The Failed Plan to Save Venice

if you're in Venice back in November 2022 you might have seen these glass barriers they're protecting Mark's Basilica from floods it's a striking measure to combat the city's most pressing problem it's sinking and has been for years but hold on a minute if you've watched this channel before you'll remember that Venice just spent decades building a 7 billion dollar sea defense system that finally started working in 2020. well as this footage shows that big expensive Mega projects isn't turning out to be so Mega so what's the deal here why does Venice still need additional methods to protect parts of the city and if a 7 billion dollar system isn't enough to save it what will people travel from all over the world to see venice's Scenic canals and architecture but the city may not be around to visit for much longer in the worst case scenario experts predict it could be underwater as early as 2100 as buildings sink further into the soil and climate change causes sea levels to rise the city gets a lovely preview of that future every so often when a high tide known as Aqua Alta sweeps in now Venice has pretty much always had to deal with this type of flooding but in recent decades it's become much more frequent and intense and the city is paying the price Venice Italy is suffering its worst flooding in more than 50 years at least two people have died these glass walls are just the latest step in venice's long-running battle to hold back the ocean you see the place is essentially floating on water it's built on top of a lagoon and its foundation is mostly mutt the first settlers lived in houses made of wood and Clay both fairly lightweight materials but as things expanded better engineering tactics were needed to create a stronger Foundation long wooden piles were driven into the ground until they reached hard clay five to six meters down each pile was closely placed together with rock packed in between which prevented the silt from rising from here wooden platforms and stone work were placed on top that worked for a time but by the 16th and 17th centuries the constant flow of sediment from the main rivers flowing into the Lagoon had essentially turned it into a swamp to solve that issue Engineers boldly diverted the around the Lagoon and straight out to sea just a hundred years later the barrier islands that divide Venice Lagoon from the Adriatic Sea were reinforced with a 10 kilometer sea wall an attempt to withstand storms then following the devastation of the 1966 flood the city installed a network of raised walkways 110 centimeters off the ground luckily one startup is already innovating and in a global market that's not currently sinking with today's video sponsored Masterworks almost anyone can invest in high value Contemporary Arts from icons like Picasso Banksy and Warhol and you're doing it for a fraction of what billionaires like Jeff Bezos and Bill Gates pay to purchase fosterworks his team has built a massive art database tracking records from auctions spanning decades they purchased the art up front store it for three to ten years and if the painting sells for a profit you receive your share in fact investors have got a return from every one of masterworks's 11x's to date new offerings are released regularly but there is also a wait list to keep them from selling out to quickly luckily you can skip that wait list right now at the link below now let's get back to Venice before it sinks foreign EST and most expensive flood defense system yet a 7 billion dollar mechanized barrier called Mosaic that promised salvation from a watery fate after Decades of controversy and planning it finally began operating in 2020. here's how it's supposed to work a series of 20 meter wide metal barriers have been strategically placed around the Lagoon's inlets they sit in huge concrete casins that were prefabricated on land then dropped into trenches on the seabed each of these massive concrete segments features a service tunnel that all connects back to land allowing access for inspections when not in use the hollow barriers are filled with water and submerged but when a high tide is forecast compressed air flows into the gates pushing the water out this causes the gates to rotate in their hinges and rise above the surface blocking the incoming tide from entering the Lagoon then when water levels lower again the gates fill back up and drop back beneath the surface allowing ships to pass over the last few years mosaic has stopped a lot of potential flooding that would have previously washed out the city but it has some drawbacks first off construction took ages it was designed way back in the 1980s and was supposed to start working in the 2010s but the system didn't go online for another decade since then our understanding of climate change and its expected effects has evolved massively and the forecasted scenarios that mosa was built for are now outdated so parts of the city still see flooding like Saint Mark's Square which becomes a rather Grand Lake whenever the tide goes more than 80 centimeters above its regular level annoyingly for businesses and historic landmarks City officials will only raise the Mosaic