Flooding on Brickell Avenue during Hurricane Irma. Miami Herald file

For Miami-Dade, Hurricane Irma may have been but a dry run for the real thing — a major hurricane that rakes across the length of the county with the full destructive force of the terrifying Category 5 monster that Irma and its sequel, Hurricane Maria, delivered at their peak.

Irma’s upward sweep through the county as a strong tropical storm, though damaging enough, fell well shy of that.

Still, experts say, there are several lessons to be drawn from Irma and some vulnerabilities to address — some of them obvious, some not.

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And there are reassuring if not conclusive indications about the state of readiness of Miami-Dade’s population and its homes and buildings — especially those built under beefed-up codes since 1992’s Hurricane Andrew — for the next time a major storm looms.

“Irma was a soft test in our part of Florida,” said Richard Olson, director of the Hurricane Research Institute at Florida International University and an expert on disaster response and recovery. “The hard test is still to come.”

 
 

Here is what Olson and three other building experts, architects and planners nonetheless say is the take-away from Irma:

Irma starkly exposed the continued susceptibility of Miami-Dade’s electrical and communications infrastructure to even tropical-storm winds accompanied by hurricane gusts well short of major-hurricane intensity. It reminded us of the related peril hurricane winds pose to the natural tree canopy, especially if it’s not judiciously maintained, and to the county’s vital agriculture industry.

Olson said he was “a little dismayed” at the widespread loss of electrical service, most it blamed on falling trees and branches that took out overhead lines, and the time it took Florida Power & Light to get it restored. He said the utility and municipalities need to put far greater emphasis on properly pruning trees before hurricane season — maybe through a mandatory spring-trimming effort. (That would also have the added benefit of helping preserve precious green canopy by helping trees stay upright in a storm, said Robert Chisholm, an architect who has been asked by the local American Institute of Architects chapter to come up with post-Irma recommendations.)

Utility workers from out of state work on power lines knocked down by trees and branches in Coral Gables on September 16, 2017. AL DIAZ adiaz@miamiherald.com



“Irma was a tropical storm. The amount of disruption to the power grid, I don’t understand that,” said Olson, who has been on numerous disaster-recovery missions around the world. “Being without power for a couple of days is one thing; being without power for a week to 10 days in tropical heat is another, as we were reminded. I do wonder what the hell it would have been like if this had been a direct hit.”

It also underscored the dangerous vulnerability of its neglected older population, in particular those hidden away in sometimes substandard retirement facilities, nursing homes or subsidized housing whose managers may be unprepared for the loss of power or structural damage.

Irma, even as it delivered less storm surge to Miami-Dade’s coastline than initially feared, may also have exposed insufficient public awareness of the high danger that hurricane-driven masses of water poses to life and property.

The chaotic scenes along the state’s highways as hundreds of thousands tried to flee brought into question the wisdom and feasibility of mass evacuations by automobile in cases when a major storm is forecast to strike much or all of the Florida peninsula, as Irma did.

On the encouraging side of the ledger, the experts interviewed by the Miami Herald noted:

Stronger building codes that require hurricane-resistant windows and elevation above flood levels for homes and towers in surge-vulnerable areas like Brickell appear to have done their job. With very few exceptions, glass high-rise windows and curtain-walls held up fine under prolonged tropical-storm-level assault and even in hurricane-strength gusts, which Chisholm noted are far stronger higher off the ground than at street level.

New homes and buildings elevated above flood level fared well, too: that river of water along Brickell Avenue everyone saw on YouTube got into some garages, but didn’t reach new skyscrapers whose bases sit at a higher elevation than an older generation of towers.

Fallen trees and electric utility poles are seen around Coconut Grove as Hurricane Irma's heavy winds pounded South Florida on September 10. PEDRO PORTAL pportal@miamiherald.com



Even new underground parking garages, a relative novelty in Miami, managed to stay dry. There was virtually no damage at the multi-block Brickell City Centre complex in Brickell, which boasts two levels of underground parking and a ribbon-like climate-regulating canopy, said its architect, Bernardo Fort-Brescia, principal of Miami-based Arquitectonica.

