Mississippi River Megafloods – Worst in 500 years!!!

Guest post by David Middleton

04 APRIL 2018

Mississippi River flooding worse now than any time in past 500 years

Efforts to control the river’s flow with levees and other structures have increased the risk of dangerous floods.

Floods on the mighty Mississippi River are larger and more frequent today than at any time in the past 500 years — in part, a new study suggests, because structures erected to control the river have increased the flood risk.


The US Army Corps of Engineers, the government agency that manages the river flow, declined to comment on the study. But Robert Twilley, a coastal-systems ecologist who directs the Louisiana Sea Grant College Program at Louisiana State University in Baton Rouge, says that the study “should be on every desk of every Corps engineer who is designing infrastructure for the Mississippi River”.

To reconstruct the river’s history, Samuel Munoz, a geoscientist at the Woods Hole Oceanographic Institution in Massachusetts, and his colleagues looked at oxbow lakes and oak trees on the lower Mississippi between southern Missouri and Louisiana. Oxbow lakes are coils of river that became detached from the main flow as the Mississippi changed course.


The result surprised Munoz. Both the frequency and magnitude of floods on the Mississippi have increased in the past 150 years. Floods were correlated with global weather patterns linked to the El Niño–Southern Oscillation in the Pacific Ocean and the Atlantic Multidecadal Oscillation, both of which influenced when and how much rain entered the system. But these climate cycles couldn’t explain all of the increase.

Human influence

Munoz and his team suggest that up to three-quarters of the increased flood risk might be attributable to the dams, walls and levees that now confine the river.



Humans build things in floodplains and try to control nature… And we wonder what could possibly go wrong… Kind of like building expensive resorts and beach houses in places frequented by hurricanes.   However, it seems like something is missing from this article… What’s missing?  No mention of fossil fuels, heat-trapping greenhouse gases or anthropogenic climate change!

The worst flooding in 500 years isn’t being attributed to Gorebal Warming! Shocking? Not really.  Mississippi megafloods aren’t unprecedented.

Cahokia’s emergence and decline coincided with shifts of flood frequency on the Mississippi River

Samuel E. Munoz, Kristine E. Gruley, Ashtin Massie, David A. Fike, Sissel Schroeder and John W. Williams

PNAS May 19, 2015. 112 (20) 6319-6324; published ahead of print May 4, 2015. https://doi.org/10.1073/pnas.1501904112

Edited by James A. Brown, Northwestern University, Evanston, IL, and approved April 8, 2015 (received for review January 28, 2015)


Our paper evaluates the role that flooding played in the emergence and decline of Cahokia—the largest prehistoric settlement in the Americas north of Mexico that emerged in the floodplain of the Mississippi River around A.D. 1050. We use sediment cores to examine the timing of major Mississippi River floods over the last 1,800 y. These data show that Cahokia emerged during a period of reduced megaflood frequency associated with heightened aridity across midcontinental North America, and that its decline and abandonment followed the return of large floods. We conclude that shifts in flood frequency and magnitude facilitated both the formation and the breakdown of Cahokia and may be important factors in the declines of other early agricultural societies.


Here we establish the timing of major flood events of the central Mississippi River over the last 1,800 y, using floodwater sediments deposited in two floodplain lakes. Shifts in the frequency of high-magnitude floods are mediated by moisture availability over midcontinental North America and correspond to the emergence and decline of Cahokia—a major late prehistoric settlement in the Mississippi River floodplain. The absence of large floods from A.D. 600 to A.D. 1200 facilitated agricultural intensification, population growth, and settlement expansion across the floodplain that are associated with the emergence of Cahokia as a regional center around A.D. 1050. The return of large floods after A.D. 1200, driven by waning midcontinental aridity, marks the onset of sociopolitical reorganization and depopulation that culminate in the abandonment of Cahokia and the surrounding region by A.D. 1350. Shifts in the frequency and magnitude of flooding may be an underappreciated but critical factor in the formation and dissolution of social complexity in early agricultural societies.


Full Text Available, PNAS

There were at least 8 Mississippi River megafloods between 200 and 2000 AD.  If the flooding is worse today than at any time in the past 500 years, it currently ranks between flooding events II and III.


