Talk:Vajont Dam

Two seperate reasons for altering the water level

There seems to be some confusion from contributors about the water level of the dam and the cause of the disaster. There were two things going on:

Firstly, the engineers were using the water level in an attempt to control the rate of the landslide. By raising the water level, they believed that they could increase the rate of the landslide, and by lowering it, that they could slow it again. This theory was based on observations during the early days of the filling, when the movement of the landslipped area could be controlled this way.

The other issue was that a "safe" water level had been determined if a catastrophic landslide should occur. The SADE engineers had predicted that, if a total landslip should suddenly occur, the subsequent displacement wave would top the dam if the water level was less than 20m from the crest. Therefore SADE recommended that the "safe" water level should not exceed 25m from dam crest. The point is that this "safe" water level had nothing to do with controlling or preventing the landslide; it was protection against the worst case scenario - a sudden and uncontrollable landslide.

Although the engineers had exceeded this "safe" water level in their attempt to speed up the inevitable landslide process, when the landslide started moving too quickly they began lowering it again. It's important to note they managed to lower the level back to the "safe level" again before the landslide took place. This is why engineers were standing on the crest of the dam as spectators - they thought it was safe.

It was totally irresponsible for ENEL to go above this "safe" level, but this act was not the cause of the disaster because at the time of the disaster the water was back down to the "safe" level. The causes were that (1) the SADE tests had not predicted the correct size of the displacement wave, and (2) Throughout the filling, the geological model of the landslip area, and their theory for controlling the landslip, were flawed.--Jason210 (talk) 12:56, 5 December 2012 (UTC)

Updated

I have made edits to the text, to include the two essential points that were missing. These are: (i)The water level of the dam was lowered to the recommended safe level to prevent a wave topping the dam by 9th October 1963; and (ii)The actual cause of the flood was the high speed of the landslide, which SADE had failed to predict correctly in their earlier model.

I also took away the bit about the displacement wave causing an air pressure wave like that of a "nuclear bomb", since I can find no evidence for this and no citation was given to support the claim. Eyewitness accounts from Erto e Casso did not report such a blast, although in Longerone eyewitnesses describe a strong wind preceding the flood, which many mistook for a squall or storm.--Jason210 (talk) 23:49, 23 October 2012 (UTC)

Name

Is there any information on the origin of the name? —Preceding unsigned comment added by Mwahcysl (talk • contribs) 10:26, 9 October 2008 (UTC)

From the Vajont torrent. GhePeU (talk) 19:00, 9 October 2008 (UTC)

In the local language it means "goes down". —Preceding unsigned comment added by 79.43.135.62 (talk) 18:16, 21 July 2010 (UTC)

Current status?

Apparently the dam was abandoned and the area filled with rock. Perhaps this could be checked and added to the article if correct. (See e.g. [1])-- era (Talk | History) 16:36, 21 December 2008 (UTC)

The "filled with rock"-part happened exactly on 3-Oct-1963 22:39 - the Monte Toc landslide. I don't see why anyone should fill the valley, with its arable topsoil, with rock after the landslide.

Yes, it WAS that huge (250×10^⁶ m³ (330 million cubic yards; 250 billion litres) of rock coming down with speeds up to 110 km/h (59 kn), if I remember correctly). --2003:C8:4714:600:49CE:C61F:D371:4268 (talk) 22:17, 11 January 2021 (UTC)

Rewriting

I have rewritten most of this page - it basically included only geological information, on what is instead one of the worst disasters in the history of Italy, and one of the worst of mankind in terms of engineering failures. It was really too cold-hearted, and omitted most of the information necessary to understand the actual causes of the failure. (If anyone is interested in more detailed geological information, there is plenty of it in the equivalent page on the Italian wikipedia - I'm not a professional geologists so I'm not going to translate it.) I have provided sources but I have not sourced each and every sentence as it would make the page too heavy, however if anyone has questions just ping me and I can provide the appropriate sources. Vbertola (talk) 16:56, 4 January 2009 (UTC)

Here's a good digest in English [2] written by an academic (Prof David Petley, University of Durham, UK, who has published papers on the disaster). Many photos and a great explanation for the layman. 86.147.162.38 (talk) 08:37, 17 February 2010 (UTC)

Last archived version is http://web.archive.org/web/20161222062706/http://www.landslideblog.org/2008/12/vaiont-vajont-landslide-of-1963.html --2003:C8:4714:600:49CE:C61F:D371:4268 (talk) 22:25, 11 January 2021 (UTC)

Seiche?

