Paris could become another Venice with next flood

PARIS, Jan 20 (Reuters) - One hundred years ago, the river Seine burst its banks and filled the elegant boulevards of Paris with torrents of muddy water, forcing thousands of inhabitants out of their homes and cutting off power for months.

The same could happen again. Only this time the consequences will be 10 times worse, experts say.

"The flood is unavoidable," said Louis Hubert, director for the Paris region at France's ministry of ecology and sustainable development.

"What we can simply say is that we are almost certain to see new considerable floods, but we don't know when."

Paris' centennial flood of 1910 -- a flood which has a 1 in 100 chance of occurring every year -- affected 200,000 people in 1910 and cost 1.5 billion euros ($2.15 billion) in today's money, said Hubert.

A similar flood these days would affect around a million inhabitants and cost 15 billion euros, he added. On top of this, another two to three million people are likely to see their electricity cut off for several days, he added.

"In both cases, there are 10 times more people concerned, and the direct cost is ten times more that of 1910. It could lead to disorganisation of the Paris region and have an effect on the national economy," added Hubert.

To commemorate the 1910 flood, Paris' Galerie des Bibliotheques is exhibiting a collection of photos, postcards and witness accounts.

Among them are sepia shots of bowler-hatted, mustachioed men travelling piggyback, trousers hoisted and knee-deep in water; a totally submerged Champs de Mars; people pulling up to Notre Dame cathedral in boats and food being delivered by ladder to second-floor apartment windows.

In most cases, Parisians seem to take the catastrophe with humour, smiling wryly at the camera while perched on precarious makeshift structures above swirling water.

Since 1910, Paris has taken pains to boost its defences, by raising the height of bridges, scooping out a deeper riverbed and carrying out hydraulic work.

But nowadays, increased urbanisation and the proliferation of electricity and telephone networks mean more people are vulnerable, Hubert added.

Such preparations would help bring down a water level of eight metres (yards) by 60 cm (24 inches) at the most, Hubert said.

"In spite of everything, the flood, if it happens, risks having consequences at least as extensive or even more so."

Paris museums at risk of flooding such as the Louvre, Musee d'Orsay and Musee du Quai Branly will be able to spirit the priceless works stored in their basements to a safehouse at Cergy-Pontoise, a town northwest of the French capital.

"We have a flood plan and are working hard on it. If anything happens we hope to be warned in time by the Paris fire brigade," said a member of the Louvre Museum's communications team, adding that the centre should be finished by 2014.

For now, photographs from 1910 are on display in Paris to warn the city's inhabitants of what to expect.

"I am not here to scare people, but the scenario will be catastrophic enough," said Pascale Dugat, member of La Seine en Partage, which is hosting a gallery on www.seineenpartage.fr.

"These are agreeable, convivial photos to say: 'yes, we are threatened; yes, it's going to happen; yes it will be more catastrophic,'" Dugat told Reuters by telephone.

"And then we will take our little pets and seek refuge in the countryside," she said.

This map shows the areas that were under water at the maximum extent of the great flood of 1910, superimposed on an
ordnance map of 1900. The image is large and may take a while to appear on your screen.

http://i49.tinypic.com/2l964b6.png

Here a close-up view of Central Paris. You can find more at www.geoportail.fr

http://i46.tinypic.com/2ef2is9.png

Here is the start of an article I wrote about the great Paris flood of 1910 some years ago. I never completed the article, but I thought you might find it interesting nonetheless.
The Seine is a rather small river compared to other large European rivers such as the Rhine or the Danube, with a mean discharge of only 273 m³/s in Paris (Rhine 2,090 m³/s in Cologne, Mississippi 5,500 m³/s in St Louis). Even inside France, the Seine presents a mean discharge much smaller than the Rhône (about 800 m³/s in Lyon, about 1,800 m³/s before entering the Rhône delta). The Seine is also not particularly famous for its floods, which are far less dangerous and extreme than the floods of other European rivers such as the Danube or the Tarn.

