Known as a dike in European countries, a levee is basically a flood bank or slope that runs parallel to a river. Either natural or man made, a levee helps protect an area from being flooded by serving as a protective dam or  wall to the rising river during heavy rains.

However, there are times when levees fail. Sometimes the water from the river is so strong that an actual part of the levee breaks resulting to a whole where the flood water rushes in. This kind of levee failure is referred to as a levee breach and is considered very dangerous. At times water from the river flows over the levees causing massive flooding on the other side. The problem with levee overtopping is that it causes further damage to the levee which can lead to a complete breach.

In the US, most of the levees across the country were manmade, having been constructed for both agricultural and flood protection purposes. A lot of the levees are old with some are even more than centuries old. Early this year, the US Army Corps of Engineers reported that 146 levees in the US were already in a sad state and are at risk of failing if a major flood occurs.

In 2005, the country saw the devastating effects of levee failure when Hurricane Katrina passed through New Orleans. The rains brought by the storm resulted to more than 50 levee breaches and water overtopping. Almost 80% of the city went underwater as a result, caused vast damages in properties, and lost of human lives.

Other historical levee breaches include the Great Mississippi Flood in 1927 where the Mississippi River breached levees and flooded 27,000 square miles (70,000 km²) in seven states, displaced more than 700,000 residents, and killed 246 people; the 1953 North Sea flood levee breach in the United Kingdom and the Netherlands which killed more than 2,000; and the Jones Tract island levee breach in Sacramento-San Joaquin Delta which happened just a year before Hurricane Katrina.

A typical levee should be at least several feet high and wide. The advantage of a levee over a flood wall is that with a solid foundation or base, one can increase its height temporarily by stacking sandbags or water-inflated dams on it.

When building a levee, it is important that the sloping surface be protected from erosion. To prevent, this engineers plant the slopes with grass or shrubs. Also, aside from erosion levees can have problems with burrowing animals and tree roots. The integrity of the base is compromised with tunneling from the animals which increases the risks of breach.

Moreover, you need to understand that a levee may very well keep the rising river from flooding an area but in cases where overtopping occurs, the levee becomes an enemy as well. When the area becomes flooded, the levee traps the water inside the levee.

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About 80 years ago, one of the worst flooding in the history of the United States devastated seven states and placed more than 26,000 square miles of land under water. Affected were the states of Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri and Tennessee.

The 1927 Mississippi flood began a year before when torrential rains fell in the region. The area experienced extraordinary heavy rains during the summer of 1926 and went on through winter until spring. The record rains was ten time more than the previous years. The Mississippi river is known to overflow its banks on a  regular basis. But because of the heavy rains, floods began to occur in the lower Mississippi area during the early months of 1927. And every time a flooding occurs, it bested the previous one in magnitude, area covered, and damages incurred.

By February 1927, the Mississippi has inundated more than 100,000 acres with ten to fifteen feet of water. The coverage grew to as big as one million acres of land by April 9. And yet the rains still continue to fall. The US Army Corps of Engineers assured the public that the levees that they built to control the regular rise of the Mississippi would hold. But this was no ordinary rise in the water level of the river.

On April 15, 1927, more rains came. The rainfall was already a record high and yet there seems to be no break from the downpour. Rains fell in the states of Missouri, Illinois, Arkansas, Mississippi, Texas, and Louisiana.

Soon the river overpowered the levees which the Army has, at some areas, stacked up from an original 7 feet to as high as 38 feet. Nature again proved that she is more powerful than man. One of the biggest breaks in the levees was at Mounds Landing where the water from the river flooded an area more than 50 miles wide and 100 miles long. Trees, cotton fields, houses and infrastructure, and whole communities went under 20 to 30 feet of water.

The flood waters began to withdraw back to the river by July 1. However, more than 1.5 million acres of land was still under water. Even so, the river still measured an unbelievable 70 miles wide.

The 1927 Mississippi flood is permanently written down in history as among the worst mother nature dished at us. The flood waters claimed more then 500 lives, and made more than 700,000 people homeless, not to mention the millions in damages it brought to the infrastructure and agriculture in the area.

There were a number of socio-political issues that came out because of the 1927 flood. Among them was the maltreatment of Southern blacks in the refugee camps. The floods also catapulted then Secretary of Commerce Herbert Hoover to the presidency since he was in charge of the flood relief operations. He got the blacks’ vote when he promised reforms for their better treatment but lost it four years later in his reelection bid when he broke most of his promises.

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A lot of areas in UK are at high risk of being flooded. The series of floods that hit England and Whales these past few months is a testament to that fact. There are an estimated 5 million people and around 470,000 properties in England and Wales situated in flood risk areas.

