Green infrastructure for stormwater management is a term referring to facilities which are built to handle stormwater in a way which is closer to the natural water cycle, i.e. they should allow infiltration into the ground and evapotranspiration through plants. In addition, they can provide room to store and retain water for a certain time. Examples are grassed swales, retention ponds or green roofs, but all green areas can to some extent serve these purposes. Compared to the traditional way where stormwater is drained through pipe systems, green infrastructure reduces the runoff volume. Some facilities are also designed to improve the quality of stormwater runoff, i.e. to retain pollutants, as e.g. biofilters or rain gardens. Apart from these hydrological purposes, green infrastructure has several other positive effects, e.g. on the microclimate or liveability of the public space.
“The goal to infiltrate storm water and the use of green facilities is not new. E.g. grassed swales have been used for a long time to receive stormwater from roads. However, they are often connected to pipes and thus their full potential is not used. With our new project we want to provide tools for planners to make better use of the full potential of green infrastructure and still ensure that urban areas are safe from floods”, says Günther Leonhardt, Post Doctor at Urban Water Engineering.
Green infrastructure is not a new concept, but we are far from using its full potential. But we see an increasing interest in Green infrastructure from citizens, planners, and politicians. This applies to Sweden and many other European countries. Due to the lower density of many cities, Sweden has a great potential to use more green infrastructure, or to use the existing facilities in an even better way.
"On the other hand, the cold climate imposes special demands on these facilities (e.g. the snow and the thawing of frozen soils in spring), and in our project we will of course address these issues as well”, says Günther Leonhardt.
The project is financed by Formas, Luleå, Skellefteå, Umeå Vatten och Avfall AB, Galären AB and Stormwater&Sewers.