Paris Flooding, Again

Guest Essay by Kip Hansen

 

Paris_Flooding_AgainParis, France is flooding again.  The River Seine has risen over its banks and streets are covered with slowing moving yellowish water.  The Louvre is building sandbag barriers to protect its statuary.

There is talk, as always, that the culprit is the dreaded modern boogeyman — Climate Change.

As our introductory image states, Paris is not just flooding, it is flooding again, and again, and again, and again.

“Why does the Seine, famous for its bridges, flood at all?

As one of France’s major commercial waterways, the river is closely monitored so it can accommodate a constant procession of barges and other commercial vessels. The river begins in Burgundy, in east-central France, and meanders 485 miles westward until it reaches its mouth, near the port city of Le Havre.

Upstream from Paris, four large dams control the flow of the Seine and three of its major tributaries: the Aube, the Marne and the Yonne. According to Charles Perrin, a hydrologist at the National Research Institute of Science and Technology for Environment and Agriculture, in late spring the dams start stocking large reserves of water that can be released in the drier summer months.

Dams and locks normally keep the water level consistent, particularly in the Paris region, where the Seine’s traffic is especially heavy, in part because of tourist and other recreational vessels. If the water level drops too far, the barges could scrape the riverbed and get damaged. If it gets too high, vessels cannot pass under the city’s lowest bridges.”

Last spring “The dams were already at 95 percent capacity when heavy rains started in late May, so their ability to take in the excess water was limited.”  So, Paris flooded — again.

“Public authorities said they expected the Seine to crest on Sunday at up to six meters, or about 19.6 feet. In the floods of June 2016, which killed four people in France, it peaked at 20 feet.”

“Although some experts said it was hard to determine whether global warming was behind the current flood, others warned that a worrying pattern was emerging.

“Because of climate change, we can expect floods in the Seine basin to be at least as frequent as they are right now,” said Florence Habets, a senior researcher at the C.N.R.S., France’s national center for scientific research. “No matter what we say, the more we reduce our greenhouse gas emissions, the more we reduce our impact on droughts and floods.”

The French scientist tells us that “Because of climate change…”  the flooding frequency will remain the same.  Brillant!

What is the flooding frequency?   Every recent flood is compared to the great flood of 1910, “in 1910, a January deluge turned Paris into Venice for a week — river levels rose nearly 30 feet above normal — causing roughly $1.5 billion worth of damage, in today’s terms.  …  Topographically, Paris is a basin, with hills in Montmartre and Montparnasse rising in the north and south of the city, respectively. When it comes to flooding, that means big trouble for anyone who lives in the city center, which in 1910 was not so different than it is today”  [source].   “A very severe period of high water in January 1910 resulted in extensive flooding throughout the city. The Seine again rose to threatening levels in 1924, 1955, 1982, 1999–2000, June 2016, and January 2018.” [source]

The New York Times carried the story of the 1910 Paris flood — read the full original report on the front page of January 27, 1920.

Jan_27_1910

This “worrying pattern”  really began in the 17th Century with major Paris floods being recorded in 1649, 1651, 1658, 1690, 1711, 1732, 1740, 1779, 1795, 1802, 1830, 1836, 1879-80, 1882-83, 1886…..you get the idea here.

What’s the deal here?  Again, as with Bangladesh:  GEOGRAPHY.

Geography_of_Paris

There we have it.  Four rivers flow into one another and converge just before Paris:  The Seine itself, the Aube, the Yonne, and the Marne.

Google Earth reveals that the Seine is no longer a river but a channeled and closely controlled canal, complete with flood control devices and locks for the river traffic.

Locks

We see once more that the efforts to control great rivers and put them solely to our own purposes leads to unforeseen, or at least, unacknowledged, problems.  The upriver dams, used to store water against the dryer summers, to maintain river levels appropriate for shipping,  are allowed to fill in the Spring, find themselves nearly full — and if late summer rains come, there is nowhere to store the resultant excessive river flow — floods start upstream and spread down the river to Paris.  We see this same pattern with the great rivers of the American Midwest — the Mississippi and the Missouri.

Of course, the Europeans have known all about this situation for years and years, and publish reports and recommendations such as OECD Reviews of Risk Management “Policies  Seine Basin, Île-de-France: Resilience to Major Floods”.

Still, Paris floods and the blame gets shifted to anything but the real cause — inadequate action to remedy the known problems of Seine River managenment.

Remember our expert Climate Science opinion:   “Because of climate change, we can expect floods in the Seine basin to be at least as frequent as they are right now,”

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Author’s Comment Policy:

 Love to read and respond to your on-topic comments.

Paris floods — that’s weather — so it must be Climate Change.

If you want me to respond specifically to a question or comment, address it to “Kip…” so I am sure to see it.

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Mayor of Paris Anne Hidalgo said the city was coping – but said that the flooding, coupled with recent summer heatwaves, was “clearly a question of the town adapting to climate change”. What an idiot. How do these people get elected?

icisil

Idiots elect them.

Bryan A

One possible solution would be to extend a tunnel from where the Marne meets the Seine to channel 1/2 of the water normally carried through Paris running along the south side of the city with 2 outlets, 1 outlet at Meudon and the other outlet at Poissy. This would effectively bypass the Paris Flood Zone with 1/2 of the water flow.
https://www.google.com/maps/d/viewer?mid=1ukvqQG-X96C1Y7UtUb_5FTTuybSYb6-k&hl=en-US&gl=us&ll=48.836284818880905%2C2.309294397070289&z=12

Bryan A

Then a 10′ tall, 50′ wide tunnel that is 7′ below the surface would place the bottom of the outflow duct 10′ below the top of the inflow and shouldn’t present a drainage issue during times of peak water flow

ratuma

right !!

