Archive for March, 2010

Having reviewed the  barest  basics of acqua alta, and the barest technical outlines of the “floodgate” project intended to keep Venice as dry as the Nebraska Sand Hills, I’d better warn you that not everybody is on board.  

“This is a way of funneling a huge amount of money to business allies of the government,” a city councilor told The Christian Science Monitor last year.   “There are better alternatives but they were never considered.   There is a big question mark over whether it will really work.”

So has anybody spoken up?   Only thousands of people.   The project been protested, sued against, blocked and stalled in all sorts of ways for 30 years (yes:   it’s taken three decades to get this thing to where it is today), and even now  the arguments pro and con continue to be lobbed back and forth between the opposing believers.

1x1.trans MOSE: yes?  no?  maybe?  dont know?

Construction proceeds at the inlet at San Nicolo, the one closest to Venice. The artificial island in the middle, built to accommodate construction equipment, has already affected the tidal flows. It will not be dismantled.

There have been a few times when it appeared that perhaps the project would be annulled for various reasons: lack of money, the bizarre absence of the required Environmental Impact Statement, legal loopholes that kept being found and then quickly closed.   But nothing has been able to stop its  implacable progression toward completion.   It’s like throwing gravel at the Kraken.

By the end of 2009, despite all the myriad stops, starts, and slowdowns,    63 percent of the project had been completed.     There isn’t enough money to restore historic palaces and churches which are visible every day, but somehow money has been found to block exceptional high water, an event which might occur four to seven times a year.   Or maybe not  at all.   You may have noticed that the weather is not operated by the  Swiss railway system.  

But doesn’t everybody in Venice want to save their city from the sea?

In a word: No.   At least not everybody in Venice wants this to be the way to tame the tides.   In fact, it is difficult to find anyone who is not directly benefiting from the project who thinks it’s a good idea.   Quite the contrary.

There are four general categories to which most objections belong.  Let’s look at the them:

Political:   Not much to say here, because this is a sphere in which nothing is ever resolved.   The political fortresses from which accusations have been hurled like stone cannonballs are very well defined: right, left, extreme right, extreme left, and a mass of foot soldiers in the middle with all sorts of commingled ideas.   But if you don’t belong to some group, nobody will ever listen to you (not that they listen so much anyway).   Only thing is, each group has an agenda which includes lots of other issues as well, so if you join one to reject the MOSE project, you could find yourself on mailing lists as being against a batch of other undertakings as well.   Maybe you’re not against those, maybe you don’t even care.  

1x1.trans MOSE: yes?  no?  maybe?  dont know?

The lagoon has no idea there is a famous city sitting out there somewhere.

Others point out that the Special Law for Venice, by which federal funds are earmarked for the city,  specifically authorized interventions to stop pollution and re-establish the morphologic equilibrium of the lagoon.   It doesn’t appear that MOSE will  satisfy  either of those requirements.   Au contraire.

Even more important, each side considers it a good day’s work if  it has  managed to frustrate or thwart the other.   No other result is really necessary.   This reality is the cholesterol in the political metabolism, hardening and constricting the arteries through which ideas and energy and good will might otherwise have flowed to produce something beneficial to the organism (the city and the lagoon) as a whole.  

Economic: Every enormous public work since the Great Pyramid of  Cholula (and perhaps even that one) has exceeded its projected cost.   The original date of completion was given as 2010.   This has now moved to 2014.   Hence the costs have also changed.   MOSE was budgeted at $4.5 billion, more or less, depending on whose estimates you follow, a number which it has now overtaken without even slowing down to wave.   In 2008, the cost had risen to $7 billion.  

There is also the  cost/benefit aspect to consider.    I think it’s fair to say that anyone who is not personally involved would  concede that the costs and the benefits of this colossal undertaking do not come anywhere near matching up.  

One foreign  newspaper reported that $30 million a year is lost in business each time  the Piazza San Marco floods (meaning that these 40-some  shops can make $30 million in six hours, when the tide is in?   Wow…. ).   But let’s say acqua alta does cost $30 million, even if that number is cited only by the people  who would benefit from the effects of such a prediction.

