The Buenos Aires Urban Planning Code zoned and delimits districts, defining the District Ecological Reserve Area -ARE- and defines it as an area, which, due to its environmental character, its physical configuration and its evolutionary dynamics, gives rise to the formation of natural environments where different species of flora and fauna can be maintained in perpetuity or even increase their density, either by maintaining natural conditions or with the contribution of scientific management.
The Costanera Reserve arose from an effort by environmental movements in the city of Buenos Aires to conserve environmentally important areas of the city in the face of real estate pressure. As a result of this process, the Ecological Reserve was formalized in the Buenos Aires Urban Planning Code, which zoned and delimits districts, defining the District Ecological Reserve Area -ARE- and defines it as an area that, due to its environmental character, its physical configuration and its evolutionary dynamics, gives rise to the formation of natural environments where different species of flora and fauna can be maintained in perpetuity or even increase their density, either by maintaining natural conditions or with the contribution of scientific management.
This instrument has as its antecedent the project to gain land from the river in 1972. The Costanera Sur Reserve was therefore not created on purpose, but its origin is due to the construction material that was thrown into the river with the opening of the roads created in the city of Buenos Aires. Little by little, nature was reconquering the land, as the River, the wind, the birds and other elements made the plants and the habitat of wild animals reborn among the rubble. In the face of real estate pressure, environmental movements succeeded in transforming the area into an ecological reserve, which, having been landscaped, now covers an area of 353 hectares, representing 24% of the city's public recreational spaces. The reserve was declared a "Natural Park and Ecological Reserve" by municipal ordinance under the jurisdiction of the Secretaría de Urbanismo y Medio Ambiente del Gobierno de la Ciudad de Buenos Aires.