Javier

Once over 10% of the constituency is convinced of something, the smart thing to do is to address their concern, no matter how unsound it is. If I was the major of Paris I would also be talking about climate change to get reelected. If you want to be truthful, you don’t get into politics.

Bob Burban

As Napoleon allegedly noted: “In politics, stupidity is not a handicap.”

PiperPaul

Propaganda and a compliant press.

joelobryan

Climate Change provides the ultimate political scapegoat for poor management and mismanagement. A convenient excuse for politicians to use against an ignorant public.

Ed Chombeau
kaliforniakook

icisil – I don’t think it’s so much that I’m an idiot, but rather that I believe their promises. I’m almost always disappointed. (Except for 2016 election – jury’s out, but so far, so good.)

Graham Richards

We’ve got the same problem in Brisabane, Australia. The city & it’s suburbs are built on a flood plain which floods from time to time. 1890 (twice in 2 weeks), minor flood 1956, major flood 1974, similar level flood 2011. We have dams for mitigation but nature always throws a curved ball from time to time. Get your timing wrong & you’ll take a bath!
Any way we had a guy named Tim Flannery tell us we’d never see rain again in our lives.
Tim is not qualified in anything except Anthropology, but our politicians don’t know what anthropologists actually know about climate! But they employed him anyway to scare everybody including themselves!

Stan

Beat me to it, Graham. The dam engineers believed Flannery when he said the dams would never fill, so they kept the flood mitigation dams as full as possible even when the forecast was for very heavy and sustained rain. Thus, a flood occurred “due to global warming.” Much the same as Paris, now, from the looks of it.

rms

We should all re-read John McPhee’s “The Control of Nature”. Sobering.

John M

Kip and rms,
The issue of scale comes to mind.
Atmospheric Rivers are common in California. Is France impacted by extreme weather events?

John M

Kip,
Extreme wind and related rain events are common in Europe resulting in Annual insurance claims in excess of 1 billion.
Seems like your post points out inadequate weather forecasting sufficient to alert River Management in France.

Ian Magness

That’s inseine.

PiperPaul

The rain in the Seine is the cause of the complain.

PiperPaul

The rain in the Seine is the bane of the insane. <=== better?

RayG

At PiperPaul, I think you’ve got it. By Jove you’ve got it.

paqyfelyc

Flood (haiku):
the pain out of rain in the Seine
is the complain of inseine.

Here in Southern California we have flood control basins with big dams and flood gates that are kept bone dry all year waiting for flash floods. Apparently this technology, implemented here in the 1940’s, has not made it to Europe.

Juan Slayton

And they largely work, too. Until they don’t. San Gabriel Dam was finished just in time for the big 1938 flood. But that flood filled the reservoir and they lost control as water poured over the spillway. Washed out the western end of “The Long Bridge” in Duarte. Cogswell had advocated building three dams: One on the West Fork (now named after him), one on the East Fork, and one on the main channel (San Gabriel Dam). The East Fork dam was never built.
A repeat of the 1938 rainy season would be mitigated by the newer Santa Fe Dam, with a large impound basis downstream. But that would not protect the cities above the dam. We will never have absolute protection from unpredictable weather.

Trying to mitigate weather completely is a fool’s errand. We can, however, exact some control.

They don’t have flash floods in Europe- this flood was already pre-set up. The French just failed to do anything about having 95% full dams and predictable more rain. Brisbane in Australia failed to do anything about its full dams and so it flooded.

Asp

The some of the effects of the last major Brisbane flood we accentuated by the mismanagement of the Wivenhoe Dam, which is part water storage, and part surge capacity for flood mitigation. Unfortunately, due to Queensland having experienced a severe drought in the preceding 7 years, that dam was allowed to retain water well in excess of its water storage design capacity. So when the serious rains returned, there was no options but to release very high volumes of water at short notice. The consequences were tragic, but maybe understandable given the circumstances.

Henryp

Say again?
Trying to understand the au problem

Cloa5132013 —
Oh yes we do! Possibly not on the scale of parts of the US but being generally more compact and therefore more crowded, the impacts can be just as severe!

John F. Hultquist

@ Henryp
Here is a newspaper report from years ago: “The conditions were so bad that Tim Flannery, now Australia’s Chief Climate Commissioner, declared rather bizarrely in 2007 that hotter soils meant that “even the rain that falls isn’t actually going to fill our dams and river systems”.
Some claim that because of Flannery the dams were more full than they should have been if flood control issues were considered. LINK
Learn more by searching with Wivenhoe Dam and Tim Flannery.
Jo Nova’s site had posts.

Komrade Kuma

“worrying pattern was emerging.” Yeah , idiots in charge of the flood mitigation/management regime. e.g letting the dams get to 95%

Gary Pearse

They need a few more in California, too, to reduce flooding and drought problems.

StephenP

I thought dams were regarded as not green?

