Whether or not to evacuate in the event of a hurricane? Given the forecast for an unusually active hurricane season, this is a question thousands of Houston area families may have to face this year. Unfortunately, for most the answer is not as clear as we might hope. Many emergency managers recite the well known adage, "run from the water; hide from the wind." As a general proposition this is good advice and supported by the statistical evidence that the vast majority of deaths in hurricanes are caused by drowning. However, attempting to interpret this admonishment in residents' individual situations is not always clear and, I believe, there are significant exceptions to this general rule.
We discovered in Hurricane Rita that there are very serious consequences from the decision to evacuate. Approximately 150 individuals died in the Rita evacuation. Most were elderly and died from stress-related afflictions. A few died from carbon monoxide affixation while sitting in an idling automobile. Of course, hundreds of thousands were trapped in miserable circumstances. While evacuation plans have greatly improved since Rita, she proved that the idea that evacuating is "better-safe-than-sorry" is not necessarily accurate.
There is one group for which the answer is very clear. If you live in the State designated evacuation zones you must evacuate. These are areas that have been identified by the State as likely to be inundated by a hurricane's tidal surge. They are demarcated by zip
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code. Residents of these areas have no hoice. They must, by law, evacuate. You can find out if you live in one of the surge zones at:
http://www.hcoem.org/documents/EvacuationMap.pdf
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For any of you that live in those areas and are thinking that you might ignore the evacuation order, think again. A hurricane tidal surge is like a tsunami that keeping coming for hours. As the surge destroys structures in its path, the flotsam created from that debris becomes a battering ram that flattens anything in its path. If you doubt this, go on-line and do a search for pictures of the Mississippi coast after Katrina. In the area hardest hit by the surge it appears that God took his hand and wiped everything clean for a mile or so inland.
And the water coming at you is not pristine beach water. It has picked up everything in its path, including oil, sewer from over-run
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treatment plants, chemicals and dead animals. It is a filthy, polluted soup that can kill you. If you live in the surge zone and do not evacuate, you are seriously jeopardizing your life and your loved ones who live with you.
If you do not live in the surge zones, the question of whether you should evacuate becomes much more difficult. At the outset let me say that absent special circumstances, you should not to evacuate because you are concerned that you may lose electricity. If you are only concerned that you will not have electricity you will be much better served to wait out the storm and see if you lose service or not. If you do, then you can leave after the storm has passed and the roads are clear.
This is especially advisable when you consider the degree of forecast uncertainty that still exists. When Rita was 24 hours from landfall, the area in which there was a one-in-four chance of being the direct hit was still almost 250 miles wide. Considering that we will have to call an evacuation in the 48-72 hours ahead of landfall, many calls for evacuation will likely be false alarms. If you evacuate every time a storm threatens our area because you are concerned that you will lose power, you may find yourself on the road a lot for no reason.
For most residents who do not live in the hurricane evacuation zones, sheltering place or, as Judge Emmett has now made famous, "hunkering down" will be the best option. However, there are some good reasons for people living outside the surge zones to evacuate or shelter in the area in a location other than their home. There are principally two risks that you should assess.
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Rita Cone of Uncertainty 24 hours before landfall
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The first is the risk from wind. A Category 4 storm will have 100+mph winds extending as far inland as Montgomery County. Most structures will survive even these winds. I took a helicopter flight over the path of Rita. Many homes lost their roofs and had significant water damage, but few totally collapsed.
There are, however, significant exceptions. One, of course, is mobile homes. If you live in a mobile home and you are anywhere near the central wind cone, you should leave or find other shelter. The other exception is trees. When I took my helicopter tour of the Rita path it was hard to comprehend the number of trees that were blown down. Pine trees are particularly problematic. On that flight I saw a number of instances where a pine tree had fallen through a house, cutting it in two like a knife going through a cake. If you have large trees in your yard (and particular pine trees) that would fall on your house if they came down, I would recommend that you evacuate or find other shelter.
Even if you do not have either of these special risks to deal with, you should be mindful that while a hundred-mile-per-hour wind might not blow down your house, it will pick up all sorts of things and turn them into lethal projectiles. This is particularly dangerous for homes that have large plate glass windows. If you have this situation and are unable to secure the windows with plywood or other protective covers, again, I would leave or find other shelter.
In addition to the wind, residents outside the surge should also consider their vulnerability to upland flooding. This is flooding that is caused not by the hurricane pushing the Gulf of Mexico up on us, but rather from the storm dumping torrential rainfall on the watershed and flooding the bayou system. The tidal surge can exacerbate upland flooding by acting as dam and not allowing the bayous to drain as they would normally.
Rice professor, Phil Bedient, has created a model that projects flooding in the event of a simultaneous 22-foot surge and a 100-year rainfall. The model shows flooding over an enormous area extending as far west as SH99 and as far north as Beltway 8. The Brays Bayou and White Oak Bayou watersheds are particular vulnerable to this type of flooding. While having a bayou back up into your house does not create the same danger as the tidal surge, there are risks associated with any flooding and it is obviously extremely unpleasant. I believe that anyone living in the 100-year flood plain should also evacuate or find other shelter on higher ground in the event of a storm with a forecast of heavy rainfall. You can determine whether your home is in this area by accessing http://maps2.tsarp.org/tsarp/.
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But here is the most important point, make your plans for evacuating or sheltering in place now. Do not wait to decide if you are going to evacuate and where you are going to go as a storm is grinding down on us in the Gulf. We all tend to make poor choices when under stress and people around us are panicking. Also, the last few storms we have faced have originated in Caribbean which gave us nearly a week to prepare for their arrival. However, there have been a number of storms that originated in the Gulf giving us as little as 48-72 hours to make preparations.
Set aside some time over the next couple of weekends and think about this issue. Do the research and determine if you are in a surge zone or a 100-year flood plain. Decide in advance at what level storm you will evacuate or seek alternative shelter. Make a plan regarding where you will go and what you will need to take with you. If you are going to shelter in place make a plan on what you will need to do to be ready. Make checklists. There is a detailed hurricane planning software that is available free on-line at
www.OneStorm.org.
In the middle of the night on Wednesday, September 21, 2005, the Houston region was staring down a loaded gun barrel. Hurricane Rita was on a course to make landfall around Freeport and one of the strongest Category 5 hurricanes on record. Similarly even though Hurricane Ike came ashore as a Category 2 storm, if he had made landfall 20-20 to the west, the storm surge could have easily been ten feet higher. The truth is that we have dodged two bullets in just the last four years. We now know that a catastrophic storm making landfall is not just a hypothetical possibility. We also know what a mess a full scale evacuation of the area can be. Even with the improvement made to the evacuation plans since Rita, evacuating 1-2 million residents is never going to be a pretty picture. Nonetheless, you can minimize the effect of a major storm on your family by planning ahead. Do it today.
