Stockholm Royal Seaport (Norra Djurgårdsstaden) has developed a comprehensive, integrated stormwater system that purifies and slows storm water and meltwater before it is released into the sea. The system connects green roofs and rooftop gardens with ponds, open storm drain water, surface water drains and urban greenery.
Norra Djurgårdsstaden (Stockholm Royal Seaport) is Sweden’s largest urban development area, spanning 236 hectares and is planned to be an attractive, resource-efficient, fossil-free neighbourhood. Its vision is to be an international model for sustainable urbanisation. The new city district will have at least 12,000 homes and 35,000 workplaces.
Combining resilient and attractive environments
One of the most important sustainability issues for Stockholm Royal Seaport is to design the entire district so it can withstand possible future effects of climate change such as high seawater levels, more intensive rain and risk of flooding. It’s also intended to offer attractive outdoor environments during warm and dry periods.
Integrated stormwater system
The area’s stormwater system is integrated with green roofs and rooftop gardens, which interact with water flows in courtyards, streets, grass lawns, rain gardens, ponds and stormwater sewers. The greenery in courtyards and on walls and roofs enhance the surrounding park ecosystems, contributing to a robust ecosystem overall. Urban greenery, stormwater ponds and urban wetlands all work to delay and purify the storm water, which is eventually released into Husarviken bay or Värtan strait.
Directing 75 percent of storm water to plant beds
The objective of the system is to create a robust system to combat flooding, purify storm water and be a resource for irrigation and other ecosystem services. The elevation in the area is designed so the water flows above ground when the system is overloaded. The scheme primarily aims to direct storm water to plant beds for delay and purification. The target is for at least 75 percent of storm water in streets and squares to be directed to plant beds.
Public spaces are designed to provide filtration locally in the form of plant beds to ensure satisfactory stormwater management. The plant beds have a storage capacity that allows them to withstand a long period of drought without irrigation, and to resist high water flows from intensive rain.
The intricate water management system makes Stockholm Royal Seaport a showcase for developing urban and seaside areas that are both resilient and attractive.