Levees and floodwalls are among the main
structures used to confine the river water and prevent flooding the adjoining
countryside. Levees and floodwalls are especially important when the
water level rises due to heavy rain and storm. When levees and floodwalls fail, the disaster strikes and rushing water floods the area
resulting death and destruction of houses, farms and industries.
In the last days of August 2005 a
category 5 tropical store named hurricane Katrina moved inland in the Mississippi
area. Its storm surge soon breached the levee system that
protected New Orleans from Lake Pontchartrain and the Mississippi River.