Peta of Newark

Paris is flooding (again) because of this:
https://wattsupwiththat.com/2018/01/24/todays-food-is-a-modern-agricultural-miracle-so-why-is-it-under-attack/
We know this because the report tells us that

The River Seine has risen over its banks and streets are covered with slowing moving yellowish water

The operative word in there is ‘yellow’
Unless something epically catastrophic gas happened upstream, the water should NOT be yellow. or brown. or red. That is farmland dirt washing away.
The reason Hidalgo and ‘most everyone else blames Climate Change for that is simply because they eat the mush described in the link above.
Very very simple – yet a mush eaters will (try to) make it ever so, *ever so*, complicated so as to protect their own fat, lazy and brain dead backsides.
Yet its the consumption of mush that causes that causes the braindeadness.
A perfect positive feedback.
Will doubtless have a Happy Ending, because mush eaters tell us that positive feedbacks are good, stable and long lasting things.

MarkW

Every hectare of land upstream of Paris is farmland.
Didn’t know that,.

People have selective and short memories. That’s why we invented writing.

AllyKat

And why those in power prefer an illiterate population.

knr

To be fair this classic , heads you lose tails I win, is the standard approach in climate ‘science’ Hence why this easy life attracts so some third-raters looking for cash.

JBom

Even to this day Paris lacks what goes for modern sanitation just about anywhere except India. The Seine is the French sewage “removal” system … hence the brown-yellowish color depending of the proportions of excrement and piss that has a daily cycle of brown in the morning and yellow in evening.
On another thought the Seine serves as an analog model for the Paris Accord and the UN-EU that controls it!
Ha ha

Nigel S

They grow vegetables on the sewage farms downstream at Gennevilliers for instance.
https://www.researchgate.net/figure/Paris-main-sewer-system-and-sewage-farms-at-the-beginning-of-the-20th-century-Gerards_280878846
“politics is downstream from culture.”
Andrew Breitbart

Nigel S

A quick look at the link immediately above shows that Paris has a sophisticated sewage system with construction beginning in about 1860 and largely completed by about 1915. Bazalgette sorted out London at about the same time with interceptors picking up rivers like the Fleet which had been covered and turned into sewers. Dickens and ohers described conditions in earlier times.
‘Sweepings from Butchers Stalls, Dung, Guts and Blood,
Drown’d Puppies, stinking Sprats, all drench’d in Mud,
Dead Cats and Turnip-Tops come tumbling down the Flood’
Jonathan Swift, 1710
http://www.londonslostrivers.com/river-fleet.html

Frederic

“hence the brown-yellowish color depending of the proportions of excrement and piss that has a daily cycle of brown in the morning and yellow in evening.”
———————-
The Seine is brown-yellow only during floodings. The rest of the time, it has the color of water.
A river is brown or not depending only on its content of mud and has nothing to do with pollution.

AllyKat

There may be a kernel of truth in Habets’ comment, “…the more we reduce our greenhouse gas emissions, the more we reduce our impact on droughts and floods.”
Reduce your “greenhouse gas emissions” enough, you will not have the money to do anything about the effect of droughts and floods.

thomasjk

“Reduce your “greenhouse gas emissions” enough, you will not have the money to do anything about the effect of droughts and floods.”
This is a part of natural reality that seems to escape millions of people (who prefer to believe otherwise. So they remain stubbornly mind blind. And, by the way, you won’t have money with which to subsidize the cost of so-called “renewables.”

mikewaite

But surely France’s use of nuclear and hydro as sources of power mean that the energy sector is virtually carbon free already.
So what causes France to fail to meet its CO2 emission targets as imposed by the EU ?
Cars ? How would the French respond to demands that they give up their traditionally fuelled Peugeots , Renaults , etc?

Frederik Michiels

oh no Paris floods again… must be something with the system as here we got no floods. or at least the designed flood zones did flood, but that’s why they are there.
why do i say this? i live just 260 miles up northeast of Paris and we had the same amount of rain as paris had but Belgium has a completed “sigma plan” (bit like the delta works in the Netherlands) to avoid river flooding.
it worked pretty well there are just 2 zones that are nearly finished that experienced some minor flooding. but that’s because they are built in flood prone area’s

Why be surprised? The French invented the phrase, “Le plus ce change, le plus c’est le meme-chose!”

flynn

FTFY Plus ça change, plus c’est la même chose.

Roger

Also ‘Après moi le déluge’ and ‘Plus belle qu’une Poubelle’, in memory of the man who tried to clean up Paris.

co2islife

Paris is flooding for the exact same reason Californian dams are breaking. Instead of spending their public money wisely, and building needed infrastructure, they wasted their money on ineffective climate change policies. France, however, didn’t make the mistake Germany did, and at least they use Nuclear Power. That was a very wise decision, that is until they become a Califate and that nuclear material will be used to produce bombs. Open Borders and Nuclear Material is about as idiotic a policy progressives have ever devised, and they put all the world at risk.
This isn’t Paris. It’s only men here’ – Inside the French Muslim no-go zones where women aren’t welcome
http://www.telegraph.co.uk/news/2016/12/17/french-bar-tells-women-isnt-paris-men/

old construction worker

When was the last time they drudged the river?

Sam The First

No river dredging allowed under EU environmental policies – which has been the cause of a lot of flooding in the UK in recent decades. And no doubt elsewhere!
Water voles are more important to these city functionaries than people and their homes and businesses

old construction worker

‘No river dredging allowed under EU environmental policies’ Then France should send the EU an invoice for the clean up cost.

Frederic

“No river dredging allowed under EU environmental policies ”
Fake news.
All rivers in France have a regular yearly dredging schedule accessible to the general public (for navigation purposes), the schedule of the Seine bassin can be found here : http://www.bassindelaseine.vnf.fr/1-1-programme-des-dragages-2017-a904.html

Steve Keppel-Jones

Better check the Drudge Report!

