Controlling the Mississippi river did not come into peoples’ minds until they saw that the Mississippi was slowly starting to change its course again and totally avoid New Orleans. This first started to get serious after Captain Henry Shreve cleared a large logjam in 1831 that was blocking water from going down the Atchafalaya River. After he had cleared the raft (logjam) the waters from the Miss started to flow down the Atchafalaya more and more. This started to worry the people that owned businesses in New Orleans and the politicians in the state. Not only was New Orleans a popular place for tourists to go, it was also one of the major ports in the United States. In an attempt to slow or even stop the natural process the river wanted to take the Army Corp of Engineers built a structure that would monitor and control the amount of water that flowed into the Atchafalaya from the Mississippi. This structure is called the Old River Structure. With this new structure built the Army Engineers can also stop major floodwaters from reaching New Orleans. If a flood that would threaten New Orleans would start to flow down the Mississippi river the engineers could open up the locks that control the waters form going down the Atchafalaya and let the waters go down toward Morgan City instead of New Orleans.
Interesting links related to history of rivers in area and possible impact of flood events:
The Mississippi Levee System and the Old River Control Structure (ORCS)
http://www.tulane.edu/~bfleury/envirobio/enviroweb/FloodControl.htm
Ecology of the Mississippi River Delta Region
Controlling the Mississippi River
http://www.loyno.edu/lucec/mrdcontrol.html
Floods on the Lower Mississippi: An Historical Economic Overview
http://www.srh.noaa.gov/topics/attach/html/ssd98-9.htm