Katrina's Surge, Part 10

A Weather Underground 16 part series about Hurricane Katrina, by Margie Kieper.

For the remainder of the month, we're traveling the coastline destroyed by Hurricane Katrina's record storm surge. This is something that has never been shown on the news or talked about, either in the overall, or in detail. What you'll be seeing here is what people on the Gulf Coast have been calling the “Invisible Coastline” for almost a year now.

Today we'll see the effects of the surge on the communities surrounding St. Louis Bay, including Bay St. Louis and Pass Christian, and two communities bordering the area where the bay joins the Jourdan River, Kiln and Diamondhead.

From Google Maps, the location of this area along the Gulf of Mexico coastline impacted by Katrina:

Bay St. Louis, Hancock County, MS

Image courtesy of Google Maps

Pass Christian is part of Harrison County, and the remaining communities, along with ones mentioned in the last two blog entries, comprise the bulk of the population in Hancock County. In other words, there was not a major community in Hancock County that was not decimated by the storm.

And with the publication of an article on being prepared for disaster in this week's Time magazine, titled, “Floods, Tornadoes, Hurricanes, Wildfires, Earthquakes ... Why We Don't Prepare,” it's an appropriate time to look at some demographics.

As in most coastal or river areas throughout the country, the population in the MS Gulf Coast is clustered tightly to the shoreline. Much of the inland area of the coastal counties is either river basin, estuary, and marsh, or forest, and the livable areas are unincorporated, with few roads. Here is a map (PDF File) from the US Census web site, showing the population density of the MS Gulf Coast (population density increasing with the darker colors):

US Census population density of MS coastal counties

Image courtesy of US Census Bureau

The areas that are the lightest color correspond to marshland, estuary, and river basins; in southwest Hancock County, the Pearl River basin, and in the center of Jackson County, the Pascagoula River basin.

Now compare the above map to the surge inundation for the MS coastline; you'll see that the populated areas were the ones that were hit with the surge. Over 95% of the coastal population of MS was affected by Katrina's surge:

FEMA surge inundation of MS coastal counties

Image courtesy of FEMA

Why do those people live there? Why don't they just move away? Part 2: Remember my “stock response” to that comment about the Gulf Coast, which has been settled since the 1600s: I'm sure you're right, and by that logic everyone should move out of New York City as well? Lest you think I was blowin' smoke – yesterday Max Mayfield, head of the National Hurricane Center, was quoted in an article on CNN titled Hurricane Chief Sees ‘Mega-Disaster,' saying this: "One of the highest storm surges possible anywhere in the country is where Long Island juts out at nearly right angles to the New Jersey coast. They could get 25 to 30 feet of storm surge ... even going up the Hudson River."

Check out the maps on that census site for big, modern states like New York and California - or actually for any state. You'll see the population clustered around river basins and coastlines just exactly the same way it is along the Gulf Coast. And here's another interesting demographic from the USGS, that was referenced in the Time article:

Number of Flood Disaster Declarations

Presidential disaster declarations related to flooding in the United States, shown by county: Green areas represent one declaration; yellow areas represent two declarations; orange areas represent three declarations; red areas represent four or more declarations between June 1, 1965, and June 1, 2003 – image courtesy of USGS

That's right – about two-thirds of the country has had disaster declarations for flooding four or more times. So – where is it that “those people” should move to? The Time article notes:

In fact, 91% of Americans live in places at a moderate-to-high risk of earthquakes, volcanoes, tornadoes, wildfires, hurricanes, flooding, high-wind damage or terrorism, according to an estimate calculated for TIME by the Hazards and Vulnerability Research Institute at the University of South Carolina.

So the next time you get that question, just smile -- and have these stats handy.

Here's a closer look at the communities around St. Louis Bay:

Mapquest St. Louis Bay area, MS

Image courtesy of Mapquest

Although the detail is not shown on the map, the Jourdan River runs alongside Diamondhead and up into Kiln. And the way that the surge flooded this area, was that water poured into the bay, and flooding occurred first along the low-lying areas inland, bordering the bay. In other words, Kiln and Diamondhead started to flood before the bulk of the surge came, and water flooded Bay St. Louis and Pass Christian from behind, as the bay widened into the adjoining land area. From an eyewitness account, this flooding covered most of Bay St. Louis until all that was above ground was the bluff near the bay, and the narrow area of high ground near the reservoir (the latter was high enough to not flood, as the surge fell just short of the Cat 5 level). Then, as the bulk of the surge continued to quickly push in, just ahead of the eyewall, water rose incredibly quickly and overtopped the 20-foot bluff from the coast side, with around five feet of water, flooding St. Stanislaus (which can be seen in a video on the web), and inundating the Hancock County EOC that was set up in the county courthouse. In the EOC, not knowing how much higher the water was going to rise, everyone wrote a number on their bodies with a magic marker, to aid identification, and a list of names with the corresponding numbers was tacked on the wall, up high near the ceiling.