R. Shearer

It’s a sad day when the Paris underground pumps stop and metro stations are flooded.

co2islife

California is suffering from the same mental disorder, it is called Progressivism.
Hey California!!!, Wind and Solar Don’t Work in a Flood
I hate to say I told you so, but I told you so. Climate realists like myself have been trying to call attention to how dangerous the misallocation of resources caused by this war on climate change truly is. Now California is finding out…too late. Live updates: Evacuations below Oroville Dam remain in effect as officials … Continue reading
https://co2islife.wordpress.com/2017/02/13/hey-california-wind-and-solar-dont-work-in-a-flood/

commieBob

Given all the civil works controlling the Seine, I am reminded of the Corps of Engineers and their role in New Orleans. link

Everything is Hurricane Katrina — nobody thinks about the levees … link

Kip’s point is well taken:

Still, Paris floods and the blame gets shifted to anything but the real cause — inadequate action to remedy the known problems of Seine River managenment.

Jonny Scott

I remember the earlier stalwart work of the Core of Engineers when they blew up a log jam in the Colorado river and ended diverting it about 100klicks further down the coast affecting oyster beds and causing massive coastal erosion because up coast there was no input of sediment…… power to you guys!

HDHoese

You must have been very young if this was the Texas Colorado. A log jam was removed allowing the flood of 1929 to break a delta out into the bay in 1932, across eastern Matagorda Bay by the end of the decade to the Gulf. Similar thing happened on the Red River in Louisiana, (blamed on one Captain Shreve, hence Shreveport) and much later the downstream Atchafalaya in 1973, the latter due more to sediment accumulation and diversion of Mississippi River water. Oyster reefs were destroyed from the Colorado event where diversion plans into the bay were later developed.
The biggest oyster reef (Pt. Au Fer Reef) in the world was at the mouth of Atchafalaya, destroyed well before these events, date uncertain. While there was some erosion, in both cases there was new delta formation. Oysters off the Atchafalaya River mouth now only grow in the Gulf to the west.
Not sure about the mouth of the Seine. A lot, maybe most of the fishery was in the south of France where it got fished out in the 19th century. The origin of the ecosystem concept (as in biocoenosis) came from study of oyster communities there by a German (Karl Möbius). While a different and a little more cold and less flood adapted oyster, it was subject to climate change, especially, like grapes, at it northern edge of its range.

PiperPaul

Some super smrt guy told me it’s actually pronounced as, “Corpse of Engineers”.

tmitsss

Paris is there because of the river

Bruce Cobb

If “climate change” didn’t exist as an excuse for not addressing actual problems, they’d have to invent it.
Oh wait, they did.

john

This is not climate change, this is building in a low spot that has a habit of flooding.
https://bangordailynews.com/2018/01/26/news/hancock/flooding-ice-blamed-on-climate-change-damage-acadias-birthplace/
On that note, in Maine, the Kennebec river has frequent floods. Ice jams being the culprit in most cases. Years ago when loggers were river driving, (floating woods down rivers to mills) they would have occasional log jams. If they couldn’t manually break the jams, dynamite did the job. Handy stuff…in the winter/early spring, they would use dynamite to clear ice jams. In more serious cases, the Army Air Corps would drop small bombs to clear them on the upper Kennebec river.
Alas, those days are long gone. As are the river drivers (my father ran the last one in 76).
Not gone are the buildings along the flood plain in the Hallowell/Augusta region now occupied by city slickers who have no clue about the rivers history.
Flooding will happen again and they will blame globull warming instead of their own stupidity.

john

Now about ice jams and environmentalists removing flood control and other dams. (Hint: it makes matters worse).
http://s3-us-west-2.amazonaws.com/ucldc-nuxeo-ref-media/971d5aaf-689c-4cb9-82ee-ea261ad64c1d

Paul Schnurr

Why couldn’t they store a little less water upstream in the Spring in anticipation of the late Summer rain?
Must be some answer to this obvious question but I didn’t see it.

john

The water level in lakes are lowered in the fall to accomodate the spring runoff. The old timers had a pretty good handle on it considering the vast drainage areas involved, snow pack total during the winter and spring/winter rain.
Moving ahead, many of the old driving/flood control dams have either failed due to neglect or taken out dur to pressure from environmental groups.
Herein lies the rub. Back in the day, the flood control/ driving dams mitigated flooding and allowed folks to build waterfront homes/businesses in floodplains. Now that the old timers and many of the dams are gone, well, the rivers revert back to what they were and flood once again.

john

Back in the logging days, the thousands of square miles of drainage area was managed to provide flood control and water resources via thousands of smaller driving dams on brooks and streams, some even built on mountains to hold water back to drive wood down small streams to larger waterways later on in the summer months as it was not effective to have horses haul wood many miles to the larger rivers. This method kept the mills operating and as a plus, prevented flooding.