Fig. 2. from Munoz et al., 2015 “Median particle size and PC1 scores for Horseshoe Lake (Left) and Grassy Lake (Right) alongside composite core photographs by depth from surface–water interface. Depths of chronological controls used in age–depth model are marked with black boxes. Flood events (numbered I–VIII) are denoted with gray horizontal bars.” (Just like correlating well logs!)

The megaflood hiatus ran from roughly the nadir of the Migration Period Cooling to the peak of the Medieval Warm Period.  The megaflood frequency abruptly increased near the onset of the Little Ice Age:


Ljungqvist, 2009 NW climate reconstruction (on its side) correlated with Munoz et al., 2015 cross section.

While our dams, levees and other flood-control structures may have ironically contributed to the worst Mississippi River flooding in 500 years, they had nothing to do with the previous eight megafloods.

Speaking of megafloods that humans didn’t cause… Have you ever heard of the Zanclean megaflood?  It was triggered by the Messinian salinity crisis (MSC).  It was a doozy.  If Gavin Schmidt’s Silurian civilization had been thriving on the Messinian  salt flats during the Late Miocene, the Zanclean megaflood would have wiped them out without a trace.  The transition from the MSC to the Zanclean megaflood marks the transition from the Miocene to the Pliocene.  It left a serious mark on the stratigraphic record.

Some reconstructions of Zanclean megaflood suggest that sea level in the Mediterranean could have risen at a rate of 10 meters per day during the peak flow of water from the Atlantic into the Mediterranean basin.

A Megaflood-Powered Mile-High Waterfall Refilled the Mediterranean

Evidence of the Zanclean megaflood in the eastern Mediterranean Basin

Catastrophic Flood of the Mediterranean After the Messinian Salinity Crisis



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Where is that 40 ft diameter pipe that would transport a lot of that water to the Colorado river. California could use it.
Invest the future insurance claims to the pipeline.

Richard G.

Ironic isn’t it that in the Mississippi delta lands of Arkansas, Mississippi and Louisiana they have built great waterworks of ditches to drain the water OFF the farmland, while in the arid west they have built great waterworks of ditches to carry water ONTO the farmland. One man’s waste is another man’s treasure.


Now that would be a hell of pump to carry that water over the continental divide. A better solution would be to not use that water in LA. and associated s**tholes.

Jacob Frank

How dare they not mention the CO2 apocalypse? Clearly not scientific

Komrade Kuma

What denier allowed this to get through peer review!!!!

Maybe they are all so transfixed with the Russia collusion story that they just rubber stamped it to get it out of the way.

Eustace Cranch

The pre-Zanclean Mediterranean basin doesn’t sound too hospitable to me, for Silurians or anybody else. Two kilometers below sea level, so salty it’s hard to imagine anything much growing there, and likely hot as hell.

Samuel C Cogar

The erosive power of the “mega-flooding” of the pre-Zanclean Mediterranean basin gives credence to the “mega-flood” responsible for the 277-mile-long channel known as the Grand Canyon.

a 2009 Nature study, which showed water violently rushed into the desiccated Mediterranean after shifting tectonic plates reopened the Strait of Gibraltar. The deluge carved a 200-kilometer-long channel along the seafloor as it filled the western part of the basin.


The Colorado River has to refilled a few things.

Samuel C Cogar

David Middleton – April 20, 2018 at 5:47 am

The Colorado River didn’t refill anything. The uplift of the Colorado Plateau enabled the Colorado River to carve the Grand Canyon in about 6 million years

I agree, David M, that is what you were taught to believe. But what you were taught to believe about science ……. and what is actual factual believable science are oftentimes quite contrary to each other.
Here are some GC stats:
•The Grand Canyon is 277 miles (446 kilometres) in length.
•At its widest point the Grand Canyon stretches 18 miles (29 kilometres) across.
•At its narrowest point it stretches 4 miles (6.4 kilometres) across.
•The Grand Canyon is around 6000 (1800 metres) feet deep
Here is a GC photograph:
Now, David M, study the above photo for a few minutes and then tell me why you truly believe it was possible for that widdle ole Colorado River to erode out an 18 mile wide by 6,000 feet deep canyon, ….. with vertical side-walls up to a mile high in places, ….. and with all of the hundreds of “dead-end” side canyons where the Colorado River water never flowed with erosive force.
And David, after you decide there is only one (1) reason for your GC belief, ……. then read the following, to wit:
The “new” science employs common sense thinking, logical reasoning and intelligent deductions to resolve what the physical evidence provides, to wit:

