A common situation in Brazilian cities, channeling streams is not a tropical invention. In Europe, this type of intervention dates back to the 19th century. The idea on that time was to rectify water courses, expanding the space for buildings or creating space to open streets.

In Munich, for example, there are 175 kilometers of watercourses running underground. The Green City organization has analyzed one of these streams that is able to run again in the open air. The study revealed that this could happen with the stream that runs through Herzog-Wilhelm-Straße in the central region.

Today, the water runs about four meters below the ground. It would return to the surface with the aid of energy-efficient and greener pumps or turbines – a bit of the energy generated by the river’s water would be used to bring some of it back to the surface. But anyway, why unearth streams?

The reasons are innumerable. The contact of the people with the river, the return of the fauna, attracted by the water, and even the resurgence of the flora on the banks are important within the idea of renaturation and a better quality of life.

But one of these reasons is quite persuasive: air conditioning. Streams naturally chill the environment. On hot days, fresh air corridors are very important to regulate local temperatures. And when the water of such courses is below room temperature, the air circulating with the current produces just that refreshing effect, explains Wolfgang Heidenreich, from Green City.

Brazilians have the idea that even in summer, temperatures are pleasant in German cities. Not always! Hot days are as uncomfortable as our high season. Even the elderly keep avoiding to leave home because of the heat, according to Green City. There, it is always worth to enjoy the outdoors on the rivers banks, fountains, or in the parks that offer the splashes of water so celebrated by the children.

The best-known model when referring to air conditioning is the bächle, small waterways, running through ditches that intertwine in the central part of Freiburg. Conceived for centuries, it had the function of supplying the city with water, also used for firefighting.

Over time, they have inspired legends – they say that anyone who crosses one of these channels will always return to Freiburg, and someone who accidentally steps into one of them will marry someone else.

Another important function, however, is to air the center of this charming university city. Open for most of the year, the bächle can make the well-built region a more pleasant place on hot days.

For this reason, the difficulty with which many Brazilians accept projects to daylight rivers is perplexing. The benefits are numerous and have a positive impact on the poor quality of life of our major centers.