Climate crisis | "The buildings and infrastructure are not climate crisis-compatible"

Mr. Olcina, there are two camps when it comes to flood protection: those who favor technical infrastructure like dams, and those who favor renaturation. What do you recommend?

A clever combination is most effective. In the Valencia region, we will build new canals, divert existing ones, and simultaneously implement nature-based solutions. These include flood-prone parks, unsealed surfaces, and green spaces —even where buildings still stand today. The key is always to keep the goal in mind: protecting human life.

Valencia is densely populated and a key infrastructure hub. How can we even think about it in a new way?

A reconstruction of this magnitude requires coordination at all levels—national, regional, and local. Municipal plans, in particular, must be reviewed; dense development there contributed significantly to the devastating consequences of the floods . We also need to consider partially diverting or canalizing rivers. Above all, however, the guiding question should be: What use of the land still makes sense under the conditions of the climate crisis?

A major problem: Many buildings are located where water breaks through. How could this happen?

In Spain, much construction has taken place on former river land since the 1960s. Since many riverbeds in the Mediterranean region often carry no water for months, people have even built directly in or very close to the riverbeds. This was initially done out of ignorance, but later out of greed. During the construction boom of the 1990s, the permitting procedures and land sales brought significant revenue to local authorities. People were happy to turn a blind eye. Flood-prone areas have only been required to be designated since 2015. But this doesn't help with the thousands of buildings that were built before then.

What does this mean for these buildings? Do they now have to be demolished?

In some cases, this will be unavoidable. At least in high-risk areas where life is at risk, relocations must be considered in the medium term. Elsewhere, protective infrastructure, dams, diversions, or similar measures, might be possible. Because, of course, no one likes to move out of their own home. Nevertheless, in some cases, it will be unavoidable to save lives.

Is this also due to the worsening climate crisis?

Definitely. Extreme weather events such as heavy rain and so-called cold air drops are occurring more frequently and with greater intensity, especially in the Mediterranean region. Our existing hydraulic infrastructure – dams, weirs, canals – is no longer sufficiently dimensioned. During the flood in Valencia, 700 liters of rain per square meter fell – within just a few hours! Such quantities overwhelm any system.

What exactly needs to change?

We need a law that requires municipalities to adapt their development plans to new climatic realities every 15 years. Currently, there is no mandatory revision requirement in Spain—many plans date back to the 1980s. This is a structural risk. Unfortunately, implementation is politically difficult.

Why?

Because governments often roll back projects initiated by their predecessors for ideological reasons. I know this from my own experience. In 2019, I co-developed the "Vega Renhace" plan, which was created after the 2019 floods in southeastern Spain. At that time, floodwaters destroyed the artificial riverbed on the lower reaches of the Segura, causing enormous economic damage. Together with the local community, we collected proposals, partially renaturalized the river, created infiltration areas, and redesigned green spaces – and then a change of government came along. The entire program ended up in a drawer.

There are currently two reconstruction commissions—a state and a regional one. Why is there no cooperation?

This is unfortunately symptomatic of Spain: The different levels often work against each other rather than together. Yet we need the exact opposite – especially when it comes to issues like disaster management. Nature is also often viewed only in terms of its utility: What can I do with the land, how can I develop it? We must finally learn to respect nature's limits.

What do you suggest to change this?

More space for science and experts, for example in risk management. The fact that a political decree was necessary in Valencia to send warnings to the population is absurd. Politicians should set goals and budgets – but the measures must be developed by experts. Otherwise, we risk ideology triumphing over expertise.

Do you have an example of this?

The debate about climate change. Whether it exists or not – that's not the question. The data is clear. We should rather ask ourselves: What are we doing to minimize damage and adapt?