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Huge Blizzard Brings Major Flooding

Winter storm Jonas, January 23 2016

Winter storm Jonas roared through the southeastern parts of the U.S. on January 22-23, bringing record-breaking amounts of snow that adversely affected 50 million Americans. The storm was projected to be a sort of winter hurricane; bringing winds of 60mph, widespread power outages, ‘thunder-snow’, and massive snowfall that would bring cities like Washington DC and New York to a standstill.

In reality, many of these dire projections did not occur, and the storm was a bit milder than had been projected. The 60mph winds did not materialize, although high winds were a problem in many area, and high-profile vehicles were warned to stay off the roads during the storm. Jonas was a particularly dangerous type of storm, one that has struck fear for many centuries: it is called a nor’easter. Nor’easters are named for the direction from which the winds are moving across the land, and they are known to bring very heavy precipitation, hurricane force winds, blizzards, severe coastal flooding, and powerful storm surges that can devastate coastal communities.

Winter storm Jonas, January 23 2016. NASA image by Jeff Schmaltz and Joshua Stevens, LANCE/EOSDIS Rapid Response.

During winter storm Jonas, many communities suffered from a snowfall that accumulated 2-4 inches of snow per hour… for almost 24 hours. Snowfall records were set in Baltimore, MD, Allentown, PA, Harrisburg, PA, Newark, NJ, and parts of New York City, with records dating back to 1892. The city of Philadelphia received as much snow in that one day as is normally recorded for an entire year!

With all that snow, flooding does not seem likely to be a major concern; at least, not until the melting begins. But that was not the case. Jonas brought major flooding in several areas, even before the first snowflake melted. Particularly hard hit were the Jersey Shore communities, which have yet to fully recover from Hurricane Sandy. In fact, many residents are comparing the two storms, so destructive was this winter storm in terms of flooding. One Jersey Shore community, Cape May, recorded its highest storm surge ever, at almost 9.5 feet. The tidal flooding in these communities brought widespread power outages, major flood damage, and scenes of city streets flooded with icy water dotted with mini-icebergs.

The more widespread danger from flooding may be still on the horizon, however. As communities focus on clearing the massive amounts of snow from streets and parking lots, warmer weather is forecast for Tuesday, along with rain showers. This warm rain could melt the snow much faster than the frozen ground can absorb, and a flooding disaster could result. As if this is not bad enough, more snow is predicted for later in the week! When all this new snow, melted old snow, and rain converges upon super-saturated and/or frozen ground, a severe run-off problem will likely result. When all is tallied, flooding may be the most surprising, and damaging, aspect of winter storm Jonas.

Source:: FloodBarrierUSA

The Great Galveston Flood, Part II

Relief party working at Avenue P and Tremont Street.

Even prior to the disastrous hurricane of 1900, there were some who voiced concerns about the vulnerability of the city of Galveston. Galveston in 1900 was one of the largest and most important cities in Texas, with major shipping and economic importance- but it was also the most precarious. The city is built on what is essentially a large sandbar in the Gulf of Mexico, and in the year 1900 the most elevated spot on the island was less than ten feet above sea level. In hindsight, it seems obvious that Galveston was horrifyingly exposed to the elements, especially in the face of a hurricane.

In 1898, when Galveston city officials evaluated their vulnerability to storms, one possibility under discussion was the construction of a large sea wall to act as a flood barrier in the event of a large storm. Isaac Cline, the Galveston Weather Bureau Director, penned an article in the Galveston Daily News in which he stated his opinion that a seawall was absolutely not needed to protect Galveston. Cline went so far as to dismiss as “a crazy idea” that a deadly hurricane was likely to ever imperil Galveston. For many, Cline’s opinion was accepted as gospel — and believed that no major hurricane would ever strike. Galveston.

Galveston disaster, 1900, relief party working at Avenue P and Tremont Street.

