Daylighting Østerå

After years underground, Aalborg's lost river Østerå will be brought to daylight to bring new nature-based resilience and life to the city.

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Karsten Thorlund

Head of SLA Aarhus, Architect MAA


Aalborg, Denmark


7 ha over a 2 km stretch


2018 — 2023


The municipality of Aalborg


Design leadscape architect

Partners & Collaborators


Daylighting Østerå is an ambitious landscape and climate adaptation project, aiming to reconnect the city of Aalborg with the nature surrounding it.

The water flowing from the southern river valley to the Limfjord has been culverted ever since industrialization. But times have changed: The sewage system has been modernized, and the stream water is clean. Aalborg Municipality now wishes to develop the Østerå area in a way that brings new nature qualities and stronger biodiversity, that adapt the city center to a changing climate, and create new social meeting places.

SLA’s design includes an eventful 2-kilometer route passing through three new lush city parks – along with a multitude of new recreative connections through the city.

The fjord and the river valley
Karolinelund Park

The project connects three new nature-based parks; Karolinelund, Åparken and Gabriel. From here you can follow the open course of the stream and a rich city nature with varied species. With a walking and cycling path throughout the city, the landscape design connects the city from one end to the other: From the magnificent nature to the urban part of central Aalborg.

The opening of the stream will protect Aalborg against extreme rainfalls and cloudbursts. The greater capacity for diversion of rainwater relieves the rainwater catchments of the river and helps to make the city more robust to extreme rain events and cloudbursts.

Daylighting Østerå is a part of Aalborg Municipality’s comprehensive strategy for creating a greener, climate-adapted and biodiverse Aalborg.


Herbarium of plants found around Østerå As part of the early analysis, our biologists did a thorough registration of the local plants and wildlife. The analysis feeds into our planting design while also working as a biodiversity baseline.

The three new riverside parks consist of:

Karolinelund: First a military garden with canals, then an amusement park, now an urban neighbourhood-park with large old trees, historical traces, and activities all day around.

Åparken: A former railway area that has been left to itself, where a unique mix of species, also known as ruderat or terrain-vague, has been allowed to grow between railway tracks and large lamp posts.

Gabriel: The area where the river meets the city, where the watermills and later industry used the hydropower of Østerå river. A green and lush area where the running river will be a good living place for fish.

In each of the three parks, SLA is working with the local vegetation characteristics, aiming at creating a landscape rich in nature, constantly in process, evolving over time.


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