River rehabilitation in urban areas – restrictions, possibilities and positive results

Reaching the goal of good ecological status stipulated by the European Water Framework Directive (WFD) is generally difficult in German rivers. Appropriate habitat conditions for multiple and abundant incidence of flora and fauna are still missing. Existing water bodies, particularly in urban areas, are extremely affected by anthropogenic-induced pressures, resulting in reinforced river bottoms and river banks. In such regions, river rehabilitation is a challenging task and often requires a step by step approach to alter the given conditions. Nevertheless, work must be done and may create successful results as in the case of the Sprockhoevel creek. Over recent years this 11-km-long river in the western and industrialised part of the Ruhr River basin has partly been changed in shape to better resemble nature. Such change implies the widening of the river bed, the improvement of the river bottom by inserting natural gravel substrate, the removal of drop structures and the construction of a new river bed. Presently, this part of the river has again become a valuable habitat for aquatic life. Moreover, the area surrounding the rehabilitated Sprockhoevel creek is now also attractive for the neighbourhood community. Rehabilitation projects have the additional effects of reconnecting people to nature, encouraging public interest in near-natural aquatic systems, and catalysing further investments in similar projects.