“The city has done a respectable job. All the codes that we passed as a result of Andrew have worked pretty well,” Fort-Brescia said. “We did pretty well, better than most cities would have. We don’t take this for granted. Because we had Andrew.”

Miami-Dade residents mostly took storm warnings seriously and began preparations early, putting up shutters on homes and businesses and largely avoiding panic-stricken assaults on supermarkets and home-supply stores, though those were busy and eventually ran low on supplies such as plywood, D batteries and bottled water.

“Construction-wise, I think people have learned,” said Charles Danger, the now-retired county building director who helped spearhead stronger post-Andrew building codes — often in the face of opposition from the building industry — and promoted the use of rigorously tested hurricane shutters and impact-resistant windows. “I was pleasantly surprised at the number of houses with shutters and the number of people who took the trouble of putting them on. People understood they have to put them on. All those things that we did, they do help.”

People in low-lying coastal zones appear to have heeded evacuation calls at higher-than-usual rates — possibly because of still-fresh impressions of the widespread flooding damage from Hurricane Harvey in Houston, Olson said.

“The research has not been done, but we really have to think compliance rates were higher than they normally are,” he said. “We had a Harvey effect here. It was so recent, and so terrible.”

Elected leaders and other public officials delived firm, clear and consistent messages to the public that likely contributed to the largely orderly preparations and the large numbers of people deciding to evacuate from mandatory zones.

 
 

But there is also plenty of room for improvement, the experts noted.

One area: evacuations. Olson said the mandatory-evacuation message for certain low-lying areas got “muddied” somewhat. That, and the size and fearsome potency of the approaching Irma — at a time when it was bearing down on Florida’s southeast coast — sent too many people fleeing in their cars, clogging highways for hours on end. Surreal scenes of people forced to abandon cars that had run out of gas because none was available, or sleeping by the highway for desperately needed rest beside stilled traffic, were common.

“Some of my staff took to the road, and came back and said it was the last time they would do that,” said Chisholm, who lives in Coral Gables but moved to a motel in Brickell for the storm. “One of my staff members spent 30 hours in a car. Running for the hills could be a worse experience than the hurricane itself.”

Traffic heads slowly north along the Florida Turnpike near Homestead, Fla., as tourists in the Florida Keys leave town on Sept. 6, 2017. AL DIAZ AP



The lesson, Chisholm and Olson said, is that it’s likely much better to stay put at home, or nearby on safer ground, than trying to leave by car just before a storm hits.

“I don’t think anyone was expecting the number of people who hit our relatively small number of arteries north,” Olson said. “I think it got a little confused between evacuating from particular zones and getting the hell out of the southern part of the state.”

But for more people to stay safely at home during and after a hurricane may require a return to basics for Miami-Dade — basics that Chisholm said we have neglected in the 12 years since Miami last experienced the full brunt of a hurricane.

That means stocking up on supplies like water, non-perishable food, batteries and battery-powered lights at the start of hurricane season, not as the storm approaches, and having enough of that to survive for several days afterwards. That’s a message that used to be drummed into Floridians aggressively in the past through ads, publications and public service announcements, but the emphasis seems to have dropped off in recent years.

“You have to keep it very simple and basic,” Chisholm said of supplies needed to live through several days without electricity. “A hundred years ago people lived under those conditions. We’re just not ready to survive a week without these things.”

That’s a realization Chisholm believes has already hit many Miami-Dade residents in Irma’s wake.

“I guarantee you, next time around people will be ready,” he said. “Now they know what it’s like, that it’s not the hurricane, it’s the aftermath.”

Even with better individual preparation, though, the experts say Irma still points to a crying need for improvement in the performance of the electric grid under storm conditions.

FPL and municipalities need to more aggressively push the undergrounding of electric lines where feasible. Alyce Robertson, executive director of the Downtown Development Authority, said some areas of downtown Miami, where the grid is largely underground, never lost power during Irma. In Brickell and downtown Coral Gables, where the same holds true, power was quickly restored after the surging waters receded.

“One big lesson is that places with underground cables and wires did better than those that have elevated wires, like Coconut Grove,” Fort-Brescia said.

He noted that typhoon-vulnerable Asian cities such as Singapore and Hong Kong, where Grove-based Arquitectonica has an office, put their power and communications grids below ground.

