Multi-criteria Evaluation of Sustainable Urban Drainage Systems

Abstract

This paper evaluates the use of Sustainable Urban Drainage Systems (SUDS) measures with hydrological-hydraulic modelling and multi-criteria analysis on a case study of Girona, Spain. To assess their effectiveness for rainwater runoff reduction and consequently the reduction of combined sewer overflow (CSO) the software Giswater was employed for development of the urban catchment model. This software couples spatial data from QGIS with EPA Storm water management model (SWMM). In accordance with the conditions in the urban catchment, five scenarios were developed consisting of following SUDS measures: Infiltration basins, infiltration trenches, green roofs and their combinations. These scenarios were evaluated with multi-criteria analysis based on CSO reduction, CAPEX, OPEX, amenity, biodiversity, and feasibility regarding ownership. According to the results, the scenario that included only infiltration basins was most favourable (average grade: 4.1/5), followed by the scenario which combined infiltration basins and tranches (average grade: 3.5/5).