Wetlands are ecosystems where water is present, either permanently or temporarily, and acts as an environmental regulator. They are found in coastal, Andean, rural, and urban areas. They can be natural (lakes, estuaries, marshes) or artificial (rice fields, dams), and present enormous biological diversity.

These are natural or artificial areas. They are soils saturated or flooded with water, which can retain water temporarily or permanently depending on the type of soil, vegetation, rainfall, and the water cycle. Wetlands benefit flora and fauna thanks to the presence of water, in addition to filtering pollutants and regulating water. Despite their value, they are often threatened by human action due to pollution and inappropriate land use. Their protection is essential due to their benefits to flora, fauna, and society.

Wetlands perform a variety of essential functions for both the environment and human communities. These ecosystems act as living systems that maintain the natural balance of the planet. Its main functions include water regulation and protection against natural disasters, among others.8

Wetlands are typically found in areas where water accumulates naturally or artificially, such as on coasts (estuaries, mangroves), river valleys, plateaus, areas with high humidity or high groundwater levels, and even in urban areas. They form where the soil remains saturated with water for much of the year.

The loss of aquatic biodiversity, mainly caused by human activity, has severely deteriorated the ecological dynamics of wetlands. This has affected key functions such as the nutrient cycle, biomass production (the total matter of living beings inhabiting a given area), and the flow of organic matter (matter made up of chemical compounds containing carbon atoms). This is revealed by a study published in Nature Ecology & Evolution, which warns of the urgent need to reduce human pressure on these ecosystems.

In this context, Chile enacted LAW 21.202, known as the Urban Wetlands Law, with the aim of protecting and conserving these spaces within urbanized areas. This law requires municipalities to identify, declare, and safeguard wetlands, recognizing their importance for biodiversity and the ecosystem services they provide, such as water regulation, purification, flood control, and protection against climate change. However, its real impact depends on effective implementation and on political and civic will that prioritizes conservation.

The importance of this law lies in protecting and preserving areas of urban ecological relevance. It is worth noting that a law encompassing rural areas—which tend to be overlooked by the State—is also necessary.

Wetlands are home to a wide variety of animals (waterfowl, amphibians and reptiles, fish, invertebrates and mammals), as well as vegetation (cattails and rushes, duckweed and algae).