Floods, Channelization and the Army Corps of Engineers

I could use some help making this report more complete. I can't give it the time it deserves. But here are the basics:

Environmental Defense Fund challenges Army Corps of Engineers' channelization projects

I started getting newsletters from the EDF warning about channelization in the 1970's. I didn't know what to do with the information, except to send them a little dough. I sort of forgot about it.

Their web site doesn't go back to the 1970's. But they are still warning us about the dangers of channelization!

Here's a short 2006 article on the subject: www.edf.org...

And their plans for 2011 still emphasize the restoration of freshwater habitats destroyed by channelization:
www.edf.org...


Studies on the effects of channelization

I ran across more than one academic thesis about channelization. One favorite study subject was the Hocking River channelization project in Athens Ohio. Ohio University is right there, and flooding there was one reason the river was channelized. So more than one Ohio U student has done studies on the project.
Wikipedia has a photo of the channel that is more accessible than the ones in the academic papers.
en.wikipedia.org...
But here are two such papers:
etd.ohiolink.edu...
etd.ohiolink.edu...
The second one is quite lengthy and goes into the whole history of it. As the story goes, the "reclaimed" floodplain land was used to build a huge shopping center with Lowe's, Wal-Mart, Kroger, MacDonalds, etc. This shopping center serves the whole region. Athens itself is a small historic town now dominated by its student population. It is in southern Ohio very near a major national forest. The largest nearest city is Columbus, about 50 miles away. Many Athens residents feel the town has lost its charm, and has become economically unbalanced, mostly due to the huge retail stores that now line the new river channel.

Human attempts to control the Mississippi

Here's an interesting page from the Tulane University website:
www.tulane.edu...

To quote:

In 1852, the federal government appropriated $50,000 in order to conduct studies on how to further eliminate the flooding problem. The first study was done by an engineer named Charles Ellet Jr., whose study produced some startling conclusions. His report to Congress attributed the increase of flooding in the Mississippi River Basin to four major developments, including:


"The extension of the levees along the borders of the Mississippi, and of its
tributaries and outlets, by means of which the water that was formerly allowed to
spread over many thousand square miles of low lands is becoming more and more
confined to the immediate channel of the river, and is therefore, compelled to rise
higher and flow faster, until, under the increased power of the current, it may have time
to excavate a wider and deeper trench to give vent to the increased volume which it
conveys."

It was clear even then that our attempts to control the flooding upstream were just resulting in worse flooding downstream.

The Army Corps

The Army Corps of Engineers is an interesting organization. Armies need engineers to build bridges, fix roads, etc, to assist in the movement of troops and equipment over land in wartime. So why are they dug in so deep in our domestic flooding problems?

The Corps of Engineers were established by President Thomas Jefferson in 1802. They were responsible for all military civil engineering, in particular fortifications and navigation aids. This is how they became involved in the inland lakes and the Mississippi. Ones of its early projects was the fortification of New Orleans during the War of 1812. In this way, the Corps became the de-facto federal construction company. It built the Washington Monument. It built the Panama Canal. It built the Bonneville Dam, The Pentagon, The Manhattan Project, and the JFK Space Center. It built anything for the government that they did not want civilian access to. That means it has also probably been deeply involved in all the underground bases that we aren't supposed to know about.

They also became deeply involved in flood alleviation schemes on all our major rivers.

Being officially attached to the Army, they serve whoever the Army serves. And, unfortunately, that does not necessarily mean the people of the United States.

Natural Flood Cycles

As a fiercely industrialized nation, we tend to ignore the importance of natural systems in sustaining life on this planet. The EDF has some good articles on this, but most concerning wild plants and animals. Around the world, other cultures have been living with the annual ebb and flow of their rivers for centuries.

"The Flooding of the Nile has been an important natural cycle in Egypt since ancient times." states the short Wikipedia article on the subject: en.wikipedia.org...

The people of the Nile lived in harmony with this cycle for centuries. In 1970 the Nile was dammed, and no longer floods as it once did. The article does not go into why this was done.

As reflected in this page from the UC Davis website, the Yellow River of China has one of the longest recorded histories of any river in the world.
mygeologypage.ucdavis.edu...

There, flooding was considered a huge problem. Serious channelization attempts started around 58 AD. That's almost 2,000 years ago! As the narrative explains: Each year during peak flow, the river would "silt up." In Egypt they learned to use this silt in their agricultural cycle. But all silt does when you are trying to channelize a river is cause problems. The channels fill up, and the river starts flooding again. The silt problem was made worse by misuse of land in upstream watersheds, causing excessive soil erosion during each rainy season.

The Chinese decided that river control was a necessary evil in order to increase agricultural production in the floodplain, but we have seen in recent weeks how this strategy has been defeated.

We have a similar, though shorter, history and outcome on the Mississippi and other US rivers.

Using computer simulation to redesign a floodplain

After considerable search, I found a freeware program that does water flow simulation. It is offered on the EPA's website. It's not a very beautiful program, but if you want you can play with it and learn how upstream channelization can affect downstream water levels during peak flows.

www.epa.gov...

The graphics it produces are not cool enough to include here, but I did a very simple simulation to estimate the effects of a narrow or wide channel of about the same depth on water levels during a heavy rain. I only had to widen the channel from 30 to about 150 feet to reduce the peak depth from flood level to half that.

From that data and common sense, "safe zones" around smaller rivers seem like the most obvious way to handle flood risks. These exist in many communities.

But the Mississippi just above Saint Louis is about a mile wide. To leave a "safe zone" around this river of about 5 miles in width is asking a lot!

Yet much data points to the potential benefits of giving the river more space. And it also very clearly points to the fact that these floods are largely man-made, or at least man-assisted, events. We know these rivers rise and fall each year. It was us who decided it was a "problem" that needed to be "fixed." Now many people are paying for those decisions.

I welcome posts that would expand on this data or provide usable flow simulation graphics for us all to ponder.