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Water-dependent ecosystems are highly vulnerable to climate change and human-induced alterations. This is especially true for ecosystems of urban catchments where aquatic habitats are already being degraded. This study examines prospective impacts of future climate change and anticipated urbanization on water quantity and quality in the urbanized Torrens catchment, South Australia. The eco-hydrological model SWAT has been applied to simulate flow, total nitrogen (TN) and total phosphorous (TP) for the following scenarios: (1) Scenarios based on future precipitation and temperature patterns for the period from 2021 to 2050, by means of two representative pathways (RCPs) of six downscaled global circulation models. (2) A scenario on the hypothetical urbanization of the Torrens catchment over the next 30 years, based on the projected population growth in the region. Scenario (1) suggests there will be a declining monthly flow due to increased temperature and decreased precipitation, and consequently reduced TN and TP loads. In contrast, scenario (2) predicts a higher monthly flow and TP loads resulting from extended impermeable areas due to urbanization, but lower TN loads due to the shrinking grassland taken over by urban land use. The combination of both scenarios shows the offset of their effects on the flow and TP loads, along with decreasing TN loads. The results of this study suggest that, in the long term, urbanization is of greater concern for the Torrens catchment than future climate change. Management decisions have to take into account the enhanced vulnerability of urban ecosystems under future local and global changes. (C) 2018 European Regional Centre for Ecohydrology of the Polish Academy of Sciences. Published by Elsevier B.V. All rights reserved.