The Ill river and its tributaries have the characteristics of typical upland streams, with near-natural formation of riverbank vegetation, particularly in the upper reaches. The core area comprises the waters themselves and the parts of the catchment area with a long-term influence on the functionality of the riverine system (riverbanks, floodplain areas, land in use from which the diversion of drainage water or erosion could impair water quality). A distinctive feature is that the flood cycle has been allowed to occur naturally over large stretches (especially along the lower reaches of the Ill). In succession sites, typical river floodplain communities occur, e.g. tall forb vegetation, sedge swamps and reedbeds. The endangered species found here include the minnow (Phoxinus phoxinus), European brook lamprey (Lampetra planeri), red-backed shrike (Lanius collurio), whinchat (Saxicola rubetra), lapwing (Vanellus vanellus),and the short-horned grasshopper species Mecostethus grossus.

The objective of the project is the restoration of a naturally stable and intact riverine system which represents a diversity of habitats for flora and fauna. The priority is to bring the condition of the stream to a high ecological status which does not require permanent management measures, and to reinstate a high level of structural diversity in the aquatic, amphibian and terrestrial environments. Furthermore efforts are to be made to restore adjacent floodplains to a near-natural condition.