Sharing Knowledge for Greener and More Resilient Cities in Riga’s Cross-Border Event

Experts, researchers, and city representatives from across the Central Baltic region gathered in Riga for the 5^th and final international cross-border event of the Interreg MUSTBE project. The seminar, hosted by the City of Riga, focused on knowledge exchange, pilot site progress, and practical ways in which nature-based stormwater solutions can support climate resilience and improve the ecological state of the Baltic Sea.

Project Manager Marija Balabka from the City of Riga opened the event by welcoming the participants and outlining the objectives of the day. In her remarks, she highlighted the importance of working across borders to address shared environmental challenges and to accelerate the development of sustainable stormwater management solutions in the region.

Following the introduction, Project Lead Siim Reinla from Viimsi Municipality, Estonia, presented an overview of the MUSTBE project. He highlighted how the project brings together stormwater treatment, reuse, and online water quality monitoring into one multi-benefit system designed to reduce pollution entering the Baltic Sea and strengthen climate resilience. Reinla also reflected on lessons learned during implementation, noting that planning and procurement for novel solutions require flexibility, that even experienced engineering companies face challenges when working with first-of-its-kind systems, and that budgeting innovative infrastructure can be difficult to estimate. His message underscored the need for adaptive project management when working at the forefront of nature-based innovation.

Urban Greening and Pilot Site Insights

The seminar continued with Liene Griķe from the City of Riga and LatestAdapt presenting the city’s strategic framework for urban greening, demonstrating how nature-based approaches support climate adaptation, reduce heat island effects, manage stormwater, and enhance biodiversity. She also stressed the importance of long-term governance models and sustainably managed green infrastructure as key elements in creating a greener, more climate-resilient Riga.

Jurijs Kondratenko from Riga Technical University’s Water systems and biotechnology institute presented Riga’s MUSTBE pilot site design on behalf of architect Anna Katlapa from Group93. The design, conceptually divided into a stormwater treatment section and river renaturalisation section, includes meandering of the watercourse, sedimentation ponds and floodplains along an 800-meter section of the Šmerļupīte stream. Kondratenko also introduced the evolution of the design solution, baseline monitoring and catchment context of the pilot. The Riga pilot site aims to be completed in early 2026.

Real-Time Monitoring and Measurement

Ritvars Stradiņš, Technical Director at WILL Sensors, introduced approaches to stormwater monitoring, explaining how different sensors and systems can provide real-time insights into water quality and system behaviour. He emphasised that reliable data is essential for understanding performance, improving maintenance, and supporting transparent decision-making in cities.

The theme of monitoring continued with Jurijs Kondratenko’s presentation on monitoring and measurement practices for the MUSTBE pilot sites. He showed how a combination of automated monitoring and manual sampling will be used in the project to track nutrients, hazardous substances, and toxins. Kondratenko also highlighted the wider environmental and social benefits of NBS and outlined the next steps of harmonising monitoring approaches and connecting the pilot sites to shared online platforms to support future planning, transparency, and replication.

Field Perspectives and Practical Applications

Professor Ainis Lagzdiņš from the Latvia University of Life Sciences and Technologies presented edge-of-field practices, such as surface and subsurface flow constructed wetlands, sedimentation ponds and woodchip bioreactors, that help reduce nutrient and sediment losses from agricultural areas. Through examples from the EU LIFE Good Water IP project, he demonstrated how comprehensive monitoring and tailored interventions can reduce runoff and protect water bodies. His key message was that each site requires its own combination of measures, as there is no universal solution that fits all agricultural landscapes.

Real-life examples of implementing NBS continued with professor Floris Boogaard from Hanze University of Applied Sciences presenting the history of NBS and maintenance guidelines. Professor Boogaard stressed that moving from grey to green infrastructure requires a shift in mindset, clear responsibilities, realistic maintenance plans, and long-term stewardship. He also highlighted the importance of citizen participation and education when implementing NBS. Since NBS evolve over time, regular evaluation and data-driven adaptation are essential to ensure lasting performance.

After the seminar, participants had the opportunity to join a study tour in the Skanste district, a newly developed urban area where blue-green infrastructure, such as ponds, swales and canals, are integrated into the urban landscape. The visit provided a practical example of how stormwater can be managed in multi-functional public spaces that combine ecological benefits, urban comfort, and sustainable design.

The cross-border event in Riga marked an important milestone in the MUSTBE project’s work towards cleaner waters and evidence-based NBS. By sharing expertise across borders, the seminar strengthened cooperation, supported the development of comparable practices, and advanced collective understanding of how to build greener and more climate-resilient cities in the Baltic Sea region. The MUSTBE project is organising its final project event in Estonia in the spring of 2026 – more information will be published soon so stay tuned!