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 This barrier,
known as the
Morganza Spillway,
can be opened to
divert water from the
Mississippi when the
river is flooded. The
spillway allows the
floodwater to flow
safely out into the
Gulf of Mexico.
A Great Flood
Between April and May 2011, huge storms
dumped record rainfall on the Mississippi
basin, causing some of the biggest floods
in nearly 100 years. Crops and
livestock
were destroyed. Many people had to
leave their homes when floodwaters were
diverted to protect the cities of New
Orleans and Baton Rouge.
Levees
Along the banks of the Mississippi, sloping
walls called
levees
(right)
have been built
to keep the river from overflowing.
The levees reduce the impact of
floods, but they do not remove
the danger completely.
Levees help to prevent flooding
by containing the flow of a
river within low mounds or
embankments. Because levees
tend to make a river flow faster,
they can make flooding more
likely at other points of the river.
For this reason, once one levee is
built, others have to be built at
all low points of the river system.
Levees
