The purpose of WP3 is to address degraded river systems. The aim of the first deliverable D3.1 was to begin the development of metrics which indicate the impact of hydromorphological degradation on biota  using existing data. The output, an informed choice of key metrics, aims to support the stakeholder decision making processes and their ability to target desired project goals. These indicators of degradation should be viewed as an interim solution while a more comprehensive and tested approach is produced from WP2 and the final system developed will be an integral part of WP6.