Below the surface – Sediment from risk to resource in urban stormwater flows

Project partners: Växjö Municipality, Luleå University of Technology, Tecomatic AB, Tekniska verken in Linköping, Linköping Municipality, Örebro Municipality, Stockholm Vatten och Avfall, Mittsverige Vatten & Avfall, Lumire, Trafikkontoret och Miljöförvaltningen i Stockholm Stad, Miljö och Vatten i Örnsköldsvik AB

Grant: 13,500,000 SEK

Project period: 2025-11-05 to 2028-11-04

Contact person: Malin Engström, Växjö Municipality

Linked to tasks: Secure the supply and management of water; Ensure good drinking water quality; Adapt society to flooding and drought; Build and manage society in harmony with water; Recycle and reuse water and its resources; Reduce negative impacts on the water ecosystem; Prevent and reduce the spread of hazardous substances

Purpose and goals

Pollutants from urban environments are often bound in sediment and transported to stormwater facilities such as ponds, ditches, and wells. These facilities aim to purify the stormwater, as well as protect lakes, watercourses, and groundwater, and they also function as buffers to reduce the risk of flooding. However, their function deteriorates when the sediment is not removed. Maintenance is often insufficient due to unclear lines of responsibility and the challenges associated with managing large quantities of sediment, even though the sediment constitutes a previously untapped resource. The project’s purpose is to change the perception of urban sediment, moving from a waste problem to a resource, and to integrate it into water management through technical solutions, policies, and forms of collaboration that reduce the spread of pollutants, strengthen infrastructure, and enable circular use and resource extraction.

Expected effects and results

Efficient and regular maintenance of stormwater facilities contributes to Resilient water supply and management in society. Well-functioning and long-term sustainable water solutions in water-friendly urban areas reduce the spread of harmful substances to surface water and groundwater and strengthen climate adaptation. Sustainable sediment management contributes to stormwater sediment being seen as a resource in circular flows, in line with the goal of Wise water use. By capturing hazardous substances before they reach recipients, the project contributes to Thriving lakes, watercourses, and groundwater. Since the results are relevant to both Swedish municipalities and the rest of the world, they are scalable at a national and international level.

Planned structure and implementation

The project is based on collaboration between research, municipal operations, regulatory authorities, and technology developers who collectively cover the entire spectrum of roles required for development and implementation: from needs owners, users, and recipients to enablers, solution owners, and experts. The project is structured into three developmental journeys—concrete sub-projects that reflect the system’s central change needs: Technical framework for smart maintenance and sampling in stormwater systems; Institutional framework for governance of maintenance and sediment management in stormwater systems; and Extraction and reuse of stormwater sediment to prevent spreading to water bodies.

The text on this page was formulated by the project group itself. The content has not been reviewed by our editors.