MOSE cleaning day/year/decade, and more

One morning not long ago I noticed this unusual bit of traffic trundling along toward San Marco and onward to the shipyards at Porto Marghera.  This grotty yellow object was instantly recognizable as one of the caissons that form the MOSE floodgate barriers.

As you may recall, they are fixed to the lagoon bottom and raised when needed — “needed” being a word now open to unexpectedly large definition.

More than ten years have passed since this caisson was installed.  This is more than enough time for masses of mollusks to attach themselves to the convenient metal surfaces.  This fact has been bothering the people in charge for a while, in part because the extra weight the creatures add is a potential problem to the functioning of the caissons.  For lovers of statistics, this caisson is 20 meters (65.6 feet) wide, 9 meters (29.5 feet) long, 3 meters (9.8 feet) high, with a total weight of 350 tons.

The MOSE floodgate barriers were raised for the first time on October 3, 2020, to great amazement and jubilation, and have been raised 60 times in the following three years for a total cost of 10 million euros.  (That’s what it cost to raise them, not to build them.)

Expensive?  Not really, when we now read that cleaning and maintaining them (a process that began last year) is estimated to cost 63 million euros per year.  What?   It turns out that this is the sum allocated per year for cleaning; if each gate costs one million to clean, and let’s say optimistically that three could be cleaned per year, it’s unlikely those funds will be exhausted any time soon.  Unless other problems were to present themselves, of course, which could totally happen.

“Maintenance of MOSE 189 million arriving for three years.” (May 6 2022).  That seems to be where 63 million came from; that’s the amount that earmarked for each year.  But as we see, that will never be spent per year if only one or two or even — dream on — three gates were cleaned each year.
I can’t keep up with all these numbers.  “MOSE: One million to clean each gate” (Jan. 19 2023).  That sounds normal, at this point.  But that would mean a total of 78 million over the next 26 years.  Any financial forecast stretching that far into the future is bound to be fanciful.  You see how the pixie dust makes it hard to see anything clearly, much less understand it.

MOSE figures always sound extreme.  All these millions of digits fall from myriad bank accounts like cosmic pixie dust on poor old spavined, rumpsprung Venice and its spavined ledgers and reports and endless requests for yet more money.

We are long since accustomed to bulletins involving millions of euros. Here’s one example: “538 million arriving to finish MOSE” (December 3, 2022).  It sounds like a lot, but you can be sure it will turn out not to have been enough.
Or this: “MOSE one million in four days to defend Venice” (Nov. 25, 2022).  That was an unusual period of frequent high tides, and that was still when “one million” sounded like a lot.  By now it sounds like a fire-sale bargain.
“Ten million spent in two years to raise MOSE” (June 29, 2022).  Okay wait — in November it cost only one million to raise MOSE four times.  So this must mean that in one year it cost five million…no wait, ten million divided by 211,000 (the cost of each raising) is 45 times.  But they were raised 60 times.  So 60 times 211,000 is 12,660,000.  Pixie dust!

But back to the repairs.   The caissons languished underwater for 11 years, accumulating crud, until July 5, 2023, when the first of the 78 caissons was taken to the shipyard of Fincantieri in Marghera for spiffing and fixing.  So far, though, only three have been cleaned.  The work  can be done only in the summer because that’s when high water is usually doesn’t occur.  At this rate the last gate will go through the process in 2050.  Time to start over.

As for cost, Fincantieri has estimated that cleaning and repair will cost more than twice what it cost to build them.  Awkward.  And of course that number will change, by which I mean increase.

But money well spent, yes?  In the three years since the inaugural gate-raising, the barriers have been raised 60 times, for a cost of 10 million euros ($10,850,875).  All those digits!  Pixie dust!

The “mouths” are clearly visible here; they aren’t all the same width, hence the caissons aren’t all the same size.  Bit of not-actually-useless trivia.
This photograph shows the stretch of yellow barriers raised across the northernmost of the three inlets to the lagoon.  Each inlet is called a “mouth of the port” (bocca di porto), and here the “mouth of the Lido” is divided by a constructed island into two sections.  The lower is referred to as Treporti and the farther is San Nicolo’. (ytali.it, unattributed image)
Perhaps this detail makes the positions clearer.  We are looking south, with the Adriatic on the left.

A recent inspection — the Gazzettino reports — revealed that the condition of the 20 caissons at Treporti is “good.”  But inspection has yet to take place on the 21 at San Nicolo’, the 19 at Malamocco, and the 18 at Chioggia.  No telling when those inspections will be made, and there’s even less telling as to when action will be taken on whatever is found.

