Record Missouri flooding was manmade calamity, not climate change, scientist says

Remember when some low caliber science pundits immediately jumped on the “climate change” bandwagon of blame? It turns out that as usual, they were wrong. This new study shows extreme flooding on Meramec and Mississippi rivers in late December cannot be blamed solely on 3-day rain, “channelization” of river was a major factor, according to the study


Intersection of Interstate 44 and Route 141 in St. Louis County, Mo., on Dec. 30, 2015. Water levels more than 4 feet higher than previous record floods closed a 20-mile stretch of the highway. CREDIT Copyright Sid Hastings.

Intersection of Interstate 44 and Route 141 in St. Louis County, Mo., on Dec. 30, 2015. Water levels more than 4 feet higher than previous record floods closed a 20-mile stretch of the highway. CREDIT Copyright Sid Hastings.

At the end of December 2015, a huge storm named “Goliath” dumped 9-10 inches of rain in a belt across the central United States, centered just southwest of St. Louis, most of it in a three-day downpour.

The rain blanketed the Meramec Basin, an area of 4,000 square miles drained by the Meramec River, which enters the Mississippi River south of St. Louis.

The Meramec’s response was dramatic. Gauging stations recorded a pulse of water that grew as it traveled down the main stem of the Meramec River, setting all-time record highs in the lower basin in the Missouri cities of Eureka, Valley Park and Arnold.

While extraordinary rain drenched the entire Meramec Basin, only 5 percent of the Mississippi River’s giant watershed above St. Louis was so affected. Yet only a day after the flood on the lower Meramec peaked, water levels on the Mississippi at St. Louis were the third-highest ever recorded. A few days later, record flood stages were recorded downstream at Cape Girardeau, Mo., and Thebes, Ill.

Why was the flooding so bad? Most news reports blamed it on the heavy rain, but Robert Criss, PhD, professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, said there was more to the flood than the rain.

“I think there was significant magnification of the flood levels on the Meramec by recent developments near the river,” he said. “Sure it rained a lot, but what happened here cannot be explained by the rainfall alone.”

The flood on the middle Mississippi River, in turn, was remarkable for its short duration and the time of year. “It was essentially a winter flash flood on a continental-scale river,” Criss said. “The Mississippi has been so channelized and leveed close to St. Louis that it now responds like a much smaller river.”

In the February issue of the Journal of Earth Science, Criss and visiting scholar Mingming Luo of the China University of Geosciences in Wuhan, China, take a close look at data for the New Year’s flood, treating it as a giant natural experiment that allowed them to test their understanding of changing river dynamics.

“Flooding is becoming more chaotic and unpredictable, more frequent and more severe,” Criss said. “Additional changes to this overbuilt river system will only aggravate flooding.

“In the meantime,” he said, “inaccurate Federal Emergency Management Agency flood frequencies based on the assumption that today’s river will behave as it has in the past greatly underestimate our real flood risk and lead to inappropriate development in floodways and floodplains.”

What happened at Valley Park and why?

The prior flood of record in most of the lower Meramec Basin occurred on Dec. 6, 1982, Criss said. Given that the 1982 flood, like the 2015 flood, was a winter flood during an El Niño event, they should have been similar. Criss thought it would be revealing to compare them.

When he did this, he discovered that the peak flood stage at Valley Park in 2015 was three-feet higher than it would have been had the river responded as it had in 1982, and more than a foot higher upstream from Valley Park at Eureka in 2015 than in 1982.

What had happened at Valley Park between 1982 and 2015? A three-mile-long levee had been built next to the river; a landfill partly in the river’s floodway (as defined in 1995) had expanded; parts of the floodplain had been built up with construction fill; and development along three small tributaries of the Meramec had destroyed riparian borders, so that they became torrents after a rain but no longer flowed continuously.

The record high water levels on the Meramec were associated with these developments, Criss said. “The biggest jump in the flood stage was next to the landfill in the floodway and to the new levee, which restricted the effective width of the floodway and ‘100-year’ floodplain by as much as 65 percent.”

He drives home the point by breaking the flood data into two chunks and looking at the earlier half separately from the later half. When he does this, it becomes apparent the river is becoming more chaotic and unpredictable and that floods are more frequent, higher and more damaging than they once were.