MOSE, as already mentioned, not only has cost $7 billion by now with 35 percent  and two more years to go.      Few if any mention is made of the estimated cost of annual maintenance of this behemoth: a mere $11.5 million.  Of course, this  will be eternal income to the interested parties.  The project will be finished, but maintenance is forever.

1x1.trans MOSE: yes?  no?  maybe?  dont know?

Plenty of people would like to keep living here, if they could. But to the locals, it can seem like it's one of the great forgotten cities of the world.

But that isn’t the crux of the objections to its price tag.   Simply put, it’s that money dedicated to MOSE is lost to anything else.  

Stories which focus on the cost/disturbances inflicted by a few hours of water on the ground don’t tend to refer to the financial scorched earth the MOSE project has  made of  the quality of daily life for everybody everywhere  in Venice, not just the shopkeepers around San Marco.   Paying for this project, which might bring a temporary benefit to the city a couple of times a year,  has  deprived the city of the money required for numerous, more humble needs  (schools, ambulances, restoration of monuments and private buildings, etc.).

Just about every facility or service which  is important  to city life, more important  than the occasional need to put on the Wellies, has been cut in some way.   The administrations’s constant cry “We have no money” tends not to explain why.

Environmental:   When UNESCO designated Venice as a World Heritage Site in 1987, it specifically  included the entire Venetian lagoon.   It is the second-largest wetland in Europe (Europe has lost 2/3 of its wetlands in the last 100 years).   It is  vital area for plants, fish,  and birds,  some of which are already endangered.   Every year some 200,000 birds winter, nest, or pause here in their twice-yearly migrations.   One could make a reasonable case that the lagoon has a value which rivals that of Venice.  

Local, national and international environmental groups have  raised countless alarms about the effect of this project on the lagoon environment.   Prominent among these are  the World Wildlife Fund, LIPU (the bird people), RAMSAR (international wetland protection), Italia Nostra, and more,  down to a local citizens’ group called simply “NoMose.”  

In one of many reports, Italia Nostra summarized its concerns: “The dams will render permanent the Lagoon’s environmental imbalance: The deep channels dredged in the last century through its outlets will become concrete.   The erosion that is now eating away the Lagoon’s precious wetlands would become permanent, and this rich coastal lagoon, protected by European law, would be transformed into an area of open sea.”

1x1.trans MOSE: yes?  no?  maybe?  dont know?

What is so elegantly called a cavaliere d'Italia (knight of Italy), in English is merely the black-winged stilt. Still beautiful, though.

The deepening of the channels to accommodate the cement frame for the caissons has already intensified the tidal flow — I can see and feel it every day.    Faster and stronger tides mean many things: More erosion of the bottom sediments (one of the defining characteristics of a lagoon environment), consequent damage to the eelgrass which serves to anchor the sediment and which provide a habitat for many small marine species, and so on up the chain.  

1x1.trans MOSE: yes?  no?  maybe?  dont know?

My favorite of many favorite ducks is a wintering species called a "tuffetto" (little diver). Their arrival and departure are parentheses around the winter.

There is also great concern about the physical impact of the materials used, specifically the caissons’ zinc plates (zinc is forbidden by European law) as well as the anti-fouling paint, which contains many toxic chemicals  such as TBT compounds, assorted heavy metals, and solvents.   Coats of anti-fouling paint have to be periodically renewed, so that will contribute another dose of this stuff to the environment.   Damage to the lagoon and the Adriatic is seen as virtually inevitable.   I must mention that the builders deny this.

Data and forecasts which justify the project have been questioned by many different sources.   Some of the data does not appear anywhere but in the builders’ documents.

Engineering: Plenty of engineers from assorted countries, those who are not directly involved in the project, have always voiced doubts about whether it’s likely to work the way it’s supposed to.

1x1.trans MOSE: yes?  no?  maybe?  dont know?

Another perspective on the system, which clearly shows the the caissons fitting snugly together, forming a perfectly even wall. It will be great if nothing shifts or leaks.

