Wetlands, those complex ecosystems that combine water and land, have been historically seen as useless land. Until the 20th century, they were considered an obstacle to agricultural development and a source of disease. In Spain, this vision changed in the 1980s, although by then between 60 and 70% of the original surface of these ecosystems had already been lost, according to the Ministry for the Ecological Transition and the Demographic Challenge.
Antonio Guillem, wetlands coordinator at the Global Nature Foundation, explains that these ecosystems act like “sponges” that store and gradually release water, thus protecting from floods and droughts. For a wetland to fulfill this function effectively, it must be in balance, conserving its natural components and maintaining its hydrological cycles. This is the definition of a “healthy” wetland included in the Ramsar Convention, an international agreement for the preservation of these environments.
Spanish wetlands play a critical role in this sense. Guillem mentions cases such as the Doñana National Park, the Ebro Delta and the Santoña marshes, which During heavy rains they retain large amounts of waterregulating its release and reducing the risk of flooding in populated and rural areas. Thus, these wetlands contribute to protecting natural resources and minimizing the impact of extreme weather events on vulnerable communities.
On what occasions have they been effective?
The ability to buffer floods was demonstrated in recent episodes. During Storm Gloria in 2020, the Ebro Delta mitigated the impact of heavy rains in Catalonia. Similarly, in the 2019 DANA, the Albufera de Valencia helped contain water from torrential rains, preventing it from reaching surrounding municipalities en masse. However, andIn the DANA of 2024, the Albufera was overwhelmedhighlighting the importance of preserving the absorption capacity of these wetlands.
Guillem points out that it is essential to avoid pollution, eliminate invasive species and maintain ecological balance, since wetlands They can only fulfill their protective function if they are in good condition. The foundation has revealed worrying data about the situation of wetlands in Spain: barely 20% of them are included in the National Wetland Inventory, which represents an obstacle to their conservation. According to Guillem, protecting these ecosystems should be a priority because they are one of our main natural defenses against climate disasters.