The municipality of Leeuwarden, project partner of IB-Green, has ambitious climate goals: Leeuwarden aims to become climate-neutral by 2050, but also more adapted and resilient towards the negative impacts of climate change. Indeed, for the municipality in the Dutch province Friesland, it is urgently necessary to adapt to the consequences of climate change: Studies show the region is vulnerable to diverse risks as a result of climate change, for instance flooding or heat stress.
(c) Photo: Gemeente Leeuwarden
The industrial and business park Hemrik, which is located in Leeuwarden and was built and developed from the 1970s till the 1990s, is particularly vulnerable and affected by the consequences of climate change. The reason for this being that the industrial site not only has very few trees, but is highly sealed, specifically, the surface of Hemrik is made up to 77% of stone. This construction has its price: Heat maps show that the business park will be significantly warmer than the surrounding rural parts of Leeuwarden by 2050. Already now, during periods with severe rain events, the sewage lines beneath Hemrik can become flooded. These effects will be felt by several of the 400 companies that the business parks comprises, and of course the 4,000 employees working in the Hemrik.
In order to counter these risks, the municipality of Leeuwarden is implementing green-blue infrastructure in the Hemrik. Leeuwarden will remove pavement and transform the area into a green space (on 10.000m² in total). Already, the Dutch municipality has successfully planted 103 trees in the business parks on public ground. In addition, Leeuwarden is constructing a bioswale or “wadi” (water infiltration and drainage pasture) on 1.400m².
(c) Photo: Municipality of Leeuwarden; map of IBP Hemrik with location (and species) of planted trees
Bioswales are landscape features in the form of ditches, but with a porous underground. They are specifically designed to soak up water that cannot be absorbed by the ground (like in business parks, which are highly sealed through buildings or pavements for streets). Native plants are used within bioswales to absorb water, but also to prevent erosion.
Specifically, the aim of the bioswale in the Hemrik is to reduce heat stress in the surrounding area, create a livable place for plants and insects, but also to act as a water buffer in case of a heavy rain event, to prevent the sewage system from overflowing. More specifically, the bioswale will work as follows: Rainwater is collected in a sewer pipe or drained upstream to the bioswale. With this we solve flooding in the area around the bioswale. In the bioswale, some water infiltrates into the groundwater. In the event of heavy rainfall, the excess water is drained to the nearby ditch.
(c) Photo: Gemeente Leeuwarden: 1) Status quo of the space where the bioswale is planed, 2) and 3) different variations of how the bioswale could look like
Just recently, there were heavy rainfalls in Leeuwarden and as a result, flooding in the business park Hemrik, showing how necessary and important climate adaptation measures such as the bioswale are.
(c) Photo: Gemeente Leeuwarden
Currently, in Leeuwarden the external procurement of services for the bioswale is ongoing, so that the activity can hopefully be implemented at the beginning of 2025. In addition to these adaptation measures, as part of IB-Green, Leeuwarden is also working with a municipal “green coach”. The aim of this green coach is to offer advice and guidance free of charge to companies on how to implement green-blue infrastructure, as well as to connect these businesses (collectively) with NGOs or national programs that can further aid them in their activities for climate adaptation. In Leeuwarden, this approach is essential, since 75% of the space in industrial and business parks are privately owned.
Contact at Municipality of Leeuwarden:
· Ewout Oppers, ewout.oppers@leeuwarden.nl
Link: https://www.leeuwarden.nl/en/leeuwarden-in-europe/ib-green/