Concretitis in cities versus green and blue infrastructure – how to avoid flooding and inundation during heavy rainfall?
13/05/2022
Concrete squares, trees cut down, tiny lawns and ubiquitous asphalt – this is more or less how most Polish cities look today. This phenomenon is called conretitis. The word perfectly reflects the nature of the problem, emphasising the almost morbid intensification of the trend of making the cities look concrete. Unfortunately, it is associated not only with a purely aesthetic issue, but also – or even primarily – with great difficulties for the Polish cities. Water drainage is inadequate, resulting in increasingly frequent flooding and inundation.
Concretitis – what does it actully mean?
In scientific and media discussions, as well as in public space, the word concretitis can be heard more and more often. The term, invented by Jakub Madrjas and popularised by Jan Mencwel, has become a symbol of the changes taking place in many Polish cities. Changes for the worse.
The trend to talk about concretitis in Poland began in 2019. It was then, during a summer heat wave, that Mencwel began publishing on Twitter a series of posts with photos of Polish town squares and urban spaces that, as part of an ill-conceived revitalisation, had turned from green squares into concrete-covered courtyards.
This has many unpleasant consequences. A simple thermometer test is enough to discover how rapidly the temperature rises in areas where trees have been felled. In the summer, trees serve as natural umbrellas that effectively protect us from the sun, giving us respite in the heat. Places without them become hotspots, deserts in which it is impossible to stand.
Trees provide shade, are great at storing water, inhibit street dust from entering homes, and filter the air. And these are just a few of their functions. Activists from the Krakow for Residents group took temperature measurements on streets planted with trees and those without. The conclusions are shocking. In certain spots without trees the temperature rises by as much as 20 degrees!
Floodingsof the Polish cities – where does the problem come from?
But the problem of tree felling is not everything. Concretitis is affecting the urban fabric in a wider context. Lawns are disappearing and being replaced by asphalt, cobblestones and other water-repellent materials. And this has serious consequences. One of these is flooding and flooding associated with heavy rainfall.
An example of poorly conceived revitalisation that has taken place in Poznań is the renewal of the Łazarski Square. Unfortunately, the modern design did not take vegetation into account, replacing it with geometric blocks and single flower pots.
Green-blue infrastructure
Urban concretitis is a disease that affects many cities, making it difficult for residents to function normally. Problems arise both in hot weather and during heavy rainfall. To stop this phenomenon, systemic measures are needed.
One of the changes Polish cities should make is to invest in green-blue infrastructure. This is based on a modern approach to climate change and the problems associated with it. As part of such work, localities are to change the way they are being developed. Green roofs, facades or elements related to sustainable water management should appear.
In urban, highly developed environments, these nature-based solutions (NBS) can support ecological activities. They can be successfully placed, for example, among elements of road infrastructure, in housing estates or office buildings. NBS are supposed to eliminate problems connected with concretitis in the cities by introducing elements necessary for reasonable management of, for example, water. In this way, a single element of such infrastructure can simultaneously contribute to safe rainwater collection, drainage and mitigation of urban heat island effects.
The Bydgoszcz revolution, a step towards a sustainable future
Bydgoszcz is one of the cities that have decided to carry out such a green-blue revolution. The city’s authorities decided to adapt it to climate change and invest more than 230 million PLN in the expansion of the rainwater system. Almost 20 kilometres of rainwater canals, numerous retention tanks and almost 30 rainwater treatment plants are currently being built.
A Hydrozone retention tank with a diameter of 8000 mm, a height of 5.4 m and an internal length of 17 m was installed in Bydgoszcz at Równa Street. The entire structure was made of high quality watertight concrete, and the capacity of the retention tank was 312 m3.
Thanks to the changes that are taking place in the city, the problem of flooding and inundation will be reduced or perhaps eliminated altogether.
HYDROZONE retention tanks allow the retention, treatment and use of rainwater and snowmelt. There is also an increase in the possibility of safely draining excess water from city centres, which translates directly into more effective flood control measures.
This, fortunately, is already happening. More and more local authorities are recognising the importance of the problem and are starting to invest in green-blue infrastructure elements. And this saves us from the serious consequences of short-sightedness.