As the New Year’s flood demonstrates, when we assume an unchanging river, we greatly underestimate our flood risk, he said. “The St. Louis levees protected us from the 1993 flood, considered a 330-year event,” he said. “But if a real ‘200-year’ flood occurred on today’s river, the structures protecting St. Louis would be overtopped.

“The heavy rainfall was probably related to El Niño, and possibly intensified by global warming. But new records were set only in areas that have undergone intense development, which is known to magnify floods and shorten their timescales.

“People want to blame the rain, but this is mostly us,” Criss said. “It’s a manmade disaster.”

During the New Year’s flood, roughly 7,000 buildings near St. Louis were damaged, two interstate highways were closed for several days, the community of Valley Park was evacuated, and two Metropolitan Sewer District plants were swamped so that sewage was dumped directly into the water. The flood killed more than 20 people in Missouri and Illinois, caused several hundred million dollars of damage, and left millions of tons of debris in its wake.


54 thoughts on “Record Missouri flooding was manmade calamity, not climate change, scientist says

  1. “Remember when some low caliber science pundits immediately jumper”

    Should that be “jumped”?

  2. I grew up in that area. I remember highway 141 under water before. The oldest houses on the river were built with their living floors one story up and masonary foundations.
    Valley Park and Eureka were flood plains surrounded by hills. Just like Times Beach was. It appears they still are.
    Of course as the area population grew, people who remembered the flooding in the 70’s and 80’s become fewer and fewer. Town councils see an opportunity for easy development and developers don’t care.

    • I live in the area, and slowly and surely they continue to hem the rivers in with more and higher levies. Huge areas that should be flood plain are walled off and developed. The rivers have nowhere to go but up.

  3. Dang evil humans. Haven’t we learned that making changes to mother Gaia will lead to nothing but more calamity? :))

    Sounds like somebody didn’t do their engineering design study very well before they built the levee.

    • Maybe they shouldn’t build levees at all. When you restrict flow in one area, you increase it in another, or it backs up upstream. Just not a good idea, unless you count on events like the one described.

      • Back in April, 2011 I was in Missouri and Arkansas leading a field trip in our research area as part of a thesis and more than 20 inches of rain fell in less than a week.

        We simply went on about our business as the rain was simply a nuisance and gave us no issues and didn’t appear to cause any flooding like we were accustomed to with that much rain.
        I remember turning to my adviser at one point and remarking how there was no sign of flooding and how efficient the karst drainage must be in preventing extensive surface flooding.

        Discharge through karst is much slower and as water gets backed up in the main caverns it back-flows into a vast network pore space, acting essentially as a sponge. Channeling rain water much faster through ditches and city canals may be contributing to filling the narrowed river valleys faster.

  4. “Remember when some low caliber science pundits immediately jumper on the “climate change” bandwagon of blame?”

    Have you noticed how low caliber science pundits are pretty much the Mike “health ranger” Adams of the climate, linking anything to climate change just like the “health ranger” will link anything to GMO, vaccines…?

    And yet the pompous progressive liberal scientists/”skeptics” pose as fighters against “nature is good/tech is bad” claims? How can you fight what you do on every occasion?

  5. Not sure what year and it might have been 1982 as IIRC it was around that era – I don’t have the reference at hand either

    But I remember that record flood in the Mississippi being assessed as having been achieved with considerably less water than previous ones due to levees, channeling etc

  6. So good to see genuine, critical science coming in to answer the silly, knee-jerk reaction, from the media and others who should know better, to every unusual flood coming our way.

  7. Meanwhile the MSM spewed the ‘consensus’ that it was caused by AGW and that’s all they hope the people will remember. They/MSM knows exactly what they’re doing……and I believe people have caught on. You can’t trust the media any more than the politicians these days. Sad state of affairs for America.

  8. i’m not surprised.

    In Belgium we have a ver unique system of rivers but we overbuilt their natural banks and natural flood plains, so at each event we get flooded. This has nothing to do with global warming (as they so wish it would be) but with constructing in flood prone regions, redirecting the rivers so that their natural “flood buffers” are cut off and that their “land building abilities” are entirely destroyed.

    this makes that the 19th century (yes you read this right they never optimized the suice gate systems for these important changes!) sluice gates that were once efficient, obeslete and so at every little downpour that’s not “normal” we get flooded.

    they so love to blame this on “climate change”, but more respectfull hydrologic investigations do point the human intervention on the natural balance between river and land, altering the natural course of the rivers and altering the land by funneling the rain into large rain water collectors as the main culprit.

