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Flood Protection for Hospitals

Photo: Rio Grande City, Texas, July 26, 2007 — FEMA Public Assistance Specialists Sheila Luster and and William Ciarelli inspect the Starr County Memorial Hospital with administrator Thalia Munoz to determine if the county will be eligible for federal assistance to offset expenses caused by the recent flooding. Bob McMillan/FEMA Photo

When a community suffers a flooding emergency, there are often injured people who need immediate medical assistance. But what happens if the nearest hospital is also affected by the flood? What if the hospital itself is flooded?

Hospitals present numerous challenges as far as flood protection. Because the patient areas must be kept clean and hygienic, it is very common for electrical equipment to be housed in basement areas, even though the loss of electrical power at a hospital can be deadly for patients who may rely on life-sustaining machines. Most hospitals have emergency back-up power systems, but these are not sufficient to weather lengthy outages. One facility in Houston was left without power for a full two weeks after a hurricane flooded its first and second floors, knocking out the electrical systems. Patients at this facility had to be evacuated, which can be a risky and complicated operation.

Once a medical facility floods, there are many epidemiological issues that would not be present in a non-medical building. For eaxample, after any large intrusion of water, there will be mold issues left behind. In the best case scenario, the water may have been relatively clean freshwater. But in most cases, the water is tainted with sewage or other pollutants. If dirty or polluted water seeps into walls and flooring, it often cannot be adequately cleaned to hospital standards. What ensues is a very costly and time-consuming process of removing the affected materials, cleaning and disinfecting the foundation, and installing new floors and walls. This operation cannot take place while patients are in residence, so there may be a need for patient evacuation during the repairs. The process is pain-staking, extremely expensive, and requires a lot of time.

Given the extreme measures to which a medical facility is subjected after a flooding event, it is no surprise to learn that these facilities go to great lengths to prevent flooding and to protect vital operations. Because hospitals play such a critical role in society, and their full capacity is required during disasters like flooding events, these facilities are given extra protection from floods while still in the blueprint stages. The most common form of protection for hospital buildings are flood barriers or gates that automatically deploy at the first sign of trouble. These flood barriers are best when built into the original design of the building, but can also be retrofitted to an existing building. As we have seen a remarkable geographical expansion in active flood plains across the country, there are many older hospitals that were once flood-safe, but are now at risk.

Fortunately, there are commercial companies that can install permanent or temporary flood protection devices that can reliably defend even huge medical compounds. Depending on the type of items or buildings that must be kept dry, there are several strategies, including:

  • Permanent waterproof casings for outdoor HVAC units.
  • Temporary flood panels that can be installed quickly by maintenance staff.
  • “Puddle guards” that can be installed in doorways to block small amounts of water.
  • Automatic flood panels that deploy instantly without need for human engagement.
  • Flood doors that can be securely closed by staff when needed.

All of these types of flood protection devices and systems can be customized to fit any existing building, and they can also be fitted during the planning and construction of new buildings. Because society relies on functioning hospitals in particular during a disaster, it is of utmost importance that medical facilities be protected by the latest technology. We have seen great strides in flood protection during the past decade, and this expertise will increasingly be required as climate change brings ever more frequent natural disasters to our doorstep.

2020 Hurricane Season Smashes Records

GRAPHIC: The list of 30 named storms that had occurred during the 2020 Atlantic Hurricane Season as of November 24, 2020. The 2020 season surpassed 2005 as the busiest on record. The season officially ended November 30. (NOAA)

The year 2020 was truly an annus horribilis for many, many reasons. It was the year that brought a global pandemic with its attendant economic and mental health crises, record-breaking fires in Australia and the western US, painful racial justice reckoning, a traumatic election year in the US, an exacerbation of climate-related natural disasters, and armed conflicts around the world. In keeping with this slate of death and horror, the 2020 hurricane season claimed its place as the very worst in recorded history.

At the very beginning of the 2020 hurricane season, a hyperactive year was predicted by meteorologists. There was talk that the number and intensity of this year’s hurricanes could even approach that of the most dreadful year in history: 2005, the year of the notorious Hurricane Katrina. Luckily, no hurricane that struck the US was able to equal that monstrous storm; however, the year nevertheless closed out by smashing a number of records.