 Some of their concerns are:  

  • It has never been completely tested.  
  • The only positive assessment rendered by an independent panel of engineers was  restricted to saying whether the design could function as intended — that is, whether it would work as designed.   Virtually all other independent evaluations have been extremely cautious, if not negative.   No engineers except the builders, to my knowledge,  have risked saying whether it should be built.   Maybe that’s not what engineers are supposed to do.  UNESCO wrote an analysis in 2003 which concisely evaluated the project’s drawbacks, including the meteorological predictions on which it is based.
  • There are discernible aspects of the design which must ALWAYS function PERFECTLY (difficult in a salt-water environment),or they won’t  perform the way they’re supposed to.   For one thing, there is a high risk of the seal between the caissons not being watertight.     If water begins to pass between the caissons,  the wall they form could be dangerously compromised (fancy word for “weakened”).  If the caissons for any reason do not align perfectly, ditto.  
  •  If for some reason encrustation of any sort  remains on the caissons and/or their anchoring hinges  (salt-water is great for fostering encrustations of minerals and critters), the barrier may not rise in the manner or at the rate necessary.  
  • If sea-level increases fulfill the darker prophecies, not only will the caissons have to be used more often and kept in place for longer periods of time than predicted (undergoing stresses for which they were not designed), but eventually their maximum height may not be enough.  
  • After decades of legal battles, the design was already obsolete before construction even began.   Thirty years is an eternity in engineering terms.  (Imagine buying a car designed 30 years ago.)   Whatever its flaws, it should have been modified or updated in some way by now.   But no.

Perhaps most important, critics point out that this titanic construction  flouts several principles sacred not only to the hydraulic engineers of the Venetian Republic (not exactly amateurs) but also to commonly-accepted principles of environmental and engineering prudence.   Those principles are:

  • The project should be gradual, to permit evaluation of the results obtained at each stage and, if necessary, permit changes to the original plan.   This obviously isn’t the case here.
  • The project should be reversible.   MOSE obviously isn’t.
  • The project should be experimental.    By “experimental” the Special Law clearly intends that a project should be tested experimentally before it is definitely approved and funded and built.   That never happened.

How did this project ever get approved?

I can’t swear that I know.   Here is what I do know: That the project was assigned to the Consorzio Venezia Nuova,  a consortium which the city has exclusively authorized  (some have used the word “monopoly”) to  intervene in the lagoon.   This consortium is made up of more than 20 Italian engineering and construction companies — in a word, businessmen.   Scientists who promote or  defend the project are often consultants for the consortium.

So here we are.   It’s too late to be any use, but I’d like to recall a comment by Wendell Berry, the farmer/writer/environmental critic.

“A good solution to a problem,” he said, “is one which does not create new problems.”  

Seems kind of obvious, when you think about it.

Next:   How will it all come out?

Categories : History, Nature, Problems, Water
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Now  that I have pounded the subject of acqua alta into unconsciousness, you may be wondering if there are any solutions.   It’s not unreasonable, I guess, to want to suppose that there could be some action(s) that would limit or even prevent water from inconveniently covering your street, even for only two hours.

Certainly many of the articles which continue to appear, year after year  — there must be a workshop in a cave where some crazed Geppetto keeps producing stories on how Venice is being engulfed — tend to make it sound as if   Venice’s health and future happiness depends almost exclusively on keeping the water out.

1x1.trans Acqua alta:  MOSE will fix everything

This is not acqua alta, it's just acqua.

So let me urge you, before we continue, to disregard, as far as you can, the drizzle of extravagant statements drenching almost every article about this project.   Such as comments by journalists in love with their clever way with words (“…soaked Bruno Maglis have become more the rule than the exception…” You’ve got money for Maglis — or for  any kind of shoes —  but you haven’t figured out that you can  take them off to keep them dry?   Wow… And by the way, it isn’t true),  or this, by an Italian professor of physical oceanography at MIT:   (“”The gates are really the only solution.”   Really?   The only?), or the  claim that high water really, really distresses the old people.   All the old people I’ve ever talked to are the ones who make the least fuss about it of anybody.    

The good news: There is no lack of useful and feasible ideas on how to limit or prevent high water in the city.   In fact, we have been inundated by a plethora of proposals, many of them simple, easy, not damaging to the environment and cheap.

