The water-sensitive city meets biodiversity: habitat services of rain water management measures in highly urbanized landscapes

Urban water managers face numerous challenges, including limited natural resources for maintenance of technical infrastructure, changing demography, and dramatic environmental degradation. Although the vision of the "water-sensitive city" helps to develop tools and strategies toward more sustainable urban water systems, it does not consider biodiversity effects. We therefore aimed to determine habitat provision or habitat services provided by important rainwater management measures (e.g., ponds, swales, rain gardens, green roofs, green walls, permeable pavement), and to highlight how specific design and management practices for such measures enhance urban biodiversity. There is evidence of habitat services provided by rainwater management measures. Nevertheless, the categorization of such measures as civil engineering structures and their related rules limit efforts to optimize the biodiversity friendliness of design and management. The main factors to provide enhanced and more sustainable habitats are shaping design and maintenance according to target species and favoring connectivity by integrating rainwater management measures into the urban blue-green network. We find that strategic implementation of combinations of rainwater management measures into existing built-up areas allows greater multifunctionality of urban infrastructure. The "biodiversity-friendly and water-sensitive city" implies the efficient integration of ecological design measures in urban planning at building, neighborhood, and landscape scales