Criteria for identifying free-flowing river stretches for the EU biodiversity strategy for 2030

Table of Contents

• Contents 3
• Abstract 4
• Acknowledgements 5
• The authors gratefully acknowledge the many detailed and constructive comments that were received on a draft version of this report, which has been submitted for consultation to the members of the Working Group on Ecological Status (ECOSTAT) of the Wa... 5
• Authors 5
• 1 Introduction 6
• 2 Basic principles 7
• 3 Procedure 8
• 3.1 Step 1 - Identify homogeneous river reaches 10
• 3.2 Step 2 - Homogeneous reach assessment 12
• 3.2.1 Step 2a - Addressing longitudinal connectivity 12
• 3.2.2 Step 2b - Addressing lateral connectivity 13
• 3.2.3 Step 2c - Addressing vertical connectivity 18
• 3.3 Step 3 - Large-scale assessment of upstream and downstream off-site pressures 19
• 3.3.1 Upstream off-site pressures (sediment load) 19
• 3.3.2 Downstream off-site pressures (fish migration) 21
• 3.4 Step 4 - Minimum length of Free-flowing Rivers 21
• 3.4.1 Minimum length to support typical morphological patterns 22
• 3.4.2 Minimum length to support sustainable populations of typical fish species 24
• 4 Conclusions and next steps 28
• References 29
• Definitions 31
• List of boxes 35
• List of figures 36
• List of tables 37
• Annex 1. River types considered in the free-flowing rivers procedure 38
• Annex 2. Overview of FFR relevant barrier types with their key attributes and impacts 39
• Annex 3. Detailed description of a proposed method to derive minimum length to support sustainable populations of fish based on macrohabitats and stream order 57