While the Coastal Bend dodged a bullet when Hurricane Emily came ashore in Northern Mexico, a Texas A&M University-Corpus Christi professor warns that a direct hit by a major storm could be devastating for Corpus Christi and the surrounding areas both in terms of property damage and loss of life.
Through the sponsorship of Sen. Kay Bailey Hutcheson, Dr. Gary Jeffress, a professor of computing and mathematical science, recently received a $665,000 grant from the National Oceanic Atmospheric Administration to start a program to re-establish height elevations in Texas where thousands of ground points marking elevations above sea level have deteriorated or disappeared since being put in place more than 50 years ago.
The problem is complicated by other factors such as subsidence, which is the sinking of land due to extraction of water, oil and natural gas, and the rise of sea levels due to the melting of the polar ice cap. These circumstances, he points out, have increased the probability that a category four-or-five hurricane would quickly flood the highways marked as escape routes for people fleeing inland.
“The prudent thing to do when a hurricane is approaching is to get out of the way,” stressed Jeffress. “You have a window to evacuate when all designated routes are capable of handling traffic but, because of the changes in elevation, with a category four hurricane or higher it won’t take long before those roads will be impassable.”
According to Jeffress’ worst-case scenario, if a category four hurricane came ashore near Bob Hall Pier on North Padre Island, a 20-foot storm surge could cover that part of the Island and flood major portions of Corpus Christi much like the 1919 storm that destroyed the city’s north beach and much of the downtown area. That unnamed storm, which was the fourth most powerful to hit the United States during the 20th century, killed an estimated 600 people and led to the construction of the sea wall along Shoreline Drive.
“With a category four hurricane, storm surge models predict that Highway 37 would soon be flooded by the Nueces River and the Oso Bay Bridge on Highway 44 would also be under water,” said Jeffress. “Because the elevations along Highway 77 haven’t been charted we don’t even know where the low points are and what the road conditions would be at any given time.”
While Hurricane Celia, a category three storm that struck Corpus Christi in 1970, destroyed much of the A&M-Corpus Christi campus Jeffress says that most of the buildings along the coast could withstand a direct hit by a category four storm. However, a category five hurricane could flatten many buildings and result in significant fatalities.
“To accurately predict what affect a hurricane will have, you have to factor in both the storm surge and the amount of rain that falls,” Jeffress explained. “Add in the fact that a category five storm will spawn tornado-like winds throughout the area, and you’ve got the potential for a serious loss of life.”
The lack of up-to-date elevation data is also a problem for developers who must rely on topographical maps based on data compiled in the 1950s. A prime example is Ward Island, home of A&M-Corpus Christi, where the elevation is actually a foot lower than the 18 feet listed on the maps. The discrepancy is even greater near Rockport where tide gauge records indicate the coastal elevation has dropped a full 18 inches since 1948.
“Since 1970 elevations have changed dramatically,” said Jeffress. “Corpus Christi is relying on information that’s more than 50 years old, and because it’s so flat around here, a foot can make a major difference. Areas that may not have been inundated a few decades ago may now be subject to flooding during a severe storm.”