The simoom of pixie dust from the Accounts Payable department also blows from the zone of the jack-up.  This is the rig that was built to raise and transport each caisson to the repair shop and back.  It cost 53,000,000 euros ($57,000,000).  But after years of construction and repairs and what-not, in 2014 it was discovered that the jack-up wasn’t yet ready for work, and it still isn’t, ten years later.

The jack-up has been living its best life for years moored by the Arsenal.  At the moment, not only is it not working, it’s in the drydock by the huge crane.  I made this picture in 2017.  It has remained there since then, on its way to becoming another Venetian monument.  In all fairness, it’s clear that if the gates weren’t scheduled to be removed for cleaning, there wasn’t anything for the jack-up to do but sit there, accumulating its own crop of mollusks and algae.
The jack-up in drydock.  I took this picture a few days ago.  No news about how long it will be there, or what they’re doing, or how much it will cost, or anything.

But not to worry, there is the “Cavaletta” from the Fagioli company that does the same job as the jack-up and costs less.  Wait, what?

Here the “Cavaletta” lifts the detached caisson before loading it onto the platform to be towed to the mainland.  This construction is ideal for the task at the Lido, but can’t be used at Malamocco because the caissons there are too long for it.  So the jack-up will have to be used, whether it’s ready or … not?

When MOSE finally got to work in 2020, the authorities stated that it would be raised when the tide was forecast to reach 140 cm above mean sea level, a category listed as “exceptional” acqua alta.  But after the first few times the gates went up and the water in the canals did not even reach the streets, I could sense what was going to happen.  And it did.

Nobody wanted water underfoot anymore.  So we heard that the gates would be raised when the forecast was for 130 cm maximum height of tide.  Then when it was for 120 cm.  It has just been lowered yet again to 110 cm.  It’s like an auction in reverse — the prize goes to the lowest bidder.

At this point, why not just pump all the water out of the lagoon, and be done with it?  Save everybody so much trouble — and money!

But doubts have always been raised, and they continue to be raised, concerning the system’s short- and long-term prospects, the effect on the lagoon, costs (of course), and also how inconveniently illegal these recent gate-raisings at lower tide levels actually are.

To summarize and give some perspective is a letter (translated by me) written on October 10, 2024 by Andreina Zitelli and re-published on ytali.it.  I’m leaving the link in case you were to be interested in reading other articles/opinions by her, though they’re mostly in Italian.

“MOSE inadeguato.  Come volevasi dimostrare”  (MOSE inadequate.  As one wanted to demonstrate)

Dear Director,

It emerges clearly from the last meeting of those responsible for its management that the Experimental Electromechanical Module (Mo.S.E.) — not by chance that the opinion of the national Environmental Impact Statement of 1998 was and remains negative — is not the system that can provide for the safeguarding of Venice.  Mo.S.E. was designed to block the “exceptional high waters,” not to regulate the lower and medium high tides that progressively invade the urban areas of the islands.

The conflict between the Port and the City was also one of the critical elements at the base of the negative opinion, a conflict, for that matter, stressed also by international experts.  Finally, from the environmental point of view the frequent closures are in conflict with the needs of the exchange between the sea and the lagoon.  The conflict between Port, City and Lagoon can’t be resolved with Mo.S.E.

Just for mood.

As part of the Evaluation Group that expressed the negative opinion of the national Environmental Impact Statement on the Mo.S.E. project, I feel obliged to remind those who today are concerned to safeguard Venice from the high water at or below 100 cm that:

  1. MoS.E. isn’t the system to defend Venice from medium-low and medium-high water;
  2. the height of 110 cm — established by the decisions taken in the political quarters — cannot be regulated by the closing of Mo.S.E. (it was one of the principal reasons for the negative opinion) for the fact that the variability of the phenomenon and the problems of the forecasts cause operative uncertainty;
  3.  The model forecast of the 110 cm height falls within a reliable interval of +/- 20 cm from the tide forecast.  To shorten the time for deciding (whether to raise the gates or not, N.B.) causes false alarms and leads to discretionary operative decisions, if not even to false closures;
  4. For these reasons it is even more unacceptable to maneuver the Mo.S.E. at tide heights even lower than 110 cm;
  5. The height of 110 cm — as the Opinion put forward — entails such uncertainties as to render useless and damaging for more functional, environnmental and economic aspects, entrust to Mo.S.E. the defense of the City from the medium tides;
  6. the increase in the cases of high water, connected to more frequent tides of low-medium size, aggravates the incompatibility of Mo.S.E. toward the urban, port and environmental object of Safeguarding.
  7. The lagoon is just as complicated as Venice is.  Just a thought to ponder.

