Ash from summer fires pollutes river

Residents of Orense, the Bierzo region or northern Cáceres have seen firsthand rivers of ash falling like silent avalanches from the mountains. in some towns The tap water is no longer drinkable and the fountain is leaking brown liquid.. “We warn about this, but as incredible as it may seem, the fire doesn’t go out even when the flames go out,” recalls Victor Lesko, a forestry engineer and professor at the University of Lleida. “The effects last for months, even years.” And toxic rivers are the first sign.

“Chemical cocktail” for health

Mr Lesko explained to the ABC that the problem with sewage is not just visual, but most notably that this drag can have a “very negative impact on water quality”, particularly rivers, reservoirs and the surface water that the population as a whole depends on. The river is “Chemical cocktail”That’s what I say.

Particles from burned mountains contain remnants of heavy metals and organic materials such as arsenic, lead, and mercury. “These compounds can permeate aquifers and cause chronic toxicity if ingested,” he warns. May cause neurological, kidney, and liver damage. In addition, water treatment plants are being overwhelmed due to increased turbidity and biomass.

dead plants and animals

But that’s not the only problem. The ash also impoverishes the remaining organisms that are part of the ecosystem and depend on the contaminated water: plants and animals. And these impacts on river ecosystems are immediate. In the channel, Ash suffocates fish and invertebrates The bottom becomes clogged and dissolved oxygen decreases. It also releases nutrients that change the pH and cause toxic algae and cyanobacteria blooms.

Additionally, heavy metals can adhere to fish tissue and poison the birds and mammals that feed on it. The plants growing at the bottom of the river then die due to lack of light and oxygen, destroying the entire food chain in the process. “Without plants, there are no insects, without plants, there are no fish, and without food, the otters and herons die,” Miguel Ángel Soto, spokesperson for Greenpeace’s Forest Campaign, exemplifies, hoping to make this clear: “Water is not drinkable or usable by humans or animals.”.

“skeletal” terrain

In addition to this reduction in quality, land degradation. Soils without vegetation lose nutrients and become “more skeletal”, slowing the natural regeneration of both forests and crops. “Fires destroy the vegetation that supports the soil, and without natural protection, erosion increases rapidly,” Lesko explains. Then, when torrential rains arrive, this mixture of sediment and ash settles to riverbeds and contaminates reservoirs and springs. “This would not have happened without the combination of large burned areas, high slope areas, and heavy rain,” Soto added.

Experts sum it up in one word: “The perfect storm.” And while the toxic levels will subside as the weeks go by, the immediate effects will be severe, especially in villages and small towns that rely on rivers and springs for their drinking water supplies.

The most affected areas in Galicia are: Valdeoras region (Orense), site of the largest fire in the history of the region, which destroyed 30,000 hectares this summer in the city of Larouco. In areas like Petin, a lack of resources has forced residents to take on the responsibility of prevention and containment. « The situation changes daily depending on the rain situation. At some points, the water appears black, but generally it is not as severe as in Villamartín de Valdeoras,” explains Mayor Raquel María Bautista.

Bautista recognizes that “it’s not suitable for drinking, but it’s suitable for using the washing machine or taking a shower,” and blames a lack of protocols and coordination among authorities. “We’re doing what we believe is best,” he says. Meanwhile, the Sunta de Galicia announced the installation of embankments and plant cordons, the use of straw and matrix materials to prevent erosion (the “mulching” or “heli-mulching” technique when applied from a helicopter), but the lack of communication with the Minho Sil Waterways Federation once again led to the usual situation. Crossroads of blame regarding abilityin the case of these preventive tasks, it concerns the central government of mountainous Galicia and river basins and reservoirs.

For Professor Agustín Merino, an expert in soil science and agricultural chemistry at the University of Santiago, the problem is twofold. The scale of the fire and the cost of repairing the burned items. “In a large fire, 10-15% of the surface is in a serious condition. That’s where these techniques should be applied, but in Galicia they have only been implemented on 1% of the affected land,” he warns. The steep slopes of Orense increase runoff and, therefore, risks. “The cost of purifying these waters will be enormous,” he warns. It also warns you about what’s to come. “The greatest danger will come in the summer, when the nutrients carried by the ash become a breeding ground for cyanobacteria.”The added heat creates toxic blooms, making the water unusable for bathing, let alone for consumption. ”

In Bierzo, the neighbors also live overlooking the water supply. Puente de Domingo Flores, a small town with a population of 900, and Salas de la Ribera, home to another 250. Local governments have banned drinking tap water They left a large deposit on the street until further notice. Neighbors fill their jugs according to their needs, and when the water runs out, tankers refill the jugs. A few kilometers away, in the Lama de Cabrera watershed, fires have destroyed the vegetation that protected the soil, leaving gray seals in the water.

In the Tremor de Arriba district of Higueña city, residents have been without drinking water from the tap for almost two months, fires destroyed eight kilometers of water pipes, and autumn rains filled the Tremol River with ash. At the request of neighboring councils, the León Provincial Council is distributing bottled water to residents. In other disaster-affected municipalities, town councils They enhanced their water analysis If you need to limit your consumption.

The effects of the fires and rain have been devastating in Extremadura. Paco Castañares, a forestry expert, said the worst-affected areas were around Harilla and Las Fuldes, where this summer’s wildfires reached the mountains at the headwaters of the Ambros and Jerte rivers. “The throat is dead. There is no possibility of life inside them.he warns. “The soil had a very thin fertile layer and was completely bare. With no roots to support it, the rain drags down the slope. Today, some towns in northern Cáceres receive their water from reservoirs, “like in the 60s,” Castañares wryly laments.

Experts say fire, water and erosion share the same diagnosis: uncontrolled, unprotected territory. “We have to invest in green restoration, not black restoration,” Lesko argues. Rather than spending millions of dollars after a disaster, they advise allocating resources to prevention, such as managing forests, maintaining large-scale livestock farms, deforestation, conducting controlled burning, and promoting agriculture.

Experts agree that the rivers of ash that fall after rain are just the most visible symptom of structural problems. Spain flares up every summer, and even when the fires are extinguished, the landscape continues to burn from within.