Manage and Restore Aquatic and Riparian Habitats

This measure is concerned with the management and restoration of hydromorphological functioning and diversity to improve aquatic habitats. Hydromophology is concerned with the physical form and the flow of a water body. This can be affected by Flood Risk Management and land drainage activities which alter either the physical form, processes or both.

Hydromorphology is a key factor underpinning the ecology of aquatic ecosystems. Whilst the relationship between hydromophology and direct ecological response is not fully understood, typically, increasing habitat diverstiy can be associated with increased species richness. Therefore, it is important that hydromorphology is considered when assessing the impacts of new or historic Flood Risk Management or land drainage activities. The Water Framework Directive recognises that hydromorphological condition underpins ecological status and specifies a range of relevant quality elements for that purpose. The Directive requires monitoring programmes to establish the degree of risk from hydromorphological pressures as expressed by the consequent modification of ecological status.

Quality element

Definition of high status

Hydrological regime The quantity and dynamics of flow, and the resultant connection to groundwaters, reflect totally, or nearly totally, undisturbed conditions
Morphological conditions Channel patterns, width and depth variations, flow velocities, substrate conditions and both the structure and condition of the riparian zones correspond totally or nearly totally to undisturbed conditions
River continuity The continuity of the river is not disturbed by anthropogenic activities and allows undisturbed migration of aquatic organisms and sediment transport
Additional post-implementation monitoring is required to improve our understanding of the links between hydromorphology and ecology. The assessment of links between ecology and physical habitat has become a major issue in river research and management. Key drivers include concerns about the conservation implications of human modifications (e.g. climate change) and the need to understand the ecological importance of hydromoprhology as prescribed by the EU's Water Framework Directive.