The evidence suggests the western Grand Canyon was cut to within 70 percent of its current depth of 3,280 feet (1,000 meters) long before the Colorado River existed. The results appear today (Nov. 29) in the journal Science.
“Our data suggests that there was in fact a large canyon present for most of the Grand Canyon by about 70 million years ago in its western segment, and that canyon was carved to nearly modern depths,” said Rebecca Flowers, lead study author and a geology professor at the University of Colorado, Boulder.


Samuel C Cogar

As an added note, a rebuttal statemen from: David Middleton – April 20, 2018 at 5:47 am

The Colorado River didn’t refill anything.

David M, is there some reason that you are associating the “refilling of a basin” via flowing water …… with the “eroding of a canyon/gorge/trough” as the result of flowing water?
A “quoted” statement posted by David M, to wit:

As the land rose, the streams responded by cutting ever deeper stream channels.

Now that was a silly statement iffen I ever heard one. Creeks, streams and/or rivers don’t respond to anything, …… but the water contained within their outflow channel does respond to the force of gravity.
If the flow of the Colorado River had sufficient erosive force for the “cutting” of a deeper channel in the bedrock as the Colorado Plateau was being uplifted, …… then surely to goodness the Colorado River had sufficient erosive force for the “cutting” of a deeper channel in the bedrock long, long time before the uplifting of the Colorado Plateau ever began, ……and thus the depth of the GC should be closer to 12,000 feet instead of its current 6,000 feet.

Samuel C Cogar

David Middleton – April 21, 2018 at 7:29 am

Your comparison of the Grand Canyon to the Zanclean megaflood is the reason I associated it with refilling a basin.

You stated in your published commentary that ….. “…. the Zanclean megaflood marks the transition from the Miocene to the Pliocene. It left a serious mark on the stratigraphic record.
And via your cited links I found out that “serious mark” you made mention of was a “200-kilometer-long [eroded] channel along the seafloor”.
Anyway, I sincerely apologize.
I had just assumed that the 1st four (4) words of my post, to wit, …. “The erosive power of ….. ”, …… was all that was necessary to explain/define my implied correlation of the hydro-eroded 277-mile-long Grand Canyon channel and the hydro-eroded 200-kilometer-long Mediterranean seafloor channel.

Samuel C Cogar

The breakup, cracking, crevassing, fracturing of the Colorado Plateau was surely the result of the “uplifting” pressures pulling and stretching of the topography some 70+-my BP and it is quite possible that there was a horrendous glacier created water impoundment (aka: like Lake Agasiz) in the upper mid-west that was breached and the outflow went rushing down what is now the Colorado watershed instead of the Mississippi watershed.
I believe there has been a lot of material “flushed-out-of” what is now known as the Grand Canyon and I believe the present day (5ma) Colorado River is only responsible for a very small portion of said “flushing”.
Future research may provide answers.

Samuel C Cogar

Whether the Grand Canyon was carved …..

To carve, …. or to erode, …… that is a hydrological question.

Geologists couldn’t account for the strange landforms of eastern Washington State. Then a high school teacher dared to question the scientific dogma of his day.
The Channeled Scablands – Formed by Megafloods, This Place Fooled Scientists for Decades
In the middle of eastern Washington, in a desert that gets less than eight inches of rain a year, stands what was once the largest waterfall in the world. It is three miles wide and 400 feet high—ten times the size of Niagara Falls—with plunge pools at its base suggesting the erosive power of an immense flow of water. Today there is not so much as a trickle running over the cataract’s lip. It is completely dry.
and explained to the expert assemblage how a massive ice-age flood had carved three parallel tracts of flood channels south of the Cordilleran ice sheet (which covered Canada and the northern United States), pooled in a temporary lake twice the size of Rhode Island at the southern edge of the scablands, and then drained like an overflowing tub into the Columbia River Gorge. On the way, the floodwaters carved the famous Grand Coulee, a canyon up to three miles wide with walls up to a thousand feet high, ……

Read more @ https://news.nationalgeographic.com/2017/03/channeled-scablands/

If one never questions the scientific dogma of his/her day, then they will be relegated to forever being a “mimic” and will never be any more learned than their mentors see fit for them to be.

