Bayou Lafourche, originally called Chetimachas River, is a 106-mile-long (171 km) bayou in southeastern Louisiana, United States, that flows into the Gulf of Mexico. The first settlements of Acadians in southern Louisiana were near Bayou Lafourche and Bayou des Écores, which led to a close association of the bayou with Cajun culture. Today, approximately 300,000 Louisiana residents drink water drawn from the bayou.
The name Lafourche is from the French word for "fork", and alludes to the bayou's large outflow of Mississippi River water. It was formerly a Mississippi River outlet, but was dammed at Donaldsonville in 1905. The dam cut off nourishment and replenishment of a huge wetland area of central Louisiana. It changed the formerly flowing bayou into a stagnant ditch.
A project to reconnect Bayou Lafourche to the Mississippi River at Donaldsonville is under design. The plan is to use a control structure to regulate the water discharge. The purpose is to mitigate the accelerated land loss that followed the interruption of the distributary flow, and to improve water quality in the bayou.
The Bollinger Shipyards, founded by Donald G. Bollinger, was launched on Bayou Lafourche in 1946.
The film Southern Comfort is set on Bayou Lafourche.
- "Course Of The River Mississipi, from the Balise to Fort Chartres. Ross, Lieut. 1775" rumsey.geogarage.com
- U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data. The National Map, accessed June 20, 2011
- Louisiana Department of Culture, Recreation and Tourism. "Bayou Lafourche Historical Marker".