SOUTH PORTLAND — Last October, “Superstorm Sandy” hit the U.S. East Coast, killing 72 people and leaving 8.5 million people without power.
Several factors made Sandy a “super”storm, according to Jay Tanski, a coastal processes and facilities specialist with New York Sea Grant and John Cannon of the National Weather Service, who presented at the Maine Beaches Conference on July 12.
For one, Sandy was huge, with tropical force winds more than 1,000 miles in diameter (hurricane winds usually span 50 to 100 miles). The storm’s impacts were felt across nearly two million square miles and 24 states. The storm remained “tropical” throughout its travels because of abnormally warm water in the Atlantic Ocean.
Then, in true “super” style, the storm quickly transformed from a somewhat unpredictable tropical cyclone to a more predictable but powerful nor’easter. The winds expanded and accelerated as Sandy made a hard left turn and slammed into the Jersey Shore, bringing rain and even snow to areas west and north.
Sandy’s winds stacked waves into a flooding surge from Florida to Maine, a surge which arrived in the New Jersey-New York region at the same tide as high tide. The storm tide (high tide plus surge) reached the highest levels in Manhattan and western Long Island, which are located at the narrow end of a funnel-shaped shore. So where the Hamptons on L.I.’s east end saw a surge of five feet, New York City saw 12 feet of water pouring into the subway system.
Maine experienced only minor erosion and flooding, but according to Tanski and other experts at the conference, Maine can learn more from the aftermath, the $65 billion in damages and the recovery effort which is still going on nearly ten months later. Here, then, are Sandy’s lessons for Maine:
* Enforce coastal construction standards.
Sandy damaged or destroyed 650,000 homes. Some towns lost 10 percent or more of housing stock. Dwellings built in the 1970s to new flood insurance standards did better than older structures. “The [National Flood Insurance Program], you can argue about it, but in some cases, especially developed areas, it has done was it was supposed to do,” said Tanski.
The Army Corps of Engineers is looking at elevating 5,000 structures at a cost of $400 million. In many towns, local restrictions on height prevented people from raising their homes, but after Sandy communities removed those restrictions.
* Protect, restore, and maintain sand dunes.
Photographs from before and after Sandy show that areas with healthy, maintained dunes did better than those without. Where beachfront properties were developed or where beach nourishment/dune-building projects had not been maintained, damage occurred.
* Identify debris staging and storage areas.
Sand that washed into the streets had to be plowed and shoveled like snow, piled somewhere, tested for toxics and sifted to remove debris before it could be spread back on the beach. Sandy left behind 250,000 flooded and ruined automobiles (some of which were parked on an old airport runway to prevent them from leaking oil). Demolition debris from splintered homes and flooded businesses (nearly four million cubic yards on Long Island alone) had to be trucked and barged to landfills (with towns footing the bills). Scientists are just beginning to understand the impact of millions of gallons of untreated sewage that entered local waters, and the thousands of oil spills and leaks from hazardous chemicals stored in flooded basements and closets.
* Keep an eye (and an ear) on the forecast, but don’t wait to take action.
Meteorologists weren’t sure about Sandy’s track or strength, with three different models predicting three different futures. But even when the warnings were issued, people did not always heed them.
“Sea Grant is embarking on a major study of how people receive and react to warnings,” Tanski said. John Cannon of the National Weather Service admitted that weather forecasts “aren’t going to really get any better,” and so his agency his trying to improve communications. Cannon noted a personal plea from one New Jersey meteorologist as being more effective than the standard, computerized language.
* Imagine your own personal superstorm.
Stephen Dickson and Pete Slovinsky of Maine Geological Survey have been testing ingredients for a superstorm in Maine, using as a benchmark a January 24, 1921 storm when the Portland tide gauge recorded a 6.5-foot surge. That flood could have been much greater if the storm surge had arrived five hours earlier, when a full, close (perigean) moon drew the highest tides of the year.
To see how such a storm would translate on the ground, Slovinsky simulated the “superstorm” conditions on several southern Maine communities, showing how a six-foot surge at a time of the highest tides could wash away beaches and put beach communities, oil storage facilities, transportation corridors and sewage treatment plants under water.
As one property owner noted at the conference, scenarios can be hard for some coastal residents to digest. People want numbers, probabilities of whether or not a storm like Sandy will happen, to help them decide whether or not they should plan for extensive and costly preparations.
But if Sandy showed anything, it’s that preparation still makes sense, even an unpredictable world, presenters stressed.