Samuel C Cogar

David Middleton – April 24, 2018 at 4:57 am

Our discussion started here:

[quoting Sam C] “The erosive power of the “mega-flooding” of the …. yada, yada

And has gone exactly nowhere.

You got that right …… and the fault for aforesaid “intellectual stalling” is all of your doing.
The only question is, ….. was your “stalling” actions intentional or solely due to being misnurtured/miseducated or maybe an inherited disability? Why would you post such a silly statement as follows, given the FACT the “topic” of our discussion was “the erosive power of mega-floods” , to wit:

The megafloods of glacial Lakes Bonneville, Agassiz and Atna are also not analogous to the formation of the Grand Canyon, nor is the Black Sea megaflood hypothesis.

“DUH”, ….. megafloods are denoted/named as such simply because of their, per se, “sudden occurrence” and their “major erosion” of the topography, ……. NOT because of the location on the earth’s surface that they occur.
Anyway, David M, given your inferred brilliant intellect of most every thing associated with earth’s natural sciences, …… please provide me with actual factual scientific proof or evidence that there has NEVER BEEN a per se “megaflood” occurrence anywhere near what is now known as the Grand Canyon.

Samuel C Cogar

David Middleton – grabbing at straws ……. to CHA:

Your’e the one who referred to the Grand Canyon as a megaflood.

Sure I did, …… and your’e the one who referred to past flooding of the Mississippi River as being “megafloods”, …. at least six (6) times, in your above published commentary, to wit:

Statements made by David Middleton:
#1 – Mississippi River Megafloods – Worst in 500 years!!!
#2 – The worst flooding in 500 years isn’t being attributed to Gorebal Warming! Shocking? Not really. Mississippi megafloods aren’t unprecedented.
#3 – There were at least 8 Mississippi River megafloods between 200 and 2000 AD.
#4 – The megaflood hiatus ran from roughly the nadir of the Migration Period Cooling to the peak of the Medieval Warm Period.
#5 – The megaflood frequency abruptly increased near the onset of the Little Ice Age:
#6 – they had nothing to do with the previous eight megafloods.>

And then David M, after referring to the “slow n’ steady” Mississippi River flooding as being “mgafloods”, you were silly enough to provide proof of your “elitist” attitude and your devious, dishonest personality by stating the following in your CYA attempted criticisms of my good name, reputation and learned knowledge of the physical/biological sciences, …….. to wit:
David Middleton – April 23, 2018 at 5:01 am

The thing is… A megaflood is an infrequent, large, relatively sudden, surge of water.

Shur nuff, David M, shur nuff, ……. a Mississippi megaflood suddenly surging all the way downriver to New Orleans, …… like maybe Paul Bunyan had “flushed” his outhouse commode in North Dakota.


I must be missing something: the “megaflood” events were defined by having a peak of SMALLER particle sizes? I’d have thought larger. Larger because more water is flowing, more quickly. Clearly there’s more to this than meets the eye. GoatGuy

Richard G.

Consider this dynamic of water transport: the higher the water velocity, the greater the ability to carry larger sized sediment particles. Unrestrained by levees, the Mississippi’s waters used to spread out over the enormous delta flood plain that starts in southern Missouri and extends down to Louisiana. As the water spreads, the velocity drops and the larger sediments fall out of the water column. Where there is high velocity you get sandy loam deposits. Where there is low velocity (backwaters) you get fine gumbo mud.
“I never would have made it through that Arkansas mud
If I handn’t been ridin’ on that Tennessee Stud”

Tom Halla

Chicago, one of the heads of navigation on the Mississippi watershed, is only 176 meters elevation, so flooding is inevitable given the lack of slope. It is like a giant case of what happened last year in Houston, another place with minimal slope for drainage.


I’m 100 miles from Galveston, and at 139 feet above sea level. It’s not just flat, it’s REALLY flat….I didn’t flood but a lot of folks around me did.


What caused those floods 500 years ago?


Pick one: Greenhouse gases. CO2. Global warming. Climate Change. Methane-ing mammals.

