Flooding and flood control

Whenever there is a flood, there is always a flock of people who are quick to point out that our flooding is much "worse" because we have too many levees and not enough wetlands.  The fact is true as far as it goes, but it leaves out a lot of information that ignores the value of levees.  The fact is that levees protect a great deal of property in flood events.  Flood elevations have increased as levees have been built higher, but the higher levees keep areas such as New Orleans, Baton Rouge and St. Louis relatively safe from flooding.  Also in most years, levees protect a good deal of cropland up and down the river.  Farmers in those cropland areas know the risks involved in where they farm.  Farming has been done in floodplains since people first planted crops in Mesopotamia and Egypt.  Soils are rich and productive in floodplains and flooding is one of the thing that makes them productive.  It is always easy for the news media to find someone to complain about the flooding that they are suffering.  I certainly would not wish a flood on anyone.  I experienced the flood of 1993 first hand.  It is no fun when a river reclaims it's floodplain.  The St.Louis Post Dispatch  has a good article this morning about the flooding in Louisiana. No direct link because of AP rights.   This New York Times article puts a face to those affected by orpening the gates.

Levees have been around in the United States since before the Civil War.  General Grant took advantage of levees to march his army around Vicksburg on the Arkansas side of the river.  That is how he got his troops through the swamps.  Levees started out being built to connect sand ridges to keep water out of lowlands.  The system worked pretty good in lot of years.  Farmers built levees by hand and with small scrapers and horses or mules.  Everyone had to provide a certain amount of labor and equipment based on the benefit they received.  When there was a flood, levees were often built higher to protect against the flood of record.  There were also levee wars in those days.  Whoever could build their levees higher might protect their land at the expense of someone else. 

In 1927 the lower Mississippi River experienced the worst flood ever.  Over 900,000 people were displaced and several million were affected.  John M Barry wrote a book called Rising Tide about the flood and how it changed the Mississippi River Valley and the way we fight floods.  It is worth a read.  One of the things he describes is how City of New Orleans officals blasted a levee in panic and without compensation to anyone.  This was probably the biggest levee war ever. 

After 1927, the Corps of Engineers and the Mississippi River Commission began a coordinated effort at flood control.  The system in the news now is using flooding in floodplains and wetlands to reduce flood damages in populated areas.  Are they damaging farmland?  Yes, but mostly temporarily.  People were compensated for the potential damages when the system was set up.  Are they dislocationg people?  Yes, but the people are living in an area of known risk. 

The Atchafalaya Swamp is the largest wetland in the United States.  Yes it is bigger than the Everglades.  The Morganza Spillway shown below lets water out of the Mississippi River and into the Atchafalaya River and Swamp, an old channel of the Mississippi.  Yes people live in  harms way, but far fewer than are endangered by the rising river.  The Bonnet Carre spillway is the last spillway that can be used to protect New Orleans.  It drains into Lake Ponchartrain.  It may or may not be opened this year.  I am amazed at how well the whole scheme works.  We use an old floodplain in Missouri, we use a swamp in Louisiana and we use a tidal lake in Louisiana to protect populated areas.  Isn't that what people are saying we should do when they want levees removed?  What we are doing is leaving the levees in place except in the most extreme circumstances. 

Could we have a better system?  Yes, we could but we would have to turn the clock back to 1600 and have a whole different floodplain management strategy than we do.  One of the best strategies we have, is to make it government policy to get people out of the floodplain, but the next thing you will hear is someone complaining that FEMA will not let them rebuild their home.  I think we do well in managing floods with the modern coordinated effort, considering what we have to work with.  If people want to live in harms way, they should be able to, but follow rules about elevation or take on the risk yourself.  Floods tend to be a losing situation for some to the gain of others.  Bill Graff provides a great viewpoint on the current situation and past experiences with floods.  I hope you check it out.  I hope my  blog does not offend.  I am trying to present all sides of the issue here in a fair way.  Some night I hope to share a somewhat humorous story about the Morganza spillway.