In the Pass Christian area, which was closer to the mouth of the bay, and with no bluff to protect it, the surge that came from behind was higher and faster, and was able to completely rip apart the buildings it encountered, even before the main surge came from the other direction, the shoreline, and finished the job. The result was that in Pass Christian the wreckage was pushed together and piled 30 and 40 feet high. The National Guard, using heavy equipment, couldn't even get out of Long Beach and into the area right away, working into the night and the next day.

Some photos of the area:

Beach Blvd in Bay St. Louis

Beach Blvd in Bay St. Louis -- image courtesy of FlemingW at pbase

Historic home in Bay St. Louis

Historic home in Bay St. Louis -- image courtesy of FlemingW at pbase

Railroad track and bridge in Bay St. Louis

Railroad track and bridge in Bay St. Louis, looking across the bay to Pass Christian -- image courtesy of FlemingW at pbase

Surge debris in Bay St. Louis

Surge debris in Bay St. Louis -- image courtesy of David Bailey

Surge debris in Bay St. Louis 2

Surge debris in Bay St. Louis -- image courtesy of David Bailey

Surge debris in Pass Christian

Surge debris in Pass Christian

Here are a couple of close-ups from the NOAA aerial images taken days after the storm, and the reason I wanted to show these was because there was a tremendous amount of mud deposited in Bay St. Louis and Pass Christian from areas that were flooded via the bay overflowing, that is, from the back, not the gulf side. And in the image from Pass Christian, the small area on the left that does not have the mud, and is lighter in color, is actually adjacent to Hwy 90 and the beach -- the flooding from behind, from the bay, came that far south, before the rest of the surge pushed in from the gulf.

In the Bay St. Louis image I've included the entire image as well as a second zoom so you can see the horrific debris field there as well.

BSL flooding from the bay side

BSL - image courtesy of NOAA

BSL mud - flooding from the bay side

BSL mud - image courtesy of NOAA

BSL debris - flooding from the bay side

BSL debris field - image courtesy of NOAA

Pass Christian mud - flooding from the bay side

Pass Christian mud - image courtesy of NOAA

Think you've seen everything? The vice president of Diamondhead (I'll explain that in a minute), Mario Feola, built a combination hanger and house (on top) right off of the airport runway. He designed the structure for wind. His elevation is around 10-11 feet, and they got eight feet of surge into the hanger. "I never in my wildest dreams thought water would come up," Feola said. "The bay is miles away and we've never had flooding." Miles away? Try hundreds of feet (look at the above Mapquest image -- the runway is the two long parallel lines that run south of I-10 in the SW corner of Diamondhead), and not only that, wedged in-between the marsh at the head of the Jourdan river, and the bay. The article goes on to say, Before Katrina, the Hancock County community had 3,600 residences. About 250 were made uninhabitable on the south side, Feola said, and about 460 on the north side.

The Sun-Herald article notes Diamondhead is chartered as a corporation and run by a board instead of a mayor-council. I didn't even know you could do that. Hey, Mario, your home is way cool, and so are you -- vice president of a town, for crying out loud -- but the next time you take off, look out the window. You're living in a flood zone!

Spending time on the Sun Herald Before and After -- a wonderful, wonderful resource -- I came across another house story. This is the Hymel home, built in Waveland.

Hymel consulted engineers and academics on building for hurricanes, something to withstand 150 mph winds.

The floor was 20 feet above sea level..."I was very surprised that the house went in the storm," Hymel said.

Surprised? Ok, let's consider this. Waveland probably had around 30 feet of surge with waves on top of that of perhaps five to seven feet, which, after a short distance, would have gone down to one to three foot breakers -- still a good-sized wave. That means if you could have imagined yourself standing on the beach, there would have been almost four stories of water above you -- heavy, moving water. Building for wind in what is called a "velocity" zone -- a coastal zone that is vulnerable not only to surge but to current and waves -- is just not the hot issue. If you have a hurricane with strong winds, and you live in an area vulnerable to surge, then you're surely going to have surge as well, because the surge is generated by the winds.