There is also an aspect that’s hardly secondary to consider.

The quota of 110 cm isn’t part of — as comprehensible also just by common sense beyond the conclusions of the study of the series of the phenomenon — the category “exceptional high water” referred to by the Law 798/84….

The closings of Mo.S.E. that are not aimed at regulating exceptional high water are to be considered against the letter of the law.

Of the discretional use of Mo.S.E. beyond the purpose established by the Law 798/84 the Public Prosecutor of the Financial Court should intervene for the accounting aspects of the extra costs that are certainly not attributable to harmful situations for which is would be possible to make an exception.

I realize MOSE is supposed to help the city, but it isn’t doing anything to help the lagoon.

Further, it should be remembered that Mo.S.E. has not yet demonstrated the capacity to keep up with a real and serious exceptional high tide that could have a catastrophic result, a result that can’t be excluded.

It also remains to consider the difficulty of assuming the decision of closure in the face of extreme weather and tide conditions in the absence of procedures that define the operational limits of the maneuverability and closing of the gates of Mo.S.E. in extreme conditions.

Who will take the responsibility of closing in the absence of a defined procedure?

Other and wider actions and interventions at the territorial level were planned, beginning with the reduction of the depth of the maritime canals and the “mouths of the port,” to realize diffuse urban defenses (as proposed then by Venetian engineers and architects) to join numerous experiments of raising the ground, to regulate the water coming from floods on the mainland.”  That is, as everyone knows, many other solutions were proposed to defend the city from acqua alta, but MOSE steamrolled them all.

I could go on, but that’s enough.  So let’s conclude that MOSE needs to be cleaned and maintained, nobody can be sure it’s going to keep working if it continues to be raised far more often than predicted, and it will cost craptons of money forever.

A glimpse of the future?  I can’t know if this person is being sarcastic or prophetic.

You may also like

10 Comments

  1. Thank you for describing a costly and frustrating situation with literary wit and style… and pictures!

    How have a I lived in the middle of a desert for 19 years without knowing the useful word “simoom”? We do use the Arabic word “haboob”, but simoom escaped us.

  2. Hi Erla,
    Always so informative as well as entertaining, thank you.
    The type of auction you mention is known as a Dutch Aiction, or auction of descending price.
    How they sell all those flowers in Aalsmeer!

    1. Thanks, Annabelle. I love knowing things like this. I wonder why “Dutch” gets attached to various things (you must know the list by heart).

  3. Many thanks for this, Erla….it’s reassuring that you are on the evaluation committee. Oh wait! whose committee?

  4. Intriguing email showing much work in bringing the (illustrated) facts together as well as sane comments as to the whole business. Your work is much appreciated. I suppose it naive to wonder why the caissons cannot be cleaned in situ by raising and scraping (or whatever one does with mussels) as much as possible above water and using divers to scrape below. Cheaper, but I assume not possible.

    I was unaware of the Treporti/San Nicolo made-up island between the entrances so that was very helpful especially with illustrative confirmation. Next time I get to Venice I shall look more closely.

    Thank you for sharing your thoughts on your choice of matters pertaining to Venice. I always read each one and very often file it away for future reference – as this one will be.

    1. Thank you, Hugh. Your appreciation is hugely encouraging. There are undoubtedly problems with maintaining/repairing the caissons that are not necessarily related to mollusks. The caissons are lying in salt water, hence corrosion (some anti-corrosion materials, such as those containing zinc, are outlawed by European environmental laws) and undoubtedly some deterioration from the mechanics of being raised and lowered (my supposition). If indeed the only work to be done were to scrape off bivalves, experiences leads one to suppose that they would almost certainly come up with an expensive and time-consuming method for dealing with it.

  5. Thanks, Erla, for this somewhat more frustrating post. Public spending is indeed an interesting subject and nothing seems easier than spending other people’s money. I must admit that I, as an engineer, was quite fascinated by the idea of the MoSe gates at first but I realize now that it wreaks havoc with the fragile environment. My bad!

    1. I suppose it’s an occupational hazard for engineers, who are focused on solving problems and not on thinking about how to avoid creating new ones. It seems to me, intending no offense.

  6. I remember when MOSE was first started, suspecting it’d be a white elephant amongst the many other expensive white elephants “they” dream up.
    Very thoughtful and well-written accounts. Thank you again.

  7. No offence taken whatsoever. Occupational hazard it is. Solving problems is fun, thinking of possible side-effects is less fun. Therefore one sometimes ends up with a solution in want of a problem.

Leave a Reply

Your email address will not be published. Required fields are marked *