Harvey made its first landfall on the northern end of San Jose Island along the Texas coast on the night of August 25, 2017. Three hours later, this Category 4 storm made a second landfall near Bayside of Refugio County after crossing Copano Bay west of Holiday Beach.
Although the coastal areas where the storm eye passed were mostly unpopulated, its nearby communities along the Gulf coast, from Port Aransas to Port Lavaca, were devastated with maximum wind gusts over 130 miles per hour and storm surge as high as 12 feet. After the landfalls in the Coastal Bend, Harvey turned east toward Houston and brought record amounts of rainfall and massive flooding to southeast Texas.
Harvey’s eye was about 30 miles northeast of Corpus Christi. What if the city took the direct hit instead?
This scenario was probable given the great deal of uncertainty for Harvey to even impact the United States just days prior to its landfall in Texas. Imagine what would have happened if, on that day of August 25th, Harvey stayed on its northwestern trajectory instead of turning more northward. If this happened, Harvey would have become the costliest storm in the United States ever, suppressing Hurricane Katrina of 2015.
One Degree Deviation (ODD)
The following describes some outcomes of a counterfactual exercise under the assumption that Corpus Christi took a direct hit from Harvey. This means that the eye of the storm would have passed through Mustang Island south of Port Aransas.
Instead of the coordinate of 28.0 degrees north and 96.9 degrees west, Harvey would have made landfall at 27.75 degrees north and 97.1 degrees west. This hypothetical location is within one degree, or 25 miles, southwest of the actual landfall location.
Much of Harvey’s impact in the Coastal Bend would have shifted about 30 miles southwest. The city of Corpus Christi and most of its nearby communities, such as Odem and Robstown, would have sustained wind gusts more than 120 miles per hour, instead of the actual less than 90 miles per hour.
During Harvey’s landfall, the maximum wind speed recorded near the eyewall was about 150 miles per hour. Being on the left, or weaker, side of the storm, the city of Corpus Christi experienced the equivalent of Category 1 winds no more than 90 miles an hour.
With a direct hit, however, Port Aransas and Corpus Christi in Nueces County and most areas in San Patricio County would have faced the Category 4 winds that actually devastated Rockport, Holiday Beach, and Bayside. Harvey damaged about 80 percent and completely destroyed about 30 percent of structures in those coastal communities.
Should Harvey cross Corpus Christi Bay instead of Copano Bay, the entire metro area of Corpus Christi would have bore the brunt of the storm. Since Aransas and Refugio counties would now be near the north side of the storm, their communities would have still sustained at least Category 2 winds of more than 95 miles per hour. The majority of homes and business properties in those areas would still have been impacted.
All three counties in the Corpus Christi metro area and Refugio County would have sustained the damage those smaller coastal communities actually experienced last August. Based on this assumption, some estimates can be made under our hypothetical scenario. Harvey’s winds alone would have affected more than 462,000 residents, instead of about 45,500 in reality.
Instead of 3 deaths, the storm would have claimed 30 lives. The National Weather Service estimated about 36,500 homes across the Coastal Bend region were damaged by Harvey, and 12,600 destroyed. Under the counterfactual scenario, the storm would have damaged about 119,500 homes and 6,500 business establishments in the region. In all, 68,000 structures would have been destroyed.
Harvey caused storm surge of 4 to 7 feet above ground level near Copano Bay. So, under the new scenario, the combined effect of surge and tide would have caused inundations in Corpus Christi up to 7 feet above ground level. Because Rockport would now be close to the north side instead of the center of the storm, it would have faced the highest storm surge over 10 feet, as Port Lavaca actually experienced during Harvey.
Drawing on Climate Central’s data, an average sea water level at 7 feet would affect about 20,000 people and damage more than 15,000 homes across the Corpus Christi metro area. Most homes on North Padre Island and Mustang Island, including Port Aransas, would have submerged.
For the Coastal Bend region as a whole, the National Weather Service estimated a total of $4 billion in wind storm damage and $520 million in flood damage. Under the counterfactual scenario, the total losses from wind and flood would have been close to $46 billion. In other words, the storm’s economic toll would have been about 10 times more than what was realized in 2017. Communities that were directly hit by Harvey, including those in Aransas and Refugio counties, would not have been spared either.
Harvey’s widespread and catastrophic effects over southeast Texas have made it one of the nation’s costliest storms. Including indirect fatalities in the Coastal Bend, Harvey claimed more than 100 lives in Texas. According to the National Oceanic and Atmospheric Administration (NOAA), Harvey’s economic cost is $125 billion, second only to $160 billion in property damage caused by Hurricane Katrina in 2015. Most economic damage occurred in areas near Houston due to flooding. Conditions over these areas would not have changed under our counterfactual scenario.
So if we simply replaced the estimate of $4.6 billion for the Coastal Bend region with the counterfactual estimate of $46 billion, the economic losses for the entire disaster region in Texas would have totaled $166.4 billion. In other words, Harvey would have become the costliest storm in U.S. history.
Our counterfactual analysis describes would have happened in 2017. But how well could Corpus Christi have recovered? Today, about one year after Harvey, about 65 to 85 percent of businesses in Rockport and Port Aransas have reopened, although at least 20 percent of pre-Harvey residents did not return. This pace of business recovery runs in contrary to the general prediction of the Federal Emergency Management Agency (FEMA) that at least 40 percent of impacted businesses will not return following a major disaster.
One aspect of resilience refers to how fast a community recovers from a disaster. Despite the rebuilding activities among the impacted communities in the Coastal Bend so far, it remains too early to draw a definitive conclusion on their pace to full recovery.
According to FEMA, Aransas County and, in particular, Rockport are areas with the least internal capacity to rebuild within the 41-county Harvey impacted zone in Texas. The capacity to restore infrastructure in Aransas County is limited by its relatively small government size and thus limited financial resources.
However, other than fiscal constraints, Aransas County seems to be more resilient to natural disasters than other counties in the Coastal Bend. According to one comprehensive study of local disaster resilience by the University of South Carolina, Aransas County ranks high at least among all counties in the Harvey disaster zone.
The university’s Hazard and Vulnerability Research Institute complies Baseline Resilience Indicators for Communities (BRIC) based on social, economic, infrastructure, communication, institutional, and environmental aspects of individual counties. These indicators depict a community’s vulnerability to a natural disaster as well as its capacity to recover from it.
Aransas County’s overall resilience index is slightly below other Coastal Bend counties’ and the national average, but it scores particularly high in the “institutional” category, which includes such factors as mitigation plans and other community services. Except for Duval County, institutional support in most Coastal Bend counties also appears to be greater than the U.S. average, due in part to officials’ awareness of the region’s vulnerability to tropical storms.
According to the BRIC data, however, most counties in the region are relatively less resilient to a given natural disaster from the “economic” and “social” perspective, as measured by per capital income, educational attainment, healthcare access etc.
Likewise, a study by researchers at University of Buffalo’s Regional Institute ranks Corpus Christi’s disaster resilience capacity very low among all U.S. metro areas.
Photo Credit: Joe Raedle / Getty Images
Read this article in print (PDF).
- HARVEY: Immediate Impact & Recovery, 2018Q2 Update
- Hotel Performance After Harvey
- Business Recovery After Harvey
- Harvey’s Impact on Corpus Christi
- Harvey Facts & Stats
Notes: The counterfactual (“what if”) exercise in this article was suggested by an attendee at the Corpus Christi Northwest Business Association meeting on July 19, 2018.
A previous version of this article contains incorrect data on the BRIC indicators for counties.