On little cat feet: Why is surge so underestimated? Let's start with some basic facts about moving water. First of all water is dense and heavy. A cubic foot of water weighs 64 pounds, and a cubic yard, as much as a Volkswagen Beetle (an old one, not a new one) -- over 1700 pounds. Picture yourself driving one of those old Beetles at 15mph right into the side of your house. Make a dent? And when surge comes in, it's a lot more than a cubic yard's worth of water.

A common flood fact: six inches of moving water can knock you right off your feet. Picture yourself in a swimming pool in waist-deep water. How fast can you walk from one side of the pool to the other? Not very, and even if you tried to thrash around and go a little faster, you'd lose your balance after a couple of steps. That's water only three feet deep that isn't even moving. Lives are lost every year by people who think they can drive through a road or over a bridge with less than a foot of running water on it, and the water picks up the car and floats it away, overturns it, drags it underwater.

But if you don't make your living around the water, you tend to not be aware of and respect the power of water.

Another water fact: water is for all practical purposes not compressible. When that water is moving inland, all that heavy water, exerting a very large psi on structures, which aren't built to withstand a side load anyway, it isn't going to compress, and it isn't going anywhere. It's going to very easily be able to push away anything in its path.

The surge comes in at the speed of the storm; with Katrina, about 15 miles per hour. In terms of white water, that is the equivalent of a Class III or IV rapids; very difficult or nearly impossible to maneuver in. But I don't understand the mechanics of the surge completely. The stronger current may be underwater, not on the top. Bill Bradford told me the current behind the railroad tracks was a gentle continuous flow, and he was able to swim in it. However I know there were cases where small rescue boats had trouble trying to navigate in the strong currents of the surge. So current could be very localized, but overall it is reasonable to assume that the speed and volume of the moving surge is deadly. My brother talked with a woman in Porteaux Bay area right after the storm who watched her fiance get pulled from a tree and washed out into the gulf and drowned, from the force of the current.

People have a hard time understanding that those innocuous-looking waves can mow everything down in their path. At the shore, the surge starts to come in just like a high tide -- water starts to lap over the land, each tiny wave running up a little higher than the one before it. This can be seen below in these two images from the stormchaser website, Ultimate Chase.

Surge coming into Gulfport

Surge coming into Gulfport over the beach road, Hwy 90 - image courtesy of Ultimate Chase

I found this quote on the web, which is representative of many similar comments -- it isn't just wind speeds that are exaggerated:

...the winds came unobstructed off the water, driving a wall of water 20 - 35 feet high, moving at almost 100 MPH. Imagine a bulldozer with a blade 35 miles wide, 20 - 35 feet high, moving at 100 MPH.

No. But it doesn't have to be some horror movie vision to be deadly. It is already deadly - so very deadly - without the hyperbole. Here's a link from the same chasers, to a video from a unique camera designed to record surge, that was fastened to the metal-and-glass door of a Holiday Inn in Gulfport. In this condensed four-minute video, the gentle pushing of the surge, water coming from inside the hotel lobby, slowly disintegrates the entire entrance. The camera ends up floating along the side of the hotel (right past a "No Lifeguard On Duty" sign). No bulldozer blade of water moving faster than a speeding bullet in sight.

And surge is sneaky. It comes in, to paraphrase Carl Sandburg, on little cat feet. In Ivan, two different homeowners who were trying to ride out the storm opened the front door to find three feet of water start pouring in. When Katrina's surge came, people who had not followed evacuation orders had no warning before the water came. And it came fast. Remember Judith Bradford saying that in a matter of minutes water had filled the entire first floor of her home? Minutes.

A little after 8am, the 911 calls started coming in. Most of them were simply screams. Just before 8:30am the main part of the surge came ashore, very quickly, and that is when most of the drownings occurred. Those people didn't have much of a chance. The first bodies my brother found when coming into Gulf Hills in the afternoon, when the winds had let up, by boat, from the bay side, were in the living room; the water came in so quickly and the current was so strong, they never had time to even leave the living room.

Why write about such horrible things? To save a life. The next storm that comes won't be like Camille or Katrina or any other storm, because the circumstances for each storm are unique. What happened before is no guideline for what will happen next. And your home is not safe, not from surge. No standard type of home can withstand surge. Not too much may be known about predicting hurricane intensity, but surge prediction is advanced and for the most part quite accurate. Trust that your local emergency management have the maps, the SLOSH output, and know what areas will be inundated by surge. Never, never stay, when there is a risk of surge. If you are told to evacuate, and you live in a surge zone, then do so.

