“Before artificial levee construction, the river avulsed and a new delta was constructed every 1,000-1,500 yr: the active Plaquemines-Balize Delta began to form about 1,000 yr ago, and was for some time contemporaneous with the older Lafourche Delta, whereas diversion to the Atchafalaya River course began about 500 yr ago, but is now managed by the US Army Corps of Engineers.”
[Michael Blum and Harry Roberts, “Drowning of the Mississippi Delta due to insufficient sediment supply and global sea-level rise”; PDF link]
