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Rhine estuary 'closeable but open' - a multidisciplinary exploration : Effects on nature and environment

Afsluitbaar Open Rijnmond - een eerste integrale verkenning : Effecten op natuur en milieu


A major part of the area outside the dikes in the Rhine estuary is likely to flood when water levels increase due to climate change. An explorative study by RIVM shows that flooding of these areas may give rise to environmental risks. Implementation of the plan Rhine estuary 'closeable but open', which tries to reduce the water levels, limits these risks only to a small extent. In the study RIVM has evaluated the effects on nature and environment of the plan Rhine estuary 'closeable but open'. The environmental risks arise from residential and industrial areas as well as a number of industrial activities outside the dikes which have to comply with the Seveso Directive concerning the handling and storage of hazardous substances. Moreover, the old centres of Rotterdam and Dordrecht contain a large number of potentially serious and urgent soil sanitation sites. RIVM advises to make a survey of the potential environmental risks outside the dikes due to increasing water levels. The plan Rhine estuary 'closeable but open' was presented in 2008 by the Dutch Delta commission as one of the alternatives to safeguard the residential and industrial areas outside the dikes in Rotterdam and Dordrecht. According to this the plan all major waterways in the Rhine estuary will be closed by adjustable dams when water levels become too high. In this plan the water of the river Lek, which normally flows into the sea through Rotterdam, is redirected via a new waterway towards Hollands Diep and Haringvliet. In this study RIVM analysed the future water levels in the Rhine estuary simulated by Delft Technical University and HKV consultants.

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