The bad news: Only one solution has been chosen, and it is none of the above.   Sometimes referred to as the “floodgate project,” this savior is called MOSE.   It is  the biggest, most expensive, most drastic, most irreversible, heaviest-impact-on-the-lagoon-as-a-whole solution  that anyone could have imagined.    I say that because if  there were a solution that could have been more drastic and more expensive,  they would have picked that one instead.  

What is it?

MOSE stands for Modulo Sperimentale Elettromeccanico, or Experimental Electromechanical Module.   It consists of a sequence of a total of 79 steel caissons — boxes, really —  lying on the lagoon floor, which can be raised to form a wall which will block an exceptional incoming tide.

Where is it?  
1x1.trans Acqua alta:  MOSE will fix everything

A view from the Adriatic, looking over the Lagoon and the three "mouths," or inlets, through which the tide comes and goes every six hours. (R to l): San Nicolo, Malamocco, Chioggia.

The Venetian lagoon is enclosed by a long strip of barrier islands which block the Adriatic Sea except at three inlets (called “bocche,” or “mouths”) through which the tide passes every six hours, coming in or going out.   This exchange of water is crucial to the lagoon’s ecosystem.

How does it work?  

Each of the three “mouths” of the lagoon has been dug to  accommodate a  concrete frame installed on the bottom and sides of the channel.   Attached to this frame, by means of hinges, are the aforementioned 79 metal boxes which normally will lie on the channel bottom, filled with water.    

1x1.trans Acqua alta:  MOSE will fix everything

These diagrams show the steps involved. Note that one caption states that there 78 of these caissons; there are 79.

If an exceptional high tide is expected (or more than 110 cm [3 1/2 feet]) above median sea level, the water will be pumped out of the boxes  and compressed air pumped in which  will cause them to rise up and form a wall preventing the water from entering the lagoon.   When the tide subsides, these caissons will be filled with water again and they will return to their dormant state on the inlet floor.

When will it be used?

The job of this colossal construction is to prevent — not just any high tide, but  an exceptional one — from reaching the city.    The frequency of a tide of this magnitude is predicted by the city as being  four times a year.  

Therefore, any high water up to 110 cm is going to come ashore just as it always has, and we will continue to break out the boots and merchants in low-lying parts of the city will continue to stow their merchandise and  keep their squeegees at hand to sweep the receding water out the door.   Their keening laments will also be primed and ready to go.

Who thought this up?

As with many large public works, it is the love child of politicians, engineers and  builders.  In this case, an assortment grouped together as the Consorzio Venezia Nuova (New Venice Consortium).    These are not lagoon-huggers.   Many of its members are in  business, often doing the sort of work that MOSE requires.

1973:   The Special Law for Venice is passed, which declares the city’s welfare to be of “preeminent national interest.”  

1975:   The Ministry of Public Works announces an international competition  for project designs which would limit high water.   Five projects are accepted for evaluation.

I will leap ahead here and spare you the year-by-year chronicle of yes/no, he said/she said, did so/did not, claims and counterclaims.   It’s like Jarndyce and Jarndyce.   A full account of this 30-year struggle would be a ponderous assortment of lists of names and companies and government agencies and ministers, environmental organizations, suits and countersuits at every level, from Venice itself to the European Court of Justice in Luxembourg.    By now, the only people in the world who have not been involved in this in some way  are you and me.    

By now, 63 percent of the work is finished.   But the controversy is still very much alive.

Next: Why everybody isn’t excited about it

Categories : Nature, Problems, Water
Comments (1)

Here are two elements  of high water  which aren’t usually — perhaps not ever — mentioned, much less interpreted, in the typical story, the kind that likes using emotional words like “invade.”    ( As in, “The water invaded the city.”   Stormed the battlements.   Conquered the kingdom, wrought havoc, death and destruction, setting towns to the torch and sending everyone into slavery.   You know, the usual high-water scenario.)   Where was I.

1x1.trans Acqua alta: reviewing the basics II

Venice is not sitting at mean sea level. That wouldn't make any sense.