Two years later, the Great Storm of 1900 ripped through Galveston, killing up to 12,000 people and obliterating most of the structures on the island. In the days that followed the storm, however, the people of Galveston showed true courage, pluck, and heroism. There were many tales of bravery and sacrifice as literally every soul on the island contributed to the rescue of survivors and recovery of bodies. Galveston immediately began the rebuilding process, and within one week, crucial telegraph and water services were operating again.

When officials convened after the disaster to determine the steps needed to rebuild Galveston, this time there was no question about the need for a seawall: the city would never again be able to rest easy without a massive flood barrier. In addition to the seawall, the elevation of the island would also be raised, by a large margin. The project of raising the elevation of an entire city is daunting even with today’s technology, so it is impossible to overstate the difficulty of achieving such a task in 1901.

One year after the storm, a team of engineers was hired to get the job done, and as quickly as possible. It was decided that the elevation of the city would need to be raised at least 17 feet on the side facing the gulf, tapering off somewhat on the inland side. Millions of truckloads of material were needed to accomplish this, and the engineers came up with an ingenious solution: they would dredge the shipping channels, and pump the slurry onto the island. When the water drained away, the sediment would remain, and this would be held in place by walls and other barriers. This solution achieved two important goals: raising the city and clearing the channels. But in order to do this, all the remaining structures, as well as gas, water, and sewer mains, had to be raised first. It was a mammoth project, even by the standards of present-day capability!

The other flood prevention project, of course, was the seawall that Isaac Cline had deemed unnecessary. No one who had lived through that dreadful night of September 8,1900 would ever again feel safe in Galveston without a massive flood barrier. The project required 60 years to fully complete, but at last the city of Galveston was protected by a huge seawall that today stretches 10 miles in length between the Gulf of Mexico and the rebuilt Galveston. The wall, which is is 15.5′ in height, was partially built by the U.S. Army Corps of Engineers, who are today responsible for inspection and maintenance of the wall.

Sea Wall, From West of Rapid Fire Battery, Fort Crockett

Isaac Cline, who had helped doom Galveston when he pooh-poohed the idea of building a flood barrier, survived the Great Storm of 1900, but barely. Unfortunately, his pregnant wife was not so lucky, and she perished that terrible night. After the storm, Cline claimed that he had personally gone through the crowds at the Galveston beaches as the storm approached, urging people to seek higher ground. There is little evidence to back up this claim, and most historians believe that Cline was most likely speaking from feelings of intense regret and guilt over the fact that he had opposed the flood barrier project. A mere 15 years after the Great Storm of 1900, Cline was alive to see Galveston struck by another big storm, but this time the city was spared — thanks to the brand-new flood barrier that had been put into place, just in time.

Source:: FloodBarrierUSA

The Great Galveston Flood, Part I

Galveston Disaster, Texas, 1900: house on Avenue N slightly moved with flood

Most people know that Hurricane Katrina was the most expensive natural disaster in U.S. history. That storm was so destructive that the name “Katrina” was retired from the list of recurring names used by the National Weather Service to identify large storms. But as horrible as Katrina was, there is another storm in our national history that was even worse, especially in terms of lives lost.

In early September of the year 1900, the city of Galveston was packed with people from far and wide who were enjoying a late summer vacation at the seaside. This city is situated on a small island located about 2 miles off the coast of Texas, and at the time of the flood, the elevation was less than nine feet above sea level. The 29-mile length of Galveston Island faced the Gulf of Mexico, and its long sandy beaches attracted vacationers from mainland Texas every summer.

Galveston Disaster, Texas, 1900: house on Avenue N slightly moved with flood

In those days, sophisticated storm warning systems did not exist, but nevertheless there were some warnings about a large storm approaching the area. Ships at sea had encountered and reported the storm, and the hurricane had passed through parts of Florida, but damage to telegraph lines hindered communication. In addition to this, at that time there was no way of knowing where the storm was headed. Unfortunately, neither locals nor visitors heeded the alert — even after an official hurricane warning was issued — and most continued their holiday activities until it was far too late to flee. The Galveston Hurricane slammed into the island with a sudden fury, making land as a Category 4 storm with sustained winds of 145 mph.

