River restoration is becoming a matter of great concern in urban and peri-urban environments of Mediterranean cities. A river restoration project can have different approaches, but from a geomorphological point of view, this means that the river is capable of undertaking the fluvial and geomorphological processes that are intrinsic to the nature of a river’s behaviour. However, the variety of restoration projects according to the objective defined is wide and highly heterogeneous. Some approaches are indeed more focused on aesthetics, aiming to provide high-quality environmental space for the use and enjoyment of the inhabitants. However, if processes are not considered, the project could end in failure. The Congost River, in the location of Granollers, a city with 61,000 inhabitants is a good example of the river restoration trends currently in the Barcelona metropolitan area. The Congost river was channelized, fixed by concrete structures and disconnected from its floodplains during the 1970’s, to allow the growth of the city of Granollers. After 40 years of river constraint and in response to social requirements for open and high-value ecosystem spaces, the city council has partially removed some of the structures that were fixing the river. As a result, the river has recovered fluvial processes by forming bars and a trend to become braided. However, the width is not fully recovered, and incision processes, due to the river’s trend to widen, has produced undesired effects on the walking areas, which may become a threat during flood events. The aim of this presentation is to unveil the hidden processes in a strongly modified urban river and the effects when the river is unleashed, and to draw the attention of river managers and planners in the way these restoration processes should be addressed.

Joaquim Farguell
Departament de Geografia, Universitat de Barcelona

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ID Abstract: 876