Spain is destroying more dams and reservoirs than anyone else in Europe. It’s good and bad news

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If someone were asked about the number of dams in Spain, the first answer would probably be well below 1,200. However, a few years ago that figure would have been a good approximation. Specifically, they reached 1,226 according to data from the Spanish Society of Dams and Reservoirs, but this answer would not be correct today either. Only in 2021 they collapsed more than 100 of these dams. This is good news for Spain’s natural heritage, but it also has its dark side.


Free the rivers.
The main reason for dismantling dams is to allow rivers to return to natural channels through which river fauna can move without the impediment of these concrete masses.

This plan to eliminate obstacles is part of the National River Restoration Strategy, which has been implemented for more than 15 years. However, the concern for the conservation of the natural heritage has already in the 1940s to introduce the obligation of dams to have climbed areas to allow the transit of fish and other animals. The problem is that this measure had a low level of implementation.

Not only recover natural channels.
The reason for the dismantling of a dam does not only have to do with ecological reasons. Economic reasons can also be part of the equation, since dams are infrastructures that require maintenance. The rupture of one can cause flooding downstream, with its consequent environmental and economic impacts.

Dams also sometimes fall into disuse. Most of the existing dams in Spain were built between the 1950s and 1990s, but there is a significant number of dams that are more than 75 years old. The uses of water have changed considerably since then, and with it, some of the winners of these infrastructures have lost interest in maintaining them.

The lack of water is not only due to the drought: the impact of electricity with the emptying of reservoirs

Mixed opinions.
The demolitions, however, have not been without controversy. Some of these dismantlings have run into the opposition of neighbors, as in the Los Toranes dam case in the province of Teruel. Dams like this one still generate income in the area, either by providing water for irrigation and firefighting or for their tourist contribution.

Attention is also drawn to the fact that ecosystems adapt to circumstances, and that demolishing dams also implies the rupture of ecosystems that have had decades to adapt. An example of this It is the Cristinas Dam, which channels the Cabriel River, in Cuenca. The opening of this dam, indicate those who oppose its demolition, would put an end to the dragonflies of the Oxygastra curtisii species in the region, and would also negatively affect loina, a fish endemic to the Iberian Peninsula.

A problem that will get worse.
Perhaps the main objection to the destruction of dams also has an ecological motivation, and is the aridification process that climate change could cause in the Iberian Peninsula, with the consequent increase in pressure on water systems.

This year has been especially hard, with swamps at a minimum due to the lack of rainfall and abnormally high temperatures. If the trend continues, Spain will need to collect as much water as possible when it is abundant.

Dry soils also imply a greater possibility of flooding. The interactions between flooding and channeling of river channels are complex, but dams can help retain part of the water that circulates through them, reducing the risk of flooding in many cases.

It is not just about water as such.
The importance of dams lies not only in the water they contain, but also in the energy they store. Hydroelectric power is second renewable energy source in Spainand this in turn depends on some of these dams and some of the reservoirs that the watersheds of the peninsula have.

If possible, the importance of hydroelectric plants is increasing. In the first place due to the rise in energy prices that we have suffered in recent months. Second, because water is the only renewable source whose flow we can control. To the point that we can use water to store the electrical surplus created by other energies (renewable or not).

While some dams are collapsing, reversible or pumped hydroelectric plants seem to be on the rise. An example of this is the Tâmega dam in Portugal, a project that should result in a battery capable of generating 1,158 MW and storing up to 40 million kWh.

Difficult reconciliation.
For hundreds of years, human beings have built dams with very different objectives: reserving water for human and agricultural consumption, diverting riverbeds, generating energy, first mechanical and then electrical… The uses of dams change depending on the human needs and with them the way in which we relate to them.

This does not imply that decisions are easy. Except when a multitude of factors intersect, such as the preservation of natural and industrial heritage, the demand for energy and water, agriculture and tourism… and all with the shadow of climate change as a background.

For now, the only fact is that Spain, without stopping building new dams, is advancing in the dismantling of some of the oldest ones. Whether this is a good idea remains to be seen.

Image | Negratin Reservoir, Wilton BSE LTD

If someone were asked about the number of dams in Spain, the first answer would probably be well below 1,200.…

If someone were asked about the number of dams in Spain, the first answer would probably be well below 1,200.…

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