Københavns Universitet      -        Det Natur- og Biovidenskabelige Fakultet

Innovative stormwater solution unveiled to tackle record rainfall in Denmark

Del

RAIN WATER: Denmark faced unprecedented rainfall in 2023, breaking historical records and posing ongoing challenges with stormwater and flooding of streets and basements. Rather than resorting to expanding CO2-intensive concrete sewer networks to handle runoff, Professor Marina Bergen Jensen from the University of Copenhagen proposes to manage stormwater at its source and treating it as a valuable resource.

The invention, disguised as a three-meter-high willow garden fence, is named the "Green Climate Screen." This solution has already been successfully implemented in the Copenhagen district of Valby. Photo: Department of Geosciences and Natural Resource Management.
The invention, disguised as a three-meter-high willow garden fence, is named the "Green Climate Screen." This solution has already been successfully implemented in the Copenhagen district of Valby. Photo: Department of Geosciences and Natural Resource Management.

In response to the increasing frequency of heavy rainfall, many Danish cities are considering extensive sewer expansion projects. However, Professor Marina Bergen Jensen argues that this traditional approach is outdated. Her research focuses on implementing nature-based solutions for urban stormwater management, emphasizing the need to capture stormwater locally, near individual buildings and roadways, to alleviate stress on sewer systems and promote resilience against both flooding and drought.

"It's as if we only see one side of the climate extreme – too much water. We forget that there can also be far too little water and that water is a resource. Instead of expanding our sewers and making giant concrete tunnels and basins, which in themselves contribute to global warming, we should manage stormwater locally around individual buildings and roadways. In this way, we can become more resilient against both flooding and drought, while relieving the pressure on our sewer systems," says Professor Marina Bergen Jensen of the Department of Geosciences and Natural Resource Management.

Professor Jensen acknowledges the challenges associated with implementing nature-based solutions, known as stormwater-NbS, as they often require additional space. However, professor Jensen and her colleagues have developed an innovative technology that outperforms both traditional sewer expansions and first-generation space requiring Stormwater-NbS solutions.

A three-meter-high willow garden fence

The breakthrough invention, disguised as a three-meter-high willow garden fence, is named the "Green Climate Screen." This solution has already been successfully implemented in the Copenhagen district of Valby. The Green Climate Screen doubles as a noise barrier and manages runoff from a neighboring building's roof, redirecting the water upward into the screen instead of sending it to a sewer.

Using gravity, the system channels roof water to the top of the fence, where it is absorbed by the central material. The water then evaporates from the climate screen, providing an efficient and sustainable solution. During heavy rainfall events, excess water can be stored on an adjacent lawn, demonstrating the system's capacity to handle extreme weather conditions, exceeding the 100 y event.

"The system utilizes the potential energy of the roof water to lead the water away from the building and up into the freestanding green climate screen from which it evaporates, infiltrates or is detained on a neighbouring area surrounded by a shallow soil dyke," explains Marina Bergen Jensen.

Importantly, the Green Climate Screen achieves all this without the need for soil excavation, pumps, or concrete. This opens up new possibilities for implementing effective stormwater solutions even in confined spaces, according to Professor Jensen.

In addition to noise reduction the Green Climate Screen can provide other unique opportunities, such as linking to biodiversity, recreational areas, or urban cooling initiatives.

Widespread adoption of local systems

To bring about a substantial impact in stormwater management, Professor Jensen points to the need for widespread adoption of local systems like the Green Climate Screen. Here social housing and cooperative housing associations may provide good starting points. However, she emphasizes the need for legislative support, guidance, and financial incentives for landowners to facilitate the transition to these innovative solutions.

"One could begin by introducing it in social housing and cooperative housing associations. They are often well-organized and can take responsibility, as well as having large rooftops and green areas that could benefit from the water. If we could get that far, we will have come a long way," says Marina Bergen Jensen.

