Wanderlust World Wanderlust World New Orleans was not built on glacial outwash. It sits on the Mississippi River's meander belt and natural levees—raised banks formed by sediment deposition during floods. The city is essentially built atop the river's delta, where distributaries spread sediment across a broad, low-lying plain. This geography makes the city vulnerable to subsidence and flooding, but it is a product of fluvial (river) processes, not glacial outwash.