Floods have always been a major issue in Britain because they happen quite frequently, affects a large number of people, wrecks considerable amount of properties, and are very very costly.

June 2007 was one of the wettest months in the history of the UK and the above than average rainfall brought forth floods after floods, causing an estimated damage of £2billion. But the bad thing in this situation is the fact that things will get worse in time. With the climate changing quite drastically in recent years, it is expected that similar wet months are to be expected in the next forty years.

Having this foreboding scenario in their midst, the Department for Environment, Food and Rural Affairs or Defra launched a new scheme to protect or at least minimize the effects of households from the devastating effects of floods. The government offers individual households grants for improving their own flood defenses.

Improving the properties’ flood resilience can protect them from major damage in case of floods. Flood defenses include setting up flood guards, tiled concrete floors, resilient plaster, and raising electrical appliances on a higher grounds or platforms.

Installing one-way valves into drainage pipes is also useful. This way, the water and sewage is prevented from backing up into the house during floods. If you have any chipboard appliances or units, it is best to replace them with plastic or steel since later materials will not get soggy when they get wet. .

Reposition your electrical sockets higher up the walls. Use lime plaster or cement render to re-plaster the inner walls. These plaster are made from water resistant materials.

Speaking of water -resistant, the doors and window frames could be made from UPVC or good-quality hardwood to make them more resilient to water. Place barriers on your doors, windows and airbricks. A pump system can also be used. The pump would get the water from the first floor once the water starts to get in.

Defra split £500,000 between six areas as part of the pilot flood resilience program. The areas are Uckfield in East Sussex, Bleasby in Nottinghamshire, Morecambe in Lancashire, Halton in Leeds and Kirkby-in-Furness and Appleby in Cumbria.

Another problem with having areas and properties flooded all the time is when applying for home insurances. It has been reported that due to the massive damage of recent flooding in the UK, insurers are no longer willing to give homeowners low premiums on house insurance payments.

According to reports, it is quite possible that the value of houses affected and damaged by the floods would decrease by as much as 80%. This is due to the refusal of insurers to cover their houses because of possible future claims of the same nature.

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Communicable diseases are, simply put, contagious diseases. They are any disease that can be spread through the air, by direct contact or through contaminated body fluids. Some examples of communicable diseases include diarrheal diseases, tuberculosis, malaria, measles, pertussis, tetanus, meningitis, and hepatitis B.

How do these diseases relate to floods? Well, floods can readily increase the spread of communicable diseases, but not all of them. We can classify the diseases transmitted during flood disasters into water-borne and vector-borne diseases. Some of the more common water-borne diseases include typhoid fever, cholera, leptospirosis and hepatitis A. Meanwhile, vector-borne diseases include malaria, dengue and dengue haemorrhagic fever, yellow fever, and West Nile Fever.

Water’s the culprit
Obviously, when flooding occurs there is an increase risk of water-borne diseases going around due to the excess water from the floods. Moreover, the risk increases in relocation areas or areas where people are housed temporarily due to the fact that they were forced to abandon their homes because of the flood waters.

One of the major considerations during floods and mass displacement of people is where to get clean water supply. Because floods can easily contaminate drinking-water facilities, diseases like diarrhoeal diseases and typhoid fever can easily become an outbreak.

Also you need to look after other infections that could result from polluted waters. Wound infections can be one of them, dermatitis, conjunctivitis, and even ear, nose and throat infections can become a problem.

Floodwater could also lead to leptospirosis, which is a bacterial disease that come from urines of rats. Once rat urine mixes with floodwaters, the soil or even vegetation, any contact to the skin could result to the transference of the bacteria.

The air could be a problem
Aside from the contaminated waters, there are other diseases, specifically vector-borne diseases that can easily hit an flood affected area. A vector-borne disease means it is transmitted by vectors to humans. Vectors here refers to any animal capable of transmitting the disease.

So in case of flood calamities, probably the most notorious animal that spreads diseases is the mosquito. Due to high chances that standing water exists inside or near the flooded areas, if is expected that mosquitoes would breed in the millions. Although, the risk of being contaminated via mosquitoes is far less during a flood than after one. After the floodwater subsides and everything settle down, the risk increases.

The most common vector-borne disease during flooding include Malaria and the West Nile.

Other flood related risks
During floods, the risk of drowning, having injuries and trauma are higher. Be careful during wading on flood waters and also maneuvering yourself in flooded ares. Also, watch out for hypothermia. Long exposure to the cold floodwaters can easily lead to it. Children are more prone to hypothermia than adults.

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