Paul Schnurr

Now that makes sense. Also, I guess they have to keep the water up to a certain level to make it navigable.
A very complex problem with multiple trade-offs.

john

Back to France…
Here’s the OECD Seine Basin flood risk executive summary.
https://www.oecd.org/gov/risk/Flood-risk-management-seine-river-executive-summary.pdf

Coach Springer

If we are to see an end to heat waves in Summer, cold waves in winter, floods in Spring , droughts in Summer, …,some of it record breaking and unpredictable, there is zero evidence that it can be eliminated by anthropogenic CO2 control. Or as the IPCC might put that: extremely likely that 100 to 101% of it will not be eliminated by anthropogenic CO2 control.

co2islife

Ban on Fracking is Causing California’s Earthquakes
Keeping with the spirit of climate alarmist fake news, I’ve decided to apply their best practices to the recent earthquakes in California. Best Practice #1: Start with a conclusion that supports your political agenda and work backward. I want to expose the Sophistry used by the Climate Alarmists. Best Practice #2: Identify a completely natural phenomenon, … Continue reading
https://co2islife.wordpress.com/2018/01/27/ban-on-fracking-is-causing-californias-earthquakes/

The cycle time of 86.5 years (GB, by my own result/ calculation) can vary because of various reasons.
I suspect that this \Paris flooding now is similar to the 1924 flooding.
Note that the tables 2 and 3 suggest that major US droughts are coming up soon….
http://virtualacademia.com/pdf/cli267_293.pdf
This is confirmed by my own investigations and history: i.e. dust bowl drought in 1932-1939 and 1845-1856
Pity everyone there, like Nero, is still playing the violin.

Must say,
I cannot find the Burroughs 1992 paper, showing the tree ring results proving the 90 year cycle [drought].
Anyone there who has a clue what happened to it?

JohnWho

” “Because of climate change, we can expect floods in the Seine basin to be at least as frequent as they are right now,”
Yikes!
It is the same, only different!

Har-old

Perhaps the experts controlling the water have been convinced that global warming means no snow to melt in the Spring. So they keep the dams full all winter because the record snow this season should never happen ? Is this too simple ?

D P Laurable

I highly recommend The Conquest of Nature by David Blackbourn. It is all about German water engineering. One of the unintended consequences of taming the Rhine was the exacerbation of floods due to the elimination of natural flood buffers.

TDBraun

Their system needs a “relief reservoir”… a basin into which excess water can be temporarily diverted in flood situations to lessen the effect on Paris. After the crisis has passed they pump the water out of that reservoir back into the river.

beng135

What a surprise! All the urbanized, impervious surfaces there, and channeling of all the rivers, and it rains hard, and then………..

The Original Mike M

“If the water level drops too far, the barges could scrape the riverbed and get damaged. ”
So why don’t they just dig it deeper? Twice as deep would double the maximum flow capacity to handle the heavy rain periods and make it much easier to maintain a constant level.

The Original Mike M

Bryan A: “Then I have to ask…exactly how does dredging the base of the river deeper stop flooding?”
By increasing the flow capacity of the river to be there when it is needed!
There is no difference between making a river wider or deeper, either way increases cross sectional area.

Bryan A

But the flow capacity isn’t there if the river height is still maintained for shipping purposes. The difference would be instead of shipping on a river that is 20′ deep with a surface 18′ below street level you would be shipping down a river that is 30′ deep and 18′ below street level. Regardless, the distance between the surface of the river and the street level is unchanged. The extra depth is still full of water and gives no additional room between the surface and the street. Th Gove the extra room,.you would need to dredge AND lower/extend the other shipping infrastructure (locks, platforms, stairways, etc.) down to the new river surface level. Then you would need to dredge more than the area where flooding occurs, you would need to feather the dredged depth back into the normal depth much farther downstream.
In essence, dredging the river deeper through the flood zone will only give you a deeper river but won’t affect the river level.

The Original Mike M

Bryan A –

But the flow capacity isn’t there if the river height is still maintained for shipping purposes.

It’s unclear what you mean by that. The nominal level of the water at normal flow would remain unchanged. The deeper depth will provide more cross sectional area and therefore a higher flow capacity.

Regardless, the distance between the surface of the river and the street level is unchanged. The extra depth is still full of water and gives no additional room between the surface and the street.

That’s correct and there is no need for “additional room” because with the added capacity the water isn’t going to rise anywhere near as much as it does now in flood stage.

.. need to dredge AND lower/extend the other shipping infrastructure (locks, platforms, stairways, etc.) down to the new river surface level.

Huh? Now you contradict what you stated above implying that the surface will be lower. No … it will NOT be lower and does not ever have to be lower! You were right the first time so there is no need to change existing locks, docks and stairways.

Then you would need to dredge more than the area where flooding occurs …. you would need to feather the dredged depth back into the normal depth much farther downstream.

Nowhere did I make the silly suggestion of dredging only the area where flooding occurs. Capacity has to be increased to be at or above some minimum “X” from the flooding point all the way downstream to the sea.

In essence, dredging the river deeper through the flood zone will only give you a deeper river but won’t affect the river level.

Basically repeating your wrongheaded assumption that I am stupid and suggested dredging only in the flood zone or that I suggested changing the level of the water. Neither is true and repeating it will not change that fact.
Would it be a massive project? YEP! .. and I never suggested it would not. It’s possible that every single one of their level/flood control points (gates and spillways) would need to be rebuilt/augmented/expanded to accommodate the increased capacity.
If they had started 150 years ago they would have been done by now which leads me to suspect that either Parisians really don’t care all that much about the occasional flooding or it has been doing it for so long (flooding in 1658 matched 1910) that they think it is something they are forced to accept.
150 years ago the Mississippi presented massively larger flooding problems including issues like yellow fever, (1878). Lucky for us there had not been much of a population established along its banks for centuries before then thus affording a greater variety of options for mitigation such as the TVA for example.