Nonetheless, a major flood of the Seine has regularly occurred every century or so in history. Because the Seine flows through Paris, the historical floods of this river are among the best documented in the world. Statistical records of the floods in Paris started in 1658. Between 1658 and today, the three most important floods occurred in:
- 1658: on February 27, 1658 the Seine rose 8.14 meters (26.7 feet) above its normal level
- 1740: on December 26, 1740 the Seine rose 7.23 meters (23.7 feet) above its normal level
- 1910: on January 28, 1910 the Seine rose 7.80 meters (25.6 feet) above its normal level, reaching 8.62 meters at the ''Pont d'Austerlitz'' gauge (normal level of the Seine in Paris is 0.82 meters at the ''Pont d'Austerlitz'' gauge)

http://www.savoirs.essonne.fr/fileadmin/bds/MEDIA/la_terre/environnement_ecologie/crue_paris/Crue_Paris_intro.jpg

To enable comparisons, during the Great USA Flood of 1993, one of the largest floods ever to hit the US, the Mississippi River rose approximately 12 meters (40 feet) above normal in St Louis on August 1, 2003, reaching 49.58 feet at the Saint Louis gauge (normal level of the Mississippi River is 9 to 11 feet at the Saint Louis gauge). This was 6.97 meters (19.58 feet) above flood stage, whereas on January 28, 1910 the Seine rose 5.42 meters (17.78 feet) above flood stage. However, in Saint Louis the 52 feet St. Louis Flood Wall, built to handle the volume of the 1844 flood, saved the city from being submerged by the waters, with just over two feet to spare, whereas in Paris in 1910 the waters topped the quais, which had been built to handle the volume of the 1876 flood (6.69 meters at the ''Pont d'Austerlitz'' gauge), and submerged large areas of the city.

http://upload.wikimedia.org/wikipedia/commons/thumb/c/c4/Paris_1910_flood_p1200010.jpg/950px-Paris_1910_flood_p1200010.jpg

Of all the Paris floods, the 1910 flood is, unsurprisingly, the best documented and most remembered today. Several plaques can still be seen in the streets of Paris showing the level reached by the water. The 1910 flood was not particularly deadly, as the waters swelled slowly over many days. Only one person died in the city of Paris, while a handful of people died in the suburbs. However, the material damages brought about by the flood were massive. 200,000 people were affected by the flood, either because their dwellings or their work places were flooded. In areas closest to the river, people had to use canoes through the streets for more than two weeks before the waters receded. Due to the particular geography of Paris, areas far away from the Seine, such as around the Saint-Lazarre train station, were also flooded, the waters reaching these areas through the sewage system. One-third of the Métro tunnels were flooded and remained closed until April 1910. Most train stations were flooded and badly damaged, Paris being cut from the rest of the world for weeks. The large plant producing compressed air was flooded, which stopped all the public clocks and all the elevators in the city, as well as the machines in many factories. The delivery of gas was also severely disrupted, and 5,800 lampposts were out of order, plunging many areas of the city in the dark, without heating in the buildings. Garbage collection was also stopped, because the incinerators were flooded. Telephone, telegraph, and electricity networks were either shut down or seriously disrupted. The list could go on and on. Suffice to say that the damages amounted to 400 million gold francs, which corresponds to 1 billion euros today (US$1.28 billion).

http://historic-cities.huji.ac.il/france/paris/photos/flood/gare_de_lyon.jpg

The days have much changed since President Mac-Mahon's only reaction in the face of the 1876 flood was the now famous "''Que d'eau ! Que d'eau !''" ("So much water! So much water!"), which has become a byword for political ineptitude and inaction in France. Today, French authorities are very much concerned about flood risks in the metropolitan area of Paris. In all likelihood, a major centennial flood equivalent to that of 1910 will happen in the Paris metropolitan area before the end of the 21st century. It should be noted that a new centennial flood would not cause the waters to rise as high as in 1910 or 1658: dams and flood control reservoirs were built upstream the Seine river to defuse the effect of new floods; the dredging of the bed of the Seine river, in order to enable the traffic of barges on the river, also helped to increase the speed of water flow, thus causing the river to discharge more rapidly in case of a new flood. Nonetheless, even if not as severe as in 1910 or 1658, a new centennial flood would have catastrophic consequences in the now heavily urbanized metropolitan area of Paris.

