Atchafalaya (əchă´fəlī´ə), navigable river, c.170 mi (270 km) long, S central La. The Atchafalaya meanders south, in a former channel of the Mississippi, to the Gulf of Mexico. A distributary of the Red and Mississippi rivers, the Atchafalaya flows to the Gulf through an extensive system of guide levees and floodways. Important to the agriculture and energy industries of the region, the system serves as a flood control for the lower Mississippi, especially around New Orleans.

Bayou Teche (bī´ō tĕsh, bī´ōō), 125 mi (201 km) long, S La., formed by tributary bayous and flowing SE to the Atchafalaya River near Morgan City. Navigable for more than 100 mi (161 km), it flows through a fertile sugarcane area. Bayou Teche was the setting for Henry Wadsworth Longfellow's Evangeline.