Shanghai Dan

Rehearsal for what to do when evil man generated all that CO2!


Rain, melting snow, runoff from more rain, rain and more rain, hail, sleet.


An overabundance of H2O in the watershed.

Samuel C Cogar

What caused those (Mississippi) floods 500 years ago?

Most likely an extremely deep winter snowpack in the upper mid-west, …. followed by early Spring temperatures in the 80’s or 90’s that included heavy rainfall.
Said flooding could have been exacerbated by the winter “ice-breakup” on the Missouri and Mississippi Rivers, thus causing ice “jams” or ”dams” blocking the river channel outflow.


“Kind of like building expensive resorts and beach houses in places frequented by hurricanes. “….
Are people that live on islands, or work on the water……supposed to live in aluminum single wides?
Here’s a great idea….let’s move them all to places that get snow storms, fires, tornadoes, floods, earthquakes, straight line winds, ice storms, sinkholes, avalanches and landslides, hailstorms, etc


Water that once took weeks to reach the river is now collected via man made structures like rooftops and parking lots, and then expressed via channelized tributaries, magnifying flash flooding. Yazoos and wetlands are now bypassed.


Worst in 500 years? Anybody who says we have even come close to the 1927 floods on the Mississippi is smoking some of that California weed. The 1927 flood event was the most widely destructive flood in US history, eventually inundating over 27,000 square miles. It appears that the authors of this piece have gotten so deeply intoxicated by their statistical nonsense that they don’t even know that it happened.



Dan DaSilva

Sounds like the hockey stick and medieval warm period. We need a study on the legalization of weed and decline of modern science.

paul courtney

wws: I’ve read about ’27, but can remember 1993. Is current flooding up to that level? I hope somebody here knows how to find info like the level in St. Louis in ’93 v. 2018. 500 years indeed! My googling showed a WaPo story with the 500 year headline, so Nature magazine got the CAGW memo, too.

John Bell

I recall 1993 well, I was living near Milwaukee and i got rained on every weekend.


St. Louis: 49.5 feet was the max level, according to water.weather.gov on August 1, 1993. There was a similar level in 2013. The 1993 floods were memorable in part because they seemed to last all summer.


I remember 1995 also. Bad business. Ol;’ Man River doesn’t take too kinldy to being told where he can flow and how much he can float along.

Stan Wisbith

If I’m thinking about the right event, the 93 flood totally disappeared after it reached Thebes. A small town about 44 river miles upstream of the junction with the Ohio. If I may add an additional fun fact. On an annual basis, about 2/3 of the water in the Mississippi River below the junction actually comes out of the Ohio Basin. The Upper Mississippi basin covers more area but the Ohio basin is a lot wetter.


I live less than a mile for Allegheny River, ice jam/dam flooding happens every year. Had a rather big one early in the season at East Brady and smaller ones later on above Parker. Lot of people don’t get the varied dynamics of river system flooding, just think it is rain.

David Riser

Concur, there is no way that we are currently in anything like a flood that goes from Illinois to Louisiana with the mighty miss 80 miles wide at its widest point. That was the 1927 flood!



Michael Jankowski

“…The result surprised Munoz. Both the frequency and magnitude of floods on the Mississippi have increased in the past 150 years…”
My math says that 1927 is within that 150-yr window. Unwad your panties, y’all.

paul courtney

Michael: Your math is correct, but so are my reading skills: “Mississippi River flooding worse now than any time in past 500 years.” Dave Middleton has a good explanation, but we all who have wadded panties (maybe just speak for myself here) did not misread. And yeah, they do get wadded up pretty bad, I’ll get a bit less wadded when Mann v. Steyn is over.

Indiana Sue

The National Weather Service site below shows river level observations. Let it load a few moments, then zoom down to your area of interest. Clicking on a river gauge will bring up current and historic flood levels and interesting factoids about the extent of flooding at different flood levels.

paul courtney

Thank you Sue. As Dave M. has pointed out, the headline gave a different impression than the text. But I enjoyed the posts about other floods, shows that there is nothing new under the sun: Human effects on local “climate” (UHI, deforestation etc) are abused by CliSci, falsely claimed as evidence of a CO2 effect to avoid the fact that there is NO evidence of a negative CO2 effect on climate.


