Why it Happened: History of Water Management

During the past century, hurricanes have flooded New Orleans six times: in 1915, 1940, 1947, 1965, 1969 and 2005. New Orleans is completely surrounded by water, and its average elevation is 6 feet below sea level. 

New Orleans under water

Levees and seawalls were built throughout the 20^th century by the Army Corps of Engineers to prevent flooding. When Katrina hit, the water overwhelmed drainage canals and unstable levees and swept some completely away. Over 50 levees and flood walls failed. Specifically the levee system that held back the waters of Lake Pontchartrain and Lake Borgne were completely overwhelmed by the storm surge. 

Failed Levees in New Orleans

By August 30, 80 percent of New Orleans was under water. Katrina affected over 90,000 square miles of the United States. 

80% of New Orleans under water

All of the areas in red were flooded by Hurricane Katrina

Works Cited:

The Editors of Encyclopædia Britannica. “Hurricane Katrina.” Encyclopædia Britannica,

Encyclopædia Britannica, inc., 22 Dec. 2017, www.britannica.com/event/Hurricane-Katrina.

History.com Staff. “Hurricane Katrina.” History.com, A&E Television Networks, 2009,

www.history.com/topics/hurricane-katrina.

Smith, Greg B. “Hurricane Katrina 10 yrs. later: New Orleans still struggles.” NY Daily News, New

York Daily News, 23 Aug. 2015, www.nydailynews.com/news/national/hurricane-katrina-10-yrs-new-orleans-struggles-article-1.2334479.