After the floods in Spain, the difficult equation of reconstruction

"The degree of destruction and ruin has been historic" in the Valencia region, where nearly 80 towns were devastated by the torrential rains of October 29, points out the Higher Council of the Order of Architects (CSCAE) of Spain.

The meteorological episode left behind disfigured cities, disused infrastructure and cost the lives of at least 230 people, mainly in the Valencia region (222 dead), making it the worst natural disaster in the country since the floods that killed 300 in Andalusia in 1973.

For the president of the Order of Architects, Marta Vall-Llossera, the reconstruction must "be carried out with empathy, technical rigour and a great deal of responsibility".

"With global warming making weather phenomena more intense and more frequent, architecture will play an important role," she continues. "We will therefore have to build differently," insists the architect, advocating a return to "the traditional, compact Mediterranean city."

"Renaturalizing cities"

In the Valencia metropolitan area, urban expansion in the 1960s increased the artificialization of soils, increasing its vulnerability to flooding, since concreting prevents water absorption.

In Paiporta, considered the epicentre of the disaster, for example, the main roads were transformed into torrents of mud on 29 October, sweeping away everything in their path.

"We must try to renaturalise cities, reduce car use, make pavements less hard, more permeable, with better performance in the face of intense heat and torrential rains," Vall-Llossera said in an interview with AFP.

In the case of the Autonomous Community of Valencia, a territorial action plan on flood risk prevention already exists: approved in 2003, it does not, however, have "retroactive effects" and is not binding, explains María Jesús Romero Aloy, an expert in urban planning law and lecturer at the Polytechnic University of Valencia.

According to the data in this plan, the Valencia region represents 5% of the national territory at risk of flooding but has suffered 20% of the episodes of heavy rains in the last 10 years. The highest flood risk is concentrated in 12% of the regional territory, or 270.000 hectares, and affects 600.000 inhabitants.

In this area, the regional authority recommends that owners have "an internal staircase with access to the roof and watertight doors and windows of 1,30 metres".

But for María Jesús Romero Aloy, more must be done, "rethinking the territorial model and considering eliminating buildings or installations that pose a high risk."

Today, an owner has the right to rebuild on his flooded plot, even if it is located in a high-risk area. The only recourse to prevent this is "forced expropriation", as was the case in 2019 in Onteniente, a municipality located about 85 km south of Valencia, where "a neighborhood was eliminated" and transformed into a flood-prone park, the lawyer recalls.

But mayors are "reluctant to expropriate" because it is "a complicated political decision" to which is added "the housing shortage", she underlines.

"Natural barriers"

However, a month after the tragic floods of October 29, "there is an awareness among decision-makers," analyzes Federico Jesús Bonet Zapater, territorial advisor in Valencia for civil engineering, canals and ports.

"The projects for building dams or diverting canals that have been on the table for some time will finally be studied," rejoices the engineer, who is campaigning for "better coordination of regulations between central and regional authorities."

The abandonment, envisaged by local elected officials, of "industrial expansion and unbridled urban growth is a fable", predicts Rafael Delgado Artes, a specialist in regional planning and risk prevention.

Failing that, this professor of forestry advocates for "natural barriers" to minimise the damage, such as reforestation to "cushion the flow", intermediate overflow spaces for rivers or even "artificial beds to divert rivers away from city centres".

In the city of Valencia, spared by the recent floods, the river that crosses the city had been diverted after destructive storms in 1957. And in place of the Turia, dried up in the city centre, there is now a 110-hectare urban park.