Just leave it to the “experts” – the US Army Corps of Engineers. Let them carry on their good work – to ensure that every flood from now on will be bigger and more destructive than all previous ones!!


The worst recorded flood in US history was the MS river flooding of 1927. There’s a book about it: “Rising Tide.”


The involvement of an alien race in the flooding of the mediterranean forms a significant part of this series of science fantasy books:
“At the start of the story the Strait of Gibraltar is closed and the Mediterranean Sea is dry and empty. The Many Colored Land and The Golden Torc are set in Europe just before and during the rupture at Gibraltar. The rupture and the rapid filling of the Mediterranean form a Wagnerian climax to The Golden Torc, in which aliens and time-traveling humans are caught up in this cataclysm.”

Bruce Cobb

Sorry, but a 500-year megaflood is due to climate change. No mitigating “other factors” allowed. Thems the rules. Climate is easy, once you understand the rules.

John Bell

There is a big scale model of the Mississippi river in the same state near Jackson that was built during WWII to model the flooding, it is abandoned now.


I have seen that! We took a school trip to tour state capital and we went to ACoE as part of it. It was pretty impressive.

Walter Sobchak

We have covered this territory before:
LOUISIANA: They’re trying to wash you away by Kip Hansen / February 27, 2018
My Comment then still holds:
The Mississippi River Problem is complex and mufti-faceted. Solutions will be complex and expensive. i would urge one and all to start with the John McPhee essay linked below.
The Mississippi River should be allowed to go where it wants to go: the watercourse of the Atchafalaya river. The river should be replaced as a transportation artery by canals — big ones that start that from Cape Girardeau. The canal system should allow river traffic to be trans-shipped to ocean ships at Mobile Bay which is a superior natural harbor.
None of this can happen until the last lawyer is strangled with the entrails of the last environmentalist.
“… [R]ead John McPhee’s “Atchafalaya.” https://www.newyorker.com/magazine/1987/02/23/atchafalaya It was published in February, 1987, and it’s about the Herculean effort of the U.S. Army Corps of Engineers to control the flow of the Mississippi River, the fourth-longest river in the world. “Atchafalaya” is the name of the “distributary waterscape” that threatens to capture and redirect the flow of the Mississippi. If that happens, the cities and industrial centers of Southern Louisiana could find themselves sitting, uselessly, next to a “tidal creek,” and economic ruin would be the inevitable result. To prevent that, the Corps of Engineers embarks on a vast project to artificially freeze the naturally shifting landscape. McPhee meets the engineers and explores the structures they’ve built to “preserve 1950 … in perpetuity.”
* * *
In 1989, McPhee incorporated “Atchafalaya” into a book called “The Control of Nature.” http://www.amazon.com/dp/0374522596/ (He’d been passing by the engineering building at the University of Wyoming, and had been struck by its inscription: “STRIVE ON—THE CONTROL OF NATURE IS WON, NOT GIVEN.”) Like the Mississippi, “Atchafalaya” is long—around twenty-seven thousand words. But it’s all available online, and it gives you a real sense of what it’s like not just to live and work beside one of the world’s great rivers but actually to struggle with it.”


Floods like this are obviously rare and exciting events.
People were in danger of not knowing what floods were.

Walter Sobchak

Can’t leave until I link this:


Okay, take out all the dams and levees in Illinois and let’s all watch and record.

Philip Mulholland

“In the space of one hundred and seventy-six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over one mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oölitic Silurian Period, just a million years ago next November, the Lower Mississippi River was upwards of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing rod. And by the same token any person can see that seven hundred and forty-two years from now the Lower Mississippi will be only a mile and three quarters long, and Cairo and New Orleans will have joined their streets together, and be plodding comfortably along under a single mayor and a mutual board of aldermen. There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.

– Mark Twain, Life on the Mississippi, Ch. 17


“Have ypu ever heard of the Zanclean megaflood?”
ypu = you?


“River flooding worse now than any time in past 500 years” Considering the population density increase over the last 150 years, it’s more likely the problem is not increased flooding, but increased people. No one cares if it floods where people don’t live. It’s about people, not rain and water.


