Freshwater ecosystem services and the implementation of aquatic ecological networks in urban areas: what are the expected impacts?

Abstract

The various existing aquatic ecosystems in urban areas are nowadays considered as central parts of many urban development programmes but also in designing future sustainable cities. However, the consistently observed ecological degradation of watercourses draining urban land for decades limits the delivery of a range of ecosystem services and goods that benefit people's well-being. In this context, the development of aquatic ecological networks in many urban areas together with projects for the ecological restoration of aquatic environments, can improve the provision of different services thanks to an ecological condition more closely resembling streams not affected by urban land use. Locally, provision and quality of regulating, supporting and cultural ecosystem services can evolve favorably. We highlight the need to consider all identified natural, artificial and "hybrid" water components of the urban hydrosytem able to contribute to the provision of services as well as the central role of ecological engineering. While the benefits of an aquatic ecological network in cities will mainly affect the local environmental quality, while facilitating an integrated water management, the recovery of a regional upstream-downstream hydrological continuum can likewise allow to limit urban effects on peripheral hydrosystems.