Urban river restoration design based on multi-criteria assessment

Many river restoration projects in urban areas fail to improve overall ecohydrological river metrics. The main reason for this, in our view, is poor pre-restoration assessment, which considers hydromorphological and open channel hydraulic aspects, but forgets crucial in-stream fluvial-morphological and hydrobiological processes. Our study presents a restoration concept for a small stream in an urban landscape, based on a multi-criteria approach to assess its baseline ecohydrological condition. Stream sediment dynamics, rainfall runoff regime and maximum channel flow capacity are assessed. Hydromorphological condition is determined and restoration effects modelled using the Hydroecological Monitoring Method (HEM). Surface water quality and stream ecological health is examined using basic physico-chemical parameters and aquatic macrozoobenthos (PERLA methodology and POL-INT software). Based on the detailed pre-restoration survey, a restoration design is proposed that results in a positive shift in most of the above-mentioned metrics while improving the ecohydrological quality of the watercourse, flood protection and accessibility for residents.