Swedish Cities Adopt Nature-based Solutions for Stormwater Management

Urban areas rapidly expand, and climate change alters precipitation patterns, leading to more intense and frequent rainfall events. This increase in rainfall heightens the risk of flooding, which can damage property, infrastructure, and the environment.

Both water sources flow to wastewater treatment plants in some cities with combined stormwater and sewer pipe networks. Heavy rains can overwhelm these systems, causing them to overflow and pollute the environment.

Such flooding incidents have occurred in Swedish cities, including Gävle in 2021 and Jönköping in 2024, resulting in significant material and economic damage. This emphasises the need for better Swedish Cities to Adopt Nature-based Solutions for Stormwater Management and integrate climate adaptation measures in urban and stormwater management.

In response to the increasing flooding risks and to mitigate damage and costs to cities and their residents, the Swedish government has established two key milestones for sustainable stormwater management. First, all municipalities are required to incorporate sustainable stormwater management practices into new building plans or major renovations by 2023. Secondly, municipalities at risk must have complete mapping and action plans by 2025.

The report “Nature-based solutions in municipal stormwater management in Sweden: costs, co-benefits, responsibilities and policies,” published by the Stockholm Environmental Institute in January 2025, focuses on sustainable stormwater management in Swedish municipalities. It aims to enhance understanding of the planning and policy context surrounding the implementation of nature-based solutions (NbS) in Sweden.

The authors analyse cost estimates associated with various nature-based solutions used for stormwater management in 29 cities across the country. Their research involves searching through databases and municipal websites for relevant information. They then review stormwater management documentation from these municipalities to understand how NbS are discussed regarding their benefits, costs, responsibilities, and the policies that govern them.

The report also assesses how NbS aligns with laws and policies at the national, EU, and international levels. It connects NbS’s benefits to Swedish environmental goals, the EU Taxonomy—which classifies economic activities as environmentally sustainable—and the Sustainable Development Goals (SDGs).

The report focuses on the eight types of nature-based solutions (NbS) used for stormwater management in Swedish cities: green roofs, infiltration trenches, permeable/porous pavements, vegetated/bioswales, rain gardens, wetlands, retention ponds, and detention ponds.

The report finds that of the 38 municipalities studied, 29 had at least one stormwater document. The analysis shows that NbS have been incorporated into stormwater management strategies across all 29 municipalities.

It is clear that NbS plays an integral role in stormwater management in Sweden, even though the specific term “nature-based solutions” is not widely used in these documents. Instead, terms like “open,” “local,” “green and blue,” “sustainable,” and “multifunctional solutions” are highlighted as preferred approaches for managing stormwater.

The co-benefits from these different NbS vary significantly as each provides a distinct benefit. However, identifying the most desirable benefits from each NbS allows urban planners to select what NbS or combination can deliver the best outcome.

All the municipalities’ stormwater documents identified wetlands, retention ponds, detention ponds, and multifunctional surfaces as the NbS that provide the most vigorous stormwater management, flood risk control, and water quality benefits. Lesser co-benefits from these NbS include improving the heat island effect, biodiversity, aesthetics, health and well-being, carbon sequestration, air quality, energy consumption, and noise reduction.

Regarding the division of responsibilities for managing nature-based solutions (NbS) in stormwater management, it is complex for municipalities to do so, as no single entity has full authority. With about 70% of land privately owned, municipalities often lack the legal power to enforce stormwater solutions on these properties. This situation complicates coordination among stakeholders and underscores the need for clearer responsibilities in stormwater management.

The analysis also indicates strong regulatory and policy support for Nature-based Solutions (NbS). Despite this support, regulatory and policy frameworks often fail to fully acknowledge NbS’s multiple co-benefits, which limits the potential to develop a strong business case for their implementation.

To expand the implementation of NbS, the report recommends that cities take the following actions:

1. Support the development of stormwater documents.
2. Standardise cost estimates.
3. Improve data on operation and maintenance requirements.
4. Broaden the focus on co-benefits.
5. Conduct post-implementation evaluations.
6. Clarify and establish roles and responsibilities within municipalities.
7. Increase stakeholder engagement.
8. Recognise and promote the multiple benefits of NbS.

“The findings are intended to provide relevant stakeholders, such as Swedish municipalities, with insights into the availability of cost data for NbS, municipal steering documents for stormwater management, and an understanding of how NbS align with different policies. Limitations of the report include the absence of stakeholder involvement, comparisons with other regional and municipal steering documents, and a thorough economic evaluation of the value of NbS and related co-benefits.”

To learn more about the report, click the link in the “Source” section below.