	1,005,544	$269,585,189,074	692,966	$140,725,947,012
Very High	899,461	$228,229,456,329	522,841	$100,635,403,441
High	851,057	$214,135,275,085	711,698	$144,250,778,260
Moderate	677,692	$173,729,009,413	481,814	$94,191,387,359
Low	325,483	$65,241,738,808	343,622	$65,769,023,156
Total	3,759,237	$950,920,668,709	2,752,941	$545,572,539,228

Rank	State	Extreme	Very High	High	Moderate	Low	Total
1	Florida	789,090	459,090	519,409	347,860	372,828	2,488,277
2	Louisiana	160,744	102,347	262,340	134,588	78,146	738,165
3	New York	128,462	114,949	132,179	91,329	N/A	466,919
4	New Jersey	116,613	178,037	74,284	76,994	N/A	445,928
5	Texas	44,569	70,732	110,487	114,945	93,688	434,421
6	Virginia	93,969	115,232	98,190	83,768	27,353	418,512
7	South Carolina	99,884	52,358	59,113	41,490	27,349	280,194
8	North Carolina	72,597	51,016	48,588	40,074	36,889	249,164
9	Massachusetts	31,023	65,124	73,781	48,985	N/A	218,913
10	Maryland	47,825	39,807	27,740	28,719	N/A	144,091
11	Georgia	38,891	48,394	26,513	18,136	8,087	140,021
12	Pennsylvania	1,468	45,582	37,860	32,007	N/A	116,917
13	Mississippi	15,071	20,871	28,644	26,408	10,828	101,822
14	Connecticut	25,227	23,350	22,187	26,462	N/A	97,226
15	Alabama	7,365	12,765	10,182	14,080	13,937	58,329
16	Delaware	11,497	10,416	13,016	13,605	N/A	48,534
17	Rhode Island	6,635	5,972	6,731	7,220	N/A	26,558
18	Maine	5,254	2,942	7,558	7,685	N/A	23,439
19	New Hampshire	2,326	3,317	3,194	2,016	N/A	10,853
20	District of Columbia	N/A	1	759	3,135	N/A	3,895
Total	1,698,510	1,422,302	1,562,755	1,159,506	669,106	6,512,178

Rank	Metropolitan Area	Total Properties Potentially Affected by All Categories of Hurricane	Total Reconstruction Value
1	New York, NY	687,412	$251,038,846,466
2	Miami, FL	562,410	$103,160,570,812
3	Tampa, FL	444,765	$79,149,326,645
4	Virginia Beach, NC	394,705	$87,178,838,156
5	New Orleans, LA	381,149	$85,679,653,561
6	Cape Coral, FL	299,508	$60,430,683,073
7	Bradenton, FL	227,821	$42,955,130,837
8	Houston, TX	216,880	$41,903,647,756
9	Philadelphia, PA	213,668	$42,204,432,570
10	Naples, FL	177,651	$41,259,312,520
11	Jacksonville, FL	174,180	$36,509,802,458
12	Boston, MA	169,102	$46,713,411,965
13	Charleston, SC	108,045	$27,880,315,028
14	Lafayette, LA	106,166	$21,266,042,348
15	Myrtle Beach, NC	104,707	$19,373,709,040
Total	4,268,169	$986,703,723,235

CBSA	Total Homes Exposed to Flood or Surge Inundation	Total Homes in Both a SFHA and a Surge Zone	% of Homes in Both a SFHA and a Surge Zone	Total Homes Located Only in a FEMA SFHA	% of Homes Located Only in a FEMA SFHA	Total Homes Located Only in a Surge Zone	% of Homes Located Only in a Surge Zone
Virginia Beach-Norfolk-Newport News, VA-NC	395,584	55,115	13.9%	879	0.2%	339,590	86%
Philadelphia-Camden-Wilmington, PA-NJ-DE-MD	230,074	17,775	7.7%	16,406	7.1%	195,893	85%
Jacksonville, FL	187,861	30,653	16.3%	13,681	7.3%	143,527	76%
Boston-Cambridge-Newton, MA-NH	187,801	29,936	15.9%	18,699	10.0%	139,166	74%
Deltona-Daytona Beach-Ormond Beach, FL	113,172	19,857	17.5%	10,858	9.6%	82,457	73%
New York-Newark-Jersey City, NY-NJ-PA	725,020	192,202	26.5%	37,608	5.2%	495,210	68%
North Port-Sarasota-Bradenton, FL	230,344	83,795	36.4%	2,523	1.1%	144,026	63%
Washington-Arlington-Alexandria, DC-VA-MD-WV	25,462	3,788	14.9%	7,225	28.4%	14,449	57%
Cape Coral-Fort Myers, FL	300,988	140,736	46.8%	1,480	0.5%	158,772	53%
Tampa-St. Petersburg-Clearwater, FL	481,525	197,875	41.1%	36,760	7.6%	246,890	51%
Houston-The Woodlands-Sugar Land, TX	338,090	51,114	15.1%	121,210	35.9%	165,766	49%
Baton Rouge, LA	127,719	29,864	23.4%	37,228	29.1%	60,627	48%
New Orleans-Metairie, LA	383,991	211,871	55.2%	2,842	0.7%	169,278	44%
Naples-Immokalee-Marco Island, FL	180,489	104,514	57.9%	2,838	1.6%	73,137	41%
Miami-Fort Lauderdale-West Palm Beach, FL	1,191,134	356,400	29.9%	628,724	52.8%	206,010	17%