Effects of Floods
The most recent catastrophic flooding in United States history occurred in New Orleans in
2005, in the aftermath of Hurricane Katrina (Figure13.18). This flooding occurred because
of the failure of the city’slevees, raised structures designed to hold back a river or lake.
The New Orleans levees were poorly designed, and broke in multiple places after the storm,
allowing water to pour into the city (Figure13.19). Ultimately, over 80% of the city was
submerged, 90% of city residents evacuated, and over 1800 people died in the disaster.
Figure 13.18: Hurricane Katrina in 2005 was one of the deadliest storms in United States
history. ( 7 )
Not all the consequences of flooding are negative. Floods deposit sediment in their flood-
plains, and these sediments are nutrient rich and good for farming. Therefore, many farmers
today grow crops in the floodplains of major rivers. This pattern of rain and flooding was
also important to such peoples as the ancient Egyptians along the Nile River.