Background Human activities over the past few decades have reduced the number of gravel banks and lateral-flowing waters in the project area. However, such habitats are crucial for fish spawning, reproduction and wintering. Fish that prefer to live in fast-flowing water (rheophile species) migrate to the tributaries of the River Danube in the Mostviertel region, to reproduce at sites where gravel banks still exist. Most of the fish species in the Danube itself need lateral (side) arms, particularity as wintering habitats. Moreover, juvenile fish find shelter in lateral waters, where they are protected against waves caused by boats in the main river. The rivers within the project area contain habitat for some 40 fish species, including 13 listed in the annexes of the Birds and Habitats Directives. Objectives The Mostviertel-Wachau project aimed to improve river habitats and the conservation status of threatened fish species included in the annexes of the Habitats Directive. Extensive river restoration measures included the construction of new side arms and backwaters for the River Danube and the creation of a new mouth for the River Pielach. Additional project objectives included ensuring the free passage of fish between a detached sidearm (the Lateiner) of the Danube and the main river channel, designating a nature protection area (Naturschutzgebiet), and implementing river restoration measures at three locations on the River Ybbs. Results The Mostviertel-Wachau project undertook a range of river restoration actions to improve habitat conditions for fish species, and a few that also improved terrestrial habitats. This ambitious river restoration project required specialist landscape design and river engineering inputs. The coordinating beneficiary, the Lower Austrian water authority, collaborated with associated beneficiaries the City of Amstetten, Stadtwerke Amstetten (an energy supplier), viadonau (a state-owned company responsible for the Danube River) and Lanius (a nature conservation association in the Wachau area). Although some land parcels were provided by land owners without any cost to the project, several parcels were purchased in a Natura 2000 network site, totalling 14 ha, within the project’s framework, to enable the river restoration work to proceed. In addition, the project purchased 1.4 ha of land (not charged to LIFE) as a buffer for nearby alluvial forests. On the project site 'Wachau', two large side arms of the River Danube were reconnected to the river, which provided important habitats for fish and also bird species. The first of these, on the Danube near Schallemmersdorf, involved the restoration of 2 km of a former sidearm, which created new spawning and wintering grounds for target fish species; in addition, 160 old trees on the island between the sidearm and the Danube were conserved as they are an important habitat for a rare Habitats Directive annex-listed flat bark beetle species (Cucujus cinnaberius). The second sidearm, near Schönbühel, was restored over a length of 1.5 km, with an island between the River Danube and the restored side-arm completely cut-off from the 'mainland' - to the benefit of species sensitive to human disturbance like the black stork (Ciconia nigra) and the white-tailed eagle (Haliaeetus albicilla). A smaller lateral arm (Frauengärten, about 300 m long) was also re-connected to the Danube at Dürnstein to provide shelter and spawning grounds for target fish species. The project restored the mouth of the River Pielach, where it joins the Danube, which created new fish spawning and wintering grounds, and attracted little ringed plover (Charadrius dubius) to breed in the vicinity. A small brook was also built to connect the River Pielach with the Lateiner Altarm, a former sidearm of the River Danube, which enables migratory fish to reach spawning grounds in the Lateiner Altarm. According to the monitoring results, 28 fish species subsequently used the brook to migrate into the Lateiner Altarm. The project created a 27 ha nature reserve (Pielach Unterlauf), with 20 ha of forest and meadow land being purchased from private landowners; this land is now owned by associated beneficiary Lanius. Other restoration work on the River Ybbs included the construction of a new 1.5 km sidearm, the addition of two fish ladders at the hydropower station in Greinsfurth, and the creation of 19 000 m2 of gravel banks as fish spawning grounds. In addition, five ponds for amphibians were created. New, though smaller, side arms were also created at Winklarn and Hausmening. Among the target species observed using the fish passes and accessing the new side arms of the river was the Danube salmon (Hucho hucho), one of Europe’s most endangered fish species. The river restoration actions have enabled willow-dominated woods to develop along the flooded banks of restored river sections, to the benefit of bird species that live in this type of habitat. The project disseminated its results through a website, information boards, leaflets, meetings with stakeholders, events (such as a fish pass opening ceremony), short project films, articles in the press and through other media, and the layman’s report. The project demonstrated river restoration actions that can be considered as 'best-practice' examples for similar work along other European rivers. Tourism will benefit from the project measures, as the restored river areas are attractive to visitors. However, tourism needs to be regulated to avoid negative impacts on target habitats and species by leisure activities. Further information on the project can be found in the project's layman report (see "Read more" section).