The Green Climate Screen's operational details include managing rooftop runoff through a communicating vessels principle, distributing stormwater along the screen's length, and utilizing mineral wool to absorb and evaporate water. The system is designed to withstand up to 10 years of rainfall and can handle extreme events, aligning with Copenhagen's Cloudburst Plan targeting 100 years events (90 mm in 24 hours).

Read further details on how the Green Climate Screen works

Kontakter

Marina Bergen Jensen
Professor
Department og Geoscience and Natural Resource Management
University of Copenhagen
mbj@ign.ku.dk
+ 45 27 24 44 47

Michael Skov Jensen
Journalist and team coordinator
The Faculty of Science
University of Copenhagen
Mobile: + 45 93 56 58 97
msj@science.ku.dk

Følg pressemeddelelser fra Københavns Universitet - Det Natur- og Biovidenskabelige Fakultet

Skriv dig op her, og modtag pressemeddelelser på e-mail. Indtast din e-mail, klik på abonner, og følg instruktionerne i den udsendte e-mail.

Flere pressemeddelelser fra Københavns Universitet - Det Natur- og Biovidenskabelige Fakultet

Twenty years on, biodiversity struggles to take root in restored wetlands11.2.2025 11:00:10 CET | Press release

While the restoration of natural areas is high on political agendas, a comprehensive new study from the University of Copenhagen shows that – after more than two decades – biodiversity growth has stalled in restored Danish wetlands. The results also suggest that time alone will not heal things because the areas are too small and dry, and nitrogen inputs from agriculture continue. According to the researchers, we need to learn from the past.

Efter 20 år halter biodiversiteten stadig i genoprettede vådområder11.2.2025 10:36:50 CET | Pressemeddelelse

Genopretning af naturområder er lige nu i politisk høj kurs, men et nyt omfattende studie fra Københavns Universitet viser, at biodiversiteten stadig halter i de genoprettede danske vådområder efter mere end to årtier. Samtidig tyder forskningsresultaterne på, at tid alene ikke vil ændre på dette, for områderne er for små, for tørre og tilstrømningen af kvælstof fra landbruget er fortsat. Derfor må vi lære af fortiden, påpeger forskerne bag studiet.

Many Greenlanders Face 10 Times Higher Risk of Diabetes – Exercise May Be Their Only Solution21.1.2025 11:07:00 CET | Press release

A significant portion of the Greenlandic Inuit population carries a genetic variant that increases their risk of type 2 diabetes tenfold. Now, researchers from the University of Copenhagen have discovered that the key to addressing this issue lies solely in their muscles. Unfortunately, existing medications are unlikely to help – and in fact may even do more harm than good. On the other hand, the study reveals that physical exercise could have a positive effect.

Mange grønlændere har 10 gange højere risiko for diabetes – motion kan være den eneste løsning for dem20.1.2025 06:16:00 CET | Pressemeddelelse

En høj andel af den grønlandske inuitbefolkning har en genvariant, som giver dem 10 gange højere risiko for type 2-diabetes. Nu har forskere fra Københavns Universitet fundet ud af, at nøglen til det hele udelukkende sidder i deres muskler. Det betyder, at den medicin, der findes i dag, sandsynligvis ikke vil hjælpe dem – måske snarere tværtimod. Til gengæld vil motion kunne bidrage positivt, viser studiet.

Antarctica: Historic Drilling Campaign Reaches more than 1.2-Million-Year-Old Ice9.1.2025 11:00:00 CET | Press release

An international team of scientists successfully drilled a 2,800-meter-long ice core, reaching the bedrock beneath the Antarctic ice sheet. These ice samples are expected to unveil, for the first time, critical details about Earth's climate and atmospheric history, extending beyond 800,000 years ago and showing a continuous record of the history of climate and greenhouse gasses as far back as 1.2 million years, and probably beyond.

I vores nyhedsrum kan du læse alle vores pressemeddelelser, tilgå materiale i form af billeder og dokumenter samt finde vores kontaktoplysninger.

Besøg vores nyhedsrum
World GlobeA line styled icon from Orion Icon Library.HiddenA line styled icon from Orion Icon Library.Eye