With the storm still on the horizon, Valencia is trying to recover from the brutal effects of the worst cold spell in a century, a “historic” event in Aemet’s words. It does so with a death toll of 92, great uncertainty about how much damage will be done, and growing political debate about whether the tragedy could have been minimized. Carlos Majón’s decision to shut down the Emergency Unit is mentioned. It is being discussed whether the ES-Alert warning system was activated late or not. And especially the role of broken reservoirs and dams in networks is mentioned.

Of all the open fronts, the last one, probably related to infrastructure, is the one that creates the most dust and also the hype.

“What a good idea to remove the dams”. This statement was written yesterday on reservoirs that could help protect settlements during DANA, which some criticized. The conversation soon went viral and the Government was accused of “destroying” four reservoirs designed to hold water during severe storms.

Destroyed reservoirs? In fact, criticism is not new. In 2023, Vox accused the Executive of holding the “record” at the European level for the “destruction of dams and reservoirs”. “You destroyed up to 108 reservoirs in 2021,” your deputy, José María Figaredo, denounced. The statement is not entirely true.

What the European organization Dam Removal actually shows is that 241 barriers have been removed on Spanish rivers in recent years, with 108 in 2021 and 133 in 2022. The important thing is not how much, but what is destroyed. At least in 2023, when the controversy arose, there were only four dams in its inventory over six meters high. What about the rest? The vast majority of the structures removed were small, disused levees, gauging stations, or even causeways.

What does this have to do with Valencia? Yesterday’s part of the discussion about what is happening in the Valencian Community once again turned to the broken dams hoax, as seen in the tweet in response to Mazón. This became so big and talk went viral that the Government sent out a statement denying that it had destroyed four marshes and reservoirs in the area as accused. The point they insist on in the Ecological Transition (Miteco) is the same as in the 2023 debate: what do we mean by “swamps”?

Teresa Ribera’s department explains that what it does is remove obstructions from the river. In fact, the work focuses above all on “small weirs or waterfalls of a few meters” that are currently out of use.

“Among other reasons, because of the risk they pose because their virulence increases during floods or floods,” Miteco insists, before noting that the “only infrastructure that has been destroyed” in the province of Valencia in the last decade was the Corindón weir in 2017. In the 1.5 meter high Turia river bed; and those of Ramba de L’Algoder in 2006. The executive also emphasizes that the National River Restoration Strategy, introduced years ago in 2005, is “essential” precisely for preventing floods.

Do we know anything else? Yes Efe agency and Country They contacted the Ministry to learn about the removed infrastructure in detail. The Ministry basically talks about the dams. Molí de Malanya in Bellús, which the Júcar Hydrographic Confederation (CHJ) demolished in 2022; The Corindón in the Turia river bed was suppressed in 2017 and is only one and a half meters high; and four other levees on L’Algoder Boulevard, which were removed in 2006. In some of these cases, the concessionaires themselves were responsible for their removal.

The government also emphasizes that the river restoration plan helps prevent floods and that it is changes in river areas that are exacerbating the problem, which is exactly what the national strategy wants to “reverse”. Data from Dam Removal Europe also shows that Spain is not the only country where old river barriers are being removed. It’s not even the main thing right now.

Last year, 487 people were eliminated in Europe. France (156), Spain (95) and Sweden (81) were at the top. Efe states that 46 percent are dams, 36 percent are collectors and 12 percent are dams. Almost 80% did not reach two meters.

“They are not used to store water.”. It matters whether we are talking about one infrastructure or another. CHJ reminds us that weirs are “a wall constructed on a river to facilitate the diversion of some of the flow for irrigation and other uses,” and many have become disused and do not serve any function. “They are not used for water storage as they are often clogged and retain only a small layer of stagnant water upstream,” the Confederation elaborates.

Arturo Elosegui, professor and researcher of river ecology, admits in a recent interview with the Efe agency that the removal of such obstacles “does not aggravate floods.” “It reduces them, prevents the formation of plugs that force water out of the channel,” says the expert, a professor at the University of the Basque Country, “they only increase the level of flooding by raising the water table.”

Forata’s role. In case of dam, it is stored and helps to keep the water inside. On Tuesday afternoon, when DANA was dropping significant amounts of rainfall in Valencia, the Embalses.net account actually pointed out the role played by the Forata reservoir in Yátova in X.

“It’s impressive what it stops, fulfilling its function of covering the roads perfectly,” explains Embalses.net before dropping a few figures around six in the afternoon. “This reservoir generally has an annual water flow of about 8 hm3, and its capacity is 100 m. Only 37 hm3 entered in less than three hours, almost 20 hm3!” World It is stated that the structure, which stopped 37 billion water bottles and reached 100 percent of its capacity, is of vital importance in preventing a much bigger tragedy.

“For this”. “There are many reservoirs in the Levant that never fill. Many people think they are poorly made, overly optimistic… That’s what they’re actually dimensioning for: laminating streets, preventing damage and victims,” Civil Engineer Ángel Gil insisted in another tweet .

In an article in 2020, he himself emphasizes that one of the biggest and at the same time most unknown functions of dams is the lamination of streets. “When someone comes, those responsible for operating the dams open the drains before they arrive to store a lot of water and release it over time.”

Franco and the flood of 1957. Another of the messages circulating in the last few hours was about the extent to which the infrastructure inherited from the Franco regime helped prevent a major tragedy in the city of Valencia. The user tweeted yesterday, a message that has been viewed 208,000 times and shared thousands of times: “After the flood of ’57, Franco ordered the construction of a new canal with a series of marshes and reservoirs to hold the water from this phenomenon.” .

The message refers to the event known as the “Great Valencian Flood” that shook the city more than 60 years ago on October 14, 1957, when a powerful storm caused Turia to overflow its banks as it passed through the city of Valencia. .

The balance was tragic. It is said that at least 80 people died, but in addition to the destruction of homes and workplaces, there are those who put the total figure much higher. The flood submerged a shanty town and the Campanar bridge. The damage was so extensive that the Regime decided that the Turia canal had to be diverted to prevent it from passing through the center of Valencia. In 1962, the project to be known as Plan Sur was approved; A work that took 13 years and a huge investment. Today, this figure is estimated to exceed 4 billion euros.

What is the Southern Plan? The project is also known as Nuevo Cauce del Turia, a name that gives a clear clue as to its purpose. Its aim was to divert the river with a ditch approximately 12 kilometers long and 200 kilometers wide. As Aguas de Valencia recalls, it was planned to discharge 5,000 cubic meters of wastewater per second into a new mouth located three kilometers south of the existing mouth. Its impact on the city’s urban planning was also notable.

Photos are doing the rounds on There are also comments highlighting how the new regulation acts as a barrier to water and helps prevent further damage in the capital of Valencia on Tuesday. “Of course the Plan Sur channel helped us,” he explains Hidden Nahúm Méndez, geologist.

“It should be taken into account that Turia flows through buildings and other architectural barriers as it passes through the city. The drainage capacity of the new canal is 5,000 m3 per second, that is, it has a drainage capacity. Two Olympic-sized swimming pools are opened every second. If there was no work, the situation would be much worse,” he insists. says Méndez. There is also chiaroscuros in the history of the plan. Perhaps the most important of these is that the Vilamarxant reservoir, which was claimed many times in the following years, was left unfinished because it was not built.

Pictures | UME (X) and Júcar Hydrographic Confederation (X)

in Xataka | DANA loses its intensity but does not fall apart: AEMET still reminds us to be very careful