While everyone on the Gulf Coast is thrilled with the lack of any fireworks so far, guess who is beating the drum? Of all places, NHC. Last Sunday, August 20th, in an interview with Reuters, Max Mayfield was quoted as saying, "The bell's going to start ringing here before long. There's absolutely nothing that I know of that is unfavorable (to hurricane development) in the eastern Atlantic," and "We have a lot of years that don't really get started until the middle or end of August."

The quote I'm waiting for, and hoping to see at the end of the season, is the one that expresses happiness that the NHC hurricane season prediction was so far over the mark. In another interview, with CNN, yesterday, Max was quoted again:

Mayfield said he remains concerned about a lack of awareness and preparedness among Americans living in areas vulnerable to hurricanes.

He quoted a survey of people living along the United States coastline from Texas to Maine that found more than half do not feel vulnerable to hurricanes nor have a family disaster plan or hurricane survival kit.

Mayfield said history shows "people who had a hurricane plan did a lot better than those who did not have a plan."

Do you think that's so? My family has stocked up on water and batteries and all that jazz, but what kind of a hurricane kit do you build to replace everything, when the storm is over and you return to nothing, because your home is destroyed? What kind of a disaster plan do you make when the disaster is that your community is destroyed, and that all the neighboring communities are destroyed? Did having a plan make that return to the slab work out a little better? A year after Katrina, the question of how to prepare for a hurricane, for the section of the Gulf Coast that is on the slow road to recovery, and where the issue of survival is already on the front burner, every day, is an ironic one -- whether the Atlantic hurricane season wakes up this year, nor not.

Yes, I think you can plan for a hurricane, but you can't really plan for all hurricanes. You can't plan for a Katrina or an Andrew. While you should never discount the power that an individual has to make a difference, and the individual effort of a lot of ordinary people made all the difference after Katrina, planning for disasters at that level isn't done by individuals -- it's done by local, county, state, and federal emergency management. Having all your ducks in a row will certainly keep you alive, and that counts, big time. And for the hurricane that is not truly a disaster, planning will keep you more comfortable and safe than otherwise. And I'm happy that Max will never get tired of urging us to prepare for hurricanes. But there is definitely some strange twisted humor in thinking about preparing now, when you never did get back to normal from last year's hurricane.

But, even so, there's one thing I know, and that I knew even at the end of the day on Monday, August 29th, 2005, when I was one of the small group of people in the country who was aware the coast was buried under water, even as newscasters crowed (preemptively as it turned out) that NOLA had dodged the bullet: the Mississippi Gulf Coast is never going to become a Homestead and Naranja Lakes, with grass slowly overtaking empty slabs. The surge and wind hadn't even finished dying away when people started picking up the pieces, and they haven't stopped.

Hurricane Katrina Storm Surge:

Weather Underground Storm Surge Articles

Storm Surge Safety Actions

  • Minimize the distance you must travel to reach a safe location; the further you drive the higher the likelihood of encountering traffic congestion and other problems on the roadways.

  • Select the nearest possible evacuation destination, preferably within your local area, and map out your route. Do not get on the road without a planned route, or a place to go.

  • Choose the home of the closest friend or relative outside a designated evacuation zone and discuss your plan with them before hurricane season.

  • You may also choose a hotel/motel outside of the vulnerable area.

  • If neither of these options is available, consider the closest possible public shelter, preferably within your local area.

  • Use the evacuation routes designated by authorities and, if possible, become familiar with your route by driving it before an evacuation order is issued.

  • Contact your local emergency management office to register or get information regarding anyone in your household whom may require special assistance in order to evacuate.

  • Prepare a separate pet plan, most public shelters do not accept pets.

  • Prepare your home prior to leaving by boarding up doors and windows, securing or moving indoors all yard objects, and turning off all utilities.

  • Before leaving, fill your car with gas and withdraw extra money from the ATM.

  • Take all prescription medicines and special medical items, such as glasses and diapers.

  • If your family evacuation plan includes an RV, boat or trailer, leave early. Do not wait until the evacuation order or exodus is well underway to start your trip.

  • If you live in an evacuation zone and are ordered to evacuate by state or local officials, do so as quickly as possible. Do not wait or delay your departure, to do so will only increase your chances of being stuck in traffic, or even worse, not being able to get out at all.

  • Expect traffic congestion and delays during evacuations. Expect and plan for significantly longer travel times than normal to reach your family's intended destination.

  • Stay tuned to a local radio or television station and listen carefully for any advisories or specific instructions from local officials. Monitor your NOAA Weather Radio.

Source: NOAA