“People understand this is going to cost, but I’m sure they’re willing to pay a little more for that,” noting that many traffic lights remained out 10 days after Irma and stressing that restoring power quickly is a matter of public safety as much as personal well-being. “People have fear in their hearts now. Once they don’t have the fear in their hearts, they won’t give a crap.

“We’re going to continue to get hit, so it’s a matter of sitting down all the parties and discussing this really, really seriously.”

Minimizing the extent of power loss, and ensuring quick restoration, will also depend on better maintenance of trees around power lines. That’s a matter of some controversy following Irma, with FPL and municipalities such as Coral Gables and Pinecrest blaming each other for insufficient pruning.

We get sloppy when we don’t get many hits” from storms, Olson said. “If we’re talking about a community resiliency thing, having power back within 48 to 72 hours, that requires a systematic countywide hurricane cut every spring. It has to be government-led. It can’t be left up to individual property owners.”

Chisholm cautioned, however, that even as more tree-trimming is needed, that it be done judiciously so as not to reduce badly needed tree canopy. South Florida already has some of the lowest percentages of tree cover among urban areas in the country. One area for improvement, he suggested, is planting more natives, like sturdy oaks, instead of shallow-rooted or brittle exotics that can topple over or splinter in a hurricane.

“The abundant vegetation is great and we need it for our general well-being,” Chisholm said. “It keeps the sun off buildings and people. It helps lower overall heat gain from concrete and asphalt. It’s part of the natural ecosystem of South Florida. We need to live in cooperation with those natural systems. Our leadership needs to think about how to minimize the impact of the canopy on power lines but balance that out with tree protection.”

Another area that troubles the experts: Storm surge.

Irma pushed a mass of water onto Brickell, parts of downtown Miami and the Coconut Grove waterfront, where it flung a squadron of sailboats crashing into public parks and facilities as well as private homes. At the Vizcaya Museum at the north end of the Grove, it badly hammered the mansion’s grounds, basement shop and cafe, even after extensive preparation.

A sailboat that washed up on South Bayshore Drive in Coconut Grove during Hurricane Irma. Douglas Hanks Miami Herald



But the reach of the surge was far less than was forecast had the storm continued on a path along Florida’s eastern shoreline instead of veering west to the Gulf coast. The experts worry that means that many Miamians still don’t appreciate the ghastly severity of a wall of water two stories high surging upland from the bay and ocean fronts onto densely populated neighborhoods.

Olson stressed that most people who are injured or perish in a hurricane don’t do so because of wind, but because of water.

“We got lucky with the storm surge. The east coast dodged a bullet,” Olson said. “The issue of storm surge, if it hits at the right angle, at the right time with high tide, we haven’t quite seen that. We love to live on the water. The trouble is, the water is not our friend, not all the time.”

Surge protection and readiness will prove especially important as climate change and sea-level rise boost the intensity of storms and the level of storm inundation, the experts say.

That’s not the end of the list of the experts’ worries. They said the revived fears of a direct hit from a major storm, something Miami-Dade has not experienced since Hurricane Andrew, points to the need for local and state officials to resist continuing efforts, chiefly by the home-building industry, to water down the state’s tough hurricane codes.

“After Andrew, we were successful in changing the minds of people, but we fought tooth and nail,” Danger recalled. “If we don’t weaken the code, and keep on doing research, we can keep improving construction. And the more we improve, then production lines are set up for new products and things get cheaper.

“Look at impact-resistant windows,” he said. “After Andrew, people in the industry said, ‘Oh, it’s going to be so expensive, no one can afford those.’ And now developers are putting impact windows in like normal windows.”

And making building exteriors as hurricane-resistant as possible is critical because a hurricane’s power increases exponentially as wind speed increases. That means a Category 5 storm is hundreds of times stronger than a Cat 1. The Florida statewide building code requires that buildings and products such as windows withstand sustained winds of around 150 mph, a strong Cat 4 storm, Chisholm said.

But beyond that? What happen to homes and buildings if a storm with the intensity of Irma at peak power hits Miami-Dade straight on?

“What happens if a 185 storm hits?” Chisholm asked.

The chilling answer: “Nobody knows.”

This story was originally published September 22, 2017 7:00 AM.