In order to grasp the outrageous scale of this record-breaking storm season, let’s first take a look at the so-called ‘named storms’. Storms are named when the winds associated with the tempest reach a velocity of 39 mph, and they retain the same name even if they morph into a major hurricane with winds up to 200 mph. Storms are named in order to simplify global communications regarding the movement and development of the storm. During an average year, there are 12 named storms. In April of 2020, meteorologists warned that we would be in for an active Atlantic season with at least 16 named storms. In June, that prediction was adjusted to 19 storms. By the end of November when the Atlantic hurricane season ended, there had been 30 named storms!

With so many storms in a single year, the slate of 21 proper names was completely used up by September 18th, when Tropical Storm Wilfred strengthened from a low-key tropical wave into a proper storm with gale-force winds. Although Wilfred never developed into a major storm, it was nevertheless significant in that we had now exhausted all the designated storm names for the season, and would be tapping into the Greek alphabet names. This was just the second time in hurricane-tracking history that the Greek names had been utilized- the previous year having been 2005.

Mid-September is very early in the season to run out of proper storm names! This leaves 10 full weeks of hurricane season still to come, and 2020 filled those ten weeks with nine more named storms- almost one per week. In doing so, the year closed out with a record-breaking total of 30 named storms, smashing the previous record of 28 named storms set in 2005. Of these 30 named storms, 12 managed to make landfall in the United States.

These 12 storms, while nowhere close to wreaking the damage and expense of a storm like Hurricane Katrina, were still extremely unwelcome during this particular year. In 2020, these storms coincided with a global pandemic that was already a disaster of epic proportions. The aims of protecting the populace from the storms and protecting the same populace from the novel coronavirus were in direct opposition to each other. Evacuation of vulnerable coastal residents required that affected individuals be housed together in often cramped shelters, in tight quarters with no chance of the social distancing that can reduce disease transmission. Now, as this horrible year draws to a close, it is a great relief that none of the 12 major storms to strike the US packed the power of a Hurricane Katrina. Nevertheless, 2020 was still a year of unrelenting disaster, and the fact that it also smashed records for named storms is somehow horribly fitting.

Eta Floods Florida After Very Wet ‘Dry Season’

Photo: Satellite imagery of Hurricane Eta. It was upgraded to a major hurricane by the National Hurricane Center on Monday, November 2, 2020. It was expected to dump 35 inches of rain in some isolated areas of Nicaragua after making landfall. NOAA

By the time Hurricane Eta arrived in South Florida, the stage was set for a flooding disaster. Although the fall season generally ushers in dry, hot weather, this year has been an anomaly. Unlike the rest of the United States, Florida has two seasons: the wet season and the dry season — which normally arrives around mid October. In 2020, however, the long wet season has been unusually prolific with rain, and the underground water tables are running very high. This is often considered a good thing, especially since the year 2020 is expected to present a set of La Niña weather conditions, which can sometimes lead to drought conditions. The La Niña expected for this year is projected to be on the stronger side, but because of the ample precipitation throughout the summer, droughts are not expected to plague Florida, in spite of this upcoming strong La Niña.

While all that summer rainfall is a boon to farmers and wildlife, it also means that the ground throughout much of South Florida is fully saturated. However, as the region enters its dry season, the record-shattering 2020 hurricane season is not yet over — as this season generally remains active until the very end of November. The threats posed by the confluence of super-saturated ground and a hyperactive hurricane season was brought home on November 9, when the remnants of Hurricane Eta arrived in the area.

By the time Eta made landfall in Florida it had already lashed through Central America and had weakened into a tropical storm. This meant that the area was spared the destructive gale-force winds that had flattened parts of Nicaragua, but even in the absence of high-velocity winds, Eta still inflicted a lot of damage in Florida. Tropical Storm Eta made landfall in the Florida Keys, a uniquely vulnerable part of the United States. Very low-lying and tenuously attached to the mainland by aging bridges, the Keys are often depicted in post-storm news photos of horrifying damage and fully submerged streets. Sure enough, photos from the Keys once again illustrated the major damage and swamped homes left behind when Eta had moved through the area.