Late last week this driver just drove along the mighty Mississippi from S. IL down through Memphis. Think I-57 to I-55. Flooding along that portion of the river is not near what I have seen even in the recent past. So this mega flood was not there as of late last week. Rivers all over the eastern US are up but none exceptionally so from what I have seen crossing over them. Earlier this week drove US-22 and 322 along the Susquehanna River around Harrisburg PA and the Monongahela River where I-70 crosses over and both looked just as one would expect for this time of year. Nothing unusual about the water level of the Ohio river around Louisville last week either!

It is still fairly cold up north from the looks of it. I wonder what were the latest spring floods to ever occur on the Mississippi? …https://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=-92.15,53.65,672/loc=-95.044,43.580

I suggest changing the title so that it is clear there is not a current 500 year mega flood.


One odd thing about those flood diagrams. The 1927 flood, the worst in recent centuries, isn’t even visible.


How high is the water Momma?


worse than 2011 floods ?
derp never mind
I see they mean the frequency of flooding

Kelly Logan

What about the 1927 flood, doesn’t show on the graph

Kelly Logan

Sorry, didn’t notice the comments above re the book “Rising Tide” . An incredible story of the flood of the river and the change it made to African American politics as well as the role of US Army

Ken Mitchell

Balderdash. Whoever claimed that has never read Mark Twain’s “Life on the Mississippi”. Twain recounts stories of the steamboats sailing through flooded fields miles outside the river channel.


We have been though this before as noted, and I don’t know enough about archaeology and sedimentology, especially about the area. I have camped and explored in and adjacent to southern Illinois. The letter accompanying the paper questions the archaeological conclusion —
Also it does seem that settlements along the river, moreso downstream, dependent on wood, would leave a lot less left to study. There is also a lot more productivity than out in the rockier west, like way up the Missouri which debouches in their study area.
The 1973 flood (I studied it a little in Louisiana) was exceptional in that it was out of its bank for two months, despite, and due to, water control. 1975 was also very high. I lived for nearly three decades up on a low plateau where the 1927 flood came to its base, constricted later successfully by levees.
Floods could come from several climates between the mountains and some of that might explain their data. Since the Missouri is the longest contributor, maybe Montana would be a better name for the Mississippi.
This is also interesting if you can find it. Cline, I. M. 1928. Floods in the lower Mississippi. New Orleans Board of Trade. 29p. The lower gets them all. Don’t forget the Missoula floods. Lots of rocks to wipe out everything.

Bill Illis

The central mass of the Laurentide ice-sheet, when-ever it melted out, it went out the Mississippi river. As in the big melt-back years from 13,000 to 9,200 years ago, but also every single summer for the last 50,000 years of the ice age.
Think of those floods.comment image


And that great watershed washed all the organic material downstream, and deposited it in the gulf.
Millions ? of years later, it turned into oil and natural gas.


Which is why New Orleans is being flooded. With all the damming, channeling and dredging, the products of erosion never reach the delta. But the reservoirs created by dams on the Missouri are slowing filling with sediment. The original proposal for the Missouri was the reservoirs would last 600 years.

And look at the map again. Anytime it rained heavily anywhere in the central US, it ended up in the Mississippi. Why did the early Chahokia culture build huge mounds in their cities based on the great corn growing culture along the Mississippi? Why did the ancient Sumerians build huge ziggurats in Mesopotamia? Why did the Sumerians cover the outside with oil from seeps?
Duh, it flooded like crazy every few years like it was a once in a 500 year flood. Everybody and their animals scrambled to get to the top and wait it out for several days.


Except for the poor farmer and herder Noah, who had to build a raft for his family and animals to ride out the annual Mesopotamian floods.

Good vid David.
And the story/myth of Noah is a perfect example of what I was talking about. A great flood happens. Noah was prepared, having built a rather large reed boat. Family and all the animals are saved and the big boat floats down the Euphrates for 40 days and forty nights before they land on solid ground. The Babylonian Jewish slaves in 600 BC understand the meaning of the story/myth and over time adjust the story and it becomes part of the Bible.
Yet, It was just a common flood. So common that Noah built a stand-by giant reed boat.


Johnny Horton does the Mississippi:

Gunga Din

Worst Mississippi floods in 500 years? And all caused my Man?
What’s not for an alarmist to like!