    In al honesty i do believe the same: yes there is a warming that can be very natural, but the main causes of floods are the engeneers who think they can “harness nature” while earth shows us that they still have a long way to go to do so….

    it feels good to read this article as i was suspecting something similar, however as i live in belgium i am not aware of the development and river altering measures taken in that region. I’m affraid that this region did become more flood prone. Not because of climate change, but because – like in our country – of bad engeneering and the thought that we can tame rivers while in all truth…..

    we can’t.

      • there was for sure flooding in the 19th century and before, but not as often and with record breaking highs as there is now. Also a lot of the “natural sponge acting riparian wetlands” are laid dry and became impermeable concrete. Most of the floods were also storm surge induced then rain induced (the tidal surges go very deep inland which creates a unique swamp-like wetland)

        in medieval times Bruges was a harbour (venice of the north) but the rivers in synch with the tidal landfill buildup did bring so much material that Bruges did fill up and the port had to move to zeebruges 10 miles further and a channel had to be dug. (in dutch terms we call this “de verzanding van het Zwin” (the fill up of the zwin, a former estuary)

        Nowadays the rivers are so dammed in that these processes can’t take place anymore, the former riparian zones are built full, and at any small offset the same regions get flooded. Also the wet swampy grasslands are drained and changed to agricultural land which increases the run off to the rivers.

        it’s only the last few years that our governement is starting to see the light and is trying to implement stricter building codes.

    • Same thing is happening in Cambridgeshire England. Cambridge is built on very low ground but its surrounded by meadow land that has routinely flooded in winter. The best known is Granchester Meadows which is protected but planners are now allowing development on Trumpington Meadows. This area appears as an area of high flood risk on the Environment Agency map and frequently floods in winter. The developers have ‘protected’ the area from flooding but what this means in fact is they have moved the flood problem downstream into Cambridge itself.

      In the 1980’s there was large scale development of the old Pye Radio factory site along the River Cam, the car park there was so prone to flooding that during wet weather tannoy messages would warn workers to shift their cars. This area became a high price housing enclave sought after by the affluent developers of the new software businesses in Cambridge. There is a problem the real estate agents don’t mention, they are already prone to flooding with many houses now having been flooded frequently in the last few years. This is exactly where the fast flowing flood waters that used to be absorbed by Trumpington Meadows will now end up. Watch this space for the headline ‘Global Warming causes Cambridge Flooding’

  9. How come Washington University St Loius says you are a tool. I recon you are the batshit craziest flip whondares to masquerade as a scientist. Your kids are going to be so embarrassed about you in the future. Still looking at your back sweetie.

    [??? Is that insult intended to be:
    How come? Washington University St [Louis] says you are a tool. Or,
    How come Washington University St [Louis] says you are a tool?
    Or are both incorrect, and the tool is to be “a fool”?
    Regardless, the mods would be embarrassed if such typo’s became highly publicized in front of any impressionable youth. .mod]

  10. If you haven’t read Mark Twain’s “Life on the Mississippi,” written when the rivers of North America meandered free, with stories telling what it was like to pilot a steamboat that plied them, by a man who could spin a yarn, well. Ya’ oughta…

    • Twain’s “Huckleberry Finn” has a great description of the Mississippi flooding. Too bad modern day journalists and climate scientists haven’t read historically accurate novels such as these and others.

  11. Its tough to coherently discuss flooding because, like climate, people use imprecise or incorrect terminology.

    Sometimes a 100-year flood is discussed as being defined by the elevation of the water (BFE); sometimes its the hydrology …the amount of rainfall or sometimes by the intensity of rainfall. FEMA will look at it after the fact and rate the event by the flow (cfs) … elevation and impact don’t matter. This, of course, causes confusion. Designers start with rainfall intensity as the defining 100-yr parameter … in the final analysis, it is the channel flow that tells you what happened.

    The channels and fringes are modeled and refined as “floodways” and “flood plains” based on a maximum theoretical water rise of 12″ given that the fringe (flood plain) were to be completely filled in, and not carry any water at all, during a 100-year event (based on a certain flow volume). SO, the floodplains are not included at all in the final model (that anticipates a 12″ increase in water elevation) and defines the floodway & flood plain.