One is what the numbers actually mean.   Venice does not float like a lily-pad at sea level.   The lowest area in the city, the Piazza San Marco, is already 80 cm above the water’s surface when the water is at mean sea-level.   Therefore any height that’s reported isn’t as high as it sounds if we were just standing on a street somewhere, measuring upwards from our feet, because the starting number isn’t zero.  

Example: 110 cm converts to three and a half feet, which sounds scary.   But someone standing in the Piazza San Marco will have water reaching up only 30 cm from their feet, or roughly just below their knees (11 inches).   Someone elsewhere in the city might well not have it even that high.   Or at all.   Because of Point Number Two.

1x1.trans Acqua alta: reviewing the basics II

Surf's up near the Rialto Market by the eponymous bridge. Just behind me there's no water on the ground at all, except for some rain puddles.

Point Number Two:    Headlines blaring “VENICE IS FLOODED”   imply that the entire city, all three square miles of it, is going under for the third time.   In fact, a tide up to 110 cm will dampen 14 percent of the city.   Not a huge percentage, I think one must admit.   Up at 140 cm (the relatively rare Code Red, “exceptional high water”), it covers  almost 50 percent of the city, which is more impressive, except that the frequency of a tide this high is fairly low — five times in the ten years between 2000 and 2010.   And still, one isn’t referring to every square inch of Venice.   Amost half of the city is still high and dry.

For all of Venice to be flooded, the tide would have to rise well beyond 200 cm (the epochal acqua alta of November 4, 1966 reached 194 cm).   The city’s tide office doesn’t estimate above 200 cm, at which level 86 percent of the city would be underwater.   I don’t say that would be entertaining, but it would be so rare that I’d suggest saving the doomsday vocabulary for it, and not waste the drama on more mundane tidal events.

1x1.trans Acqua alta: reviewing the basics II

This is the only example of this extreme solution to acqua alta I've seen so far. What it implies to me is that whoever owns this property isn't expecting to be available to sweep out any water. Or that whatever's inside is so valuable that it probably should be in a vault somewhere. My own experience leads me to wonder if a seal this tight wouldn't potentially force the incoming water up inside through some hitherto unnoticed crevice.

Our little hovel is  safe up to the three-tone level.   At four tones, it’s time to take the tarps off the lifeboats.   We discovered that last December 1 at about 9:15, when the water reached the four-tone level and began to slide under our front door.   Then I discovered it was also coming through a fissure in the wall under the kitchen sink, as well as up through a fissure in the stone flooring.   That was more  exciting than almost anything I can remember.   So please don’t suppose that my viewpoint is the result of my  not having to worry about water under the bed.   I just want to   recalibrate the popular  perception of this phenomenon.   Obnoxious.   Not catastrophic.

We have a calendar, on sale at any newsstand,  which traces the predicted tide levels each day of the year.   But those are only estimates based on what’s normal.   For more timely updates, I check the data on the city’s Tide Center website.     You can also sign up to be alerted of the rising tide via text message (SMS) on your cell phone.  

All these advisories are what make it really hard for me to feel sincerely sorry for anyone who might find that water  had caused any  damage to goods or appliances.   It’s not like it comes like a thief in the night.

I leave you with the key phrase which ought to simplify the whole business if you’re here long enough to need to know it:   Hip waders.   Just do it.

1x1.trans Acqua alta: reviewing the basics II

The fact that the pump is working demonstrates the limitations of the barrier across the door. However, it's clear that without the barrier things would be much worse. I assume he's doing rough calculations of the power of the pump relative to the speed of the rising tide.

Categories : History, Nature, Problems, Water
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Mar
08

Acqua alta: reviewing the basics I

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Let’s start with the most basic fact of all: Venice is sitting in the middle of a tidal lagoon.   This means surrounded by water that rises and falls.    I don’t mean to keep harping on this, because I know it sounds  really dumb,  but not much  dumber than all those stories that get published and broadcast that make it sound as if water on the ground here were stranger  and more upsetting than four sharks singing “Shine On, Harvest Moon.”  

How high the water  will rise might vary from the official  prediction based on a few factors, but when it’s looking imminent I’ve definitely got at least one eye on the barometer, the wind sock (on the computer) and the moon.   Wait, that makes three eyes.   Well, you know what I mean.