Gunga Din

“And all caused by Man?”


That’s Mann; Michael E. Mann………………………………!

Check the precipitation numbers.
Zero change anywhere in the world really.
The study needed to show this to prove their case but of course didn’t since they are climate scientists.


Just checked Times-Picayune and then called my brother who lives in Pearl River, LA. The degree of panic indicated from each was rather understated. One point to consider, Pittsburgh is bracing for flooding from Allegheny and Monongahela rivers. Western PA has been getting a lot of rain last 30-40 days, not to mention snow melt in the Laurel Highlands, so the Ohio will be rising, which means Big Muddy will be remaining near and above average flood stage for the foreseeable future. ACoE has been opening Bonnet Carre spillway gates since the 8th, 58 of 350 gates currently open and 10 more are scheduled to open in the next few days. ACoE does not seem quite ready to hit the siren buttons but is suggesting people get ready, since, ya know, it is spring along the lower Mississippi.


Looks like they closed the Bonnet Carre gates on the 30th of March or so.
For some reason the water level decreased dramatically about two weeks after they opened some of the “gates” to divert water to “The Lake”.
As Walter asserts, control of Big Muddy is a complex issue/problem/challenge.


Open, close, open, close, almost like it is a system of some sort. 😉 They can’t over dump into Ponch, that would kinda defeat their purpose. I remember flooding in Slidell and backing into the Pearl River region from elevated level of lake. The levee system along south shore diverts away from New Orleans, that water still has to go some place. One of my brothers works at Stennis Space Center and does some work at Michoud, flooding issues are always on their mind at both.


Once upon a time in my career we were briefed on the Mississippi River and the successes and mostly the failures of flood control efforts by the Corps. It was part of our briefing on New Orleans, the Mississippi Delta and Lake Pontchartrain. The Corps had charts of all the floods within the system back to before the Civil War. So I don’t see how the first study is anything new. Several times the Corps was relatively clear that levees and other structures had not necessarily made anything better. One Colonel, who was about the retire, said in conclusion at one briefing, the Mississippi River is going to do what the Mississippi River is going to do, we can’t stop it. The briefing generally related to New Orleans hurricane risks. Some of the very first levees built along the river were built to protect New Orleans primarily from tropical storms back in the 18th Century.


Chimp, the wikipedia link your provided reminded me that it was in and around the 1927 Flood that the federal government got into disaster relief big time and has been in it ever since. I have often wondered if the feds hadn’t gotten in the game whether people would still be building in flood plains, front dunes of beaches, etc.

Look at this current warm surface wind which is moving up the arid side of the plains. It seems that the typical pattern should have this more to the east, imo. …https://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=-103.49,53.02,672/loc=-110.216,50.088


The next 2-3 weeks will be instrumental in the flow of all the northern tributaries. If it really warms up quick everywhere at once now in late April early May and rains heavy on the more northern high snowpacks, then could definitely see a huge flood all in a hurry. Some of the biggest floods I have seen have been rain in warm weather on a high snowpack, such as the recent 1-200 Year Alberta/Calgary flooding on June 21st/2013 that did a lot of damage real quick, like overnight.
Or it may stay coolish for the next month without a lot of rain, and have an orderly freshet flow down the numerous tributaries through to the Missouri/Mississippi watersheds. Lets hope for a slow melt now. Had enough misery this winter to last several years.


Old China history has this legend, that all attempt to control the Yellow river (with levees) failed, until a man succeeded. Not with levees, but with diverting waterways, flooding selected areas they don’t cared about. The man was made Emperor, if I remember well, for the feat included successful union of lots of different people.

Stan on The Brazos

Cahokia is or was a mounded city, within the MS floodplain. The mound was built by the inhabitians over a several hundred year period. Some contest this idea and say evidence suggest the mound was build very quickly and completed about 1050. The town was deserted by 1400. Like other mounded cities is was build near the river for many reason, food and water being the most likely. Would suggestion reading the book Cahokia by Timothy R. Pauketat before getting too carried away with the issues in this article.


The region around Vicksburg had a lot of inhabitants in the past because it is naturally above the flooding, though shot through with deep ravines and watercourses. Farther south the land pretty well flattens out, so anyone living there had to take steps to survive flooding.