Are there any sources describing the wave as a seiche as it doesn't match either our article or my understanding? I have seen it described an 'impulse water wave', which makes sense or as a tsunami, which it resembles. A seiche is a standing wave and a large seiche in a reservoir water body could over-top a dam, but that is not what happened at Vajont. Mikenorton (talk) 17:41, 8 October 2010 (UTC)

Width of the dam

"...27 m (89 ft) thick at the base and 3.4 m (11 ft) at the top." Base and top width are interchanged. — Preceding unsigned comment added by 83.76.202.142 (talk) 16:07, 12 March 2013 (UTC)

Are they? I thought it was correct - that the material - front-to-back in the direction of water flow - is 27m thick at the base and 3.4m thick at the top. The article says thick but you are talking about width - the width across the valley perhaps? The article does not say "width" or "wide" or whatever at this point, just "thick", which I'd understand as correct. Whether it is clear enough is a different matter - presumably you would think not, if my guess about a misunderstanding is correct! :) Best wishes DBaK (talk) 17:46, 12 March 2013 (UTC)

Italian Wikipedia article

If anyone's interested, I'm trying to improve our article on the Vajont dam disaster in Italy. Not surprisingly the Italian Wikipedia article is better than ours, but so far I just have a rough translation of the Italian article:

• Original article
• Rough English translation

FT2 ^{(Talk | email)} 07:24, 21 September 2015 (UTC)

External links modified

Hello fellow Wikipedians,

I have just modified 7 external links on Vajont Dam. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

• Added archive https://web.archive.org/web/20090729032357/http://www.uwsp.edu/geo/projects/geoweb/participants/Dutch/VTrips/Vaiont.HTM to http://www.uwsp.edu/geo/projects/geoweb/participants/Dutch/VTrips/Vaiont.HTM
• Added archive https://web.archive.org/web/20120930084101/http://www1.lastampa.it/redazione/cmsSezioni/cronache/200810articoli/37192girata.asp to http://www.lastampa.it/redazione/cmsSezioni/cronache/200810articoli/37192girata.asp
• Added archive https://web.archive.org/web/20060813030258/http://www.land-man.net/vajont/vajont.html to http://www.land-man.net/vajont/vajont.html
• Added archive https://web.archive.org/web/20140308141643/http://en.lswn.it/press-releases/international-year-of-planet-earth-global-launch-event-12-13-february-2008/ to http://en.lswn.it/press-releases/international-year-of-planet-earth-global-launch-event-12-13-february-2008/
• Added archive https://web.archive.org/web/20060813030258/http://www.land-man.net/vajont/vajont.html to http://www.land-man.net/vajont/vajont.html
• Added archive https://web.archive.org/web/20091112220524/http://deastore.com/libro/vajont-l-onda-lunga-quarantacinque-anni-lucia-vastano-ponte-alle-grazie/9788879289702.html to http://deastore.com/libro/vajont-l-onda-lunga-quarantacinque-anni-lucia-vastano-ponte-alle-grazie/9788879289702.html
• Added archive https://web.archive.org/web/20090729032357/http://www.uwsp.edu/geo/projects/geoweb/participants/Dutch/VTrips/Vaiont.HTM to http://www.uwsp.edu/geo/projects/geoweb/participants/Dutch/VTrips/Vaiont.HTM

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Photographies

Please, if there isn't copyright, someone can upload on commons the photographies from these Italian sites about the most important protagonist about that disaster: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18. Thank you very much. --87.14.24.94 12:55, 21 September 2019 (UTC) — Preceding unsigned comment added by 87.14.24.94 (talk)

Height of the wave

Hi, I recently repeated the claim that the wave overtopped the dam by 250m which is given in the introduction to the article and a photo subtext on Reddit, but another user pointed out that there was never such a wave. As you can see in this simulation https://www.youtube.com/watch?v=NK2T_ICe8v8 the water washed up the hill on the other side 140-250m, but didn't overtop the dam by such a substantial amount. I'd like to ask some more experienced wikipedian to correct the error, because I fear to destroy the layout should I try it. Best regards 2001:16B8:265A:9E00:A5E3:959B:A130:27E2 (talk) 23:42, 13 October 2019 (UTC)

Category:Dam failures in Europe in Vajont dam

Please make sure that the Category is re-inserted after it is (hopefully) created following Wikipedia:Articles_for_creation/Redirects_and_categories#Category_request:_Category:Dam_failures_in_Europe. A totally unrelated user gave me the link to the requests page, which should have been included in the edit summary of you deleting the Category.

This is it for now, I am returning to my Wiki Break. I virtually created one article, improved three, two of them substantial, during a time of >~6h, including lectorate more like 12-18h. For that trouble, registered Wikipedia users couldn't even be bothered to create a category that already contains 10 pages or point me to the Creation Wizard.

Now I know again why I left Wikipedia all those years ago. Thanks for reminding me again. --2003:C8:4714:600:49CE:C61F:D371:4268 (talk) 22:07, 11 January 2021 (UTC)

The Northern Italy Vajont Dam

Why is it not mentioned that The Design Engineer CARLO SEMENZA's decision to keep the reservoir depth at 450 Feet NOT FOLLOWED ??????????? 107.77.234.112 (talk) 13:54, 1 February 2022 (UTC)