To demonstrate in person the practical operation and benefits of a nature-based solution – constructed wetlands – a “NATALIE” project experience exchange (twinning action) visit took place in Jelgava last week, on 12 May. During the visit, the project partners – the Zemgale Planning Region (ZPR), the Baltic Environmental Forum (BEF Latvia), and the Latvia University of Life Sciences and Technologies (LBTU) – hosted a delegation from the neighboring Biržai district, bringing together more than 20 experts and municipal representatives from water management sector. As a follower region in the project, the visit gave the Biržai delegation valuable insights and practical examples to help them better prepare for planning constructed wetlands in their own region.
The aim of the “NATALIE” project is to promote the implementation of nature-based solutions across Europe, fostering climate resilience in the regions. Zemgale is one of eight pilot areas where wetlands have been constructed for this purpose. They function as natural filters that purify pollution generated by agriculture and livestock farming, as well as domestic wastewater from small settlements, thereby protecting bodies of water from overgrowth. To practically demonstrate this technology, the project plans to build two new wetlands – in Vecauce and in Staburags parish.
As LBTU professor Ainis Lagzdiņš pointed out at the meeting, the locations for the new wetlands were chosen based on a detailed assessment of data on 76 existing wastewater treatment facilities in the region. The effectiveness of such solutions is also confirmed by the university’s long-term monitoring data (2014–2025) from the “Mežacīruļi” farm, where the constructed wetland reduces nitrogen pollution in the water by 50% and phosphorus compounds by just under 70%. To forecast water quality over the long term, LBTU’s leading researcher Artūrs Veinbergs presented a digital hydrological model (HYPE), which allows a detailed assessment of the current environmental situation. The model is also planned to incorporate various future climate change scenarios.
During the meeting, Renata Gražinienė, a representative of the Biržai district municipality, presented a feasibility study carried out in the region on the area’s most suitable for constructed wetlands, considering river density, various sources of pollution, and the impact of climate change. A public survey, “What do we know about wetlands?”, was also conducted in Biržai, the official results of which confirm residents’ understanding and support: 91.5% of respondents know what wetlands are, 89.8% support their protection and restoration, while 62.7% would like to visit such sites on excursions. At the same time, the Lithuanian colleagues highlighted the specific geology (karst sinkholes), the lack of legal regulation, and the lack of targeted funding as the main challenges, since the support programmes currently available are mainly intended to improve the efficiency of traditional land drainage (melioration) systems rather than to create such nature-based solutions.
Working language of the event: English.
Meeting presentations:
- Brief overview on CS#3 progress in the NATALIE Project (Ingrida Bremere, and Daina Indriksone, BEF Latvia)
- Constructed wetlands in Zemgale (existing, planned)(Ainis Lagzdins, LBTU)
- Hazard modelling – procedure (Arturs Veinbergs, LBTU)
- Summary of results from Feasibility study in Birzai (Renata Graziniene, Birzai)
The experience exchange visit continued with a tour of two functioning constructed wetlands in Jelgava municipality. In the village of Nākotne, the delegation learned about a solution for the additional treatment of domestic wastewater.
During the site visit, an important practical insight emerged — the technical condition of the local wastewater networks is crucial for the successful operation of such systems. They must be well-maintained and watertight, so that during heavy rainfall or snowmelt, excess surface water does not flow into them, as this causes overloading and disrupts the wetland’s natural filtration.
Meanwhile, the visit to the “Mežacīruļi” farm allowed the delegation to see firsthand the operation of a surface-flow wetland in treating agricultural wastewater. Regular monitoring at both sites is carried out by LBTU researchers.
Handout about constructed Wetlands in the Mezaciruli Farm.
The “NATALIE” project’s activities in Zemgale will continue until 2028.
Information prepared by Agnese Launerte and Līga Stokmane-Blaua.
The “NATALIE” project is being implemented under “Horizon Europe – the European Union’s research and innovation programme for 2021–2027.”
