Credit: Andy Hoang, Dines Jørgensen & Co. A/S
More frequent cloudbursts and floods are a growing threat. Copenhagen experienced this in September 2017, when sewage systems gave out, while basements and roads were under water. At Langelands Plads in Frederiksberg, near Copenhagen, a new solution called Rockflow from Lapinus, a part of ROCKWOOL Group, is being used which can both collect and divert the excess water at a more controlled pace - thereby countering flooded cities.

The violent cloud bursts that has hit Danish cities in recent years are not a passing phenomenon. They are part of the new reality that cities, citizens and all aspects of the building and construction value chain must take into account. Unfortunately, the infrastructure in many Danish cities is not built to handle the rising waters, which results in flooded roads and cellars and insurance claims in the millions.

To counter this development, the project around Langelands Plads in Frederiksberg has chosen to use the material Rockflow from Lapinus, part of ROCKWOOL Group, says Ole Larsen director of CALL Copenhagen, an organization which works for climate adaptation and green growth. The organization is a collaboration between the supply company HOFOR in cooperation with the City of Copenhagen, Region Hovedstaden and the waste water company BIOFOS.

Climate change is here now and will still be here tomorrow. The likelihood of bad cloudbursts within the next 50 years is great - and especially in big cities, the massive amounts of water can mean floods in houses and cellars. One can choose to do two things when it comes to climate change. You can sit with your hands in your lap and pay what it costs when the city is hit by extreme amounts of rain. Or you can choose to reduce the damage by using sustainable rainwater management. The latter is far cheaper for society, says Ole Larsen, who emphasizes:


Project location

Rockflow gives us better opportunities to build the sustainable city that is climate-ready.

Ole Larsen

Void Volume

Rockflow is quite innovative and flexible and has a void volume of 95 percent.


One liter of Rockflow is capable of absorbing almost the same amount of water.

Absorptive Capacity

One liter of Rockflow can absorb and retain up to 950 milliliters of water.

Rockflow Copenhagen Video Thumbnail