    Again, the total defined floodplain cross-section is used to define the BFE. The floodway is defined by assuming the floodplain is squeezed (filled in) to such an extent that the floodway flow does not increase by any more than 12″. This is why most jurisdictions require construction to be a minimum of one foot above the BFE.

    It is obvious that the models are off (primarily because of the guesses associated with the hydrology), but that doesn’t mean that they can’t be fixed, or utilized in conjunction with some safety factor. But, with respect to the modeling, filling and utilizing the defined floodplain does not create any more flooding.

    Things are different now than they were fifty years ago. If the federal government had stated that it was necessary, and that their intent was to take away almost all potential use of the floodplain area, then flood management planning would have stopped right there … the uproar would have been to great. The idea then was that the FLOODWAY had to be controlled and regulated primarily for flood control and property rights within the floodway were to be far subservient to the community good. But, now that the camel has its nose in the tent, there seems to be a growing sentiment that people who own property in the defined floodplain should loose the ability to utilize what they have worked for … that it should be coopted for the community good. (note that not all floodplain is equal … taking away some else’s property shouldn’t be done for added safety factor … if the community wants it, then the community should prove need and then pay for it).

    Regional flooding has always been regional flooding. A relatively miniscule increase in impervious area doesn’t cause a significant change in the basin characteristics and does not increase flooding. Although, screwing around with the area within the floodway can, and does, cause problems.

  12. I haven’t had cause to think about it before but I am not the least bit surprised that local flood prevention measures have simply exacerbated the problems downstream. When you think about it, it’s pretty bleeding obvious :-)

  13. Refreshing to have a scientist set the record straight on the “flooding caused by severe weather” and there’s no reason to fault him for saying “even if…”. The truth is that’s likely going to be the way most of corrections to global warming alarmism are going to be expressed rather than some kind of across the board “oh my God we were all taken in, don’t know how that happened” Paul Ehrlich still has an honored position at Standford University despite having been calamitously wrong on every pronouncement he ever made about the way population growth would play out in the course of the 21st century.

  14. They’ve known for some time now that levees make flooding worse. I should also mention that back in the 70’s, instructors in Ag classes taught us not to build on flood plains. When did that change?

  15. Why, I’m sure scientists believed an overwhelming consensus might be forged that multiple lines of evidence suggested floods could still be linked to global warming. For example, the U.S. Army Corps of Engineers might have gone mad due to ever increasing CO₂ pollution and simply overchannelized the rivers.

    That’s what the best scientists in the world are telling us, overwhelmingly.

      • Ah I see. I do need to supply the


        tag, after all.

        However, do not forget EPA is forced to accept (by court order or something), that scientists not telling such things can’t possibly belong to the elite club of the best scientists in the world.

  16. Sounds like a similar story towhat happened in the UK. Halfwitted public ploict stopped landowners talking proper sensibe orecautions to exnure decent drainage and hey presto flooding!

    In Oz fire is our constant spring-summer risk since most of our fklora is fire adapted. We don’t have that winter snow to reset the foliage so Gaia does it with fire and out local indigenous peoplke knew this in their bones and managed the place accordingly. But the genius of the arrogant European settlers produces the same old story. No prudent cold burning to keep fuel loads minimal so whet the lightning comes….. so do the do the fires and they are HOT HOT HOT.

  17. Nature and gravity have ensured that efficient optimal channels are created to cope with both normal and exceptional run off from catchment areas. We simplistically call these rivers and flood plains.

    All man made structures – buildings, levees, dams etc – interfere with this natural process. We do this often for flood protection, energy generation, draining for agriculture etc etc.

    These all compromise natural flows. We seek to understand the impact through flood studies , analysis of prior events etc. But our understanding is compromised as:

    – a “100 year event” is at best often an estimate given the limited historical data
    – modelling, despite best intentions, is often flawed
    – solutions are frequently to ameliorate adverse impacts of earlier improvements
    – immediate needs vs coherent long term strategy

    Whilst climate change may be implicated in flood events, other causes should always be eliminated before drawing populist conclusions.

