Venice spent 6 billion on a dam to stop the sea. There are those who already see it as the only future left for the Bay of Cádiz

In the first two months of 2026, Venice had to raise its large mobile dock 30 times. In the last five years, he has had to do it another 108 times in total. Nobody can say that the work of 6 billion that was going to save the lagoon has not been necessary; What can be said is that it closes so often that it threatens to suffocate just what protects.

2,000 kilometers away, in the bay of Cádiz, the sea is eating away at the largest tidal-influenced saline wetland in Spain. And the shadow of the great dam begins to hover over the problem. Is Venice the future of the Silver Cup?

Let’s start by x-raying the problem. The sea has been advancing over the bay for decades, that cannot surprise anyone. Perhaps the only thing that has changed in recent years is that salt farmers, aquaculturists, scientists and ecologists have sat at the same table with a common diagnosis. Its ambition is much smaller than that of Venice, but we are light years away from Venice.

What they are asking for is something as simple as the competent administrations coordinating.

Coordinate for what? To prevent a good part of the saline wetland from dying. This wetland is structured around the so-called “outside turns“: soft dikes that stop spring tides and storms.

They are not “natural things”, they are the product of centuries of human work. And when there is someone who maintains them, they endure, they tame the sea, they control the storms. The problem is that there is almost no one to maintain them. Today, around 80% of the salt mines are abandoned; Of the 160 artisanal salt mines that existed in the 70s, four remain.

In other words, what is happening in the Bay is a disaster labeled ‘natural’, but with socioeconomic roots.

The result is clear. In points like the south of Puerto Real, the sea advances about 3 meters a year, according to calculations from the University of Cádiz. And it is now just over 200 meters from the first houses.

A few kilometers from there, 94,000 inhabitants (the people of San Fernando) live below sea level and this protected natural park is their main line of defense. If the estimates of the Blue Bay Alliance They are right and the sea rises between 55 and 70 centimeters, there will be many people who will suffer the consequences. And we will put our hands on our heads and wonder how it was possible.

Then, just then, people will start talking seriously about the wall.

But it will be a mistake. So far no one has asked for the Venetian MOSE and, in fact, the ‘concrete’ that the Alliance talks about is something very different and much more surgical. His basic proposal is to return to the walls permeable to the tide: to use all our modern technology to try to rescue traditional engineering. That is, keeping an extremely complex ecosystem alive.

And that’s the heart of the matter: the Venice Wall could protect the new parts of San Fernando when the time comes, but it couldn’t keep the bay alive.

We have to decide if we want to invest Now it’s cheap, but the risk is diffuse. Or invest later, when it is expensive, but clear and real.

Image | Alain Rouiller

In Xataka | Venice spent 5 billion euros on flood barriers. Five years later they are already “unsustainable”