What you need to know about the unprecedented floods in Spain that have killed more than 200 people

MADRID. A flash flood caused by heavy downpours in eastern Spain swept away almost everything in its path in a matter of minutes. Before they could react, people were trapped in cars, houses and businesses. Many died, thousands of people lost their means of livelihood.

Four days later, authorities found 213 bodies — most of them in the eastern region of Valencia. On Saturday, they continued their search for an unknown number of missing persons.

Thousands of volunteers helped clear the thick layers of mud and debris that still covered homes, streets and roads, despite power and water cuts and shortages of some basic goods. Some of the cars that were washed away in piles or crashed into buildings still had bodies waiting to be identified.

Here are a few things to know about Spain’s worst storm on record:

What happened

The storms concentrated over the Magro and Turia basins, and in the Poyo riverbed, walls of water burst their banks, catching people off guard as they went about their daily lives Tuesday night and early Wednesday.

In the blink of an eye, muddy water covered roads, railways and entered homes and businesses in towns and villages on the southern outskirts of the city of Valencia. Drivers had to hide on the roofs of cars, and residents had to hide at heights.

Spain’s national meteorological service said the hard-hit region of Chiva received more rain in eight hours than in the previous 20 months, calling the deluge “extraordinary”.

By the time authorities sent cellphone alerts warning of the severity of the flooding and asking people to stay indoors, many were already on the road, working or covered in water in low-lying areas or underground garages that had become death traps.

Why did these large-scale flash floods occur?

Scientists trying to explain what happened see two possible links to climate change caused by human activity. First, warmer air holds and then sheds more rain. Another is possible changes in the jet stream—the river of air above the ground that moves weather systems around the globe—that creates extreme weather.

Climatologists and meteorologists said the immediate cause of the flooding was a low-pressure storm system that moved from an extremely wavy and stalled jet stream. But the system was just standing over the region and pouring rain. This happens often enough that in Spain they are called DANA, the Spanish abbreviation for the system, meteorologists say.

In addition, there is the unusually high temperature of the Mediterranean Sea. Mid-August saw the highest surface temperature on record at 28.47 degrees Celsius (83.25 degrees Fahrenheit), according to Carola Koenig of Brunel University London’s Flood Risk and Resilience Centre.

The extreme weather comes after Spain struggled with prolonged droughts in 2022 and 2023. Drought and flood cycles are increasing with climate change, experts say.

Has this happened before?

Spain’s Mediterranean coast is used to autumn storms that can cause flooding, but this episode was the worst flash flood in recent memory.

Elderly people in Pyport, at the epicenter of the tragedy, said Tuesday’s flooding was three times worse than the 1957 flood, which killed at least 81 people. This episode led to the diversion of the Turia River, which meant that a large part of the city was saved from these floods.

In the 1980s, Valencia experienced two more major DANAs: one in 1982 that claimed around 30 lives, and another five years later that broke rainfall records.

The flash floods also exceeded a flood that washed away a campsite along the Gallego River in Biescas in the northeast, killing 87 people in August 1996.

What was the state’s response?

Crisis management, classified by the Valencian government as level two on a three-point scale, is in the hands of regional authorities, which can turn to the central government for help in mobilizing resources.

At the request of Valencian President Carlos Mason of the conservative Popular Party, Socialist Prime Minister Pedro Sánchez announced Saturday the deployment of 5,000 more soldiers to join rescue efforts, clear debris and provide water and food.

The government will also send 5,000 more national police officers to the region, Sanchez said.

About 2,000 soldiers from the Military Emergency Response Unit, the army’s first response force to natural disasters and humanitarian crises, are now involved in emergency work, as well as almost 2,500 Civil Guard gendarmes, who have rescued 4,500 people, and 1,800 national police. officers

When many victims said they felt abandoned by the authorities, a wave of volunteers came to help. With brooms, shovels, water and basic food, hundreds of people walked several kilometers to deliver supplies and help clean up the worst-hit areas.

On Tuesday, Sanchez’s government is expected to approve a disaster declaration, which would allow quick access to financial aid. Mazon announced additional economic aid.

Valencia’s regional government was criticized for not sending a flood warning to mobile phones until 8pm on Tuesday, when flooding had already started in some places and well after the national weather agency issued a red warning for heavy rain.

Associated Press writer Seth Borenstein in Washington, D.C. contributed to this report.