Bryan A

Sorry Mike but I never once called you a name nor suggested/intoned you were anything but intelligent.
I am simply stating that increasing the river depth will do nothing but increase the river depth. It supplies no additionall capacity for emergency flow because the additional depth (currently filled by earth) will be refilled with water before any emergency situation happens. Filled is filled either way and supplies no emergency buffer.
There simply won’t be any added capacity if that capacity is already filled with water to maintain the existing water level for commerce.

The Original Mike M

Bryan A

I am simply stating that increasing the river depth will do nothing but increase the river depth. It supplies no additionall capacity for emergency flow because the additional depth (currently filled by earth) will be refilled with water before any emergency situation happens. Filled is filled either way and supplies no emergency buffer.

Wrong. You simply do not understand. As I stated earlier, deeper or wider makes little difference. Either increases the flow capacity by increasing the cross sectional area.
A bigger channel can move more water … PERIOD!!!! How can anyone disagree with that?

Bryan A

You are correct that a bigger channel can move more water. But if the river surface height has to remain unchanged, the only way to increase the channel dimentions is to go wider rather than deeper and through central Paris wider isn’t an option.
Right now, through central Paris, the Seine is 100 meters wide and around 8 meters deep with the surface of the water around 2 meters below the pedestrian walkways along the river bank. That 100 meter width is constrained by streets on both sides so going wider isn’t an option.
If your river height must be maintained at 2 meters below pedestrian riverbank sidewalk level (7 meters below street level) for river traffic to flow and ease of access for pedestrians then that traffic doesn’t care if that river is 5 meters deep or 10 meters deep. (additional water flow wouldn’t care either)
To maintain river traffic access to the river bank pedestrian sidewalks, the river would need to be maintained at 10-11 meters deep instead of 6 or the boats would be 7 meters below the walkways.
If you fill this extra space with water to maintain the original river level, you still only have 2 meters to the walkway and 7 meters to street level.
You have a 370 km distance to the sea (as the river flows). If you have a river that is derdged 5 meters deeper, you would likely need to either gradually feather out the western portion or dredge 370 kilometers to the ocean. Either way you now have a river that is 13 meters deep instead of 8 and water that is 11 meters deep instead of 6 still with 7 meters of space between the river surface and street level.

Bryan A

Think of it this way
Take 2 water bottles. Cut one off at 3″ from the bottom and the other at 4″.
The cut represente the street level and the bottom is the river bed.
Mark the 3″ deep one at 1″ from the top as this is the level that must be maintained for shipping.
Now mark the 4″ deep one at 1″ from the top. (this is the level that still must be maintained for shipping)
…The extra inch deep is the new dredged river depth
Now fill the 3″ deep one to the mark, this is the regular water height. Now add an additional 1.2 inches of water into the 3″ deep container (doesn’t hold it)
So now for the dredged river
Again fill the bottle to the mark (there can’t be any less water for shipping to function) and then add the 1.2″ of water into the 4″ deep bottle
A Bottle of constrained sides or River with constrained banks Still won’t handle the emergency flow even though both have a greater volume IF that volume is full prior to the emergence flow situation.

The Original Mike M

Bryon “the only way to increase the channel dimentions is to go wider rather than deeper”
No, you are wrong. Given identical head, a bigger channel has greater flow capacity than a smaller one regardless of whether it is wider or deeper.
I defy you to explain how that cannot be true! `(Don’t bigger pipes have a higher flow rate at a given head?)
In your earlier explanation you stated there was no difference if there was water at the bottom of the deepened channel or dirt. Yes there IS a difference because water FLOWS … dirt does not.
Bryon “…:even though both have a greater volume IF that volume is full prior to the emergence flow situation.”
Static volume is irrelevant here, only cross sectional area matters. (CSA)
Flow rate = CSA * average velocity.
You cannot get around that simple fact.
I can’t believe all the time I’ve wasted on trying to educate you.“Go to school and pay for a course in hydraulics. Here’s a calculator if you still don’t believe me – http://www.engineering.com/calculators/open_channel_flow.htm
If you don’t like the results that that gives you when you increase channel depth – pester them not me because I give up!
(it shows a more than doubling of flow from doubling the depth because there is a smaller wetted perimeter to CSA ratio the larger the channel gets. Use N=.015)

Bryan A

Mike,
Your pipe analogy is slightly flawed. Yes the larger pipe will carry more but the pipe is larger in radius (every direction.) Not just deeper.
The key is in your statement

By increasing the flow capacity of the river to be there when it is needed

This implies that the capacity will not be used when not needed but the deeper river will still be filled to the point of 7 meters below street level to maintain shipping level. This effectively uses the additional capacity before it is needed and renders it unavailable as additional capacity. It isn’t additional unused capacity if it is being used. Again refer to my bottle analogy.

The Original Mike M

Bryan – I already told you that static capacity has nothing to do with the improvement of flow capacity. You refuse to believe me and ignore my examples and explanations. You are wrong and I’m done trying to explain it to you, go bother someone else. Keep it up and I’m just going to keep giving you this same answer.

Bryan A

Have a nice day

Steve Keppel-Jones

Bryan A and The Original Mike M,
I think you guys are both right, and don’t realize it. TOMM says that making the river deeper will increase its flow capacity, which Bryan A doesn’t disagree with. But Bryan A maintains that if you make the river bottom deeper, and *still want to maintain the current surface height*, then you’ll need more water in the river (more flow) in non-flood conditions, which is true, and then where’s that water going to come from? And given that the increased flow (compared to the present situation) is going to be there all the time in order to maintain the surface height, how does the river’s capacity to deal with floods get any better?

