The Morganza Spillway was opened today for the first time since 1973. Opening the gates at the Old River Control Structure allows water to be diverted from the Mississippi River, currently in massive flood, into the Atchafalaya River.
Sadly, this also means many homes and much farm and natural land will be inundated. Nonetheless, this diversion of the waters allows the Mississippi to come a little closer to the path it would choose if man left it alone. The Atchafalaya River drains at a steeper gradient and is considerably closer to the Gulf than the current route of the Mississippi. This got me thinking about the Mississippi and how it had meandered during the past. I did a little bit of googling and found the Army Corps of Engineers site from which I extracted the extraordinary map that you see below. If you want a large (and it's very large) version, click on the map.Here we can see some of the paths that the river has taken over the centuries through the Alluvial Valley that starts just below Cape Girardeau, Missouri, and extends south to the Gulf of Mexico. First thing that strikes you is the tangle and complexity of routes. The forces that produced such meanderings are the same forces that man is trying to restrict into the channel that he has, largely by evolutionary forces and little by conscious design, designated as the one and only path. Cities, river commerce and industry rely on this lack of deviancy.
Can the Mississippi be contained? The engineers believe so. The historical evidence as shown in this fascinating map suggests otherwise. For much more extensive background on the Old River Control Structure and the Atchafalaya River, read this lengthy but invaluably informative article.