Mississippi flood Case Study (2)

• Longest river in the USA - 2340 miles.
• 4th longest river in the world.
• 3rd largest drainage basin in the world.
• Source - Lake Itasca, Minnesota.
• Mouth - Gulf of Mexaco, New Orleans.
• Flows through 10 states.
• 18 million people/50 cities rely on it.

• Ohio and tennessee rivers rise in the Appalachians, receive heavy rainfall between Jan-May
• Flood risk increased from snow melt.
• Lower mississippi has most frequent floods.

Flooding

• On 12th July 1993, the river St. Louis reached a height of 43 feet.
• Levees burst as pressure of water became to great.
• River remained at flood stage at St. Louis for 144 days.
• 150 levees collapsed.
• Dams burst, bridges were closed.
• By mid July 100 tributaries flooded.

Impact

• 50 people killed
• 62,000 families evacuated  
• 55 towns wrecked
• £12 billion worth of property was destroyed
• Valuable transport infastructure affected.
• River traffic halted for several months (oil, cereals, coal could not be transported.)
• Ground was too wet for planting crops.
• Insurance claims were high
• 26,000km sqaured land flooded.
• Took several months for the water to drain off the land
• Threat of disease from sewage been washed into waterways
• Water attracted mosquitoes and rats, led to water borne diseases like Hepatitis.

More flooding.

• In 2001 the river flooded again.
• 4,4000 people evacuated and the damage cost £13 million.

Hard engineering management strategies

• Levees -…