The Original Mike M

Steve Keppel-Jones –
“I think you guys are both right, and don’t realize it. TOMM says that making the river deeper will increase its flow capacity, {A}which Bryan A doesn’t disagree with. But Bryan A maintains that if you make the river bottom deeper, and *still want to maintain the current surface height*, then {B} you’ll need more water in the river (more flow) in non-flood conditions, which is true, and then where’s that water going to come from? And given that the {C} increased flow (compared to the present situation) is going to be there all the time in order to maintain the surface height, {D} how does the river’s capacity to deal with floods get any better?”
{A} False. I claim that making it wider or deeper will accomplish the same thing. Bryan has repeatedly claimed that that is not true.
{B} False. More water in the river is not the same as “more flow”. It will simply be slower flow than it is now.
{C} False. Flow rate at any time is managed by river level control points as it always is – making it wider or deeper only increases the FLOW CAPACITY (which is NOT the same thing as volume capacity).
{D} The same way a bigger drain pipe can empty your bath tub – a higher flow rate.

The Original Mike M

Corrections
{B} False. More water in the river is not the same as “more flow”. It will simply be slower velocity than it is now for a given flow rate.
{D} The same way a bigger drain pipe can empty your bath tub faster – a higher flow rate.

Bryan A

But if that larger bathtub drain pipe were constantly 3/4 full instead of completely empty, the bathtub would still drain just as slow as the smaller empty pipe. The river is like the pipe that is constantly 3/4 full.
Now for the dredging.
While feasible, the dredging operation, if worked from the confluence of the Marne, to the end at La Harve, the operation would require removing (presuming a 5 meter deep dredge is what you alluded to) 5 meters deep by 100 meters wide by 370 kilometers long.
This is roughly (5 meters X 100 meters X 370Km) 185,000,000 M³ of soil that needs to be excavated and barged and dumped someplace that it won’t effect fisheries or recreation areas.
It also equates to a surface area of 71.42 mi² 1 meter deep

The Original Mike M

Bryan A – “But if that larger bathtub drain pipe were constantly 3/4 full instead of completely empty, the bathtub would still drain just as slow as the smaller empty pipe. ”
It what universe is an empty pipe draining any water at all?

Bryan A

For the bathtub drain to function it has to be clear otherwise it is clogged and water will not flow…that is what I mean by empty. When the bathtub is full of water, much like he upstream dams, the drain pipe IS empty, But the river is 3/4 full. When you remove the drain plug, the tub empties into what was an empty pipe. In this case, a larger pipe will still only drain as fast as the tub drain size allows. But when the water gates (drain plugs) are opened on the dams to alleviate potential problems from rain overflow, the river isn’t empty it is 3/4 full. If the drain pipe on the bathtub were partially clogged (constantly 3/4 full like the river) the tub would only drain as fast as the smaller pipe. The only space for additional emergency flow is the space between the top of water and the street level (the unclogged portion of the pipe)
It is the air space above the river that is the emergency flow space

michael hart

Large companies saying they will relocate after Brexit can already guess who is going to pay for any long term fixes for Paris’ problem… Better to remain in a City that is ahead of the curve on flood prevention/mitigation? Nobody droned on about global warming when the Thames Barrier was on the drawing board.

Mark Eastman-Flood

Construck a spill way around the city to take the overflow controlled of course!

http://www.historyinorbit.com/wp-content/uploads/2017/11/14.jpg
The streets of Paris looked quite different during the Great Flood of 1910. Boats are seen here rowing down what would have been a busy street

Justanelectrician

That has to be photoshopped; in 1910, CO2 levels weren’t nearly high enough to cause that kind of flooding.

The Original Mike M

A lot like other spoofed stories they got away with back then like low arctic ice in 1922. (/sarc) https://wattsupwiththat.com/2008/03/16/you-ask-i-provide-november-2nd-1922-arctic-ocean-getting-warm-seals-vanish-and-icebergs-melt/

Don’t you realise that logic and facts are constructs of the Western, imperialist, white, male patriarchy? Narratives and, muh, feelings are a way valid basis for organising society. (sarc)

Sorry about error – “way more valid”

BallBounces

If climate change gets blamed for droughts on the one hand and flooding on the other, shouldn’t it get recognized and praised for all the good stuff in between?

Michael Jankowski

Climate change was recently blamed for reducing the extreme rainfall events somewhere in the southwestern US and affecting streamflows. Everything climate change does is bad bad bad!!!

Michael Jankowski

Who can ever forget Steve McIntyre coining MBH98’s “rain in Maine falls mainly in the Seine?”
https://climateaudit.org/2007/11/21/mann-et-al-2007-precipitation-teleconnections/

Wasn’t Paris built on what was originally a swamp? An area prone to flooding?

Steve Oregon

Seems their only option is to deeply dredge the 123 mile path to the sea and accelerate the 115 ft drop.
Is that insane or in some sort of theory with no other considerations buy water flowing downhill is it possible?

The Original Mike M

That’s correct, a bigger channel can move more water whether it is widened or deepened. With water surface levels kept the same the locks can remain as they are so the only other thing needed is to increase the flow capacity at the flood/water level control points to handle the higher flow rate when needed.

TRM

Maybe they should talk to the folks that did the diversion for Winnipeg. I mean this is an engineering problem that is easily solved. WTF is the problem France? Too distracted with tabloid junk just like everywhere I guess.

politicians love climate change. it shifts the blame from politicians to the populace.

