Understanding eutrophication processes and restoring good water quality in Lake Ringsjön - Rönne å Catchment in Kattegat, Sweden

The Rönne å catchment with its municipalities and two subcatchments managed by two different water councils. Source: Romina Martin, SRC
Area characterisation: 

Rönne å catchment area is a river watershed located in Southern Sweden and includes lakes (e.g. Ringsjön), rivers (Rönne å) and marine coastal areas (Kattegatt). Institutional and governance challenges are a particular issue in the Rönne catchment, site of Case Study 6. When implementing the WFD, Sweden introduced water councils in the catchments. However, the legal role / structure of water councils differs between catchments. Whereas in a neighbouring catchment (KRC), cooperation between the municipalities and councils was settled with a contract, this is lacking for the Rönne Å catchment. Additionally, water council participants (the most local institution for the WFD) often lack a legal mandate to foster decisions and restoration activities, which limits decisions and implementation. To combat these issues, there are discussions and conflicting opinions if two water councils in the catchment should potentially merge: RRC - Rönne Å River Council and the council for Lake Ringsjön. This might extend the comparatively strong restoration activities around the lake to the whole catchment where those activities where less prominent in the past.

Objective: 

Rönne å catchment area is a river watershed located in Southern Sweden and includes lakes (e.g. Ringsjön), rivers (Rönne å) and marine coastal areas (Kattegatt). The AQUACROSS Case Study looks at the process of eutrophication and restoration of good water quality and their implications for the provision of ecosystem services along the Rönne å catchment.

Actions: 

The Case Study is based on the science of Social-Ecological Systems and the resilience principles. Through stakeholder engagement and workshops, it considers options to improve the governance of the Rönne catchment. These workshops and stakeholder groups also consider management options to improve local water quality and ecosystem service provision. They include management of the turbid lake Ringsjön through biomanipulation and municipal sewage plans to decrease eutrophication from private sewage treatment. Changing the dynamics in lake Ringjsön through biomanipulation will have benefits for recreational fishing and tourism stakeholders in the future, but is very costly for the adjacent municipalities now. Upgrading private sewage systems is very costly for house owners and the benefits therefrom are difficult to visualize. The Case Study also aims to collaborate with stakeholders to identify win-win solutions or to reconcile perceived trade-offs.

Potential impacts/benefits: 

Institutions in Swedish water governance is complex with multiple actors and frameworks on all scales: local (water councils, municipalities), regional (county administrative boards, water authorities), national (Swedish jurisdiction) and EU (water framework directive). This calls for knowledge about social-ecological complexity, best-practice water governance, and how cross-sector collaboration (or lack thereof) might influence environmental problems and essential ecosystem services. In particular, the Case Study looks at the process of eutrophication and restoration of good water quality and their implications for the provision of ecosystem services along the Rönne å catchment.

Transferability of the result: 

This project is a Case Study under the Horizon 2020 project AQUACROSS, which builds on work undertaken in the previous pillars to develop concepts, practices and tools for better implementation of Ecosystem Based Management. This includes identifying and understanding the linkages between aquatic ecosystems and human well-being and identifying innovative management responses for aquatic ecosystems.

Lessons learned: 

As part of the Horizon 2020 AQUACROSS project, this Case Study seeks to advance the application of Ecosystem Based Management for aquatic ecosystems. AQUACROSS aims to develop and test an assessment framework, which considers the full array of interactions, including human activities, within aquatic ecosystems.