http://historic-cities.huji.ac.il/france/paris/photos/flood/ponte_alma.jpg

It was calculated that in order to protect the metropolitan area of Paris against a flood comparable to 1910, the flood control reservoirs upstream the Seine River should retain 2.2 billion m³ of water. At the moment, the four large reservoirs built upstream between 1950 and 1990 can only retain 830 million m³ of water, which is only 38% of what would be needed in case of a flood equivalent to 1910. In the 1950s, when the ambitious plan of controlling the Seine River was launched, it was planned to build as many reservoirs as necessary, but the building eventually stalled. In particular, three large reservoirs on the Yonne River, which is the most dangerous tributary of the Seine, have so far not been built. This means that the metropolitan area of Paris would still receive 62% of the water resulting from a new 1910 flood. In 1910, outside Paris the Île-de-France was an essentially rural region, and the flood only submerged agricultural land. Today, most of the Île-de-France lands bordering the Seine are urbanized, and from Melun to Mantes-la-Jolie the Seine crosses a continuously built-up area for 165 km (100 miles).

Under these circumstances, even with only 62% of the water of 1910, it is estimated that 550,000 people would be affected by a centennial flood, and 195,000 people would have their houses inundated for several weeks. Public transportation would be severally disrupted, numerous areas would lose electricity, telephone, and heating. Running water and garbage collection would stop. Perhaps even more importantly, the economic consequences would be catastrophic. About a quarter of the French economy is located in the metropolitan area of Paris, with many companies and factories located near the Seine River. A centennial flood would probably badly damage the economy of Greater Paris and France too, with the potential of plunging the country in a recession. In 1999 it was estimated that material damages would amount to 8.4 billion euros (12.2 billion euros if the four reservoirs had not been built), and experts say a centennial flood of the Seine would probably collapse the French insurance industry, and require government intervention.
Now after the global financial meltdown these past two years, a centennial flood of the Seine (or a bad earthquake in Greater Tokyo) is really all that we need. :|

This map shows the areas that were under water at the maximum extent of the great flood of 1910, superimposed on an
ordnance map of 1900. The image is large and may take a while to appear on your screen.

http://i49.tinypic.com/2l964b6.png

Here a close-up view of Central Paris. You can find more at www.geoportail.fr

http://i46.tinypic.com/2ef2is9.png

I just learned two things from you brisavoine. I think I'm going to start liking you!

1. Ordnance Survey (GB) = USGS (US) = IGN (France)
2. I've been forever looking for an online-deployed GIS/mapping website like the link you provided for the geoportail! I can now see the cadastral (parcel) map of Greater Paris and probably all of France plus many more map layers. They even have a layer for the building footprints!

I was about to tell you that was no ord-i-nance map you were showing above with the flood zone but rather a topographic map but you were referring to Ordnance (as in the Ordnance Survey agency of GB) which is the national agency that has mapped the topographic maps for GB like the USGS (US Geologic Survey) has for the US.

Anyway, I saw a documentary about the dangers of Paris flooding like 2 years ago. Actually, it was more of a reenactment (well, an enactment rather, I guess) of what various government officials and agencies would do, how some people would probably react and have to do, what portions would be affected. They actually showed descent special-effects to really make it look flooded, like you would expect in a movie that sells for money. It showed how people in parts of Paris would have to be displaced to parts mainly in the suburbs and it also addressed the storm water detention facilities (reservoirs) upstream, and I think they showed indeed how they would not be able to detain enough storm water, hence the flood. All of this with time being a crucial variable and how evacuations would have to be quick enough before water levels got too high. I'll see if I can find the video on youtube.

I found the video but on Google Videos!!! I can't embed it here.

It's a very interesting enactment and the video claims that an emergency plan exists for Paris. Watch it even if you don't understand French. It's much visual anyway.

http://video.google.com/videoplay?docid=-4005385001181726431&ei=1mxaS5myIKPMqQK2pcSqCg&q=paris+2011+la+grande+inondation&hl=en&client=firefox-a#

it also addressed the storm water detention facilities (reservoirs) upstream, and I think they showed indeed how they would not be able to detain enough storm water, hence the flood. All of this with time being a crucial variable and how evacuations would have to be quick enough before water levels got too high.
Actually a centennial flood in Paris wouldn't be the result of a storm. It would be the result of heavy winter rains throughout the Paris Basin and it would build up over many days. Flash flood due to a storm is impossible in Paris. That's what happens with rivers like the Ouvèze in southern France, but not the Seine.

