The Fraga town council (Huesca) has begun the necessary works to raise by two meters the dam of the 190,000 m³ reservoir that serves the city. It may seem like a minor detail, almost anecdotal in a country with 1,200 reservoirs and more than 56,000 hm³.
And it is. However, it is also the perfect metaphor for the enormous problem simmering at the bottom of our reservoirs.
The end of the Spanish miracle. Practically speaking, Spain does not build new dams because it already has 1,200. It is, in fact, one of the countries in the world with the most dams, and although there are still areas that could be ‘usable’, these are increasingly scarce, smaller and less environmentally sustainable.
In other words, even if we wanted to, we could not significantly grow our stored-water capacity. And there are plenty of examples: Mularroya, near Zaragoza, has the dam completed, but with a nullity ruling for failing to comply with the Water Framework Directive; Biscarrués, in Huesca, is still under study, but the controversy over its environmental impact is enormous; Almudévar, though finished for years, cannot be filled due to a lack of pumping capacity.
Constructing a dam in the 1980s was almost impossible and the situation has only worsened. In fact, in the last 15 years, barely 20 reservoirs have been inaugurated, totaling 803.6 hm³
A problem rarely discussed. The country loses about 100 hm³/year to sedimentation while CEDEX projects runoff declines of -11% to -14% over the next 40 years. In other words, the real problem with Spain’s reservoirs is not that we can’t build more, it’s that mud and sediments are stealing storage capacity. Mequinenza has already lost 10% of its capacity
And what do we do? That is the big question, and this is where the example of the Fraga town council becomes most interesting. Because many engineers have long argued that if we cannot create new dams on virgin valleys, perhaps we can raise the height of existing ones.
In Yesa, between Navarra and Aragón, the project (the most emblematic of this approach) would allow adding up to 1,079 hm³. More than the 803 of the other approach. Right now, as far as we know, the project is halted due to some objections. Where it has been implemented is Santolea, Teruel, adding 81.75 hm³ to the original reservoir.
And why isn’t the process sped up? Largely because a good number of people feel the dam model has reached its ceiling and believe we must kill the reservoir-culture: storage capacity already exceeds the water available and adding more empty vessels doesn’t create water by itself.
The water war is one of the fiercest battles facing Spain’s future. And I doubt anyone knows how to broker a peace agreement.
Imagen | Yoann Laheurte
In Xataka | Our reservoirs have a grave structural problem. And experts have been warning us for years