system When the tide hits 110 centimeters brewing in protection for about 86 percent of the city if the threshold was lower the gates would need to be closed 80 to 100 times a year a frequency isn't equipped to handle yet that's why despite a new 7 billion dollar system Venice still has to use glass barriers like this they're five meters long around 1.3 meters high and stop Rising Tides from sweeping into famous buildings each one is fixed onto armored concrete that extends two meters underground and works alongside a series of pumps and valves that prevent backup into the drainage system when it's not flooding there are openings within the walls then when the tide hits they're sealed off it's only supposed to be a temporary measure until something more long-term is devised and the walls and pumps can stop up to 1.1 meters of water something Mosaic isn't optimized to do yet that's right these seven billion dollar system can't keep up with these simple aquarium walls so having waded through all this context you're probably wondering why they don't just lower the flood threshold and raise that big expensive Mosaic thing more often well brace yourself because one of the big reasons they don't do that is that Mosaic is not cheap to operate every time the barriers go up it costs over 320 000 largely going on Power and teams of people you have to send 80 peoples through the Lagoon in order that they are just there in order to manually work on on these machines in order to Pump Air in there and so on so it's not just press of the button but 80 people going out staying there maybe for two days because they have bad weathers weather situation they cannot come back and so on so this makes it so costly to to be clear Mosaic isn't fully complete yet and this cost will probably go down over time it's technically still an experimental mode and is due to finish sometime in 2023 eventually it could be optimized and run with a smaller crew allowing it to be raised more often but that doesn't necessarily mean they'll use it more then remember if you close the Lagoon there is no ships that can pass so you don't have industrial ships you don't have passenger ships you don't have um commercial ships like the The Fishery the Fisher boats they cannot go out anymore or cannot come in anymore with 27 percent of the city's economy relying on these ships pushing back the floods also means pushing away income from trade the system does feature locks alongside its gates to allow some ships to pass but it hugely impacts capacity to make things worse Mosaic isn't a permanent fix jorg estimates the system might be pushed to its limits by around 2050 or 2060 depending on how quickly sea levels rise and how often they need to close the gates he believes there are better longer term options that the city could take like raising everything further above sea level by pumping water into underground Wells there's geologists that were working on these kind of projects and they showed that you can do something that you can raise Venice between 30 and 35 centimeters 30 centimeters just to to make this clear in when we started to measure the the sea level at the beginning at the end of the of the 19th century we fixed the average water level at zero so if you can raise Venice Again by 30 35 centimeters you basically go back into the past by 120 130 140 years raising land like this is something scientists have been considering for years and it's been used in places like Taipei and Tokyo to mitigate sinking and store gas but don't expect to sit in Venice anytime soon critics say that because the city injected so much money into the Mosaic system it's the one they'll have to run with for now at least though that view might of course be forced to change should the waters Truly Come to threaten venice's existence this beautiful city has been in a battle with the very tides that enable its success for centuries often engineering away around the water and finding a path forward but in a world that's now changing faster than ever before it's realizing that billions of dollars and glass sticking blasters simply Aren't Enough the result is one of our planet's most breathtaking cultural landmarks being plunged into an increasingly desperate race for survival that it seems to be losing this video was made possible by Masterworks you can learn more about that at the link below there's also the chance to dive deeper on this and the other topics on our Channel over on the world's best construction podcasts available now wherever you get your podcasts and as always if you enjoyed this video and you want to learn more about where construction is headed make sure you're subscribed to tomorrow's build foreign [Music]

Channel: Tomorrow's Build

Views: 410,198

Keywords: construction, architecture, engineering, Tomorrow's Build, tomorrowsbuild, TomorrowsBuild, tomorrows build, B1M, The B1M, Fred Mills, building, future, venice, italy, flooding, climate change, st. marks square, venice italy, mose, mose system, st. marks basilica, sinking, europe, defense system, infrastructure, glass walls, glass barriers, travel

Id: 4hKXOfQ6JmE

Length: 11min 4sec (664 seconds)

Published: Tue Apr 25 2023