Mar 07 2007
On the Level with Levees – Their Roles in Hurricanes and Why They Can Fail
It is important to take all possible considerations for safety when preparing yourself for hurricane season. Levees have been used to attempt to protect people and/or property from hurricane disaster. However, they often do not work.
A levee is a dam that runs along the bank of a river or canal. This helps confine the flow of water and helps increase the speed of that flow as well. These are usually constructed of dirt, either naturally or man-made. The natural ones are formed when sediment settles on a river bank, which raised the level of sand on both sides of a river.
A man-made levee is made by the use of piled dirt along the river banks in a similar fashion as the naturally-made levees. Sandbags are sometimes places over strategic spots along this levee.
Levees have done a great job protecting floods all over the world, including in Europe along the Po, Danube, and Vistula Rivers, and in the United States as well. The Mississippi and Sacramento Rivers have often used them.
Levees work well with floods, but sometimes for large hurricanes, such as the hurricane Katrina disaster that took place last year (2005), levees do not work. Despite these protective river guard rails at least 80 percent of New Orleans was covered with hurricane waters.
Part of the reason that levees did not help in the case of hurricane Katrina is that these levees are usually only effective in the case of fast-blowing Category 3 level storms. However, these levees are just not quite strong enough for the Category 4 level hurricane that hit last year.
New technologies to protect people from flood waters are being researched. Some are already being set in place in Europe and Japan. For example, floodgates have been built on the Thames River in London and on the Venice River in Venice. Japan has super sleeves built for protection.
Even in California new efforts are being made as well, and in Bangladesh. Sometimes it is hard to predict the effectiveness of all the different types of flood barrier devices and their effects on hurricanes because sometimes a storm can hit an area and then not return for many years.
Even if hurricanes are unpredictable various devices can provide more strength against these storms than can simple levees. These can help provide extra security in areas where people do not feel they have enough flood support.
One of the areas that was so terribly affected most recently was the city of New Orleans, which 80 percent of at least was under water in the year 2005. It is possible that many people will be pleased to know that something is holding those flood waters back besides just sand or dirt levees.
The disadvantage of course is that other types of flood and hurricane barrier technology can be costly. Taxpayers most likely would need to foot the bill. Many people will be weighing that decision over the next couple of years in various flood-affected areas like New Orleans.
After what many homeowners have been through in the past year in New Orleans as well as other areas of the United States they will most likely be all for new technology. It is mostly a matter of making sure that the public understands the risks involved as well as the cost, and this is a decision that is not going to be taken lightly.
If you are interested in learning more about these technologies you can find more information about them in national newspapers. You can also read various architecture magazines as well. Future articles may touch more on this subject as well.
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