Towards restoring urban waters: understanding the main pressures

•Many lentic urban waters are in poor ecological quality, but restoration is possible.•We identify and review important pressures on urban systems including eutrophication, altered hydrologyclimate change, and micropollutants.•Knowledge of these pressures and especially of their interactions is not always well developed.•Use of an ecological systems diagnosis may aid effective restoration action. Water bodies in the urban landscape are omnipresent, with many being small, lentic waters such as ponds and lakes. Because of high anthropogenic forcing, these systems have poor water quality, with large consequences for the provisioning of ecosystem services. Understanding of the main pressures on urban water quality is key to successful management. We identify six pressures that we hypothesize to have strong links to anthropogenic forcing including: eutrophication, aquatic invasive species, altered hydrology, altered habitat structure, climate change, and micropollutants. We discuss how these pressures may affect water quality and ecological functioning of urban waters. We describe how these pressures may interact, posing challengers for water management. We identify steps that need to be taken towards sustainable restoration, recognizing the challenges that potentially interacting pressures pose to water managers.