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BY JIMENA MARTIGNONI / PHOTOGRAPHY BY LEONARDO FINOTTI

FROM THE DECEMBER 2019 ISSUE OF LANDSCAPE ARCHITECTURE MAGAZINE.

Porto Alegre is the capital and largest city of the state of Rio Grande do Sul, in southern Brazil. With a population of 1.5 million in the city and about 4.3 million in the metropolitan area, it is one of many Brazilian port cities. Although it is not directly on the coast of the Atlantic Ocean, its location at the confluence of five rivers and at the northern end of Lagoa dos Patos—the largest barrier lagoon in South America—makes it a city that has an essential relationship with water. The Guaraní, the original inhabitants of the region, called the confluence of the five rivers Guaíba, which means the “meeting of the waters.” Today, the locals refer to this space as the Guaíba River or Guaíba Lake, indistinctly.

Given these watery proximities, the city historically has been affected by floods. In the early 1940s, after a devastating flood, a wall went up to cover most of the city’s edge on the river, eliminating its natural relationship with the water and the green spaces on the banks. The city’s residents, however, maintained their longtime habits around these natural areas, visiting and using them spontaneously. Walking, resting, drinking maté, and especially watching the sunset always continued for the locals, despite the site’s increasing state of official abandonment.

In 2011, during the term of Mayor José Fortunati (2010–2017), the Porto Alegre government finally decided to start a plan of restructuring and recovery of the areas above the water’s edge, with special emphasis on the areas near the historic center of the city. Construction began in 2015—major funding came from the Development Bank of Latin America—which put the administration of Fortunati’s successor, Nelson Marchezan Júnior (2017–present), in charge of completing the project. It is unusual in Latin America for two consecutive administrations to be responsible for a project’s implementation. Called Orla do Guaíba in Portuguese (coast of Guaíba), the plan includes the renovation and consolidation of the coastal areas and green spaces along the riverbank and the creation of a linear park at various levels on the edge between the city and the water—levels determined by shoreline modeling performed over the years.

The Porto Alegre city government decided to award the design of the project to the office of Jaime Lerner Associated Architects, based on the Brazilian architect and planner’s specialization and public prestige.

An aerial view of the site and the historic center of Porto Alegre.

In Brazil, the selection of a professional based on the title of “notório saber,” or renowned expert, is applied in exceptional cases under the law of public procurement, leaving aside any call for competitions. Although it was a controversial process that was disputed by the local professional community, Mayor Fortunati prevailed, and the decision was accepted by the regulatory and audit agencies.

Jaime Lerner was a three-time mayor of Curitiba (1971–1975, 1979–1983, and 1989–1992), who led the transformation of the city and implemented a public transportation system and environmental programs that served as models for the world. He was also governor of the state of Paraná (1995–2002), and has been recognized for his accomplishments by the United Nations Environment Program (1990), nominated among the 25 most influential thinkers in the world by Time magazine (2010), and awarded with the Leadership in Transport Award by the Organization for Economic Cooperation and Development (2011).

Image courtesy Jaime Lerner Associated Architects.

Lerner’s office is located in Curitiba, so the government of Porto Alegre created a local coordination base for the development and implementation of the project, called Coordenação de Obras da Orla (“Coordination of Coastal Construction Work”). On behalf of Lerner’s office, the architect Fernando Canalli served as the project director and works supervisor; the environmental and landscape consultant was Carlos Oliveira Perna; and the architect Oscar Coelho represented the city as the general coordinator of the project and construction. Together, these professionals took care of carrying out both the site analysis and the implementation of the different stages of the project. The first stage, completed in June 2018, covers an extension of 1.3 kilometers, and the total project, with its third stage just beginning now, will cover eight kilometers.

The inspiration and conceptual basis of the project was, from the beginning, the patterns of use by residents over the decades as they enjoyed a unique section in the city. “The project consolidates the site’s natural vocation and guarantees it as a public space,” says Coelho. Oliveira Perna, in turn, explains more specifically: “The essence of the project is the contemplation of the sunset—something that the people of Porto Alegre consider as almost their own heritage.”

The bleachers negotiate the elevation changes between street and water levels.

The provision of places to observe the sunset on the water takes on various guises throughout the project and, above all, at different elevations on the site, guided by topography and analysis of various observation points with broad and different perspectives.

The difference between the street and water level is 4.7 meters, and the local flood level is about halfway up, at an elevation of 2.5 meters above the water’s typical level. As part of the flood-protection work carried out by the local government in the past, a containment slope was built along the waterfront at this established flood level, and eventually it was consolidated as a natural part of the rim. This consolidated platform was used in the project to create a continuous esplanade for commercial spaces, cafés, services, and a large pedestrian lawn area that slopes down gently toward the water. The back of the slope was reinforced with gabions as retaining walls; on the surfaces that descend toward the water, horizontal gabions help secure the natural soil. To further hold the soil and to rebuild an aquatic environment, the design team incorporated some of the existing riverbank vegetation cover into these structures.

The full extension of the waterfront, where the first stage was recently completed.

The project segments the site by elevation at formally established levels—five general areas between the water and the street, “respecting the topography and its possibilities,” Oliveira Perna says, “and with a list of 100 percent native plants.” Oliveira Perna toured the natural reserves of Porto Alegre and the region to compile a list of species. Of the five areas, the first two correspond to the aquatic and the edge environment, where it was decided to carry out only conservation and management actions; the third area is the low esplanade and the large pedestrian area that continues toward the water, where the planting plan incorporates species of native grass (Axonopus repens or carpet grass). The fourth area corresponds to the natural slope and a system of concrete bleachers that negotiate the existing elevation changes, where diverse herbaceous plants and shrubs define edges and outline spaces. The fifth area is an upper esplanade, which includes a walking path and a bike path, and is the only section where large numbers of trees were planted, including fruit and flowering species. “With this linear space, we want to generate a buffer,” Oliveira Perna explains.

As the sun sets, tiny lights appear on the pavement and invite visitors to stay for night events and sky watching. Photo courtesy Arthur Cordeiro Rodrigues.

The highest level is the most dynamic—in direct contact with traffic, heavily used vehicular arteries, and the noise and movement of the city. This upper esplanade is also where visitors find a magical 300-meter-long installation with fiber optic lights laid into the pavement. When the sun goes down and daylight fades, thousands of tiny lights suddenly glow, all at the same time, to create a piso estrelado or “starry floor.” It’s a huge draw for people who come to delight in these new connections to the water’s edge. The sunset hour is, without exception, the most crowded.

Jimena Martignoni is a landscape architect, writer, and curator based in Buenos Aires.