Actually a centennial flood in Paris wouldn't be the result of a storm. It would be the result of heavy winter rains throughout the Paris Basin and it would build up over many days. Flash flood due to a storm is impossible in Paris. That's what happens with rivers like the Ouvèze in southern France, but not the Seine.

In the civil engineering field in which I work, that evaluates and builds the infrastructure to help drain and protect cities from floods, we refer to storm water as any water that originates from the sky, hits the ground and results in runoff and causes floods. So when I said storm water that applies to any rain. In the US, you'll hear words like storm water sewer and that just means rain water sewer. It's to distinguish it from the waste water sewer since the waste water sewer goes to a treatment plant unlike the storm (rain) water sewer which is directed to a creek or river although sometimes it's detained in reservoirs or smaller detention ponds first to allow water downstream some time to recede to protect a city downstream. Oh, and we don't use the term centennial flood but rather 100-year floodplain or 1% annual chance flood but I still understood what you meant. I did a lot of maps like the one you showed us above that shows the extent of a flood hazard zone. A lot of those maps are used by FEMA for flood insurance purposes and to hold developers liable from building on such a hazard zone.

I never knew Paris did flood?

I never knew Paris did flood?

Well technically any city whose capacity to 1) naturally abosorb water with its soil and vegetation (permeable land) due to urbanization (houses, buildings, paved surfaces) and/or whose capacity to 2) manage the water through some form of detention and redirection (e.g. detention via dams upstream, big enough reservoirs or channels) will flood beginning with its lowest elevation which is usually the area surrounding a river or other channel. Any sudden down-pour of rain or a prolonged series of showers can exceed the city's capacity to do this either naturally or artificially. Civil engineers which are involved in designing the artificial protective aspect (infrastructure and facilities that detain or hold water from rain) take into account the regions rain history, including the volume and velocity of water traveling through a system, such as a river and its basin. Some systems are poorly designed for their typical rain runoff volume and velocity and flood often while others are better designed and only flood when they reach their highest peak as dictated historically. The more you go back in history (through records or some calculation when records lack) the more likely you will find a bigger rain event that will require a better system. The better the system, the more expensive it gets to design it so cities make compromises such as: do we design for a 500-year event or do we design for a 100-year event or do we design for a crappy 10 or 25-year event, which are the other typical measures of flood extents. A civil engineer can correct me if I'm wrong but if Paris has not designed for a 100-year event (meaning people live within the extents of a flood caused by a so-called centennial flood) then Paris can do a lot better. You should wait until you see the extents of a 500-year event flood. I'm sure it's much more extensive than the one shown above by brisavoine.

^^ I forgot to say that with older cities like Paris it's a challenge, I'm sure. For example, in the zoomed-out map of Paris showing suburban areas which are younger than Paris you can see that in areas that the flood zone covers exists, it consists of industrial sectors where little to no people live (only work). But people have lived along the Seine in the center of Paris for a very long time now. Also, the flood zone going through the heart of Paris is not very extensive or wide because the land there is or has been built higher which is one way to minimize floods.

When is the flood expected!!

When is the flood expected!!

The article clearly states that they don't know when one could happen again. It's just predicted that it probably will happen.

Read the article!

I wonder which one will happen first: the Paris flood or the major earthquake in California (San Andreas)?

If Paris is in danger of flooding, can't we just go ahead and install a flood barrier to prevent this disaster?

If Paris is in danger of flooding, can't we just go ahead and install a flood barrier to prevent this disaster?

Probably, I think. Building a barrage or dam requires additional land since you are impounding water, right? So as long as environmentalists and owners of land upstream of Paris are willing to see their land claimed by a swelling river, then yes, I think. Impounded lakes destroy natural habitats but so do cities, right? And it does look like there is plenty of land upstream of Paris where a dam could be built. There are already such impounded lakes already (according to the video I put here) but they are not enough or close enough to Paris to detain water downstream of those barriers. Also, I may not be thinking of another factor that may be a bigger contributor to the next possible Paris flood than discharge from upstream of existing dams.

