New Orleans

====Drainage and flood control====
{{See also|Drainage in New Orleans}}

[[File:LPD18USSNewOrleansPassingNewOrleans.jpg|thumb|upright=1.15|A view of the [[New Orleans Central Business District]], as seen from the [[Mississippi River]] {{USS|New Orleans|LPD-18}} in foreground (2007)]]

In the 20th century, New Orleans' government and business leaders believed they needed to drain and develop outlying areas to provide for the city's expansion. The most ambitious development during this period was a drainage plan devised by engineer and inventor [[A. Baldwin Wood]], designed to break the surrounding swamp's stranglehold on the city's geographic expansion. Until then, urban development in New Orleans was largely limited to higher ground along the natural river levees and [[bayou]]s.

Wood's pump system allowed the city to drain huge tracts of swamp and marshland and expand into low-lying areas. Over the 20th century, rapid [[subsidence]], both natural and human-induced, resulted in these newly populated areas subsiding to several feet below sea level.<ref>{{Cite web |author=Kusky, Timothy M. |title=Why is New Orleans Sinking? |publisher=Department of Earth and Atmospheric Sciences, Saint Louis University |date=December 29, 2005 |url=http://www.eas.slu.edu/People/TMKusky/original%20files/Why%20is%20New%20Orleans%20Sinking.pdf |access-date=June 17, 2006 |archive-url=https://web.archive.org/web/20060623092455/http://www.eas.slu.edu/People/TMKusky/original%20files/Why%20is%20New%20Orleans%20Sinking.pdf |archive-date=June 23, 2006 |url-status=dead}}</ref><ref>{{cite news |first=Larry |last=O'Hanlon |url=http://dsc.discovery.com/news/briefs/20060327/neworleans_pla.html |title=New Orleans Sits Atop Giant Landslide |publisher=Discovery Channel |date=March 31, 2006 |access-date=June 17, 2006 |archive-url=https://web.archive.org/web/20060614211349/http://dsc.discovery.com/news/briefs/20060327/neworleans_pla.html <!-- Bot retrieved archive --> |archive-date=June 14, 2006}}</ref>

New Orleans was vulnerable to flooding even before the city's footprint departed from the natural high ground near the Mississippi River. In the late 20th century, however, scientists and New Orleans residents gradually became aware of the city's increased vulnerability. In 1965, flooding from [[Hurricane Betsy]] killed dozens of residents, although the majority of the city remained dry. The rain-induced [[May 8th 1995 Louisiana Flood|flood of May 8, 1995]], demonstrated the weakness of the pumping system. After that event, measures were undertaken to dramatically upgrade pumping capacity. By the 1980s and 1990s, scientists observed that extensive, rapid, and ongoing [[Coastal erosion|erosion of the marshlands and swamp surrounding New Orleans]], especially that related to the [[Mississippi River–Gulf Outlet Canal]], had the unintended result of leaving the city more vulnerable than before to hurricane-induced catastrophic [[storm surge]]s.{{citation needed|date=February 2024}}