Background The hydrological system in the Biebrza Valley was changed due to the digging of canals in the 19th century. Two major canals were excavated, the Woźnawiejski Canal and the Rudzki Canal, along with several smaller ones, such as the Łęg and Kapicki. The artificial canals resulted in dramatic changes in groundwater, annual flooding patterns and, subsequently, wetland ecosystems. Further change occurred due to extensive drainage activities during the 20th century. This has led to cessation of peat formation and degradation of peatlands, as well as negative changes in wildlife habitats. Therefore, it has become necessary to improve water conditions in the Biebrza Valley to protect endangered bird species and their wetland habitats. Objectives The main objective of the project is to restore the hydrological system in the middle basin of the Biebrza Valley in north-eastern Poland, in the region of the Jegrznia and Ełk rivers, within two Natura 2000 network sites: Ostoja Biebrzańska and Dolina Biebrzy. The surface area of the project extends over 13 452 ha and contains the breeding territories of a many rare and endangered bird species of European importance, including more than 20 priority bird species listed in the Birds Directive and six types of habitat listed in the Habitats Directive. The project’s specific objectives are to: Inhibit the degradation processes in hydrogenic habitats in the vicinity of the Rudzki, Woźnawiejski and Kapicki canals, and the Ełk and Jegrznia rivers; Improve natural wetland habitats, particularly for bird species; Reconcile the requirements of nature protection with the development of tourist activity; and Raise public awareness to promote more appropriate behaviour in nature reserves. Expected results: Improved integration of two Natura 2000 sites – Ostoja Biebrzańska and Dolina Biebrzy – with benefits for target habitats and species; Reconstructed water junction in Modzelówka village that enables the distribution of Ełk river water in such a way that 80% of the flow is directed to the Rudzki Canal and the remaining 20% to the Ełk river bed; Reduced outflow of water to raise the groundwater level and increase the humidity of wetland habitats in the vicinity of Kapicki Canal; Inhibition of peat mineralisation to suspend the degradation of peatlands and improve environmental conditions for wetland habitats and fauna in the project area (13 452 ha); Increased awareness of the need to improve degraded wetlands and the negative environmental impacts of agricultural intensification; Optimally located tourist infrastructure to diminish the negative impacts of tourism on wetland habitats and species.