A week after the start of the DANA of the century, there is no point – especially for those who have lost everything – to ask questions like “What would have happened if the appropriate measures had been taken?“.
One of the most controversial was the notice that citizens received on their cell phones last Tuesday, despite warnings issued by Aemet in previous days. Although there were also those highlighted decisions made decades ago.
And that was only 20 years ago The government announced the construction of a dam in Cheste to avoid flooding in 16 Valencian municipalities; among which were some of the most affected currently by DANA (Aldaia, Paiporta or Chiva). Estimates then indicated that nearly 200,000 residents would be affected in the event of flooding.
EL ESPAÑOL / Aemet
The repeal of the National Hydrological Plan in 2005 led to its paralysis. Six years later, the then Ministry of Environment rejected the damwhich appeared as the first alternative in the environmental impact study, opting for the construction of greenways, because it is more favorable “to the biotic environment, through the recovery of habitats and the reduction of the occupancy surface infrastructure and the socio-economic environment.
An “effective” measure
However, the high price of this type of construction (nearly 300 million euros) meant that with the arrival of the economic crisis, it could not be launched. a project which planned to increase the flow of the Poyo ravine to 1,500 m3/s. Current capacity is 800 m3/s. “This does not mean that the damage would have been halved, but it could have been much lower,” he assures EL ESPAÑOL. Frederic Bonetformer dean of the College of Civil Engineers of Valencia.
“Undoubtedly, this would have meant a reduction in damage” he adds Javier Baztanmember of the General Council of the College of Civil, Canal and Port Engineers. Both agree that a dam like Cheste could have stored part of the flood volume. However, they know that there were floods, since in places 2,000 m3/s were reached.
On the Magro River, another of the areas affected by DANA, there were plans to build a rolling dam at the turn of the century. The function of those also known as “hole dams” is to laminate the avenue so that the flows at the outlet of the dam are much lower to those at the entrance. Damage downstream of the dam is thus avoided.
On the Canyoles river, in the municipality of Montesa (Valencia), the construction of a dam is also underway. But, as Bonet laments, “no water works have been built for 20 years”. He suspects it’s because they are “very costly from an economic and social point of view“.
The engineers give the example of the detour made in the Turia, following the flood of 1957, to demonstrate that the channels have proven to be “effective”avoiding flooding in the city of Valencia itself”.
The director of Water and Environmental Engineering Research Institute of the Polytechnic University of Valencia (IIAMA-UPV), Manuel Pulidobelieves that “the dam would have collapsed quite a bit”, given the flow rates that were exceeded. For this reason offers forest hydrological restorationwith small containment dams in the upper basin of the ravine, where flows are generated.
With “a controversial part”
The floods caused by DANA in recent days have put Spain on notice, where there are 2.7 million people living in flood-prone areas. And as Complutense University of Madrid geologist David Uribelarrea comments, dam construction has “a controversial side.”
Por un lado, mitigan parcialmente las inundaciones. Pero por otro, también generan una falsa sensación de seguridad. Entiende, por ello, que es más conveniente llevar a cabo una buena planificación del territorio, antes que construir infraestructuras que tienen un gran impacto medioambiental: “Ahora no podemos llenar los valles del Levante español de presas porque sería un desastre ecológico“.
El delegado de Colegio de Geólogos en la Comunidad Valenciana, Joaquín Martínez, incide en llevar a cabo una buena regulación de las zonas inundables: “Entiendo que a otras profesiones no le gusta lo que nosotros [los geólogos] we say. But if you build a ravine with cement, the cause is that the water does not infiltrate and its speed increases.”
However, as the former dean of the College of Civil Engineers of Valencia points out, in the affected areas around the Poyo ravine “almost everything is built“, so he doesn’t think it makes sense to ban construction in these areas: “What I think we need to do now is protect them in one way or another.”
“And it is not a question of finding culprits,” Bonet continues, “because after the crisis came a government of Mariano Rajoy and another of Pedro Sánchez. It’s a problem for all of societyto be more aware.