According to the catchment or drainage area (basin) of the Seine, it looks like the Yonne and Marne rivers are major contributors to the Seine upstream of Paris, along with all the discharge that the Seine is bringing on its own.
http://upload.wikimedia.org/wikipedia/commons/thumb/3/39/Seine_bassin_versant.png/737px-Seine_bassin_versant.png

The Oise is another major sub-basin and contributor. Although that one is downstream of Paris it may be close enough to Paris to create backwaters if it's also discharging a lot during a given rain event. Without knowing what dams and flood control systems those contributors have themselves it's hard to know how much discharge they are allowed to put on the Seine, thus on Paris. But it does look like a dam on the Seine somewhere near Melun would detain water from 1/3 of the Seine basin. That would still leave Paris exposed to the discharges of the Marne which seems to drain as much as 1/3 of the basin on its own. The Marne river discharges onto the Seine at its confluence which is just before entering Paris, in a heavily urbanized part of Greater Paris.

I do see that there is a canal between the Aisne and the Marne rivers. I'm not sure if such canal can redirect water collected thus far by the Marne onto the Aisne which then discharges to the Oise, relieving Paris of some discharge. I doubt that such canal link so upstream of the system can relieve much, plus that canal is probably only for navigation anyway and not for relieving the Marne.

^^If you had read the article I posted, you would have found the answer to the question Jim856796 asked.

A civil engineer can correct me if I'm wrong but if Paris has not designed for a 100-year event (meaning people live within the extents of a flood caused by a so-called centennial flood) then Paris can do a lot better. You should wait until you see the extents of a 500-year event flood. I'm sure it's much more extensive than the one shown above by brisavoine.
Here again, the answers are in the article I posted.
I wonder which one will happen first: the Paris flood or the major earthquake in California (San Andreas)?
Depends where on the San Andreas fault. In any case a major earthquake in Greater Tokyo will probably happen before a major earthquake in California and a major flood in Greater Paris. A major earthquake in Greater Tokyo should happen any year now, given that the last one was 86 years ago.

http://i49.tinypic.com/2l964b6.png



Interesting.

Most of the Seine Ive seen does seem to have pretty good flood walls.

^^ But certain flood events can top flood walls. Velocity and volume of discharge can exceed the design of the flood walls if they are not high enough. Once that gets topped off then the first thing to flood is the lowest-lying land adjacent to the water way.

According to brisavoine's kind article which I failed to read entirely as he would have preferred, the following is important to know:

"It was calculated that in order to protect the metropolitan area of Paris against a flood comparable to 1910, the flood control reservoirs upstream the Seine River should retain 2.2 billion m³ of water. At the moment, the four large reservoirs built upstream between 1950 and 1990 can only retain 830 million m³ of water, which is only 38% of what would be needed in case of a flood equivalent to 1910. In the 1950s, when the ambitious plan of controlling the Seine River was launched, it was planned to build as many reservoirs as necessary, but the building eventually stalled. In particular, three large reservoirs on the Yonne River (see my little map above), which is the most dangerous tributary of the Seine, have so far not been built."

Also:
"Today, most of the Île-de-France lands bordering the Seine are urbanized, and from Melun to Mantes-la-Jolie the Seine crosses a continuously built-up area for 165 km (100 miles)." It's hard to find the land for more reservoirs when so much of the land is urbanized along a river. It sounds like with the Yonne river being a big contributor, that's where the reservoirs should focus because that's very rural so they should build the 3 there that they had planned and maybe one on the Marne river which is another big contributor. Also, the Marne is not as urbanized upstream as the Seine so they should add some there too. I can already see little reservoirs along the Yonne and Marne but sounds like they are not enough or big enough.

Wonderful maps !!

Flooding can be a major problems in some cities, but it soes not sound, like this can obliterate Paris.

Just being curious. For which flood is the flood protection of Paris designed for? 25, 50, 100 ... years floods?

Vienna seems to have a quite ok flood protection designed for a 500 years flood (maybe even 1000 year, the last of that kind was in the early 16th century), which was tested 2002 with a 100 years flood where it did very well.

Which other European cities prepared for 500 years floods?

If you had read the article I posted, you would have found the answer to the question Jim856796 asked.





-----------------------------------------------------------------------------------
Cheap WOW Gold (http://www.wly.com)
RS Gold (http://http://www.wly.com/gold/Runescape/RUNESCAPE)
Mapl Story Mesos (http://www.wly.com/gold/Maple-Story-US/)
Buy Aion Kinah (http://www.wly.com/gold/Aion-US/)