Floods are not new in the Segura basin. The Hydrographic Confederation itself has records of extreme episodes since the 13th century. They are not found in the province of Albacete. In May 2018, several municipalities such as Pétrola, Isso, Yeste, Riópar, Liétor, La Gineta… suffered floods. Hellín was one of the worst affected. In June, torrential rains caused flooding and collapses in Elche de la Sierra, Liétor and Socovos. The Government of Castile-La Mancha has activated the Special Civil Protection Plan against Flood Risks (PRICAM) after being informed by the Hydrographic Confederation of Segura of the forecast of overflow of the Segura River in the section between the reservoirs of Fuensanta and Fuensanta. The Cenajo.
They are also not strange in Letur, the town of Albacete, where on October 29 a water avalanche killed six people. A few hours before, the National Meteorological Agency (AEMET) had activated the orange warning for this part of Albacete and the forecast seems to have been lower.
Stefan Nolte is a technician in Integrated Water Cycle Management and member of the Defense Platform of the Sources of the Segura and Mundo Rivers, created in 2007 and made up of a dozen groups from the area, in response to the installation project drought wells in the region of Sierra de Segura and Campos de Hellín.
He lives in Riópar, a town an hour’s drive from Letur. He believes what happened was the result of several factors. On the one hand, a powerful DANA whose, he says, “the warning could have been red”. We know today that on that day 230 liters per square meter fell at the head of the boulevard, the ravine upstream of Letur, but “no official rain gauge recorded what happened in the town “, he laments.
He just did it the Suremet networkcreated in 2009 by a group of university researchers who collect unofficial weather data in six provinces in southeastern Spain, whose rain gauges, Nolte says, “have Wi-Fi and the one at the campsite works.” There, at the Letur campsite, the rainfall figure published on their website did not reach five liters per square meter in 24 hours that day.
It is known that in the nearby Fuensanta reservoir, about 10 kilometers northwest of Letur, 149.6 liters per m² (l/m²) were collected in 24 hours. And in ten minutes, they fell to 25.6 l/m², according to AEMET data.
“There is little coordination between AEMET and the Hydrographic Confederation of Segura and Suremet data is not used either, it is not integrated into the official network and does not reach Civil Protection either,” criticizes Nolte.
According to him, beyond the orange notice, “no one warns the population of the flood on the Rambla There is not even a gauge in the Rambla Letur which would have made it possible to measure the evolution of its flow.
In this sense, he recalls that the Automatic Hydrological Information System (SAIH) of the Segura Confederation was installed for the large avenues that flooded the area of Murcia, which, he recognizes, “is the most exposed”.
No one warns the population of flooding on the boulevard. There is not even any capacity within the Rambla Letur which would have made it possible to measure the evolution of its flow.
Stefan Nolte
— Defense Platform of the Sources of the Segura and Mundo Rivers
On the other hand, the hydrological plan of the basin, recently updated, envisaged increasing the network of gauges, but with the objective of verifying compliance with ecological flows. Not so much in flood forecasting, because, Stefan Nolte emphasizes, “the issue of flooding is the ugly duckling of hydrological planning. People think that this is something that can happen in 100 years and that if it’s not done today, it will be done tomorrow. Until this happens.
An “insufficient” system of dikes and pipes in the rambla
The source of the Letur stream is one kilometer away, with a catchment area of 65 km2 in a boulevard, a dry barracks, occasionally occupied by waters after the rains.
There are dams and water pipeline systems that were built in the 90s of the 20th century. “It was insufficient because the existing dams suppress the flood, but they only work when they are small.”
On the other hand, he says, “the pipeline that was created is much smaller than the flood channel. You can see it in the videos from this day. On San Antón Street, he explains, this pipeline has been adapted to urban planning.
There is an area, the Moreras slope, which gives access to the castle, which “in 1956 was already like this, with some later modifications” and which, he says, “is perhaps the best for maintaining human uses: a wide street is maintained, “where you can park, but it is not so much for these cases.” In general, “it’s like carrying water on a catwalk with two chutes on the sides.”
Should we clean up mountains and river beds? This is one of the controversies generated following this disaster. Nolte explains that “the headwaters of the ravines have been reforested all their lives to prevent flooding. The remains of the plant will arrive in the flood, but this will take away its strength. Clearing mountains should be done to fight fires, not floods. And on the other hand, cleaning the canals makes sense where they are narrow.”
Regarding housing, he recognizes that there will also be a debate on how and where to build, not only because the old town of Letur is an Asset of Cultural Interest (BIC) but also because many of the houses are old. “We will have to build differently. » In addition, he warns, “Spanish legislation allows it to be done in areas prone to flooding, where return times are longer and there is supposed to be less danger, if it is done respecting certain levels “.
How to reduce the danger?
When it comes to minimizing risks, Stefan Nolte commits to reforesting the upper reaches, “as long as this does not present a fire risk” and taking into account that this “will involve increasing transpiration and reduce the quantity of water that comes out through sources. »
Another option would be the construction of a dam to laminate the avenues, but “this should be very well studied because it is an ecologically sensitive area”. Or you can increase the drainage system and build a wider, more naturalized pipe system. These are options that engineers, among other professionals, must consider.
“On the Moreras slope, the footbridge that leads to the castle, it will be necessary to remove all the filling materials that have been put in place. Perhaps introduce underground drainage channels. He says it wouldn’t even hurt the DGT to mark flood zones. Not just in Letur.
In the flood risk management plans there was not a single measure for Letur, although it is identified as a risk area and surely we are all responsible because they are prepared with the participation of citizens. We have a general problem of social awareness about flooding
Stefan Nolte
— Defense platform for the sources of the Segura and Mundo rivers.
The stream of this town of Albacete was already part of the Areas of Significant Potential Flood Risk (ARPSI) of the Segura Confederation in 2010. In the preliminary flood risk assessment corresponding to the third planning cycle for review, currently During the public exposure period until December 2, the risk reappears, on a stretch of 1.68 kilometers. “In the flood risk management plans there was not a single measure for Letur, although it is identified as a risk area and surely we are all responsible because they are prepared with the participation of citizens” , he laments. “We have a general problem of social awareness about flooding. »
Jorge Olcina is professor of regional geographic analysis at the University of Alicante, where he teaches courses on territorial planning, climatology and natural risks. This Thursday he participated in a conference in Toledo to talk about “Water planning in Spain in the context of climate change: the necessary paradigm shift”, as part of an activity organized by the UCLM Chair- Soliss Tajo. According to him, the solution, not only for Letur, but for all affected areas, will come through “several measures”.
One of them will concern hydraulic civil engineering works. “There are boulevards and streams that cross the middle of city streets and where houses cannot be moved. We will have to divert the channels to prevent what happened from happening again.”
At the same time, he says, “sense and rational urban planning and management will be needed, which takes into account flood zones.” It will be necessary, he adds, “action that respects the environment, but if what has happened has taught us anything, it is that it will be necessary above all to save human lives because we see that We didn’t I did it.”
This expert who heads the Climatology Laboratory of the University of Alicante advocates reviewing flood return periods, improving communication protocols and implementing risk education measures, not only in schools but for the entire population. “Citizen associations, environmental groups, unions, business groups will have to play an important role… They will have to devote part of their annual action to training their associates in risks.”
Olcina says that “throughout Spain we have a very disorganized territory and when these disasters occur we realize how bad we are in this sense.”
