In the vicinity of rivers, flooding of available lowlands can be considered as a possibility to store river water temporarily at high water, minimizing the flooding danger of inhabited areas. It can function as a tool to deal with excessive water quantities, fitting in the concept of Integral Water Management. Creation of wetlands or controlled flooding areas can also be considered to develop a habitat for specific animal or plant species. However, due to industrial activities river water, soils, and sediments are often contaminated by metals. This can result in limitations to the ecosystem development or increased transfer of heavy metals to the food chain. As metals can accumulate, created wetlands can only be sustained if processes affecting metal mobility are thoroughly understood and metal fate can be predicted. However, they can be designed based on different flooding regimes, such as periodic inundations or permanent flooding, which has an impact on mobility, bioavailability and toxicity of heavy metals. The possible development scenarios when applying different flooding regimes are often inquired by governmental organisations, especially concerning polluted areas. Therefore, a thorough understanding of processes affecting metal mobility is needed to quantitatively predict the consequences of different management regimes on metal bioavailability, toxicity and ecosystem development. This study aims to contribute to management-oriented models to deal with questions arising from the creation of wetlands or controlled flooding areas. Such models should make it possible to predict trace metal behaviour and ecosystem development in controlled flooding areas. They should allow to evaluate whether and under which conditions ecosystem development may still be acceptable in terms of environmental quality and public health when choosing different wetland creation options. Moreover, criteria will be developed to appraise the risks arising from the creation of wetlands in polluted areas. Factorial experimental trials at the greenhouse scale will be set up to study biogeochemical processes as affected by different flooding scenarios. The influence of vegetation on soil biogeochemistry and, reverse, the impact of pollution on plant metal uptake, growth and development will be assessed by incorporating plant growth as a separate factor in the experimental set-up. Contaminant effects under the different management scenarios will be assessed using appropriate biomarkers and toxicity tests. Models constructed from these trials will be validated in a pilot-scale experiment. The data, constructed models and criteria will be brought together in a book and on CD-rom. Finally, the results will be disseminated to the various national and international research institutes and governmental bodies and a workshop will be organised to discuss the issue with national and international representatives of environmental departments.