Let nature do the work!

Stockholm Royal Seaport is being developed with nature-based and regenerative solutions that strengthen the area’s resilience to intense rainfall, drought and heatwaves. The guiding principle is to let nature do a larger share of the work by having water and greenery fulfil several functions. These solutions improve stormwater management, increase biodiversity, create recreational environments and support local urban farming.

An integrated system of different solutions

Because the area is former industrial land, stormwater infiltration is not permitted in order to avoid spreading residual pollutants. Instead, water is handled as a resource in an integrated system of green roofs, residential courtyards, planting beds in streetscapes, parks and ponds. The system reduces the risk of flooding, makes the area more resilient to heavy rain and cloudbursts, and helps to both delay and treat the water. Examples are wet corridors and ponds in Hästhagsparken, and ditches and lowered planting beds along local streets and tree plantings. To meet future sea-level rise, the ground level has been raised and the area slopes gently towards the water, which helps drainage.

Parks, streets and courtyards are designed to accommodate multiple functions on the same surface. So far the city has built 140,000 square metres of green areas – roughly the equivalent of 20 football pitches. These surfaces create meeting places, provide shade and cooling on hot days and contribute to greater biodiversity through varied vegetation. Along the streets there are planting beds with pumice or biochar mixed with macadam, which strengthen growing conditions and bind carbon dioxide.

Green corridors and parks are designed to strengthen natural values and act as dispersal routes for different species. Along these corridors, old oaks are preserved and new ones planted. An insect study shows that preserved oaks in particular are highly important for the movement of insects. To help frogs move around, a dedicated tunnel has been built connecting wet corridors and ponds.

To strengthen biodiversity and resilience, 640 trees of 20 species have been planted, of which 120 are oaks that provide especially valuable habitats for many species. In parts of Gasverket the preserved industrial character limits the scope for greenery.

Sustainability Report 2025: Stormwater and green infrastructure – public land

Strategy document: City of Stockholm's stormwater strategy (in Swedish)

Report: The insect study – Hjorthagen dispersal corridors (in Swedish)

Private land is an important part of the whole

The Green Space Index is a binding requirement that ensures courtyards and other private surfaces contribute to biodiversity, efficient stormwater management and attractive outdoor environments. Property developers generally reach high levels with varied courtyards and green roofs. Studies show that green roofs reduce stormwater flows, improve the sound environment, contribute to lower temperatures and can be combined effectively with solar panels. Resident surveys show that courtyards are appreciated and work particularly well for younger children. Interest in urban farming is rising, which can help strengthen social cohesion and create important meeting places.

Sustainability Report 2025: Stormwater and green infrastructure – private land

Strategy document: City of Stockholm's stormwater strategy (in Swedish)

Strategy document: Green Space Index for private land in Stockholm Royal Seaport (in Swedish)

Article: Nature-based solutions, Green Space Index and stormwater strategy

Article: Green courtyards and roofs in the Stora Sjöfallet block

Soil remediation contributes to better water quality

The ecological links in aquatic environments – especially along the shoreline – are crucial for ecosystem function. Marine biological surveys in Lilla Värtan, at Kolkajen and Ropsten, show limited plant and fish life. When these areas are developed, contaminated bottom sediment will be removed, reducing pollution and, over time, improving water quality. At the same time, measures are planned to strengthen marine life. The ongoing soil remediation on land also reduces the amount of pollutants reaching the water via groundwater, contributing to a cleaner water environment nearby.

Sustainability Report 2025: Improved water quality and bottom sediment

Sustainability Report 2025: Soil remediation

Challenges

Nature-based solutions work well for heavy rainfall, but longer dry spells create a need for artificial irrigation. The availability of suitable areas for food production needs further investigation to secure local growing spaces.

Knowledge of local food production needs to be strengthened.

The way forward

Green roofs consist mainly of sedum with a thin soil layer. The Green Space Index has therefore been developed to create conditions for more robust green roofs, which will now be followed up.

Treated greywater can replace drinking water for irrigation, especially during longer dry spells when water resources are stretched. The level of stormwater treatment also needs to be followed up to ensure pollutants are not carried out to sea.

Local food production is being studied further in the project “Regenerative urban farming meets circular economy”, in collaboration with Bloomberg Foundation.