1x1.trans Acqua alta: reviewing the basics I

This shopkeeper near the Piazza San Marco is keeping his high-water records this way.

Data on the tides began to be recorded regularly after an exceptional high water in 1867 (153 cm above  average sea level).   In 1908 various monitoring stations were installed to more precisely measure  the height of the tides, and in 1914 the pertinent data on the barometric pressure and the direction and force of the wind were added.    

For events longer ago, historians can only turn to various chronicles and accounts in which the quantities aren’t always easy to assess.   As in: “The water rose high enough to ruin the wells.”   A flooded well would, in my view, be much more distressing than some water on the floor, seeing as the supply of fresh H2O in Venice was not infinite.

The main high-water factors are the following:

The season.   If  the acqua is going to be alta, it will usually be between September and April.   Articles which refer to  its frequency  are often misleading  because they use aggregate numbers which give the impression that it’s a monthly occurrence all year long.   While there might be pesky clusters of high water events in winter (as happened this year), the likelihood plummets to June; it has never been recorded in July and August.  

Phase of the moon.   The tides are highest and lowest when the moon is full and when it’s new.  Actually, the moon is the only component to this phenomenon which isn’t even the tiniest bit likely to swerve from the forecast.  

Atmospheric pressure.   When it’s low, the water is high.   When it’s high, the water is low.   If we tap on the barometer and see that it’s gone to the bottom of the scale, there’s no getting around the likelihood that the water will be high.   The barometer won’t tell us how high,   but we can look out the door and make a guess.     A barometer is a great friend to have because it cannot tell a lie.

Wind.   If the scirocco is blowing, it will definitely aggravate the situation.   The  scirocco is also  obnoxious  because it’s warm and humid (get one blowing in the summer and you’ll wonder if you took the wrong exit and ended up in Amazonia).   But as it’s from the southeast, it will blow into the lagoon and — putting it very simplistically — push against the tide and prevent it from going out in a timely and efficient fashion.   On the contrary, it seems to work very hard to keep all the water in the lagoon all at once.   I try to avoid anthropomorphizing the natural world here, but I have to say that sometimes it seems like  the wind just does it on purpose.

When a strong scirocco is blowing, I don’t hear wind so much as I do the heavy surf rolling up in close-order-drill on the Lido’s Adriatic beaches.   It’s a deep, rumbling sort of roar off in the distance, impossible to mistake for anything else.  

1x1.trans Acqua alta: reviewing the basics I

Yes, the water is rising in the Piazza San Marco. But the owner of the cafe clearly is not too concerned, otherwise he wouldn't have bothered setting up all those chairs and tables.

There is a warning system to alert the city that within an hour, water will be  rising  in the Piazza San Marco (the lowest point in the city) and, by extension, at other various low-lying areas.    This information comes from a monitoring system at the mouth of the lagoon at San Nicolo, and at other points in the lagoon.  

Until two years ago, the citywide warning system  was a few  sirens which emitted a sequence of rising wails.      The first time I heard them they woke me from a deep sleep in the middle of the night — a sudden violent tone  swooping upward, overlapped by another one just following it, and then by a third.   Scared the hoo out of me — it was like the Three Weird Sisters in Macbeth going mad.

But what they didn’t tell you back then was how much water was going to come ashore.

Two years ago, the system was refined.   Now there is only one  siren-swoop, after which comes a steady tone  which indicates the maximum  predicted height.   One tone = 110 centimeters above sea level.   Two tones = 120 centimeters.   Three tones = 130.   And four tones = 140 and above.   This is what they sound like.   I can tell you they’re very effective.   There may not be any way you can ultimately prevent water from coming indoors, but you cannot possibly say you had no warning.

1x1.trans Acqua alta: reviewing the basics I

This tide-level notice board at Piazzale Roma gives the height of the tide in real time, indicates whether it is rising or falling, and what time the next maximum (or in this case, minimum) will be. And how high or low. Very useful, if you happen to be at Piazzale Roma.

1x1.trans Acqua alta: reviewing the basics I
Categories : History, Nature, Problems, Water
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