  18. The Meramac floods, A LOT. It’s the last ‘wild’ river in Missouri, meaning that it’s journey isn’t impeded by a dam. It has no flood controls so it frequently rises out of its banks. Floods on the Meramac rise to the level of severe when the Mississippi is high as that river will backwash into its tributaries when they are low, and prevents swollen rivers from draining. The Meramac has had some of it’s bottom land levied and developed, depriving it of some of it’s natural flood abatement. (Pacific, you shouldn’t have built your school there!) Long time residents are used to the river and it’s behavior. Newcomers and outsiders see it as a tragedy.

    Wild rivers flood, sometimes wildly. Every river has flooded on a regular basis until flood controls were put in place. In the case of the Meramac there is a push to keep the river wild. It’s a tough decision.

    • I was watching the rains on radar during that flood since I live near the confluence of the Mississippi and Illinois rivers (on high ground). My own pond overflowed more than it had in the 12 years it has existed, but we got relatively less rain and slower than to the south. There were heavy downpours on radar over the Merrimack valley which thankfully were mostly spent by the time they reached us. I wonder if this guy checked local rainfalls, which varied widely in the event?

      • If they did check rainfall amounts, it was only to support the theory. None of the other rivers experienced the sort of flooding the Meramac did simply because those other rivers have adequate flood controls.

      • I think what the good professor has possibly an axe to grind with the geoengineering of wetlands and might have ignored an inordinate amount of highly localized rainfall. Just a hunch based on what I saw

  19. Why not blame climate change, create a new fee or tax because of the terribleness of climate change. throw the additional revenue in the general revenue pot and use it for better benefits for government bureaucrats. Who would you know want to fix the actual problem. Why would any politician be actually interested in fixing the actual problem since in the modern era that is unheard of.

  20. Maybe it’s time for another new madrid earthquake to redefine the river’s path and boundaries. The last one was smack in the middle of the dalton minimum.
    (OK, coincidence does not imply causality, but…)

  21. When the experts start relating how the building of infrastructure, whether restricting natural waterways or adding thermal mass into the environment or the changing of land use, has repercussions on the natural order of things, then I agree that man does contribute to what appears to be climate change.

  22. Here’s what sells in the tabloids right now: An article which depicts an extreme but totally natural (very recent) weather event and skillfully weaves in the exacerbation of mankind’s presence and influence on a planet pushed into an out-of-control chain reaction of disastrous consequences. Anything else disappears into the mundane…

  23. With the Manmade Global Warming, property/real estate developers are free to do whatever they want. When teir land development eventually leads to flooding, no one examines the land use decisions, but blames the SUV drivers.


  24. After reading the above comments I am reminded of the old line familiar to people working in water management “there’s a reason why floodplains are called that.” I’m also reminded of the somewhat depressing remark often heard from the general public that goes something like “I’ve lived here for 15 years and I’ve never seen it that high before. There must be something unusual going on.”

      • There are old homes in the “neighborhood” where I live.

        Every couple of years I have a new owner (with a new mortgage) of an old (80 to 100-year) old farm house, that needs proof that they shouldn’t be required to pay flood insurance. Or they want to reconstruct the garage or add a bedroom….

        Five or six pre-dam valley wide events with no impact to the homes…. Two or three 50 to 100 year events since the dam construction(s) and no impact to the homes. Yet they are designated as being in the flood plain. And if the owner spends somewhere between necessary $800 and $30,000 to document or remodel the flawed original assumptions then FEMA will allow them to stop paying $1,200 to $3,000 per year for the protection money (insurance).

        There are more property owners getting screwed by the overzealous & bad planning which has a stated intent to protect from catastrophe, than there are property owners getting wet from flood events. (this is absolutely true in FEMA Region X)

      • I completely agree. The FEMA flood plain insurance is a revenue stream. If they reevaluate the flood plains and loose revenue from those no longer required to be insured they have to raise rates on people living in contemporary flood plains to levels that are not affordable. Of course, the flood insurance shouldn’t be cheap in a flood plain, thereby discouraging people to take up residence in a potential disaster area.

  25. The use of terms like “200 year flood” is so often misunderstood that it’s continued use is mendacious. I actually means that in any given year there is an *estimated* chance of 1/200 (0.005) of such an event. Such event probabilities cannot be properly quantified without a record that includes a statistically significant number of such events. Since the record itself is barely 200 years old for the Missouri area, the data cannot provide a significant number of such events.
    Error bars on sufficiently rare events (those obeying Poisson statistics) are typically about 100% of the mean.
    The *estimate* is just that – a wild-ass guess – and means nothing.

Comments are closed.