Rhoda R

They are missing the boat on this one — they could claim that this flood would not have happened if the US hadn’t left the Paris Climate Accord.

Michael Jankowski

Someone will claim it will happen more often because the US left Paris…

Andrew

Wait, so flooding is caused by summer rain when dams are already full?? Has anyone told Flannery?

Good post Kip. It is amazing how people knowingly built in flood prone regions, have experienced severe flooding in past 200 years yet still mindlessly blame CO2 climate change for natural variability, like in Houston, New Orleans, etc.

Gary Pearse

My first big job as a fresh new engineer was a big one indeed – doing hydrological investigation along the right-of-way of the to-be constructed Greater Winnipeg Floodway. We, too, and the folks in Fargo, ND and points south on the Red River of the North had frequent major floods. The towns and cities along the Red were also on the lake bottom of the Pleistocene Lake Agassiz and the floods were essentially a refill of the ancient lake. Being out in the plains as well when the floods came the area inundated was enormous. Here is a photo of an inundated railway bridge in the big 1950 flood – I filled sandbags in my community of St James, Manitoba as a boy scout.
http://www.rmofmorris.ca/wp-content/uploads/2014/01/313.jpg
From Wiki: “The construction was a major undertaking with 76.5 million cubic metres (2.75 billion cubic feet) of earth excavated—more than what was moved for the Suez CanalAt the time, the project was the second largest earth-moving project in the world – next only to the construction of the Panama Canal.[7] The total cost at the time was $63 million (CAD), equivalent to approximately $505 million today.”

Davis

Duff’s Ditch!

Gary Pearse

Excavation of the Winnipeg floodway unearthed gypsum crystal clusters that had grown in the clay, some several kg in weight. There are gypsum deposits north of Winnipeg and probably gypsum powder ground from the deposits by Pleistocene glaciation wound up being dissolved in Lake Agassiz, later to grow in the lake bottom muds. Gypsum is moderately soluble ~2g/L.
https://www.minfind.com/mineral-559717.html

michael hart

That takes me back to my youth, Gary. I recall digging for near perfect gypsum crystals, often several inches long, in clay mounds left from local building projects in Central England. I could understand the excitement of a miner or gold prospector.

Michael Jankowski

$505M seems well worth it…especially since it has allegedly saved over $10B in flood damage.
Instead, France will probably subsidize $500M of solar and wind, claiming it will reduce future flooding.

The Original Mike M

“Instead, France will probably subsidize $500M of solar and wind, claiming it will reduce future flooding.”
People of Galveston TX are lucky the storm in 1900 didn’t happen in 2000 because instead of spending to build sea walls, jack up important buildings and elevate the terrain they would gotten the “benefit” of the most expensive climate models our tax money can buy.

Bravo Gary – just saw your comment now.
from wiki:
Since its completion in 1968, the Floodway has prevented over $40 billion (CAD) in cumulative flood damage.”[3] It was designated a National Historic Site of Canada in 2000, as the floodway is an outstanding engineering achievement both in terms of function and impact.”

“Warming will cause a predictable increase late summer rain which we will not be able to predict, causing us to leave insufficient room for it in our reservoirs.” In other words, Gorebal warming causes brain damage. Finally a warmist proposition I can agree with.

Bob Burban

There doesn’t seem to have been much thought given as to why flood plains are called … flood plains.

Jim Heath

Hey! sanity isn’t allowed here, now behave yourself.

Stephen Richards

From the French vigicrue site. Google it . It is interactive. This the central paris data with past flood levels

Stephen Richards

Image failed to post. Probably because I haven’t a clue how to do it

Bryan A

Go to the website and click on the image. If the image opens in another window, and the URL address ends in .JPG, copy the URL (http) address and paste it into your post. If clicking on the image does nothing, right click on it and select PROPERTIES, part way down you will see the image tag with the .JPG extension. Try copying and pasting this into your post. At the top of this website in the gray bar is the test page. Try posting the image there and see if it posts first.

Jim Heath

Hendric Svensmark isn’t surprised.

Let them eat soggy cake.

Amber

Yep the French have figured out how to control the weather . Must be all those X NASA climate fabricators they are recruiting .
Most places would be happy with some extra rain .

Pop Piasa

Now hold it, weren’t the predictions extreme drought from climate change? Or, I guess maybe I did hear that it could also cause flooding, depending on your location and the regional precipitation upstream. Man… Climate Change just hits us daily.
(sarc factor 7)

Phil.

You mean like the worst drought in a century currently hitting Cape Town, expected to run out of water in April.

Michael Jankowski

Cape Town’s population has grown from 2.4 million to 4.3 million since 1995. Water supply storage has increased merely a small fraction.
Following the last increase in storage in 2009, the Department of Water Affairs and Forestry warned that demand would exceed supply by 2013 without any water conservation management and demand measures – and that those would only delay this until 2019. The catch was that this was based on “normal” rainfall levels. Drought conditions would muck this up…and that’s exactly what happened.
You can even go back to 1990 when water supplies were eerily projected to “dry up in 17 years time” by the Water Research Commission.
Level 4 water restrictions were not imposed until the end of May in 2017. Level 5 wasn’t imposed until September. Cape Town passed last May on a proposal that would have supplied 100 million liters of desal before the end of 2017 and then a full 450 million liters (2/3rds of Cape Town’s needs) by the end of 2018.
The drought has simply exposed the poor planning, lack of preparedness, and utter ignorance of government.

Henryp

True. Isnt it convenient to blame poor planning on climate change?

Extreme Hiatus