Green and blue are two colors that do not seem to fit together, but when you look around, it’s the colors that dominate nature. Green represents our forests, parks and gardens. Blue is the product of water reflection in our retinas.
So it is possible to imagine that the green and blue infrastructure relates to how we can live in greater respect for the environment, and less dependence on concrete and asphalt.
The so-called “Blue and Green Infrastructure” proposes to solve the functional problems of a city in a more economic way, privileging the environmental preservation and benefiting the people.
Within this planning mode, constructed infrastructure works in conjunction with natural or semi-natural spaces, such as lakes, tanks, orchards, lawns, and waterways. Together, they will be important for situations such as natural retention of rainwater or tides, as well as drainage, mobility, sustainable food production and, of course, recreation. The landscape thus becomes a new way of designing the infrastructure, from natural processes.
The traditional model of urban drainage is formed by interconnected networks of underground channeling. In large Brazilian cities, high-cost investments in such sanitation works are not enough for all the drainage required. With heavy rains, floods and floods are a constant.
The “green and blue” concept could complement the traditional and expensive strategy with the creation of landscaped green areas that also function as a natural drainage mechanism. It is a mixed system, in which the common channel receives the help of nature.
This strategy is also good for other systems. Instead of betting on a model that only works with for motor vehicles, it is possible to conceive a multifunctional infrastructure next to the landscape, where the parks welcome other mobility flows, such as the bicycle path.
The infrastructure, in cases like the Netherlands, also gives conditions for the use of space for much more than just locomotion. It can solve other problems of urban planning. Along with the bike ride, a park can also improve urban drainage. Instead of just increasing the underground pipe, an expensive work that closes the street, there are gardens and sports courts, planned to eventually fill with water, avoiding flooding.
A Dutch project that goes a long way in this direction is the Water Squares project – which is concerned with drainage but also offers leisure, sports and health spaces for the population.
In Denmark, by federal government policy, cities needed to plan climate change adaptation. With major cities subject to increased tidal levels and periods of heavy rains, they need to minimize losses due to extreme water events. Studies have shown that the adoption of green and blue infrastructure makes the works necessary to mitigate floods in a more economical way. The figure is a quarter of the cost, compared to the traditional urban drainage model, according to researchers at the University of Copenhagen. There are other interesting situations involving the contracts of utility companies, such as the ten-centimeter height for street flooding, which can not be exceeded in the capital Copenhagen. Thus, the utility company decided on the most economical solution, involving concepts of “green and blue” along with the traditional solution.
Curious is to notice that such a creative, cheap and useful way of thinking still finds little echo in Brazil. The multifunctionality of green and blue infrastructure should be considered here. Adding to a functional structure environmental values, such as natural and landscaped areas, and social values such as parks, is also a more economical solution for Brazilian cities. This is to solve problems in a sustainable way through urban design.