Galveston Island in 1900 had no sea wall, and some natural flood barriers such as sand dunes had been removed to fill in low-lying areas inland. When this Cat-4 hurricane swept over the island, there was nothing in place to hold back the immense storm surge that was dragged in by the storm. This surge was so huge that it completely submerged a passenger train en route to Galveston, which had been stopped by debris on the tracks. All 85 people on board the train died when the seawater washed well over the roofs of the train cars. 10 people who had fled the train to a nearby lighthouse managed to survive.

On Galveston Island, a storm surge of at least 15 feet swept over the entire island. With a maximum elevation of less than 9 feet, this meant that even on the highest point there was no place of safety. Almost all the buildings on the island were simply knocked off their foundations and smashed to bits. Between 6,000-12,000 people died that day of September 8,1900, with no chance of help for the helpless survivors, many of whom were grievously injured. Because the bridges that linked Galveston to the mainland were washed away, it took some time for the scope of the disaster to become known. One of the earliest signs of the scale of the devastation was the discovery of a large ocean liner that had been washed more than two miles inland from Galveston.

When rescuers finally reached Galveston, they found that the city had been totally destroyed, and a full 20% of the island’s inhabitants had died. Many people who had survived the storm lay injured and buried under the mountains of debris, and died slowly of injury or thirst because rescuers were unable to reach them. The ghastly business of disposing of the thousands of bodies took many weeks, and exacted a severe psychological toll on those charged with collecting and burning the corpses. The Galveston Hurricane of 1900 remains to this day the deadliest storm in U.S. history, and all the storms since then, if combined, have not yet equalled the loss of life from that one day.

Source:: FloodBarrierUSA

Houston Battered by Weakened Hurricane Patricia

Huricane Patricia viewed from International Space Station on October 23, 2015 - NASA

October 2015 was a disastrous month for flooding. During the first week of the month, South Carolina was all but stopped in its tracks by flooding that has been called a 1000-year event. Then, during the last week of the same month, parts of Texas suffered the same fate as South Carolina, with floods more severe than any living person had ever seen.

In some parts of the state, almost 4″ of rain per hour was recorded, with some areas inundated by almost 20″ of precipitation in one 24-hour period. Roads were washed out, a train was derailed, and damage to homes and property was widespread. The perilous band of storms also produced several tornados, adding to the chaos and fear that gripped the area. In the end, the storms claimed six lives, with some people swept to their deaths directly from their own homes.

Hurricane Patricia seen from the International Space Station on October 23rd 2015. Photo by NASA

The deadly storms that caused so much suffering were in part a result of Hurricane Patricia, which was said to be the most powerful hurricane ever to make landfall in recorded history. Patricia fortunately made land at a relatively uninhabited section of Mexico, and quickly dissipated when it hit a mountain range in the center of the country. However, the storm still held a lot of rain, even after its fierce winds were quelled. This rain, combined with precipitation from other nearby storms, is what deluged the Houston area at the end of October.

Houston has a lot of experience with floods, and some experts call it the most dangerous city in the entire U.S. as far as the likelihood of being injured or killed by flood conditions. The area in and around the city is topographically vulnerable to flooding, with very little elevation and too much pavement, which only runs off the precipitation without absorption. The history of Houston is dotted by major flooding events, including the Great Flood of 1935, which covered a large part of the city and led to the formation of the Harris County Flood Control District, which has overseen flood control projects that have cost hundreds of millions of dollars.

In spite of these projects, Houston remains vulnerable to severe floods right up to the present day — but with brighter prospects than in that bygone period of 1935. Today, the city is much better protected, as the flood barriers, levees, run-off canals, and other flood control measures have helped to control rainwater. During the recent storms, downtown Houston suffered relatively little structural damage, mostly because the heavy investment in flood control projects has paid off. Still, there is more to be done, and Houston cannot yet rest easy whenever the winds howl and the rains pelt down. With such a flat topography and surrounded by creeks and rivers, Houston will need to keep working on flood defense programs well into the foreseeable future.

Source:: FloodBarrierUSA

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