Valencia's floods and the consequences of short-sightedness
Image: ESA/Copernicus Sentinel-2
The severe flooding around Valencia is undoubtedly tragic but not unexpected. This disaster raises questions: was it due to mismanagement of excess water, or was it a consequence of ignoring clear warning signs, asks Matt Minshall
No disaster works in total isolation, and most situations are an accumulation of natural and fabricated circumstances leading to incontrollable climate events. This blog does not look directly at human-caused disasters, such as accelerated climate change, war, or human-induced medical problems, nor the natural ones, such as earthquakes. The focus is on water, which, if there is a single factor, is the one most likely to cause the early extinction of humanity. It will also allude to human complicity in the negative effects of nature’s power through short-termism exacerbated by delusion, ignorance, and greed.
Natural disasters are highly topical crises. It is rare that a day goes by without the announcement of an event that destroys lives and property. In 2023, the Emergency Events Database (EM-DAT) recorded a total of 399 disasters related to natural hazards, all of which took and destroyed lives and had a significant effect on local infrastructure and the global economy. But if such collapses are now so commonplace as to be prevailing, surely it requires a different approach.
The strong link between climate extremes and rising global average temperatures will mean more droughts and rainstorms that are more intense, more frequent, more severe, longer, and larger. Flooding is not new or attributable exclusively to the human acceleration of climate change. The earliest historical mention of a great flood is found in the Eridu Genesis and the tale of the Sumerian Flood. This ancient Mesopotamian text dates back to around 1600 BCE, but is believed to be much older and preserved through oral tradition. Notable examples include Ancient Mesopotamia, China, Europe, South Asia, and right up to the global daily news items.
The increasing frequency and severity of floods due to climate change and urbanisation continue to pose significant challenges worldwide. Building houses in river valleys, despite the risk of flooding, is common practice. Despite the obvious name, which indicates that the valley was carved out of the earth and rock by the effect of water, it has endured throughout history.
Image: ESA/Pléiades Neo
The reasons are understood. The land has rich, fertile soil due to the deposition of silt during floods. This makes them ideal for agriculture, historically a primary reason for settling in these areas. Apart from the benefits of proximity to water for drinking, irrigation, and other daily needs, rivers have historically served as important commerce and communications routes. Modern river valleys often host industries and businesses that rely on water, and naturally they often offer picturesque landscapes, making them attractive places to live. But it is only relatively recently that aesthetic luxury has become a factor for residence selection.
The benefits are significant, and the risks of flooding are also well-known but seem less considered than in the past. To mitigate the risks, many communities invest in flood defences such as levees, dams, and floodplain management strategies. Flood defences and dams, while effective in managing water flow and preventing floods, come with several downsides, including environmental impacts.
Dams can significantly alter ecosystems, and if the defences fail, the consequences can be catastrophic, leading to sudden and severe flooding. This risk necessitates rigorous maintenance and monitoring. While dams can control water flow, they can also increase the risk of flooding downstream if not managed properly. These downsides highlight the need for careful planning and consideration of alternative flood management strategies, such as natural flood management and sustainable urban drainage systems.
Large areas of concrete in a river valley increase flood risk due to reduced permeability, increased runoff speed, drainage system overload, loss of natural floodplains, and the urban heat island effect. These factors highlight the importance of incorporating green infrastructure, such as permeable pavements, green roofs, and urban green spaces, to mitigate the flooding risks associated with extensive concrete development. Valencia highlights these factors.
Valencia is Spain’s third-largest city, and the metropolitan area population of 1.5 million is an 80 per cent increase since 1957. Around the city is an agricultural area – the Huerta - irrigated by the Turia River using dams from the Islamic period and covers around 10,500 hectares. Valencia was hit by a known phenomenon called Depresión Aislada en Niveles Altos (DANA), which is isolated depression at high levels. According to Spain's State Meteorological Agency (Aemet) it was the most severe DANA of the 21st century, and comparable to the catastrophic ‘Pantanada de Tous’ in 1982. It also happened in 1957, twice in the 1980s, as well as in 1996. But following the 1957 flood, urban planning prioritised infrastructure over the Huerta, leading to an 8,000-hectare increase in Valencia’s artificial surface from 1984 to 2011. Noting there is evidential experience and repetition, it would seem the crisis is not the events but the refusal to accept them as normal, or that lucrative businesses have an unbalanced power over community safety. But following the 1998-2008 property boom, which further accelerated the urban sprawl, social movements began to protect the Huerta. A legislative initiative began in 2000 with popular support, but protective laws and an action plan were only approved in 2018. Since then, various initiatives have emerged, fostering balanced leadership among public institutions, stakeholders, civil society, and the private sector, and while it is too late to prevent or even mitigate disaster, it will hopefully accelerate the future protection of life and infrastructure.
In the immediate aftermath of the tragedy, Jess Neumann, associate professor of hydrology, at the University of Reading, said: "We take preparation for other hazards such as earthquakes and tsunami very seriously…it is time we afforded the same to flood risk preparedness."
Humankind can no longer hide their heads in the sand, hoping that the next deluge will happen to someone else. Flooding will happen again and in increasing regions and numbers, and unless we are prepared, each disaster will be greater than the last. The post-disaster report from Valencia will hopefully create a structure for further prevention and warning for local and global benefit. If this does not happen, it will soon become glaringly apparent that the crisis is not the flooding but the refusal to acknowledge its inevitably.