Falling atop the 14” of rain that had already inundated the area during the previous month, another 12” of rain was recorded in a single day across parts of southern Florida. This was a disastrous amount of precipitation, and it could not have come at a worse time. Even though residents and local officials were prepared for the arrival of Eta, there was very little that could be done to prevent or alleviate the flooding. Before the first drop of rain arrived in the area, sand bags had been filled and placed, flood barriers had been installed, levees and other flood mitigation measures had been readied — but there was nevertheless a massive flooding event across the region. The water simply had nowhere to go.

After the rains had moved through, giant vacuum trucks moved through the zone, sucking up all the excess water that had stranded and stalled cars, and filled homes. Some people who had attempted to continue driving through the flooded streets ended up submerged in canals or dangling from rain-slicked bridges. As the soggy ground was presented with even more water, massive banyan trees were dislodged as their root systems became unstable in the loosened earth. Floridians were somewhat lucky that Hurricane Eta had weakened into a tropical storm by the time it made landfall in that state, but very few residents of the Keys felt ‘lucky’ as they slogged through the massive cleanup of their homes and businesses.

Storm Surge 101

Click graphic above to enlarge: Storm surge is an abnormal rise of water generated by a storm, over and above the predicted astronomical tides. Storm surge should not be confused with storm tide, which is defined as the water level rise due to the combination of storm surge and the astronomical tide. This rise in water level can cause extreme flooding in coastal areas particularly when storm surge coincides with normal high tide, resulting in storm tides reaching up to 20 feet or more in some cases. Source: https://www.nhc.noaa.gov/surge/

We have mentioned the phenomenon of storm surge many times in this blog series, and now storm surge is again in the news with the arrival of hurricane after hurricane during this record-setting year. But what exactly is storm surge, and why is it so dangerous?

The simplest explanation is that storm surge is the sudden rise in sea level that happens during a hurricane, cyclone, or a particularly powerful storm. Although it is often described as a ‘wall of water’ in news accounts, it rarely appears this way in reality. Most often, the sea water will arrive with the winds of the hurricane, pushed forward by the gusts. The speed at which the water level rises can be astonishing, and this is why storm surges are so dangerous. At one moment, a person can be standing on dry land- in a location thought to be well inland from the sea- and at the next moment the person finds themselves waist deep in swirling, debris-filled seawater. This can happen with incredible speed and suddenness!

Many people do not understand this hazard, even those who may have lived near the coastline all their lives. When unprepared people hear that a 6-foot storm surge is expected, they often envision that the usual high tide mark will be extended by six feet. They erroneously picture the normal coastline, but just six feet higher into the beach zone. This can be a deadly mistake, because a 6’ storm surge means something far more dangerous!

To get a more accurate picture of a storm surge, you would need to know that a 6’ storm surge means that water will cover a given area to a DEPTH of 6’. The actual spatial incursion of the storm surge depends on many factors such as topography, obstacles, wind direction, and other variables. In general, meteorologists produce storm surge charts that can indicate how far inland this 6’-deep surge will extend, so that people can evacuate in a timely manner.

Evacuation is the only safe choice in a zone where a large storm surge is predicted. Taking our example of the 6’ storm surge, let’s imagine being confronted by the very sudden arrival of a six foot depth of water. A cubic yard of water weighs over 1,700 pounds, so a 6’ surge introduces twice that much- over 3400 pounds of water pushing its way towards you, your car, or your house. Even a very well built house on a fortified foundation can have trouble withstanding that amount of force. A person on foot has no chance at all to resist, and even a sturdy SUV will soon topple. In fact, most vehicles have trouble withstanding even a 1’ surge of water.

Clearly, the best plan of action is to evacuate as soon as possible when a storm surge is predicted. The surge can arrive well ahead of the hurricane ‘making landfall’, at times arriving a day or more before the actual storm. Waiting to ‘see what happens’ only means that you will lose precious time to make your escape, during a time when many other vehicles will be clogging the escape routes. Many people think that the forceful gales of the hurricane are the thing to be feared, but in fact it is the storm surge that kills that vast majority of storm victims who live near the coastline. For this reason, it is critically important to consult the reports- not only for expected landfall times- but also for the expected storm surge zones. Having important belongings and documents collected and packed, having a ‘go bag’ by the door, securing pets in carriers, bringing food, lots of clean water, clothing, toiletries, and bedding for everyone in the house- these are all tasks that need to be completed well ahead of a hurricane, because the most dangerous part of the hurricane may well arrive a day or two before the hurricane itself.

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