Urban water bodies are facing numerous threats to their water quantity and quality. In the past urban, especially urban rivers have often been straightened, embanked and partially tubed, and often they are directly bordering or very closely located to buildings. Further, they are often loaded by combined sewer overflow, highly polluted surface runoff after heavy rainfall as well as by various contaminations such as persistent substances, micropollutants etc. Consequently, the hydromorphological and ecological state of many urban rivers is poor. The aim of the European Water Framework Directive is to achieve a good ecological state for all water bodies. However, this is hardly achievable for many urban rivers. Therefore, the European Water Framework Directive has established the classification of heavily modified water bodies which are water bodies that have significantly changed their original appearance to suit a specific purpose. Heavily modified water bodies must aim to achieve a good ecological potential rather than a good ecological status. In addition to often limited space in urban areas, further difficulties when restoring a river may arise from restrictive administrative regulations

The Panke located in Berlin, Germany, is a small urban river or stream and it is such a heavily modified water body being faced by many of the above mentioned problems (see Fig. 1). Within a pilot project different preference variants will be developed to improve the structural quality of the channel in such a way that a good ecological potential can be expected in the future. One innovative aspect of this project is the use of various modeling tools in combination with ecological expert knowledge to develop and optimize the channel design in an iterative procedure. The models cover hydrology, hydraulics, transport of substances and sediments, morphodynamcis as well as habitats (see Fig. 2). Another important aspect in the project is that the new channel design should not worsen the flood protection. Further, the habitat model had to be adapted and extended to meat the special conditions of fish and benthos in the Panke.

• Dipl.-Ing. C. Lange, Prof. Dr.-Ing. R. Hinkelmann (TU Berlin) "Model-based design for restoration of a small urban river", 35th IAHR World Congress September 8-13, 2013, Chengdu, China