Nature-Based Stormwater Solutions In Focus at MUSTBE Final Event

Researchers, engineers and city representatives gathered in Viimsi, Estonia on March 17th to share insights from the MUSTBE project, highlighting how nature-based solutions, real-time monitoring and cross-border collaboration can improve urban stormwater management. The event culminated the collaborative work of several years across the Central Baltic region.

Throughout the event, experts shared experiences from pilot sites in Finland, Estonia, Latvia and Sweden, discussing both the technical design process and the practical lessons learned when implementing nature-based solutions in urban environments. The topics highlighted the importance of combining engineering expertise, environmental research and municipal cooperation in order to develop stormwater systems that are not only technically effective but also environmentally sustainable and adaptable to future climate conditions.

Designing Solutions For Complex Urban Environments

One of the key presentations addressed the technical design process and multidimensional analysis of the MUSTBE pilot sites. Designing nature-based stormwater systems requires careful consideration of multiple factors, including hydrology, water quality, soil conditions, available space and existing infrastructure. Unlike conventional systems, nature-based solutions often need to balance several objectives simultaneously, such as improving water quality, supporting biodiversity, reducing flood risks and enhancing urban environments.

The project applied a multidisciplinary design approach, analysing each pilot site from several perspectives before selecting the most suitable solutions. Kerta Kõiv from TalTech introduced the participants to the multidimensional analysis of the MUSTBE pilot solutions. The analysis aided in ensuring that the implemented systems respond effectively to the specific environmental and urban conditions at each location.

Experiences Across The Central Baltic Region

During the event, participants were also introduced to the Interreg Central Baltic StoPWa project, which focuses on developing innovative stormwater treatment solutions using materials derived from construction and demolition waste. Sergei Preis from TalTech presented how the project explores the use of recycled materials in filtration systems, supporting both improved water quality and circular economy principles. Laboratory and field studies have been carried out to evaluate the performance and environmental impact of these materials, alongside life cycle assessments comparing different treatment approaches.

The event also presented experiences from nature-based pilot solutions across the Central Baltic region. Indrek Tamberg from Keskkonnalahendused OÜ presented the nature-based stormwater treatment system implemented in Tondimõisa Park to improve water quality and reduce flooding risk by partially redirecting stormwater from the city’s stormwater pipe network for treatment in the park. Māra Reča from Riga City Council City Development Department showcased the Riga pilot solution, where the solution is being implemented along the Šmerļupīte river to restore natural stormwater processes and improve water management in urban catchments. Two pilot sites in Söderhamn, presented by Josefin Flink from the municipality of Söderhamn, demonstrate how stormwater solutions can be integrated into urban planning while addressing site-specific environmental conditions. In Pori, pilot sites include both an urban square solution and a restored wetland, showing how nature-based approaches can be applied in different environments, as presented by Aleksi Siirtola from the city of Pori.

Monitoring Performance Through Data and Sensors

At the core of the MUSTBE project is also monitoring and performance evaluation, which was presented by Jurijs Kondratenko from RTU. The monitoring framework developed within the project combines water quality analysis, real-time sensors and hydraulic modelling to assess how nature-based solutions perform over time. Measurements are conducted both before and after implementation, enabling comparison of system efficiency and environmental impact.

The monitoring programme focuses on key indicators such as nutrients, suspended solids, pathogens, hydrocarbons and heavy metals, alongside hydrological parameters including rainfall, water levels and flow velocity. Real-time sensors provide continuous data on parameters such as pH, turbidity, conductivity and temperature, supporting more informed stormwater management and system optimisation.

Preliminary results show varying outcomes across the pilot sites. At the completed site in Pori, monitoring indicates a clear reduction in pollutant levels. At sites newly constructed or still under construction, improvements are not yet fully visible, and in some cases temporary increases in certain indicators were observed during construction phases. The results also highlight the strong influence of rainfall conditions, underlining the importance of long-term monitoring.

Visiting Real World Examples

After the presentations, participants had the chance to visit and get to know more about not only the MUSTBE Viimsi pilot solution but also the nearby LIFE LATESTadapt pilot site, where the nature-based concepts discussed during the day could be seen in practice. The MUSTBE Viimsi solution focuses on stormwater retention, reuse and flood prevention, collecting runoff from a catchment area of approximately 19 hectares. The solution has been integrated into a multifunctional recreational landscape, demonstrating how stormwater infrastructure can also enhance public spaces. One of the visible features of the site is a fountain powered by collected stormwater, illustrating how stormwater can be treated as a resource while saving precious drinking water.

The LIFE LATESTadapt solution features a smart stormwater collection tank and a sustainable urban drainage system. Stormwater is used up to automatically water plants and additionally, a pedestrian path makes the area more attractive and functional for the public.

Lessons For Future Stormwater Management

The MUSTBE project has demonstrated how nature-based solutions can complement traditional stormwater infrastructure while providing additional environmental and social benefits. The project highlights the importance of cooperation between municipalities, researchers and engineers in developing effective and sustainable solutions. The knowledge generated through the project has been compiled into a manual of solutions, documenting the implementation and lessons learned from pilot sites across the Central Baltic region. As climate change increases rainfall intensity and urban flooding risks, these experiences provide valuable guidance for cities seeking more resilient and sustainable approaches to stormwater management.

The final event in Viimsi marked not only the conclusion of the project’s main activities, but also an important step toward wider adoption of nature-based solutions in urban water management across the Baltic Sea region.

Presentations

• MUSTBE project in short | Siim Reinla, MUSTBE project’s Lead Manager, Municipality of Viimsi, Estonia
• Tallinn pilot site – Tondimõisa park | Indrek Tamberg, Project manager, Keskkonnalahendused OÜ, Estonia
• Riga pilot site – Šmerļupīte | Māra Reča, Project manager, Riga City Council City Development Department, Latvia
• Söderhamn pilot sites – Porten and Broberg | Josefin Flink, Project manager, Söderhamn municipality, Sweden
• Pori pilot sites – Central Square and wetland | Aleksi Siirtola, Project manager, City of Pori, Finland
• StoPWa project and its results | Sergei Preis, StoPWa project team member, Tallinn University of Technology, Estonia
• Technical design process and the multidimensional analysis of MUSTBE pilot sites | Kerta Kõiv, chartered engineer, Tallinn University of Technology, Estonia
• Preliminary results of NBS efficiency report | Jurijs Kondratenko, Project manager, Riga Technical University, Latvia