River hydromorphology has long been subjected to huge anthropogenic pressures with severe negative impacts on related ecosystems' functioning and water quality. Therefore, improving river hydromorphological conditions represents a priority task in sustainable river management and requires proper assessment tools. It is well known that riparian vegetation plays a crucial role in sustaining river hydromorphological conditions. However, it has been nearly neglected in most hydromorphological assessment protocols, including the European Water Framework Directive (WFD). This paper reviews and synthesizes the relevance of riparian vegetation for river hydromorphology, focusing on its contribution to streamflow and sediment regime conditions. We also examine how riparian vegetation is considered in the WFD and how it is included in national hydromorphological protocols currently in use. Our findings point to a temporal mismatch between the date when the WFD came into force and the emergence of scientific and technologic advances in riparian vegetation dynamism and bio-geomorphic modeling. To overcome this misalignment, we present promising approaches for the characterization and assessment of riparian vegetation, which include the identification of vegetation units and indicators at multiple scales to support management and restoration measures. We discuss the complexity of riparian vegetation assessment, particularly with respect to the establishment of river-type-based reference conditions and the monitoring and management targets, and propose some attributes that can serve as novel indicators of the naturalness vs. artificiality of riparian vegetation. We argue that the hydromorphological context of the WFD should be revisited and offer guidance to integrate riparian vegetation in river hydromorphological monitoring and assessment.

River restoration is becoming a priority in many countries because of increasing the awareness of environmental degradation. In Europe, the EU Water Framework Directive (WFD) has significantly reinforced river restoration, encouraging the improvement of ecological status for water bodies. To fulfill the WFD requirements, the Spanish Ministry of the Environment developed in 2006 a National Strategy for River Restoration whose design and implementation are described in this paper. At the same time many restoration projects have been conducted, and sixty of them have been evaluated in terms of stated objectives and pressures and implemented restoration measures. Riparian vegetation enhancement, weir removal and fish passes were the most frequently implemented restoration measures, although the greatest pressures came from hydrologic alteration caused by flow regulation for irrigation purposes. Water deficits in quantity and quality associated with uncontrolled water demands seriously affect Mediterranean rivers and represent the main constraint to achieving good ecological status of Spanish rivers, most of them intensively regulated. Proper environmental allocation of in-stream flows would need deep restrictions in agricultural water use which seem to be of very difficult social acceptance. This situation highlights the need to integrate land-use and rural development policies with water resources and river management, and identifies additional difficulties in achieving the WFD objectives and good ecological status of rivers in Mediterranean countries.