Barataria Basin, located south of New Orleans, Louisiana, is an irregularly shaped area bounded on each side by a distributary ridge formed by the present and a former channel of the Mississippi River; and a chain of barrier islands separates the basin from the Gulf of Mexico.

The basin contains approximately 616 km² of swamp, 701 km² of fresh marsh, 241 km² of intermediate marsh, 416 km² of brackish marsh, and 541 km² of saline marsh.

Freshwater and sediment input to the Barataria Basin was virtually eliminated by construction of flood protection levees along the Mississippi River and the closure of Bayou Lafourche at Donaldsonville; therefore, the only significant source of freshwater for the basin is rainfall and flow from the Gulf Intracoastal Waterway. Only a small amount of riverine input, designed to mimic a natural crevasse, is introduced into the basin's wetlands through the siphons at Naomi and West Pointe a la Hache. As of 2002, The Davis Pond Diversion has increased freshwater input capacity to 283 m³sec^-1 to a portion of the basin.